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SLS / Orion / Beyond-LEO HSF - Constellation => Heavy Lift Launch Vehicle (HLV/SLS) => Topic started by: Downix on 07/14/2010 10:28 pm

Title: AJAX Launcher
Post by: Downix on 07/14/2010 10:28 pm
Someone suggested that we put the current configuration in the first entry, so here goes:

AJAX is a means of achieving the goals of the Congressionally mandated Space Launch System while reducing overhead costs by sharing resources with other United States launch systems.  By studying the various Shuttle components, it was determined the optimal configuration would be to replace the existing pair of segmented solid rocket boosters with 2 pairs of liquid rocket boosters.  For cost, political and performance purposes, AJAX chose the ULA Atlas Common Core Booster (CCB).

The AJAX configuration is centered around a reduced size core module, based on the Space Shuttle's External Tank.  To enable this to operate, AJAX utilizes between 2 and 8 CCBs, to optimize it's lift to the mission profile.  Because the CCBs have less sea level thrust than the SRBs, the ET's fuel load needs to be adjusted.  However as the CCBs have a longer burn duration than the SRBs, less fuel is needed by the core to reach orbit.  By shrinking the ET by approximately 20%, we get comparable orbital performance, while increasing the thrust/weight ratio for better safety margin.  In addition, unlike SRBs, CCBs are fueled at the pad which means you can use more of them to achieve higher lift performance.

And to further improve the overhead, AJAX would share components with the existing EELV's beyond the CCB as well.  Instead of a large, expensive customized upper stage, AJAX would utilize ULA's existing upper stages.  Part of the program would be to fund the development of ULA's proposed ACES upper stage, giving a unified upper stage across three vehicles.  In addition, by the use of the CCB, AJAX would also enable the development, and operation, of the Atlas V HLV for crew lift from LC-39.

The issue with most SLS systems is the number of unique SLS-only components.  AJAX's goal is to eliminate as many of those as practicable.  Michoud would be shared with the Orion space capsule, LC-39 with manned Atlas V Launches, and the boosters would come from Decatur.  In short, it would share overhead, spreading out the cost over multiple agencies, making an AJAX based SLS affordable to operate. 

There is no point to a launcher if you lack the budget to launch it.  AJAX solves this problem by elimination of huge portions of the STS overhead as well as sharing the remaining portions with existing systems.

We are working on a paper giving the full details at this time.  When it is ready, we will be posting it here.

-- original message --
After all discussion, the 4 CCB + 4 SSME w/ full length tank is the concensus.  To get to the right T/W ratio, we have the option of pre-burning the launcher before liftoff, much how the shuttle ignites its engines before liftoff. 

The concept is simple, expanding the concepts behind DIRECT, that is, to better utilize what we have now, in order to build a heavy lift vehicle on todays budget demands.  We will have threads on various elements of this paper rocket, from the MLP, LC-39, and so forth, but this thread is on the lift vehicle itself.

The performance of AJAX is that the design scales from ~70 metric tons up to ~135 metric tons, without the need for an upper stage, by varying the number of Atlas V boosters used.

The general numbers for AJAX to use in Schillings are:

Atlas CCB w/ nosecap (hard numbers):
dry weight: 21,844 kg
Fuel weight: 284,453 kg
Thrust: 4152 kN
isp: 338

Core (rough numbers with margin):
dry weight: 58,000 kg
Fuel weight: 590,000 kg
Thrust: 3-4 engines, throttling between 1402 kN and 2277.2 kN
isp: 453
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/14/2010 10:31 pm
I'm not sure we reached a consensus vis-a-vis the full-length tank and the pre-burn.
Title: Re: AJAX Launcher
Post by: Downix on 07/14/2010 10:41 pm
I'm not sure we reached a consensus vis-a-vis the full-length tank and the pre-burn.
Preburn is only an option, the rocket will take off in any case.  The performance loss from the shrunk tank just does not add up to me.
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/14/2010 10:45 pm
I'm not sure we reached a consensus vis-a-vis the full-length tank and the pre-burn.
Preburn is only an option, the rocket will take off in any case.  The performance loss from the shrunk tank just does not add up to me.
Does it make sense to lengthen the tank, then?

My point is that there's an optimization step that needs to be done, here. We shouldn't just ignore it. For the CCBs, yes, we are just going to live with whatever they're filled to, but the tank is undergoing such drastic changes that we really should consider what the optimal tank size would be.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/14/2010 10:50 pm
I'm not sure we reached a consensus vis-a-vis the full-length tank and the pre-burn.

Its not a question of full length OR preburn. Its a question of Full length: preburn, or Full length: CCB LOX float valve to 80%

My vote is a block 1, 2 phasing plan:

Block 1 preburn
Block 2 80% float valve (2 years after block one IOC).
Title: Re: AJAX Launcher
Post by: neilh on 07/14/2010 10:58 pm
What are the open questions regarding the launcher that can begin to be addressed in this forum?
Title: Re: AJAX Launcher
Post by: Downix on 07/14/2010 11:02 pm
I'm not sure we reached a consensus vis-a-vis the full-length tank and the pre-burn.
Preburn is only an option, the rocket will take off in any case.  The performance loss from the shrunk tank just does not add up to me.
Does it make sense to lengthen the tank, then?

My point is that there's an optimization step that needs to be done, here. We shouldn't just ignore it. For the CCBs, yes, we are just going to live with whatever they're filled to, but the tank is undergoing such drastic changes that we really should consider what the optimal tank size would be.
it's not just that, however.  the shrunk tank was not a major redesign, it was removing a ring out of both the LOX and LH2 tank.  A stretched tank, for comparison, would be adding another ring.

We're still utilizing the parts of the ET, so we do need to keep that in mind.

We can discuss growth options as well in here, set a long distance goal, and figure out the steps to get there.

The other thread had one discussion topic, how would AJAX impact EELV evolution.

It helps to understand Atlas evolution:

Phase I, new upper stage, called ACES

Phase II switch to 5 m core with 2 RD-180.

Phase III new 8.4m core.

AJAX would still be using the ACES for it's upper stage, so this would be funneling the resources for that.

AJAX would also get a huge benefit from the Phase II, as the 5m core w/ two RD-180 would get the better T/W ratio.

So, I see this as being a shot in the arm for EELV evolution as well.  But we're not counting on it, only putting on the table that so we can ponder the Block I, II, III, etc when it comes to it.

Part of the process will be in the use of Atlas as the crew launcher.

Ok, still exhausted from the trip, chew a bit and I'll process more later.  I hope this is not too rambling.
Title: Re: AJAX Launcher
Post by: jml on 07/14/2010 11:05 pm
The current Senate draft of the NASA Authorization specifies that NASA shall develop a heavy-lift "Space Launch System" to succeed STS and build upon STS and CxP equipment, infrastructure, and workforce. Interestingly enough, the bill does not actually state that the new SLS vehicle must use solid rocket boosters.

There is this wording that seems to apply only if NASA decides that SRBs are necessary:
The Administrator shall, to the extent practicable, extend or modify existing vehicle development and associated contracts necessary to meet the requirements in paragraph (1), including contracts for ground testing of solid rocket motors, if necessary, to ensure their availability for development of the Space Launch System.

And there's this wording that tells NASA to use stuff they already have:
The Administrator shall, to the extent practicable, utilize existing contracts, investments, workforce, industrial base, and capabilities from the Space Shuttle and former Orion and Ares 1 projects, including Space Shuttle-derived components and Ares 1 components that use existing United States propulsion systems, including liquid fuel engines, external tank or tank-related capability, and solid rocket motor engines, and associated testing facilities, either in being or under construction as of the date of enactment of this Act.

So....does this sound like RD-180 powered CCBs and maybe even wide-body Atlas Phase II CCBs using Delta IV 5m tanking are not prohibited from being used on the "SLS" vehicle?

If that's the case, then NASA can use this ambiguity either as leverage to bring ATK on-board with building 4-seg solids for the new program, or as a way of getting rid of those pesky solids by building AJAX, depending on what is more politically advantageous.

(But do the RD-180s have to be domestically produced?)
Title: Re: AJAX Launcher
Post by: neilh on 07/14/2010 11:32 pm
We can discuss growth options as well in here, set a long distance goal, and figure out the steps to get there.

The other thread had one discussion topic, how would AJAX impact EELV evolution.

It helps to understand Atlas evolution:

Phase I, new upper stage, called ACES

Phase II switch to 5 m core with 2 RD-180.

Phase III new 8.4m core.

One of the more intriguing future possibilities would be to utilize the mid-air engine recovery that ULA (or was it LM?) proposed for the Atlas. An AJAX based on Phase II or Phase III boosters with mid-air engine recovery for the SSMEs and RD-180s could potentially achieve a pretty incredibly cost/kg, and also involve developments which would help the cost-effectiveness of the Atlas V.

Moving to Phase II or Phase III could also potentially enable evolution to a crazy super-HLV if you increased the ET length, although of course that brings it back to the question of what sort of payloads one would put on it.

Anybody know what mass figures would be like for Phase II/III-based CCBs? I imagine the thrust figures would be more-or-less a multiplier of the RD-180.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/14/2010 11:45 pm
Mid air recovery might be interesting for future operations. For the next 5-9 years we should focus on bare bones stuff, IMO like DIRECT to keep LV per year costs as low as possible. Mid air recovery (plus the systems needed to make the engines ejectable) would drive up costs.

Keep the baseline simple, introduce new concepts down the road if its prudent. :D

BTW for those who don;t know the Baseline is the AJAX 440. We were pretty settled on the full legnth ET, but the shortened ET is still on the table if everyone wants to continue discussing it. The preferred option is the full length ET, however, ATM.
Title: Re: AJAX Launcher
Post by: Jim on 07/14/2010 11:59 pm
Preburning will never be accepted.  There is no such thing as a full length (or "unmodified") ET for this application.  Both ends of the ET will be heavily modified, so make the right size.

There is nothing to gained by keeping it the same length/volume as the shuttle.  Don't touch the CCB's or don't preburn, you will lose support.

Neither preburn nor partially filling of tanks are acceptable engineering solutions.
Title: Re: AJAX Launcher
Post by: martin hegedus on 07/15/2010 04:07 am
A basic question.  From what I understand from previous posts is that the CCB will need to be human rated.  To do that Chuck said that a sensor package will need to be added to the RD180.  Will the engine need to be modified for the addition of this package?  Does this constitute a change to the CCB?  Will any other sensors need to be added to the CCB for human rating, such as in the tank?  Will any other changes need to be made to the CCB for human certification?
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/15/2010 04:10 am
Preburning will never be accepted.  There is no such thing as a full length (or "unmodified") ET for this application.  Both ends of the ET will be heavily modified, so make the right size.

There is nothing to gained by keeping it the same length/volume as the shuttle.  Don't touch the CCB's or don't preburn, you will lose support.

Neither preburn nor partially filling of tanks are acceptable engineering solutions.
And while changing the shape of a LOX tank and adding: 1. An extra layer of grid panels in specific positions and 2. thrust structure, do consitute changes to the overall preformance, doing all that and changing length constitute even more issues.

Point being there are problems with both solutions, the trick is finding the solution that:

Is cost effective

Is the simplest to implent

Has the least amount of preformance losses


Is the least politcally impactful (when discussing CCBs).


Perhaps core length change is the way to do this, perhaps that leads to the Ares road.........Same is true of CCB float valve or preburn.
Title: Re: AJAX Launcher
Post by: martin hegedus on 07/15/2010 04:26 am
I hope someone can clarify this for me.  The loads and the load paths for the ET have completely changed, even when compared to Jupiter.  So I assume the ET/core is being completely redesigned and tested from top to bottom.  OK, there may be a few parts reused from the Shuttle ET.  But I guess I don't understand why changing the length is an issue unless it effects the CCBs.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/15/2010 04:29 am
I hope someone can clarify this for me.  The loads and the load paths for the ET have completely changed, even when compared to Jupiter.  So I assume the ET/core is being completely redesigned and tested from top to bottom.  OK, there may be a few parts reused from the Shuttle ET.  But I guess I don't understand why changing the length is an issue unless it effects the CCBs.


1. Its not a totall redesign. There are modifications but its not a brand new ET (like for example larger diameter).

2. In theory length changes aren't a huge deal, but you have to watch out for preformance hits, fuel consumption issues (don't forget that 4th SSME), and ESPECIALLY changes to the load path ABOVE AND BEYOND the changes expected when going from the STS ET to the AJAX core.

There are already load path changes, why add more?
Title: Re: AJAX Launcher
Post by: martin hegedus on 07/15/2010 04:54 am
I hope someone can clarify this for me.  The loads and the load paths for the ET have completely changed, even when compared to Jupiter.  So I assume the ET/core is being completely redesigned and tested from top to bottom.  OK, there may be a few parts reused from the Shuttle ET.  But I guess I don't understand why changing the length is an issue unless it effects the CCBs.


1. Its not a totall redesign. There are modifications but its not a brand new ET (like for example larger diameter).

2. In theory length changes aren't a huge deal, but you have to watch out for preformance hits, fuel consumption issues (don't forget that 4th SSME), and ESPECIALLY changes to the load path ABOVE AND BEYOND the changes expected when going from the STS ET to the AJAX core.

There are already load path changes, why add more?

No disrespect, but I guess I disagree, in the sense that the design should be approached as a total redesign, even if the radius and some parts are reused.  In my personal experience, it is under appreciating (for lack of better words) changes which cause failures.  So I'm not sure how much time and money not changing the length of the core would save.
Title: Re: AJAX Launcher
Post by: jml on 07/15/2010 06:00 am
A basic question.  From what I understand from previous posts is that the CCB will need to be human rated.  To do that Chuck said that a sensor package will need to be added to the RD180.  Will the engine need to be modified for the addition of this package?  Does this constitute a change to the CCB?  Will any other sensors need to be added to the CCB for human rating, such as in the tank?  Will any other changes need to be made to the CCB for human certification?

Adding an Emergency Detection System is a change, but a planned change that ULA intends to add to all CCBs leaving the factory, so that there won't have to be different versions of the CCB for crewed vs unmanned launches.

The details of what's required can be found in these two docs:
http://www.ulalaunch.com/site/docs/publications/AtlasEmergencyDetectionSystem.pdf

http://www.ulalaunch.com/site/docs/publications/HumanRatingAtlasVandDeltaIV.pdf

NASA awarded ULA a $6.7 million Commercial Crew Development (CCDev) Program contract in February to start some basic design/definition work on the EDS for the Atlas and Delta.
http://www.nasa.gov/centers/johnson/pdf/463224main_United%20Launch%20Alliance%20and%20Amendment.pdf

Of course if an Atlas or AJAX is flown with a crewed-capsule, there will be the additional requirement of a LAS...for AJAX and Orion the sensible starting point would be OSC's work on the Ares I LAS.


Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/15/2010 04:05 pm
Id say its a good day for AJAX. Congress is mandating SDHLV project start in fy2011.

Lets keep going on this design 8)
Title: Re: AJAX Launcher
Post by: martin hegedus on 07/15/2010 04:20 pm
A basic question.  From what I understand from previous posts is that the CCB will need to be human rated.  To do that Chuck said that a sensor package will need to be added to the RD180.  Will the engine need to be modified for the addition of this package?  Does this constitute a change to the CCB?  Will any other sensors need to be added to the CCB for human rating, such as in the tank?  Will any other changes need to be made to the CCB for human certification?

Adding an Emergency Detection System is a change, but a planned change that ULA intends to add to all CCBs leaving the factory, so that there won't have to be different versions of the CCB for crewed vs unmanned launches.

The details of what's required can be found in these two docs:
http://www.ulalaunch.com/site/docs/publications/AtlasEmergencyDetectionSystem.pdf

http://www.ulalaunch.com/site/docs/publications/HumanRatingAtlasVandDeltaIV.pdf

NASA awarded ULA a $6.7 million Commercial Crew Development (CCDev) Program contract in February to start some basic design/definition work on the EDS for the Atlas and Delta.
http://www.nasa.gov/centers/johnson/pdf/463224main_United%20Launch%20Alliance%20and%20Amendment.pdf

Of course if an Atlas or AJAX is flown with a crewed-capsule, there will be the additional requirement of a LAS...for AJAX and Orion the sensible starting point would be OSC's work on the Ares I LAS.




Awesome!  Thanks.  I like it when statements are made and backed up with docs or, in the case of presenting derived numbers, a clear description of the process.
Title: Re: AJAX Launcher
Post by: Downix on 07/15/2010 07:19 pm
I hope someone can clarify this for me.  The loads and the load paths for the ET have completely changed, even when compared to Jupiter.  So I assume the ET/core is being completely redesigned and tested from top to bottom.  OK, there may be a few parts reused from the Shuttle ET.  But I guess I don't understand why changing the length is an issue unless it effects the CCBs.


1. Its not a totall redesign. There are modifications but its not a brand new ET (like for example larger diameter).

2. In theory length changes aren't a huge deal, but you have to watch out for preformance hits, fuel consumption issues (don't forget that 4th SSME), and ESPECIALLY changes to the load path ABOVE AND BEYOND the changes expected when going from the STS ET to the AJAX core.

There are already load path changes, why add more?

No disrespect, but I guess I disagree, in the sense that the design should be approached as a total redesign, even if the radius and some parts are reused.  In my personal experience, it is under appreciating (for lack of better words) changes which cause failures.  So I'm not sure how much time and money not changing the length of the core would save.

The tooling time alone would be on the order of 24 months.  That is 24 months *before* you can start even building a core.  Using the original tools, altho reconfigured, will give you a jumpstart. 

The fewer changes to the tooling means a faster deployment.  We are already making new tools for the base, the reinforcements needed, removal of SRB.  The less new tools we need, the better.

We can change the core length, so long as it is changed with the existing toolset, easily.  Remove a ring/add a ring method.
Title: Re: AJAX Launcher
Post by: Downix on 07/15/2010 07:49 pm
Something to remember as well folk, this is an initial design work, useful for a first launcher.  The T/W of a 440 is workable, and is in line with other first-launch HLV's.  (Apollo 4 was a grand whopping T/W of 1.13 don't forget)

The prelaunch burn to verify system stability would only improve the T/W.  For those saying it cannot be done, it is done already with every LRB we launch, including both the shuttle and the Atlas.  We may be running it a few seconds longer, but it is already done.
Title: Re: AJAX Launcher
Post by: Jim on 07/15/2010 07:51 pm

The prelaunch burn to verify system stability would only improve the T/W.  For those saying it cannot be done, it is done already with every LRB we launch, including both the shuttle and the Atlas.  We may be running it a few seconds longer, but it is already done.

not the same thing.
Title: Re: AJAX Launcher
Post by: Downix on 07/15/2010 08:05 pm

The prelaunch burn to verify system stability would only improve the T/W.  For those saying it cannot be done, it is done already with every LRB we launch, including both the shuttle and the Atlas.  We may be running it a few seconds longer, but it is already done.

not the same thing.
Tell me, how is it different?  You ignite before launch, correct?  We take into account the burnoff from even the 6 seconds the shuttle is burning on the pad, we get the T/W into line.
Title: Re: AJAX Launcher
Post by: nooneofconsequence on 07/15/2010 08:23 pm

The prelaunch burn to verify system stability would only improve the T/W.  For those saying it cannot be done, it is done already with every LRB we launch, including both the shuttle and the Atlas.  We may be running it a few seconds longer, but it is already done.

not the same thing.
Tell me, how is it different?  You ignite before launch, correct?  We take into account the burnoff from even the 6 seconds the shuttle is burning on the pad, we get the T/W into line.
The correct question to ask is "do we have a requirement to launch in less than N seconds, such that propellant losses / venting create issues".

When does vehicle flight verification / validation of systems become a mission risk / pad liability?

add:
This is moot anyways because the issue is one of professionalism - you don't design to a flaw (T/W at a boundary condition) that you remove/reduce at the pad (remember combustion isn't  precision). More of a mindset then anything else.
Title: Re: AJAX Launcher
Post by: alexw on 07/15/2010 09:44 pm
The prelaunch burn to verify system stability would only improve the T/W.  For those saying it cannot be done, it is done already with every LRB we launch, including both the shuttle and the Atlas.  We may be running it a few seconds longer, but it is already done.
not the same thing.
Tell me, how is it different?  You ignite before launch, correct?  We take into account the burnoff from even the 6 seconds the shuttle is burning on the pad, we get the T/W into line.
    Sound suppression water volume?
            -Alex
Title: Re: AJAX Launcher
Post by: Downix on 07/15/2010 09:49 pm
The prelaunch burn to verify system stability would only improve the T/W.  For those saying it cannot be done, it is done already with every LRB we launch, including both the shuttle and the Atlas.  We may be running it a few seconds longer, but it is already done.
not the same thing.
Tell me, how is it different?  You ignite before launch, correct?  We take into account the burnoff from even the 6 seconds the shuttle is burning on the pad, we get the T/W into line.
    Sound suppression water volume?
            -Alex
Something which can be adjusted for, I would imagine.
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/15/2010 09:54 pm
The prelaunch burn to verify system stability would only improve the T/W.  For those saying it cannot be done, it is done already with every LRB we launch, including both the shuttle and the Atlas.  We may be running it a few seconds longer, but it is already done.
not the same thing.
Tell me, how is it different?  You ignite before launch, correct?  We take into account the burnoff from even the 6 seconds the shuttle is burning on the pad, we get the T/W into line.
    Sound suppression water volume?
            -Alex
Something which can be adjusted for, I would imagine.
Build more water towers? There's a lot of water that gets dumped in a very short period of time.
Title: Re: AJAX Launcher
Post by: sdsds on 07/15/2010 10:32 pm
There's no value at this point in discussing short-loading or off-loading or pre-burning propellant.  The big value right now comes from knowing that this is a relatively easy design that doesn't involve SRBs that nonetheless puts 75 t into orbit.

So it should be sufficient to look at a cautious design and show that it reaches orbit with the claimed payload.  The cautious design would include in its mass budget a core that would carry the same propellant load that a Shuttle SLWT carries.  I suggest it is reasonable to assume that at MECO this core (including residual propellant) masses 70,000 kg.  Note that compares with an empty mass for the SLWT of 26,500 kg, so with 14,100 kg of SSME mass it leaves plenty of margin for structural strengthening, residual propellant, and a flight performance reserve.

With that mass budget for the core we can show that the vehicle would reach orbit even if the core held only 90% of the propellant in a SLWT.  Moreover when carrying that amount of propellant the vehicle has a T/W of 1.15 as soon as the RD-180s are at 100% and the SSMEs are at 109%.

There's no violation of physics here, and it gets 75 t to LEO, regardless of what experts in Utah (or elsewhere) may try to claim. 
Title: Re: AJAX Launcher
Post by: martin hegedus on 07/15/2010 10:45 pm
Sorry if this was addressed somewhere else or a naive question of mine.  But if the need is to have more T/W at takeoff for the 100% CCB+Full Core or more mass to orbit for the 100% CCB+Short Core, why not add some Atlas solids?
Title: Re: AJAX Launcher
Post by: Lobo on 07/15/2010 10:55 pm

One of the more intriguing future possibilities would be to utilize the mid-air engine recovery that ULA (or was it LM?) proposed for the Atlas. An AJAX based on Phase II or Phase III boosters with mid-air engine recovery for the SSMEs and RD-180s could potentially achieve a pretty incredibly cost/kg, and also involve developments which would help the cost-effectiveness of the Atlas V.

Moving to Phase II or Phase III could also potentially enable evolution to a crazy super-HLV if you increased the ET length, although of course that brings it back to the question of what sort of payloads one would put on it.

Anybody know what mass figures would be like for Phase II/III-based CCBs? I imagine the thrust figures would be more-or-less a multiplier of the RD-180.

yea, like this:

http://www.ulalaunch.com/site/docs/publications/PartialRocketReuseUsingMidAirRecovery20087874.pdf

Which I've advocated would be a -great- way to recover a commercial crew taxi for reusability of the capsule.  If you were launching a crew taxi capsule on an Atlas V and recovering the capsule Mid-Air, you'd already have the practice and ability to start recovering the engines if the flight rate was enough.  Although, if a SDLV was ever evolved into something like AJAX, you'd need a bunch of helicopters all in the air at once to get all those enignes!  Especially an 8 CCB variant!  Might get interesting.  :)
Title: Re: AJAX Launcher
Post by: sdsds on 07/15/2010 11:26 pm
why not add some Atlas solids?

All of the other components look "easy" to certify for use with a crew, and thus it looks like the vehicle as a whole could be certified for that purpose.  In contrast Atlas solids look more difficult to certify.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/16/2010 01:36 am
What a day. Lets keep working on this concept, it wouldn't hurt to finish it out and have it out there in case SRMS go away ;)
Title: Re: AJAX Launcher
Post by: sdsds on 07/16/2010 03:04 am
What are the open questions regarding the launcher that can begin to be addressed in this forum?

On the technical side, I'd like to see discussion of what it would take to build a core that: a) like Jupiter carries SSME thrust from below, and b) unlike Jupiter carries strap-on thrust from below.  Is this asking more of a monocoque "structural skin" LH2 tank than is reasonable?  I would also like to get a sense of where an AJAX-440 would hit max-Q.  For that some sort of ascent simulation that includes even a simplistic atmospheric density model might be useful.  It would also be good to get an estimate of when during ascent the vehicle could tolerate an early SSME shutdown.  Could we say, for example, that the vehicle still reaches orbit if an SSME shuts down anytime after T+45 seconds?

Then there are the political questions.  Has ULA ever in any context indicated any willingness to let NASA use a ULA booster in a non-EELV launch system?  Did Lockheed-Martin ever do so regarding Atlas, before the creation of ULA?  Has Energomash, PWR, or RD AMROSS ever indicated the RD-180 might be available for use outside the Atlas launch system?

Then there are the cost questions, especially when AJAX is compared to Jupiter.  For reasonable flight rates, how does a shift from Jupiter-130 to AJAX-440 change the total cost of operating the launch system?
Title: Re: AJAX Launcher
Post by: sdsds on 07/16/2010 04:27 am
Can we calculate rough LOM figures based on past Atlas V performance?

I think the best we could do is put some "bounds" on the LOM figures.  RD-180 vehicles haven't flown that often!

Atlas III -- with an RD-180 powering the first stage -- launched six times.  Atlas V has launched 21 times.  So that's 27 RD-180 flights without a first stage failure.  Seen pessimistically, the record shows a stage powered by that engine fails at most one time in 28, or that the odds of success on the next flight requiring one engine are better than 96.43%.  The odds of success on a flight requiring four independently successful engines are better than 86.46%.  Using this same approach, it would require 71 successful single-engine RD-180 launches to generate better than 95% confidence of success for a four engine launch.
Title: Re: AJAX Launcher
Post by: sdsds on 07/16/2010 05:06 am
If a chart like the one attached were a plot of an ascending vehicle's altitude and velocity, would there be a way "by observation" to determine  max-Q?
Title: Re: AJAX Launcher
Post by: cro-magnon gramps on 07/16/2010 07:11 am
What a day. Lets keep working on this concept, it wouldn't hurt to finish it out and have it out there in case SRMS go away ;)

First, listening to the Presser today, Nelson explicitly said that 70% of SRM was civilian and the rest DoD, and there was a lot of angst over at DoD about that civilian portion of the production line being shut down; so I don't think politically there is much chance that for the present the SRMS will be going anywhere;
Second, with regard to studying Liquid Rocket Booster and 8.4m ET combinations, I think this is very important, because while Direct can evolve to 150mt to orbit, I wonder if it can evolve beyond that, without a whole new rocket; the AJAX, looks like it could evolve a Direct SRB based launch vehicle beyond that limit; now before anyone asks what would a 150+mt vehicle could carry, I am thinking 30 years from now, and a study done now, like the NLS study, would be a back pocket item for some smart rocket scientist, when the need arose;

so bottom line, keep the excitement going and flesh out your design with contact with industry scientists, or who ever will help, and don't listen to anyone who says it isn't needed; heck, who knows, 8.4m ET tanks may become a Commercially available off the shelf product for purchase by the makers of the Atlas rockets, once things settle down; and I JUST KNOW, JIM IS GOING TO TELL ME IT CAN'T BE DONE!! but neither was a NASA rocket suppose to be available for Commercial use, if memory serves; but I heard THAT IT WILL BE, mentioned at least once today;
Title: Re: AJAX Launcher
Post by: neilh on 07/16/2010 07:18 am
Can we calculate rough LOM figures based on past Atlas V performance?

I think the best we could do is put some "bounds" on the LOM figures.  RD-180 vehicles haven't flown that often!

Atlas III -- with an RD-180 powering the first stage -- launched six times.  Atlas V has launched 21 times.  So that's 27 RD-180 flights without a first stage failure.  Seen pessimistically, the record shows a stage powered by that engine fails at most one time in 28, or that the odds of success on the next flight requiring one engine are better than 96.43%.  The odds of success on a flight requiring four independently successful engines are better than 86.46%.  Using this same approach, it would require 71 successful single-engine RD-180 launches to generate better than 95% confidence of success for a four engine launch.

It's worth noting that the human-rating publication for the Atlas & Delta calculates the LOM for the full Atlas V 401 (that's both the first and upper stage) as 1/250 (0.9960 success) at 50% confidence interval. It has a lengthy discussion about various ways to calculate LOM and LOC.

http://ulalaunch.com/site/docs/publications/HumanRatingAtlasVandDeltaIV.pdf
Title: Re: AJAX Launcher
Post by: alexw on 07/16/2010 07:46 am
heck, who knows, 8.4m ET tanks may become a Commercially available off the shelf product for purchase by the makers of the Atlas rockets, once things settle down; and I JUST KNOW, JIM IS GOING TO TELL ME IT CAN'T BE DONE!! but neither was a NASA rocket suppose to be available for Commercial use, if memory serves; but I heard THAT IT WILL BE, mentioned at least once today;
    Shuttle was available for commercial use, in the 1980s. Turned out that NASA had to massively subsidize the launch slots, because of STS's overwhelming costs. We already know how that story ends.
    -Alex
Title: Re: AJAX Launcher
Post by: alexw on 07/16/2010 08:00 am
If a chart like the one attached were a plot of an ascending vehicle's altitude and velocity, would there be a way "by observation" to determine  max-Q?
   With a little more data, you can find the answer you're looking for . Force of air resistance is:
       F_D = (1/2) * rho * v^2 * A * C_d
 
      So pressure is F_D / A, C_d is dimensionless, so you're just looking to maximize the quanity rho*v^2. The chart you've supplied is altitude vs. velocity, so now you need density vs. altitude; you can then eliminate altitude as an intermediate quantity.
   
      Start by looking up a table of a standard atmosphere model.

           -Alex
Title: Re: AJAX Launcher
Post by: simcosmos on 07/16/2010 11:06 am
Quick Comments next:

Simulations and Virtual Telemetry


What are the open questions regarding the launcher that can begin to be addressed in this forum?
I would also like to get a sense of where an AJAX-440 would hit max-Q.  For that some sort of ascent simulation that includes even a simplistic atmospheric density model might be useful.  It would also be good to get an estimate of when during ascent the vehicle could tolerate an early SSME shutdown.  Could we say, for example, that the vehicle still reaches orbit if an SSME shuts down anytime after T+45 seconds?


Orbiter Space Flight Simulator and the tools (Vinka's multistage.dll) I'm using to implement a first order AJAX could be used for some trajectory related analysis as well mission designs. Virtual Telemetry can be exported into a .txt file which can then be imported into an Excel file, like the one that have shared on the DeltaIV Heavy CLV Brainstorm: EDIT: ooops, I mean, like the Excel with telemetry output that shared at the 'AresIB' brainstorm:
http://forum.nasaspaceflight.com/index.php?topic=13824.msg302387#msg302387


In addition Orbiter itself can draw some graphics (via default plugin) in real time as well another software - called Virtual Mission Control (vMC) - can be used to receive telemetry data from a running Orbiter session and draw graphics in real time too (vMC could even run on an external computer linking to a host computer to receive such virtual telemetry...).

All the above, together with a properly coded automatic ascent guidance, should be good enough to provide both quantitative and qualitative first order idea about things related with the ascent (T/W on several phases, maxQ, simulation of several ascent events / constraints / ground rules,  etc).

Of course that it would be nice to also have other more complex tools – such as POST -  not only to compare results with Orbiter Simulator but also to help building a more optimised automatic ascent guidance.


 
AJAX 440 Definition

As I have mentioned on past threads, there is a need to better define some launcher properties before moving on with improving eventual simulation quality...

There would be the need to focus and agree about CCB properties for AJAX application as well about the core properties, adapter mass and also, perhaps about the dimensions, shape and mass of a baseline payload fairing for simulation purposes... Perhaps better to think about such baseline payload fairing as being a long design and fully covering the maximum expected payload mass / envelope: if less fairing would be needed (because of later specific payload integrations then, at least, the simulation work would still provide a safer maximum load)... I would perhaps suggest to baseline an 8.4m diameter PLF for AJAX-440 baseline (with shape / barrel length to be yet decided).


For the CCB, summary from a post that wrote on the other related thread
(AtlasV boosters for AJAX – Definition of Properties (Masses, RD-180 Specs))

Source:
http://www.ulalaunch.com/site/docs/product_cards/guides/AtlasVUsersGuide2010.pdf
(http://www.ulalaunch.com/site/pages/Education_PublishedPapers.shtml)

   22997   kg : Inert Mass
284087.5 kg : Propellant Mass (LO2&RP-1)

3826961.674 N : SL 100% Thrust, ISP = 311 s
4151958.646 N : Vac 100% Thrust, ISP = 337 s

~0.25% of Prop. at RD-180 shutdown initiation (~710 kg)
(burnout mass would be ~23707 kg)
 
The above is only a summary, for extra data about why I would use these numbers please see:
http://forum.nasaspaceflight.com/index.php?topic=22122.msg616689#msg616689


Regarding the core, I have been using ~71.5t (average) if the baseline would be to aim for STS ET load (which have been assuming as 728t LH2/LO2 at SSME ignition start).
 

   
Payload Range: 70t / 100t up to 150t

now before anyone asks what would a 150+mt vehicle could carry

Quick comment about this: there are some recent talks about definition of HLV payload ranges; I would just like to note that, for example, the 150t payload number does not necessarily and strictly need to represent a monolithic payload with actually a mass of 150t... Such 150t can include, for example, the upper stage propellant for beyond LEO injection, in which case such propellant is also considered to be 'mission payload' and the 'real' payload (including adapter) could be ~50t or so... Depending of extra considerations and only as a very rough example, people could think about an upper stage containing a little more than 100t prop. at a given LEO insertion + about 50t payload (with adapter)  being injected beyond such first parking orbit (depending of extra considerations about mission design, payload, upper stage design, etc, such injection could be TLI, TMI... etc). EDIT: but better focus first, for the moment, on a better AJAX-440 definition.

António
Title: Re: AJAX Launcher
Post by: martin hegedus on 07/16/2010 05:03 pm
If a chart like the one attached were a plot of an ascending vehicle's altitude and velocity, would there be a way "by observation" to determine  max-Q?

Sorry, I use programs for this sort of thing!!

Hope this is not a test.  But..  How would the graybeards do it with a slide rule?  Maybe...

q = 0.5*rho*V^2

ln(q) = ln(0.5*rho*V^2) = ln(0.5) + ln(rho) + ln(V^2)

So I gather you can plot the log of density and V^2 vis altitude and find out where the sum is the greatest.

Word of warning, my dad showed me how to use a slide rule long ago and I have no real memory of how one works and I don't own one.  Wish I did though.

Edit:
If you want to go one step further, you are looking for the point where the slope of ln(rho) is equal to the negative of the slope of ln(V^2).  So change the sign on either ln(rho) or ln(V^2) and see where the two lines are parallel.
Title: Re: AJAX Launcher
Post by: Downix on 07/16/2010 05:37 pm
Doing a bit more calcs in how to further reduce core weight without compromizing performance.  Why do we not instead figure out what the minimum mT we will accept is, and adapt it to that and see what we have?

Using the new Senate bill, 75mT seems the target, is this agreeable with everyone?
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/16/2010 05:39 pm
Doing a bit more calcs in how to further reduce core weight without compromizing performance.  Why do we not instead figure out what the minimum mT we will accept is, and adapt it to that and see what we have?

Using the new Senate bill, 75mT seems the target, is this agreeable with everyone?
Well, you know what I think about the whole issue. ;)

I think 70 tons would be okay, as well. Maybe it might also be worth it to look at performance to EML1 (on a ballistic, single-burn trajectory)?
Title: Re: AJAX Launcher
Post by: spacenut on 07/17/2010 01:32 am
Use 75 tons.  Would not using 75 tons get you greater than 1.2 T/W ratio? 
Title: Re: AJAX Launcher
Post by: Downix on 07/17/2010 04:22 am
Use 75 tons.  Would not using 75 tons get you greater than 1.2 T/W ratio? 
I am doing the math, but yes, it looks like we can.  Not needing the full mT to orbit means we can short-load the core, while retaining the future growth for larger payloads w/ more CCB's.  (Remember, the 8 CCB w/ a 130mT payload was 1.18)  That is why I asked, is 75mT agreeable?
Title: Re: AJAX Launcher
Post by: Downix on 07/17/2010 04:53 am
Incidentally, let's present a partial-load ET:

Core dry weight: 71000 kg
fuel weight: 644000

Full loaded CCB dry weight: 22461
CCB full fuel load: 284453

T/W ratio with 4 SSME @ 109%: 1.18

Mass to LEO: 75mT

Is this agreeable?  This way, we keep the T/W up for low-HLV, but can expand to full load when given when 8 CCB and the full 140mT need is there.

Amazing how clearly I think when I can relax.
Title: Re: AJAX Launcher
Post by: simcosmos on 07/17/2010 12:06 pm

I must write that do not feel very comfortable with the considerations about longer burns at the pad (than what could be required for nominal engines start and pre-liftoff verification) or about the assumption of offloading propellant from the core or the boosters by other methods.


Will share a new attachment with a slightly updated Excel file about Thrust-To-Weight calculation (than what have shared on a previous thread).

This file is still very rough and was not able yet to carefully check for errors, etc.

One of the main updates is that have introduced a new parameter that the user can tweak: despite have called such parameter as 'offload multiplier' I would prefer to think about it as the propellant (LO2+LH2 on core and LO2+RP-1 on CCB) consumed on a nominal (~6.6s) SSME ignition start sequence (to maximum power, probably 109%) followed by a short (~2.7s) sequence start to 100% of the RD-180 (during such CCB start sequence the SSME would continue at full power). 


Please note that haven't yet properly calculated the amount of prop. that would be used (both on the core and CCBs) on such start sequence... Only to have some starting numbers, assumed an initial core load of ~728t at SSME start and ~284087.5 kg on each CCB (with about 8t being spent on the core during those 6.6s + 2.7s =  ~9.3s and about 2t being spent per CCB during the 2.7s)... But again, will really need to later do more careful  math / verification, etc...


Another update is that used the AtlasV Heavy (triple core) LRB numbers of the AtlasV March2010 User Guide with ~5% margin on the inert mass (to account for eventual specific adaptations for AJAX conceptual application).


A brief description of each sheet follows next:


AJAX-440 - TEMPLATE1, simcosmos : this is a template from which derived the other sheets... it contains my suggested numbers for the core and the CCB properties, also for a long baseline PLF (?), 'offload multipliers' to simulate the described above SSME and CCB start sequence... The total payload is 75t (including on such number ~65t of 'real payload' plus the related adapter/ASE and margins). T/W of ~1.1 for SSME at 109%...


AJAX-440 - TEMPLATE1, Downix : is exactly the same sheet as above except with the core having an 'offload multiplier' in accordance with Downix's previous post. This would either need a longer burn at the pad or something else... With my assumptions (vs Downix's 1.18 result?) the T/W would still be at 1.14 for that case...


AJAX-440 - SSME + RD-180 START : this is the same as TEMPLATE1 except for the payload numbers... Here, the total payload is 85t ('real' 75t payload + adapter/ASE + margin). T/W is ~1.095, which is virtually equal to 1.1... The purpose is to compare payload amounts + margins, etc with the Template1 case...


AJAX-480 - SSME + RD-180 START : the last is the most conceptual case... the 8 boosters configuration... for this specific case it might be better to think on the Payload/Other Section as representing a more or less full Earth Departure Stage, its mission payload, etc and to think on the 'Adapter' as representing the interstage and to think on the PLF as a shorter barrel length variant of the one used on AJAX-440 template... T/W, for the values used , was ~1.13 (for 109% SSME). The number on this example are very conceptual (I haven't made an ascent simulation for this case to check the feasibility of the assumed masses neither have done much brainstorm about the impact of such configuration on support / launch facilities, ascent events, etc)



Final comments:

Once more need to say that this would require professional analysis: if possible, I think that it would be better to avoid assumptions about offloading propellant (other than the 'offload' required for nominal engines sequence start / verification).

If wishing to better 'fix' the T/W 'issue' then this might probably require shorter core or RD-180 upgrade / replacement assumptions... Also not sure about the impact of recent contextual events on AJAX assumptions.

António
Title: Re: AJAX Launcher
Post by: kkattula on 07/17/2010 01:49 pm
Incidentally, let's present a partial-load ET:

Core dry weight: 71000 kg
fuel weight: 644000

Full loaded CCB dry weight: 22461
CCB full fuel load: 284453

T/W ratio with 4 SSME @ 109%: 1.18

Mass to LEO: 75mT

Is this agreeable?  This way, we keep the T/W up for low-HLV, but can expand to full load when given when 8 CCB and the full 140mT need is there.

Amazing how clearly I think when I can relax.

Because short-filling the core, (with two cryo propellants), is so much easier than short-filling the CCBs?

Why not just base-line 5 x CCB?  What's so special about even numbers?
Title: Re: AJAX Launcher
Post by: Jim on 07/17/2010 02:20 pm
Short loading is not a viable method.  No one in the real world would agree to it.  Size the tanks for the application.
Title: Re: AJAX Launcher
Post by: Downix on 07/17/2010 04:09 pm
Short loading is not a viable method.  No one in the real world would agree to it.  Size the tanks for the application.
Not saying an actual short-load, only less fuel.  This is sizing-to-application.  It would, however, require new tooling for the tank, but that is not a game stopper.
Title: Re: AJAX Launcher
Post by: sdsds on 07/17/2010 07:52 pm
Short loading is not a viable method.  No one in the real world would agree to it.  Size the tanks for the application.

Soundbite response:
Maybe it's time for another "flagship" technology demonstration!

Detailed response:
Having the proven ability to fly a stage with two (or more) different propellant loads would allow increased commonality of production, which enables longer production runs, which reduces costs.

Agreed however that attempting this with the key USAF lift capability and what would become (if adopted) the key NASA HSF lift capability does not make sense.  These are not the places to introduce the associated risks!
Title: Re: AJAX Launcher
Post by: A_M_Swallow on 07/18/2010 01:43 am

Why not just base-line 5 x CCB?  What's so special about even numbers?

An odd number will mess up the centre of gravity.  The mass on the left hand side is no longer the same as the mass on the right hand side.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/18/2010 02:13 am
We dont need 5. If we need more mass in future (than what u get with 8 ccbs) we simply upgrad the CCBS. That would not work for the next 10 years, but after that i believe this option becomes more poltically feasible.

But with 8 CCBS and 4 SSME you get ALOT of mass (183 mt?). Thats about as much as one would ever need.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/18/2010 02:14 am
BTW the thread for any mlp modifications, ksc modifications, pads, VAB, crawler, ECT for the AJAX is located here:  http://forum.nasaspaceflight.com/index.php?topic=22268.0
Title: Re: AJAX Launcher
Post by: kkattula on 07/18/2010 10:43 am

Why not just base-line 5 x CCB?  What's so special about even numbers?

An odd number will mess up the centre of gravity.  The mass on the left hand side is no longer the same as the mass on the right hand side.

Do I really need to point out the obvious?  Apparently so...

1)  It would actually be an imbalance of thrust, since the CCBs are self supporting on the ground, and in the air provide more thrust than they weigh. 

3) Even a minor thrust imbalance is easily handled by gimballing the core engines.  See Atlas V 411 (1 SRB) and, oh yeah, the Space Shuttle.

3)  This would only apply if the CCBs were mounted asymmetrically, (3 on one side, two on the other). They could just be spread evenly around the core.
Title: Re: AJAX Launcher
Post by: Downix on 07/18/2010 05:22 pm

I must write that do not feel very comfortable with the considerations about longer burns at the pad (than what could be required for nominal engines start and pre-liftoff verification) or about the assumption of offloading propellant from the core or the boosters by other methods.


Will share a new attachment with a slightly updated Excel file about Thrust-To-Weight calculation (than what have shared on a previous thread).

This file is still very rough and was not able yet to carefully check for errors, etc.

One of the main updates is that have introduced a new parameter that the user can tweak: despite have called such parameter as 'offload multiplier' I would prefer to think about it as the propellant (LO2+LH2 on core and LO2+RP-1 on CCB) consumed on a nominal (~6.6s) SSME ignition start sequence (to maximum power, probably 109%) followed by a short (~2.7s) sequence start to 100% of the RD-180 (during such CCB start sequence the SSME would continue at full power). 


Please note that haven't yet properly calculated the amount of prop. that would be used (both on the core and CCBs) on such start sequence... Only to have some starting numbers, assumed an initial core load of ~728t at SSME start and ~284087.5 kg on each CCB (with about 8t being spent on the core during those 6.6s + 2.7s =  ~9.3s and about 2t being spent per CCB during the 2.7s)... But again, will really need to later do more careful  math / verification, etc...


Another update is that used the AtlasV Heavy (triple core) LRB numbers of the AtlasV March2010 User Guide with ~5% margin on the inert mass (to account for eventual specific adaptations for AJAX conceptual application).


A brief description of each sheet follows next:


AJAX-440 - TEMPLATE1, simcosmos : this is a template from which derived the other sheets... it contains my suggested numbers for the core and the CCB properties, also for a long baseline PLF (?), 'offload multipliers' to simulate the described above SSME and CCB start sequence... The total payload is 75t (including on such number ~65t of 'real payload' plus the related adapter/ASE and margins). T/W of ~1.1 for SSME at 109%...


AJAX-440 - TEMPLATE1, Downix : is exactly the same sheet as above except with the core having an 'offload multiplier' in accordance with Downix's previous post. This would either need a longer burn at the pad or something else... With my assumptions (vs Downix's 1.18 result?) the T/W would still be at 1.14 for that case...


AJAX-440 - SSME + RD-180 START : this is the same as TEMPLATE1 except for the payload numbers... Here, the total payload is 85t ('real' 75t payload + adapter/ASE + margin). T/W is ~1.095, which is virtually equal to 1.1... The purpose is to compare payload amounts + margins, etc with the Template1 case...


AJAX-480 - SSME + RD-180 START : the last is the most conceptual case... the 8 boosters configuration... for this specific case it might be better to think on the Payload/Other Section as representing a more or less full Earth Departure Stage, its mission payload, etc and to think on the 'Adapter' as representing the interstage and to think on the PLF as a shorter barrel length variant of the one used on AJAX-440 template... T/W, for the values used , was ~1.13 (for 109% SSME). The number on this example are very conceptual (I haven't made an ascent simulation for this case to check the feasibility of the assumed masses neither have done much brainstorm about the impact of such configuration on support / launch facilities, ascent events, etc)



Final comments:

Once more need to say that this would require professional analysis: if possible, I think that it would be better to avoid assumptions about offloading propellant (other than the 'offload' required for nominal engines sequence start / verification).

If wishing to better 'fix' the T/W 'issue' then this might probably require shorter core or RD-180 upgrade / replacement assumptions... Also not sure about the impact of recent contextual events on AJAX assumptions.

António
I was using the normal 6 second burn that is used now before release as well to get to the T/W.  If we launched at motor ignition, then yes, we'd be at T/W of 1.14.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/18/2010 06:16 pm
Why not do the six seconds?
Title: Re: AJAX Launcher
Post by: Jim on 07/18/2010 09:11 pm
Engine startup and thrust verification (there is no such thing as preburn) take less than 4 seconds for both the SSME and RD-180
Title: Re: AJAX Launcher
Post by: simcosmos on 07/18/2010 10:03 pm
Not sure if I'm completely understanding the previous posts.

On my simulations, the 4 SSME would be started first in a procedure that would take about 6s: during those 6s the SSME would then be quickly and sequentially started and would reach 109% thrust. Once all SSME verified, they would stay at such power level while the AtlasV adapted LRBs would do their own start sequence.

If SSME OK, the LRB would then start, reach 100% and verified in a sequence that would take about 2.7s.

After those ~9s (6s + 2.7s) and if all still OK, the vehicle would then be released from the MLP: in the case of something like AJAX-44X this would result in a liftoff T/W of about 1.1, with the vehicle taking something like 15s or so to clear ~187m altitude (more or less the altitude correspondent to the top of the lightning towers cage).



I was trying to prepare a little of virtual telemetry sharing  by adding an attachment with a .xls file containing some numerical output (MET, Altitude, Vspeed, Hspeed, Mass variation, Thrust) of a past Orbiter Space Flight Simulator Session of an AJAX-440...


… Things are not quite ready here to do so...  Ascent guidance would need optimisation as well it would also be needed the discussion of some ground rules or even the discussion and agreement of some launcher properties... And this, for the moment, only having in mind non-crewed application (for crewed launcher configurations there might exist the need for extra considerations).

In any case, and because do not know when will be able to get back to this, will share next a quick image: it is not the same than looking at the full source numerical data but it might provide some preliminary idea of a few things being slowly studied here.

Of course that this is assuming that T/W of 1.1 at liftoff would be OK: I haven't assumed any extra burn time at the pad beyond what have described above for the SSME / LRB start and verification sequence (as a side note, this was what roughly tried to represent with the 'offload' parameters of 0.989 for the core and 0.993 for the LRB on the update to the T/W Excel file that shared on my previous post, not sure if that was clear or not).

Ok, sharing then a cluttered picture about some very preliminary and non-optimised AJAX-440 data (T/W and Altitude vs Time). Please do note that this is only one of several possible ascent iterations. For example, if wanting to further limit the max g, the LRB burn profile would have to be adjusted (throttle down near sep... in the image have always assumed them at 100%), two of the SSME would probably also need to shutdown a little before MECO (in the image assumed all SSME burning)... Extra trajectory work would also be needed (depending of mission, payload and also having in mind things such as core disposal, etc, etc). All part of eventual ground rules discussion. 


All for now,
António
Title: Re: AJAX Launcher
Post by: A_M_Swallow on 07/18/2010 11:23 pm

3)  This would only apply if the CCBs were mounted asymmetrically, (3 on one side, two on the other). They could just be spread evenly around the core.

An even spread would made adding additional CCBs difficult without modifying the core.
Title: Re: AJAX Launcher
Post by: edkyle99 on 07/19/2010 04:06 am
Incidentally, let's present a partial-load ET:

Core dry weight: 71000 kg
fuel weight: 644000

Full loaded CCB dry weight: 22461
CCB full fuel load: 284453

T/W ratio with 4 SSME @ 109%: 1.18

Mass to LEO: 75mT

Is this agreeable?  This way, we keep the T/W up for low-HLV, but can expand to full load when given when 8 CCB and the full 140mT need is there.

Amazing how clearly I think when I can relax.

I'm having trouble seeing the benefit of this approach.  The same result could be obtained by building a serial-two-stage rocket, with the first stage powered by five or six RD-180s and the second by two, or one, respectively, J-2X type engines. 

 - Ed Kyle
Title: Re: AJAX Launcher
Post by: sdsds on 07/19/2010 04:19 am
Ok, sharing then a cluttered picture about some very preliminary and non-optimised AJAX-440 data (T/W and Altitude vs Time). Please do note that this is only one of several possible ascent iterations.

It's understood this ascent trajectory is only preliminary.  Still, it looks great!  I am very curious if your simulation bears out my tentative spreadsheet-based conclusion that, even with gravity losses, reducing SSME thrust much sooner (at T+45 seconds rather than T+130 seconds) puts the same payload into a higher energy orbit.  (I think that pushes MECO out from T+450 to T+570.)
Title: Re: AJAX Launcher
Post by: simcosmos on 07/19/2010 09:49 am
A few comments:

Regarding non symmetrical LRB AJAX configurations: professional analysis would be required (control vs payload vs ascent vs other factors). In any case, and as also noted, if such configurations would be considered for study, the LRB would have to use the expected attachment points on the central core (else the central core would not be common to all eventual AJAX conceptual configurations, defeating one of the main conceptual configuration goals...)




Configurable HLV (from 75t / 100t up to ~150t... or higher)

Incidentally, let's present a partial-load ET:

Core dry weight: 71000 kg
fuel weight: 644000

Full loaded CCB dry weight: 22461
CCB full fuel load: 284453

T/W ratio with 4 SSME @ 109%: 1.18

Mass to LEO: 75mT

Is this agreeable?  This way, we keep the T/W up for low-HLV, but can expand to full load when given when 8 CCB and the full 140mT need is there.

Amazing how clearly I think when I can relax.

I'm having trouble seeing the benefit of this approach.  The same result could be obtained by building a serial-two-stage rocket, with the first stage powered by five or six RD-180s and the second by two, or one, respectively, J-2X type engines. 

 - Ed Kyle


Ed, let me start by writing that, in part, I agree with you.

One of the benefits of something like AJAX (as well other non-solid conceptual vehicles) would be the elimination of big solids processing (advantages on transportation of elements to the VAB, their assembly  and, from there, transportation to the launchpad, elimination of solids quantity distance concerns and of eventual bottlenecks / extra facilities if aiming for higher flight rates, eventually improved abort scenarios for crewed cases, etc).


Specific to AJAX, another main advantage would be the concept of using (with minimal adaptations) the AtlasV LRB: this would not only lower the cost of CCB/LRB as well would make it possible to gain extra flight experience / heritage... Haven't produced the 3D render but you and the readers could imagine a picture showing an AtlasV 40X or 50X with some kind of commercial capsule on top, then perhaps even an AtlasV Heavy (triple core) with a crewed exploration spacecraft on top, then eventual AJAX configurations (cargo and eventually crewed too) for heavier lift duties... This beyond the other AtlasV traditional utilization profiles...


… On another hand, and as I also have written in past threads (http://forum.nasaspaceflight.com/index.php?topic=22122.msg616003#msg616003 ; http://forum.nasaspaceflight.com/index.php?topic=21938.msg604199#msg604199 ) such main advantage of AJAX – and the wish to scale from somehow 'lower' HLV payload range up to super-heavy lift range - could well also be its main disadvantage: there might exist a few configuration 'issues' (assembly and ascent operations vs complexity for larger heavy lift, eventual upgrade path constraints, etc) caused, among other things, by the wish to use AtlasV LRB...

... This when comparing with eventual other options, either similar to what you have described or, under a slightly different set of assumptions, similar to what I have described on the posts that linked above (4 SSME powered 950t prop. load core sided by two 5.5m diam. Kerolox boosters with each having the equivalent propulsion to two RD-17X or else, on a first phase, four RD-180... later upgraded to core with 5 SSME and with bigger upper stage on top, for heavier duties, with US doubling as EDS and/or being equipped with extra engines for pure 'brute force' LEO delivery, depending of payload / mission design)...

...and/or when thinking about how long – under slightly different contexts – the AtlasV will / would continue to fly as we currently know it (I mean, using CCB / RD-180) vs the impact that eventual future changes on Atlas fleet would bring to update the AJAX fleet from current design constraints...

Yet to be discussed in extra detail is also the updated contextual information of recent days, where there seems to exist a strong political push to field an heavy lift using solid boosters.   

 


AJAX-440 Trajectory (vs SSME throttle settings)

Ok, sharing then a cluttered picture about some very preliminary and non-optimised AJAX-440 data (T/W and Altitude vs Time). Please do note that this is only one of several possible ascent iterations.

It's understood this ascent trajectory is only preliminary.  Still, it looks great!  I am very curious if your simulation bears out my tentative spreadsheet-based conclusion that, even with gravity losses, reducing SSME thrust much sooner (at T+45 seconds rather than T+130 seconds) puts the same payload into a higher energy orbit.  (I think that pushes MECO out from T+450 to T+570.)

Thanks sdsds: I would have to try your suggestion on a later occasion. For the moment, and as we both kind of very preliminarily thought on past threads / posts - given a specific set of launcher configuration and procedures constraints -  something like AJAX-440 really needs the higher core thrust on a  very specific first part of the ascent (mostly to clear the pad with minimally acceptable T/W – which would still need professional input – and on the first part of the gravity turn / climb) ... For middle part / final part of the ascent things could perhaps be ok with just two SSME (extra study would be required about burn times vs a few other details, etc).  As a side note, this could also be a good place for a side brainstorm regarding TAN (Thrust Augmented Nozzles) for SSME (although that would have to be really considered as a side brainstorm to this already highly conceptual brainstorm... an eventual future upgrade and not the baseline due to extra changes to the core).


António
Title: Re: AJAX Launcher
Post by: gospacex on 07/19/2010 10:15 am
Short loading is not a viable method.  No one in the real world would agree to it.  Size the tanks for the application.

Changing tank dimensions basically means redesign. Short-loading means adding some sensors.

Do you size your car's tank to every trip?
Title: Re: AJAX Launcher
Post by: Jim on 07/19/2010 11:11 am

1.  Changing tank dimensions basically means redesign. Short-loading means adding some sensors.

2.  Do you size your car's tank to every trip?

1.  No, the core tank is already being redesigned, therefore make it the optimal size

2.  Bad analogy, the car is not driven nonstop after each tank fill and for the max range

Title: Re: AJAX Launcher
Post by: Downix on 07/19/2010 01:59 pm

1.  Changing tank dimensions basically means redesign. Short-loading means adding some sensors.

2.  Do you size your car's tank to every trip?

1.  No, the core tank is already being redesigned, therefore make it the optimal size

2.  Bad analogy, the car is not driven nonstop after each tank fill and for the max range


You are right Jim, we need to optimize the core.  I keep resisting this, or going for the cheap technique, we wind up in circles. 

So, instead of approaching this through this hap hazard way, let us instead figure out, how much excess T/W load 4 CCB have, take the surplus T/W weight, then add that to the SSME thrust, to see how heavy our core + payload needs to be.

So, the CCB weight * 1.2 is 811955 lbs.  The RD-180 provides 860,568 lb of thrust, giving us a surplus of 48613 lbs per CCB, or a total of 194452 lbs of surplus. (assuming the CCBs lift their own weight)

The SSMEs produce 409220 lbf @ 109% for a total of 1636880 lbf.  Which gives us, with the surplus from the CCB's, a total of 1831332 lbs.  Multiply this by 80%, to give us the 1.2 T/W we need, and we get a total core + payload of 1465066 lbs.  Let us use a 100 ton payload/fairing/adaptors/margin/etc, so we can now remove 200,000 lbs from that, giving us a total core weight of no more than 1265066 lbs. 

So now we have a goal core weight.  Now to figure out the fuel needs.  Too much for right now, Ill tackle that later today.
Title: Re: AJAX Launcher
Post by: Jim on 07/19/2010 02:31 pm

You are right Jim, we need to optimize the core.  I keep resisting this, or going for the cheap technique, we wind up in circles. 


I never understood the resistance.  The core does not have a ready to use structure. There is nothing magical about the shuttle system propellant quantities.   The forward LOX dome, intertank, aft LH2 dome/section, etc all have to redesigned.  So, what was the point of redesigning them to shuttle quantities? 
Title: Re: AJAX Launcher
Post by: Downix on 07/19/2010 02:46 pm

You are right Jim, we need to optimize the core.  I keep resisting this, or going for the cheap technique, we wind up in circles. 


I never understood the resistance.  The core does not have a ready to use structure. There is nothing magical about the shuttle system propellant quantities.   The forward LOX dome, intertank, aft LH2 dome/section, etc all have to redesigned.  So, what was the point of redesigning them to shuttle quantities? 
Truth is, it's out of fear of going down the same dark slope Ares V slipped.  But fearing the right choice out of someone elses bad decision is, itself, a bad decision.
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/19/2010 02:50 pm

You are right Jim, we need to optimize the core.  I keep resisting this, or going for the cheap technique, we wind up in circles. 


I never understood the resistance.  The core does not have a ready to use structure. There is nothing magical about the shuttle system propellant quantities.   The forward LOX dome, intertank, aft LH2 dome/section, etc all have to redesigned.  So, what was the point of redesigning them to shuttle quantities? 
Truth is, it's out of fear of going down the same dark slope Ares V slipped.  But fearing the right choice out of someone elses bad decision is, itself, a bad decision.
The difference is the fact that: 1) Same tank diameter, and 2) Higher Isp core engine, thus meaning you don't need as much fuel sitting on the pad and thus need less thrust to get off the pad for the same payload to LEO.

I think. ;)
Title: Re: AJAX Launcher
Post by: Downix on 07/19/2010 03:31 pm

You are right Jim, we need to optimize the core.  I keep resisting this, or going for the cheap technique, we wind up in circles. 


I never understood the resistance.  The core does not have a ready to use structure. There is nothing magical about the shuttle system propellant quantities.   The forward LOX dome, intertank, aft LH2 dome/section, etc all have to redesigned.  So, what was the point of redesigning them to shuttle quantities? 
Truth is, it's out of fear of going down the same dark slope Ares V slipped.  But fearing the right choice out of someone elses bad decision is, itself, a bad decision.
The difference is the fact that: 1) Same tank diameter, and 2) Higher Isp core engine, thus meaning you don't need as much fuel sitting on the pad and thus need less thrust to get off the pad for the same payload to LEO.

I think. ;)
Ok, back to thinking.  We have 1265066 lbs to keep it under.  Minus from that right now the SSMEs: 6990 lbs each.  So, 4 of them, we can subtract 27960 lbs.

So we're down to 1237106 lbs core. 

Now, the Jupiter core, sans engine, is 119,519 lbs, with a fuel load of 1,621,191 lbs of fuel.  This is a metal-fuel ratio of 13:1.  If we keep this ratio, and using the same material and technologies we should, we will have a core which weighs 95,162 lbs dry, giving us 1,141,944 lbs of fuel.  In short:

517,977 kg of fuel with a core weight of 123,122 kg incl SSME.  Less fuel than even the shortened core we had earlier.  But it does give us a viable lifter without T/W worries.  Doing the calcs if we run the SSME @ 109 the whole way up, I get 53mT.  If I throttle them down after liftoff and do not raise them back fully, never above 80%, I get 75mT.  This also gives a core engine-out capability, can drop an engine, and throttle the other three up to compensate.

This core also will be almost the same height as the CCBs, doing a simple math calc in my head. 
Title: Re: AJAX Launcher
Post by: spacenut on 07/19/2010 04:38 pm
Is throttling to 80% doable on the SSME to get the 75 tons?  The Atlas V phase II heavy gets 75 tons IF it is ever built using 6 RD-180's.  Don't know what type of second stage it would need though. 
Title: Re: AJAX Launcher
Post by: Downix on 07/19/2010 04:53 pm
Is throttling to 80% doable on the SSME to get the 75 tons?  The Atlas V phase II heavy gets 75 tons IF it is ever built using 6 RD-180's.  Don't know what type of second stage it would need though. 
It would need an ACES based upper stage, which is what the DIRECT JUS is also based on.

The thing is, if there is an Atlas V Phase II, the boosters would change for this as well, and it too would grow in performance.  By tying it to EELV, when EELV grows, so does this.
Title: Re: AJAX Launcher
Post by: spacenut on 07/19/2010 05:00 pm
Sounds better than solids.  Solids have about reached their effectiveness with 5 segments.  Liquids are lighter, easier to transport empty.  Only have to fill them at the pad.  Strap ons can eventually evolve into flyback boosters, or parachute back for reuse. 
Title: Re: AJAX Launcher
Post by: Downix on 07/19/2010 05:22 pm
Sounds better than solids.  Solids have about reached their effectiveness with 5 segments.  Liquids are lighter, easier to transport empty.  Only have to fill them at the pad.  Strap ons can eventually evolve into flyback boosters, or parachute back for reuse. 
Precisely.  This could even be the key to development of the Phase II, the Phase II CCB could enable much larger missions, using fewer CCB's.  The larger 5m size would cap out around the tank at 6 I'd imagine, but those 6 would have 12 RD-180's, one heck of a kickoff.

But that would be a Block III or later. 

How about we define the varying stages, and the demonstrations we can do?
Title: Re: AJAX Launcher
Post by: Downix on 07/20/2010 12:02 am
Another thought, for the larger 150-range mT loads w/ 8 CCB's, you'd be running the SSME's @ full after CCB seperation in order to get the JUS into position (yes, I'll call it a JUS for that is what it is).  This would shorten their burn time, but would give the energy needed for maximum insertion burn.  This would be a magnificent sight to see, of course.
Title: Re: AJAX Launcher
Post by: simcosmos on 07/20/2010 11:22 am
Hello Downix, all:

Before talking about applications or even about more capable AJAX variants or about crewed configurations I really think that it would be better to clearly define the AJAX-440 baseline so that slightly improved simulation work could be made...

I mean, this being the 'AJAX Launcher' thread, it would be nice to have a more solid starting point not only for eventual future simulation work (but also for things related with the outer mold line, ascent ground rules, impact on support and launch facilities assumptions, etc, etc)...

This to say that simulation work takes time, even more if wishing to be slightly more careful and preciser in the ascent analysis... So, I would really suggest that the near-term focus of this thread could be to reach a more clear set of baseline assumptions for AJAX-440!



Shorter Core (vs STS ET prop. load):

A shorter / lighter core would surely help in terms of T/W at liftoff, if the goal would be to reach a minimum of ~1.2 (it would not need to strictly be 1.2... something like 1.17 or so at MLP release moment could be good to go too... extra analysis required). Clearing off the pad would then be faster (and the launcher would also probably be safer against a wider range of launch conditions or eventual launch 'issues'), the transition to the pitch program (building horizontal velocity) would also be faster (than on the STS ET load prop. core).


Another possible advantage would perhaps be that the SSME might not be required to run at 109%, except in case of emergency, which would be similar to current STS assumptions... On the ET sized core, the SSME would probably need 109%, at least during the first part of the ascent.


The shorter core would probably see a slight increment of MaxQ (which might happen at a slightly lower altitude than on the STS ET loaded core): nothing serious, can also be tweaked with trajectory / SSME power levels, etc.



Next, something that might require extra study... The shorter core, being lighter, might require more careful attention to throttle considerations for the LRB and for the SSME... this depending of assumed ground rules, cargo and/or crewed use, etc...

In particular, as can be seen on my previously shared image with preliminary T/W history for the STS ET load core (http://forum.nasaspaceflight.com/index.php?topic=22266.msg619662#msg619662), the shorter core will probably need the LRB to throttle down (together with SSME) before LRB separation (where, on the STS ET load case, LRB could perhaps always stay at 100%). Then, later on the ascent, some extra attention might be needed regarding SSME throttle settings vs MET and, in particular, near MECO, the shorter core might require some SSME to shut-down sooner if not wishing to go beyond 4g. (on the STS ET load case, because of heavier core and eventually heavier payload mass, the Max g of less than 3.5 at MECO was obtained with all engines running at 67%). 


Unlikely the case of the STS ET sized core, the time of PLF jettison for the shorter core might be at a MET further apart from LRB jettison (which might introduce a little of performance loss, depending also on discussion about PLF properties vs payloads...).



Summary:

These are all very preliminary notes based on past simulations where played a little with a short core of about 60t for a propellant load of about 565t at SSME pre-start moment.

At that time I was using 23648 kg for the inert mass of the LRB (instead of the 21902 kg – from AtlasV Users Guide – plus 5% margin = 22997.1 kg that I'm currently assuming).

The PLF was 12t for a total mass of about 65t (56796 kg payload + 1704 kg adapter + 6500 kg margin) injected, in one of the simulation runs,  into ~207 km x 52 km, 28.72 inclination. This comparing with 15t PLF being used for about 85t total mission mass (~74272 kg payload + 2228 kg adapter + 8500 kg margin) being injected into a similar orbit (on the STS ET sized core).


I could then go back to the shorter core files (I think that the 60t inert / 565t prop. load at SSME pre-start could be a good starting point...) and update the performance implementation and ascent guidance, for example, by updating the LRB masses to 22997.1 kg, by playing a little more with the trajectory, etc...

… But  before doing so, I really think that it might be needed some discussion about ascent ground rules... For example, given AJAX specific design constraints, I would like, if possible, to see some discussion regarding 'Max g' (and, in such discussion, also some considerations vs crewed configurations...)...

... Without that kind of discussions it might not make much sense to spend time improving simulation work / analysis vs eventual payload needs (including virtual astronauts  8) ).

Thanks,
António

PS: as a final note, yes, a shorter core might allow for a slightly better integration of AtlasV LRB but need to express that have some doubts when reading that AJAX, once built on an 'alternative reality', could be 'easily' upgraded with other booster assumptions (vs when thinking on current design assumptions vs eventual impact of such other assumptions on launcher configuration, facilities, etc that would be built for the current type of assumed baseline(s)).
Title: Re: AJAX Launcher
Post by: Downix on 07/20/2010 03:40 pm

PS: as a final note, yes, a shorter core might allow for a slightly better integration of AtlasV LRB but need to express that have some doubts when reading that AJAX, once built on an 'alternative reality', could be 'easily' upgraded with other booster assumptions (vs when thinking on current design assumptions vs eventual impact of such other assumptions on launcher configuration, facilities, etc that would be built for the current type of assumed baseline(s)).
No, if we go shorter to mate better to the CCBs, then we've married them completely.  That is the sacrifice of the option.  While Phase II should fit up (they have the same connection points in order to use the same SRBs after all) it locks you in to the CCB model, pretty much forever.

Keeping it the full length, you have wiggle room for such adapter systems, which do indeed weigh more, but give more as well.

It's a real fight on pressures vs resources.  I prefer the longer core, something tells me it is the right idea.  The amount of thrust vs the weight is the worry.

Let me re-calculate the fuel for 1.15 here later on today.  (can't do it right now because we are about to drive down to Ikea to buy a new mattress, cannot validate paying $700 for a mattress when Ikea has one for $70)
Title: Re: AJAX Launcher
Post by: Downix on 07/20/2010 04:08 pm
Ok, can't wait.  CCB * 1.15 now is 778,123, which means each CCB now has a surplus of 82,445 lbs, so a total of 329,780 lbs.  Almost double.

Now, using the same as before, SSME @ 109% of 1636880 + 329780 gives us a total core of 1,966,660 lbs, which we then subtract the fairing/payload/margin/etc of 200,000 lbs, giving us 1,766,660 lbs, which we then multiply by 85% to get the 1.15 ratio, of 1,501,661 lbs. Subtracting the SSME weight of 27960, we get 1473701.  Using the same metal-fuel ratio as before of 13:1, we get a total of 113362 lbs of core - SSME.  Subtract that from the total core - SSME, we get 1,388,299 of fuel.  Only 232892 lbs fuel difference between Jupiter and AJAX, roughly 14% smaller.  Using the calculator, I now get a payload of 76mT to a 100nM orbit @ 45 degrees.

This change will require a bit more retooling, but not dramatically so.
Title: Re: AJAX Launcher
Post by: kkattula on 07/20/2010 04:16 pm
I think you math is slightly off. 

You should be multiplying by 1/1.15 = 86.956%

And previously 1/1.2 = 83.333%

:)
Title: Re: AJAX Launcher
Post by: Downix on 07/20/2010 04:24 pm
I think you math is slightly off. 

You should be multiplying by 1/1.15 = 86.956%

And previously 1/1.2 = 83.333%

:)

Hush, you realize I am actually giving extra margin by sacrificing those few extra percentage points, right?  8)

I know that I was using slightly worse numbers, remember what I said, I like margin.
Title: Re: AJAX Launcher
Post by: kkattula on 07/20/2010 04:30 pm
Hush, you realize I am actually giving extra margin by sacrificing those few extra percentage points, right?  8)

I know that I was using slightly worse numbers, remember what I said, I like margin.

As long as you know it.  :)

Just don't margin yourself into a corner...
Title: Re: AJAX Launcher
Post by: Downix on 07/20/2010 04:31 pm
Hush, you realize I am actually giving extra margin by sacrificing those few extra percentage points, right?  8)

I know that I was using slightly worse numbers, remember what I said, I like margin.

As long as you know it.  :)

Just don't margin yourself into a corner...
I am not planning on it.  I just want a little margin here, then there, and keeping notes of where it is in case I have to marginalize the margin.
Title: Re: AJAX Launcher
Post by: kkattula on 07/20/2010 04:37 pm
FWIW, I think 70+ mt to LEO for the A-440 is pretty damn useful.
Title: Re: AJAX Launcher
Post by: neilh on 07/20/2010 09:10 pm
Ok, can't wait.  CCB * 1.15 now is 778,123, which means each CCB now has a surplus of 82,445 lbs, so a total of 329,780 lbs.  Almost double.

Now, using the same as before, SSME @ 109% of 1636880 + 329780 gives us a total core of 1,966,660 lbs, which we then subtract the fairing/payload/margin/etc of 200,000 lbs, giving us 1,766,660 lbs, which we then multiply by 85% to get the 1.15 ratio, of 1,501,661 lbs. Subtracting the SSME weight of 27960, we get 1473701.  Using the same metal-fuel ratio as before of 13:1, we get a total of 113362 lbs of core - SSME.  Subtract that from the total core - SSME, we get 1,388,299 of fuel.  Only 232892 lbs fuel difference between Jupiter and AJAX, roughly 14% smaller.  Using the calculator, I now get a payload of 76mT to a 100nM orbit @ 45 degrees.

This change will require a bit more retooling, but not dramatically so.

Would this be equivalent to removing 1 ET ring?
Title: Re: AJAX Launcher
Post by: simcosmos on 07/20/2010 09:36 pm
Only for completeness, will share next a new Excel file containing a bit of formatted AJAX-440 (virtual) telemetry output relative to:

a) STS ET Sized Core (71t + 728t prop)
b) Short Core possibility (60t + 565t prop)


As noted in past times, these are results of non-optimised performance implementations on Orbiter Simulator sessions. Hope that there aren't too much copy+paste errors but some incoherency or less correct info might be possible here and there... Despite that, decided to release it: the file should, at very least, give a slightly better perspective about some of my previous posts contents.

With the disclaimer made, quick summary about each sheet:


1) INTROpic - AJAX-44X 20100718SC: the image that have shared at:
http://forum.nasaspaceflight.com/index.php?topic=22266.msg619662#msg619662
 
2) SIM-AJAX-44X, ETcore20100718SC: this page contains the formatted telemetry output from which produced the image on 1) – ET Sized Core. I have also tried to comment a little some of the major ascent events, produced a few graphics from the numerical data, added a summary of launch vehicle assumptions, etc

3) SIM-AJAX-44X, ShortCore20100720SC : yet another virtual telemetry output from a non-optimised simulation, this time about a shorter core brainstorm. It is kind of interesting to directly compare 2) with 3)  (by jumping back and forward between each sheet) in order to see how the comments or the graphics are different.

4) / 5): TW-AJAX-44X, Etcore20100720SC / TW-AJAX44X, ShortCore20100720SC: are small updates to previously shared versions of my rough / dummy 'T/W calculator' and are included in this new Excel file for completeness (included a few past renders too).



Again remembering that the information and the simulation work contained in these sheets would need to be reviewed, standardized, optimised, might not be fully correct, is very preliminary, etc, etc would perhaps end by writing that both simulation cases seem to point for a few generic common considerations:

- extra work is needed regarding LRB / SSME throttle work on the first part of the ascent (depending of ground rules...)... this is more evident on the short core case

- extra work is needed regarding SSME throttle work after LRB separation and somewhere on the late ascent part of the ascent and/or near MECO (it might be better to go for a phased shut-down of half of the 4 SSME)... again, this is more evident in the case of the short core.

- last but not least, additional trajectory work is also needed (together with better definition of some ground rules)


Please remember that all the above is regarding AJAX-440 (and mostly when having a cargo variant in mind)... I haven't really studied crewed applications / adaptations or other AJAX configurations... at least not  with this level of (preliminary) detail. Please then look at the contents of these files only as simple points of departure for eventual further study / research directions.

One last preliminary thought is that, in first order, something like AJAX could at least (and in theory) result in a good enough entry level HLV capability (where brainstorms - also discussed at length in these forums - such as those about using an existing upper stage to enable early beyond low Earth orbit crewed mission profiles would apply... example: DeltaIV Heavy Upper Stage + some kind of crewed spacecraft for cis-lunar space missions, etc).

Thanks,
António
Title: Re: AJAX Launcher
Post by: Downix on 07/20/2010 11:00 pm
Ok, can't wait.  CCB * 1.15 now is 778,123, which means each CCB now has a surplus of 82,445 lbs, so a total of 329,780 lbs.  Almost double.

Now, using the same as before, SSME @ 109% of 1636880 + 329780 gives us a total core of 1,966,660 lbs, which we then subtract the fairing/payload/margin/etc of 200,000 lbs, giving us 1,766,660 lbs, which we then multiply by 85% to get the 1.15 ratio, of 1,501,661 lbs. Subtracting the SSME weight of 27960, we get 1473701.  Using the same metal-fuel ratio as before of 13:1, we get a total of 113362 lbs of core - SSME.  Subtract that from the total core - SSME, we get 1,388,299 of fuel.  Only 232892 lbs fuel difference between Jupiter and AJAX, roughly 14% smaller.  Using the calculator, I now get a payload of 76mT to a 100nM orbit @ 45 degrees.

This change will require a bit more retooling, but not dramatically so.

Would this be equivalent to removing 1 ET ring?
No, more from done redesign.  1ET ring would be 20%.
Title: Re: AJAX Launcher
Post by: Downix on 07/21/2010 03:43 pm
Only for completeness, will share next a new Excel file containing a bit of formatted AJAX-440 (virtual) telemetry output relative to:

a) STS ET Sized Core (71t + 728t prop)
b) Short Core possibility (60t + 565t prop)


As noted in past times, these are results of non-optimised performance implementations on Orbiter Simulator sessions. Hope that there aren't too much copy+paste errors but some incoherency or less correct info might be possible here and there... Despite that, decided to release it: the file should, at very least, give a slightly better perspective about some of my previous posts contents.

With the disclaimer made, quick summary about each sheet:


1) INTROpic - AJAX-44X 20100718SC: the image that have shared at:
http://forum.nasaspaceflight.com/index.php?topic=22266.msg619662#msg619662
 
2) SIM-AJAX-44X, ETcore20100718SC: this page contains the formatted telemetry output from which produced the image on 1) – ET Sized Core. I have also tried to comment a little some of the major ascent events, produced a few graphics from the numerical data, added a summary of launch vehicle assumptions, etc

3) SIM-AJAX-44X, ShortCore20100720SC : yet another virtual telemetry output from a non-optimised simulation, this time about a shorter core brainstorm. It is kind of interesting to directly compare 2) with 3)  (by jumping back and forward between each sheet) in order to see how the comments or the graphics are different.

4) / 5): TW-AJAX-44X, Etcore20100720SC / TW-AJAX44X, ShortCore20100720SC: are small updates to previously shared versions of my rough / dummy 'T/W calculator' and are included in this new Excel file for completeness (included a few past renders too).



Again remembering that the information and the simulation work contained in these sheets would need to be reviewed, standardized, optimised, might not be fully correct, is very preliminary, etc, etc would perhaps end by writing that both simulation cases seem to point for a few generic common considerations:

- extra work is needed regarding LRB / SSME throttle work on the first part of the ascent (depending of ground rules...)... this is more evident on the short core case

- extra work is needed regarding SSME throttle work after LRB separation and somewhere on the late ascent part of the ascent and/or near MECO (it might be better to go for a phased shut-down of half of the 4 SSME)... again, this is more evident in the case of the short core.

- last but not least, additional trajectory work is also needed (together with better definition of some ground rules)


Please remember that all the above is regarding AJAX-440 (and mostly when having a cargo variant in mind)... I haven't really studied crewed applications / adaptations or other AJAX configurations... at least not  with this level of (preliminary) detail. Please then look at the contents of these files only as simple points of departure for eventual further study / research directions.

One last preliminary thought is that, in first order, something like AJAX could at least (and in theory) result in a good enough entry level HLV capability (where brainstorms - also discussed at length in these forums - such as those about using an existing upper stage to enable early beyond low Earth orbit crewed mission profiles would apply... example: DeltaIV Heavy Upper Stage + some kind of crewed spacecraft for cis-lunar space missions, etc).

Thanks,
António
Studying this, it looks as if the short core spikes the G's a lot sooner, and a lot harder than the full length core.  This tells me that it likely will need more reinforcement over the normal ET to prevent damage, or even worse, crushing the crew. (I want to keep it under 3.5G, I know these are Astronauts, but still, no point giving them more stress than a roller coaster)

I am leaning to the slightly smaller core, rather than reducing a ring, just dome redesign, to bring it down to 629722 kg of fuel on a 64103 kg dry weight. 
Title: Re: AJAX Launcher
Post by: simcosmos on 07/21/2010 05:46 pm
Only for completeness, will share next a new Excel file containing a bit of formatted AJAX-440 (virtual) telemetry output relative to:

a) STS ET Sized Core (71t + 728t prop)
b) Short Core possibility (60t + 565t prop)


( ... )

António

Studying this, it looks as if the short core spikes the G's a lot sooner, and a lot harder than the full length core.  This tells me that it likely will need more reinforcement over the normal ET to prevent damage, or even worse, crushing the crew. (I want to keep it under 3.5G, I know these are Astronauts, but still, no point giving them more stress than a roller coaster)

I am leaning to the slightly smaller core, rather than reducing a ring, just dome redesign, to bring it down to 629722 kg of fuel on a 64103 kg dry weight. 

Please note that the power levels and pitch program that resulted on the trajectories shared on my latest Excel file are just very rough work, a starting point for extra study on things such as:


Max g Control

In both cases (short and ET sized core), some of the 'spikes' might perhaps be 'softened' by further playing with the SSME and LRB throttle settings, for example, by reducing sooner the SSME to minimum power level and, in particular for a shorter core, also by reducing the LRB to less than the 60% that have assumed and also by shutting-down two SSME later on the ascent, etc 



Trajectory Work

The pitch programs also need extra tweaks: for the moment I'm trying to aim for a perigee not much higher than 56 km and an apogee from ~222 km up to 240 km or so (EDIT: the apogee could also be lower than those values, if for example the mission objective would just require a short duration / low altitude parking orbit, etc) while keeping about 1% of the initial prop. load inside the core... This would assume that the payload would have the capability to raise the perigee into a safe altitude (else the AJAX payload adapter could provide the additional m/s for that job and/or the core itself would need to insert into a safe enough orbit... but that might still require some mass dedicated to a deorbit kit - depending of a few extra considerations - I would personally prefer sub-orbital injection of the core and, if needed, some kind of propulsion assumption on the adapter)


Final Comments

It would then all depend on the agreement about ground rules related with the ascent, payload / launcher constraints, eventual mission designs, etc. Extra work needed: what I have presented was just a kind of minimal input to the ascent work, mostly to have a very preliminary idea of payload masses, some ascent environments and events and to have a better idea of the areas that might need more active 'tweaks' (EDIT: for example, related with crewed applications) in eventual future simulation iterations.


I could continue that work by using more or less the core(s) and LRB properties that have provided on the Excel sheet (to study 'softening' a little some parameters vs impact on performance and/or to tweak a little better the trajectory, etc) or I could do a similar study for new core parameters, different than what have shared (although can't advance when will be able to return to this).
 
António 
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/22/2010 03:16 am
Great work so far all! Now on to those trajectory specifics.
Title: Re: AJAX Launcher
Post by: robertross on 07/22/2010 11:30 pm
This is rather interesting.

I'm with António on the ground rules starting point, which brings me to an important point. Normally a payload has to be modified to conform to certain launch vehicle dynamics. In the case of a new design, we should consider ALL the payloads under contention. Obviously a crew complement dictates certain limitations, but I too wonder about the Max g factor. Would there be advantages to go either higher or lower to bring together the more 'lucrative' payloads?

We often think only in terms of mass to orbit, and optimize the vehicle as such. If we step back and try to emcompass more 'optimizations', including g loading & vibrations, especially if there are growth options available, it may be worth considering.
Title: Re: AJAX Launcher
Post by: Jim on 07/23/2010 01:48 am
g loading isn't a big deal, less than 6g is good .  Dynamics is and it is also a hard thing to design into a launch vehicle, most of the time it is what it is.
Title: Re: AJAX Launcher
Post by: Downix on 07/23/2010 02:18 am
This is rather interesting.

I'm with António on the ground rules starting point, which brings me to an important point. Normally a payload has to be modified to conform to certain launch vehicle dynamics. In the case of a new design, we should consider ALL the payloads under contention. Obviously a crew complement dictates certain limitations, but I too wonder about the Max g factor. Would there be advantages to go either higher or lower to bring together the more 'lucrative' payloads?

We often think only in terms of mass to orbit, and optimize the vehicle as such. If we step back and try to emcompass more 'optimizations', including g loading & vibrations, especially if there are growth options available, it may be worth considering.
This is the fun bit, figuring out the exact kind of launcher we can make here.  It would be so easy to just go "fsck it" and make the HLV cargo-only, and rely on Atlas V for crew launch, swapping in the RS-68 over the SSME, but then we start down the path of Ares V, and that is a path I wish to avoid.
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/24/2010 12:03 am
BTW, Downix, do you have those CAD models of the AJAX launcher? I'm going to see how far I can get in doing a little computational fluid dynamics... it's been a couple years, and I don't have access to the tools I had back in school (we used FEMLab, which was built on top of MATLAB, but now they changed the name to "COMSOL Multiphysics"...), but there are some interesting new tools out there for free... I'm going to see if I can import your model into GMSH (a free mesh-generator and post-processor), and then we'll see if we can get a solver working on it... (I have one in mind)
Title: Re: AJAX Launcher
Post by: Downix on 07/24/2010 12:10 am
BTW, Downix, do you have those CAD models of the AJAX launcher? I'm going to see how far I can get in doing a little computational fluid dynamics... it's been a couple years, and I don't have access to the tools I had back in school (we used FEMLab, which was built on top of MATLAB, but now they changed the name to "COMSOL Multiphysics"...), but there are some interesting new tools out there for free... I'm going to see if I can import your model into GMSH (a free mesh-generator and post-processor), and then we'll see if we can get a solver working on it... (I have one in mind)
I'll admit here being an old-schooler, and use pencil, paper and a drafting table for my engineering work.  I grew up with computers, can never get a CAD program that gives me as good a results as my old number 3 pencil.
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/24/2010 12:20 am
BTW, Downix, do you have those CAD models of the AJAX launcher? I'm going to see how far I can get in doing a little computational fluid dynamics... it's been a couple years, and I don't have access to the tools I had back in school (we used FEMLab, which was built on top of MATLAB, but now they changed the name to "COMSOL Multiphysics"...), but there are some interesting new tools out there for free... I'm going to see if I can import your model into GMSH (a free mesh-generator and post-processor), and then we'll see if we can get a solver working on it... (I have one in mind)
I'll admit here being an old-schooler, and use pencil, paper and a drafting table for my engineering work.  I grew up with computers, can never get a CAD program that gives me as good a results as my old number 3 pencil.
There is something a lot more satisfying about drying on a piece of paper versus clicking with a mouse, I will say that much! However, we're going to need a CAD model one of these days! Maybe I'll ask António....

António? Do you have a CAD model I could use? It can be simple (actually, preferably it'd be simple because I don't have a very powerful workstation), as long as the dimensions and features are accurate.
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/24/2010 04:40 am
Actually, Downix, even the basic drawings/measurements would be helpful.
Title: Re: AJAX Launcher
Post by: Downix on 07/24/2010 04:59 am
Actually, Downix, even the basic drawings/measurements would be helpful.
Let me get them scanned in.  ....

Where do I get a 3' x 5' scanner?
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/24/2010 05:41 am
Actually, Downix, even the basic drawings/measurements would be helpful.
Let me get them scanned in.  ....

Where do I get a 3' x 5' scanner?
LOL! If you have a good digital camera, you can just take a picture.
Title: Re: AJAX Launcher
Post by: martin hegedus on 07/24/2010 05:00 pm
BTW, Downix, do you have those CAD models of the AJAX launcher? I'm going to see how far I can get in doing a little computational fluid dynamics... it's been a couple years, and I don't have access to the tools I had back in school (we used FEMLab, which was built on top of MATLAB, but now they changed the name to "COMSOL Multiphysics"...), but there are some interesting new tools out there for free... I'm going to see if I can import your model into GMSH (a free mesh-generator and post-processor), and then we'll see if we can get a solver working on it... (I have one in mind)

1) I'd like to suggest that you keep things simple and model each of the bodies as axisymmetric shapes.  You can refine the model later.

2) you'll need a solver which can handle transonic and supersonic flow.  I believe the two you mentioned, FEMLab and COMSOL, are incompressible.  But I could be wrong.

3)  Which code did you have in mind?

OpenFOAM (http://www.openfoam.com/) incorporates turbulence models but last time I looked, (1 yr ago?) the equations for the pertinent solvers listed on their web page were solved uncoupled so the solvers can not solve (or at least get good answers) for steady state transonic (past supercritical) and supersonic flow.  They mention having solvers for transient compressible flow, but you'll need to validate the results for supercritical flows by comparing test cases to literature.  And, be careful with that since some WT tests can be questionable for supercritical flows.  I'd recommend comparing to axisymmetric shapes rather than 2D shapes (airfoils).  However, still be VERY careful.  There is a solver AeroFOAM (http://www.aero.polimi.it/freecase/?OpenFOAM_%2B_Code_Aster:Download) which has the elements required to solve transonic/supersonic steady state flow, but I believe it lacks turbulence models.  Also, I don't know how up to date it is.  If you have questions about OpenFOAM a good place to ask is Symscape (http://www.symscape.com/) in addition to online forums.

Another code is FreeCFD, (http://www.freecfd.com/).  I think it has the elements required, but I'm not sure.  I'm also not sure if it is being actively developed.

As for all the rest, the majority are incompressible  (Solving the coupled equations is a pain) or they don't have a turbulence model (laminar only) or they are 2D.

4)  Later, you mentioned that you don't have a powerful workstation...  Your machine may not be able to handle this...  (note:  for multicore machines, the bottle neck is not the floating point computations (cpu) but the memory bus)

5)  A suggestion, you can look in literature and get the forebody drag on blunted cones and ogives.  Then kluge in skin friction and base drag.  For example you can get blunted cone information from NASA TN D-3088 "Aerodynamic Characteristics of Spherically Blunted Cones at Mach Numbers from 0.5 to 5.0" and skin friction and base drag from Hoerner's Fluid-Dynamic Drag.  This will get you CD0.  Then spot check your results against CFD.  And, for the time, ignore CL and CM for the trajectory.

Edit:
As the CCBs move closer to one another the interference drag for transonic and supersonic flow will increase.  You May need to kluge something in or model that region up in a CFD code.  Euler results may be a good first crack at it since you are looking for the pressure rise.  Of course you'll be neglecting viscosity, but at this point the approximation is probably ok.  Of course caution must be used.  If viscosity creates a recircularization region ahead of the CCBs, the real drag may be appreciatively lower than Euler result.
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/24/2010 05:43 pm
Thank you very much, martin.

Yes, I believe you're right. FEMLab didn't do compressible flow.

And FreeCFD was the solver I was looking at.

I do have access to a more powerful workstation, but not very often.  I can manage without it for a while, though, as I figure out how to import a mesh into FreeCFD.

One thing I wanted to look into was the shock interactions... it might be a good idea to use skewed cones on the boosters, like the Russians like to use, since I think that might help avoid problems with shock impingement on the tanks.
Title: Re: AJAX Launcher
Post by: martin hegedus on 07/24/2010 06:25 pm

One thing I wanted to look into was the shock interactions... it might be a good idea to use skewed cones on the boosters, like the Russians like to use, since I think that might help avoid problems with shock impingement on the tanks.

I'm not sure what your experience level is so I apologize if my following suggestion is either basic or common sense to you.

I would suggest that you first model the CCB alone.  And a simple model, blunt nose, cylinder, and flat base.  Then cant the nose inward, but without the ET next to it.  Canting the nose inward will cause the shock to be strengthened on one side and weakened on the other.  And this is a function of nose tip radius.  For example, if your nose tip was a point, rather than blunt, and the nose was canted so that nose tip was inline with the cylinder portion of the body (i.e. nose droop = body radius) then there won't be much of a shock (mostly just a Mach wave) on one side of the body.  Of course in reality the nose tip will be blunt because of aerothermo needs.  Anyway, basic test runs and comparing to literature will give you a baseline and confidence that FreeCFD is modeling things correctly.  It will also give you a baseline for the speed of the code.
Title: Re: AJAX Launcher
Post by: sdsds on 07/25/2010 02:02 am
Trying to get up to speed on this I found CFD-Wiki (http://www.cfd-online.com/Wiki/Main_Page), "a community project to create the ultimate, free Computational Fluid Dynamics reference," which was relatively helpful.

I also noted the associated forum, including the OpenFOAM sections (http://www.cfd-online.com/Forums/openfoam/).

Is OpenFOAM (http://www.openfoam.com/) a candidate for use in AJAX modeling?
Title: Re: AJAX Launcher
Post by: martin hegedus on 07/25/2010 02:36 am
Trying to get up to speed on this I found CFD-Wiki (http://www.cfd-online.com/Wiki/Main_Page), "a community project to create the ultimate, free Computational Fluid Dynamics reference," which was relatively helpful.

I also noted the associated forum, including the OpenFOAM sections (http://www.cfd-online.com/Forums/openfoam/).

Is OpenFOAM (http://www.openfoam.com/) a candidate for use in AJAX modeling?


Please see my post above in regards to OpenFOAM http://forum.nasaspaceflight.com/index.php?topic=22266.msg621780#msg621780

I believe the OpenFOAM solvers still solve the flow equations uncoupled so they won't be able to get a good solution for steady state supercritical flows and will completely bomb when trying to solve for steady state supersonic flows.  But maybe things have changed.  Something someone can ask the forums or google to see if there are any OpenFOAM supersonic steady state solutions out there on the web.  Maybe someone has created a solver which works.  Or maybe the AeroFOAM one I mentioned is being maintained again and a turbulence model has been added. (AeroFOAM would work if you want an Euler solutions, assuming it works with the latest version of OpenFOAM)  Or maybe you can ask Richard at Symscape.
Title: Re: AJAX Launcher
Post by: spacenut on 07/27/2010 02:28 pm
What's going on with this plan lately? 
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/27/2010 05:43 pm
I'm working on modeling it a little bit. Progress is slow... It sure would be nice to have some professional software, but I'm making a little progress with just opensource. I have a mesh (with some basic geometry), and I'm working on getting the solver (freecfd) up and running. It's supposed to work with fully supersonic flows (as well as subsonic). I'll let you know how it goes.
Title: Re: AJAX Launcher
Post by: sdsds on 07/27/2010 09:07 pm
What's going on with this plan lately? 

The space elevator advocates have an interesting decomposition of the challenges they face:
"Our plan of action is based on four pillars: Technology, Law, Business, and Outreach."  http://www.isec.info/mission

Something similar for AJAX probably makes sense.  Starting with outreach, I wonder if there's any evidence AJAX has any visibility among spaceflight enthusiasts outside the nasaspaceflight.com forum?  With business, I wonder if any key corporate "players" are aware of the technical possibility?  Ditto for the law (i.e. legislative) aspect - is there any indication that anyone in D.C. thinks liquid boosters could possibly replace solids in a NASA heavy-lift system?

Oh yeah.  Then there are those pesky technical questions about float valves and such!  ;)
Title: Re: AJAX Launcher
Post by: nooneofconsequence on 07/27/2010 10:04 pm
None in this industry would dare recommend something like this - too easy to look foolish in doing so.

But its no different than recommending SRBs and ET to dig out of the Shuttle's original development malaise.

It's an element of the DIRECT story to enable budgetary/political consideration as a 'what if' - as in coping with the transition to bigger kerolox.

It's existence also undercuts 5 seg solids as a desirable future - because of cost / performance / safety / growth considerations that are better with AJAX.

And to many in the industry who wouldn't be forward with advocacy, but welcoming nonetheless - it rationalizes more of the irrational aspects of this endeavor.

So its something a staffer can raise as an example for 'what if' to push back with. 
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/27/2010 10:57 pm
None in this industry would dare recommend something like this - too easy to look foolish in doing so.

But its no different than recommending SRBs and ET to dig out of the Shuttle's original development malaise.

It's an element of the DIRECT story to enable budgetary/political consideration as a 'what if' - as in coping with the transition to bigger kerolox.

It's existence also undercuts 5 seg solids as a desirable future - because of cost / performance / safety / growth considerations that are better with AJAX.

And to many in the industry who wouldn't be forward with advocacy, but welcoming nonetheless - it rationalizes more of the irrational aspects of this endeavor.

So its something a staffer can raise as an example for 'what if' to push back with. 

In response to your first sentence: But they DID recommend Ares 1 didn't they, albeit with a considerable amount of arm twisting as foolish as it WAS and LOOKEd they still did it :P


This is far more logical and less foolish, IMO. But we need to solve this T/W issue if possible.
Title: Re: AJAX Launcher
Post by: nooneofconsequence on 07/27/2010 11:43 pm
None in this industry would dare recommend something like this - too easy to look foolish in doing so.
In response to your first sentence: But they DID recommend Ares 1 didn't they, albeit with a considerable amount of arm twisting as foolish as it WAS and LOOKEd they still did it :P
Because Dr. Griffin, "The premiere rocket scientist of these times" chose it - put his name behind it, and defended it to Congress himself.

They are still attempting to sell it on this basis. Long after it is replaced by anything else - they will still continue to maintain it as appropriate.

It is all about arm twisting with that crowd - Griffin guaranteed to them they would never look foolish ... and by damn, they won't let that happen to them. It's all about making denial work for you.

However denial sucks as propelling a post Shuttle HSF program.
Title: Re: AJAX Launcher
Post by: HappyMartian on 07/28/2010 05:15 am

You are right Jim, we need to optimize the core.  I keep resisting this, or going for the cheap technique, we wind up in circles. 


I never understood the resistance.  The core does not have a ready to use structure. There is nothing magical about the shuttle system propellant quantities.   The forward LOX dome, intertank, aft LH2 dome/section, etc all have to redesigned.  So, what was the point of redesigning them to shuttle quantities? 


A smaller core/ET sounds like an optimized design to me! Good job!

Cheers!

Edited.
Title: Re: AJAX Launcher
Post by: kirghizstan on 07/28/2010 03:42 pm
None in this industry would dare recommend something like this - too easy to look foolish in doing so.
In response to your first sentence: But they DID recommend Ares 1 didn't they, albeit with a considerable amount of arm twisting as foolish as it WAS and LOOKEd they still did it :P
Because Dr. Griffin, "The premiere rocket scientist of these times" chose it - put his name behind it, and defended it to Congress himself.

They are still attempting to sell it on this basis. Long after it is replaced by anything else - they will still continue to maintain it as appropriate.

It is all about arm twisting with that crowd - Griffin guaranteed to them they would never look foolish ... and by damn, they won't let that happen to them. It's all about making denial work for you.

However denial sucks as propelling a post Shuttle HSF program.

failure of leadership.  on the opposite end see Houbolt and LOR.  when you find a better idea no matter how few are pushing it, you go with it.
Title: Re: AJAX Launcher
Post by: spacenut on 07/28/2010 04:33 pm
Direct was/is the better idea for shuttle derived heavy lift, but wasn't chosen.  Now look where we are.  The better idea of LOR in the 60's won out.  We don't have pragmatic leadership today.  We had guys in the 60's with mindsets from WWII.  Today we have video and computer raised leadership, not real world experienced. 
Title: Re: AJAX Launcher
Post by: Downix on 07/28/2010 04:52 pm
Direct was/is the better idea for shuttle derived heavy lift, but wasn't chosen.  Now look where we are.  The better idea of LOR in the 60's won out.  We don't have pragmatic leadership today.  We had guys in the 60's with mindsets from WWII.  Today we have video and computer raised leadership, not real world experienced. 
Getting a bit off of topic, aren't we?
Title: Re: AJAX Launcher
Post by: simcosmos on 07/29/2010 12:07 pm
I'm kind in 'away mode', not sure about the regularity with which will be able to return to the AJAX brainstorm.

What's going on with this plan lately? 

Would not call it a plan, only a conceptual brainstorm at this moment. From this side of the Net, I was trying to prepare a few comments either about 3D models vs CFD either still about T/W but the text - which have been slooooowly writing in the few past days - is becoming a bit dense (this post also turned out a bit dense by itself, despite have made some cuts!!!)...




You are right Jim, we need to optimize the core.  I keep resisting this, or going for the cheap technique, we wind up in circles. 


I never understood the resistance.  The core does not have a ready to use structure. There is nothing magical about the shuttle system propellant quantities.   The forward LOX dome, intertank, aft LH2 dome/section, etc all have to redesigned.  So, what was the point of redesigning them to shuttle quantities? 


A smaller core/ET sounds like an optimized design to me! Good job!

Cheers!

Edited.

Maybe a good time for a summary, Downix, all, feel free to correct / complete as needed...

I. The way I look at the it, we have a brainstorm going on that currently deals with the following very restrictive design trade-space assumptions:


I.a) The wish to share synergies with AtlasV by adapting LRBs powered by RD-180 (as proposed for the triple core AtlasV Heavy variant)... some practices recommend that a 5% margin should be added to the inert mass of such boosters in order to account for eventually needed modifications for the specific AJAX application.

Avoiding solids also brings considerable advantages concerning things such as transportation / integration of  the boosters to / at VAB and to the launchpad, reduction of loads on crawlerway / crawler, reduction of concerns regarding large SRB Quantity-Distance limits (vs eventual need for extra facilities to deal with such issue if wishing to increase the HLV flight rate and if not wishing to have VAB as a bottleneck),  start and verification of booster engines before liftoff commitment, more friendly abort scenarios, etc

In addition, although not the baseline and being very generic, the AJAX conceptual core could eventually be compatible with liquid boosters assumptions other than AtlasV LRB / CCB as we currently know them  (although this would need to be part of conceptual growth options and, at this moment, should be only a foot note and little more than that...)


I.b) Another constraint of the brainstorm is the wish to keep and best use still around capabilities of STS derived hardware under the form of 8.4m diameter tanks and SSME (first using the available SSME from STS, then assuming restart of SSME production more or less as currently exists while later modifications to the current SSME could result in a slightly 'simplified' and easier to produce version); utilisation of VAB / KSC39.


I.c) the wish to think about a modular heavy lift capability – where a 4 LRB config would probably be the entry baseline - built by using these basic components and, eventually, also using existing upper stages, with a new upper stage probably being built for the heaviest version of the HLV.


These considerations practically dictate that the core needs to have 4 SSME. The SSME might run from 100% / 104.5% up to 109% power levels at liftoff, depending of the size of the core vs T/W considerations at that moment...




II. This then focus the brainstorm on the core design where that specific launch vehicle component design trade space has an interval with two extremes:

II.a) on the very lower end, there could exist  a short core with about 60t inert mass for a prop. load of about 565t: this is really and probably the most lower end case... It is perhaps the simpler way to achieve T/W values at liftoff closer to  an eventually desired 1.2 value without having to consider non-standard procedures and perhaps even without having to consider the SSME running at 109% power levels at liftoff... but such shorter core option comes with a price:

- eventual non-trivial final performance reduction (when comparing with the other extreme case, the ET sized core)

- because the core is lighter, a probable increase in some ascent structural loads and/or eventual extra complexity added to the throttling programs for the LRBs and SSME on later parts of the ascent (depending of ground rules, in particular if focusing on eventual crewed applications)   


II.b) on the other extreme, the high-end extreme, there could exist  an 'STS ET' sized core with about 71t inert mass for a prop. load of about 728t: such core would in theory be able to maximize the final performance for AJAX-44X (and eventual other launcher configurations)... For AJAX-44X we could be talking of about 20t more gross payload mass than the lower-end extreme or, if wishing to think about it in another way, this higher-end core option could provide extra performance margin to play with (when considering different payloads / missions needs)...

The LRB and SSME throttling profiles could also be simplified when comparing with the lighter lower-end core...

The disadvantages are that such ET sized core would probably need the SSME to run at 109% at liftoff and even then  the T/W value at that moment would probably be closer / slightly less than ~1.1 …




III. Where are we now? How to move forward the brainstorm?

IF (and this is a big IF) this brainstorm could somehow count with professional input regarding T/W analysis vs very specific and standardized numerical assumptions for an AJAX-44X vs issues such as launcher 'controllability' when clearing the pad vs different launch conditions to then confirm (or not!) if something like T/W of ~1.1 could be an acceptable value for such specific AJAX-44X considerations, then the ET sized core would offer some extra reasons to be an attractive baseline...

However, in the lack of such professional analysis, there are two eventual options (if not wishing to change the self-imposed restrictive design trade-space):


III.a) Try to aim the core assumption to a +/- middle-point between the lower-end and higher-end core sizes that I have shared above:  this could probably lead to something similar to what Downix seems to have suggested somewhere on a previous post, a conceptual core with an inert mass of about 65t for a prop. load of about 646t or so (proper mass estimation would need to be refined later on)...

This could result in a T/W at liftoff of about 1.15 IF using SSME at 109% (and if considering a start and verification sequence for the SSME and LRB like what I have suggested on a previous post (~6s for the 4  x SSME to start and be verified at max. power level, then staying there for extra ~2.7s of the 4 x  RD-180 own start and verification sequence to 100%, then liftoff IF all engines running OK).

Of course that this 'middle-ground' approach to the core size would need new specific simulation work to better have a preliminary idea of all the ascent story / constraints, performance results, etc...
 


III.b) The other option, again if assuming lack of professional analysis about the T/W issue, would be to assume the configuration that results in the value closer to T/W at liftoff of ~1.2: this would then mean the adoption of the shorter core (~60t for 565t prop) as the AJAX baseline as well would mean the acceptance of lower final performances... The possibility, constraints, etc for crewed applications might   require a good and much more careful study for this lower-end core variant...




IV) Ground Rules Decisions about Maximum Accelerations:

I do not particularly like to share incomplete work, even more when doing so without providing extra context so that readers fully understand what is being shared... But, even with all the cuts, this post is already starting to bee a bit too long (!!!)...

Anyway, please look at the graphic in attachment:


The red and green curves are from my previous shared Excel file (http://forum.nasaspaceflight.com/index.php?topic=22266.msg620464#msg620464) with rough preliminary AJAX-44X simulation work of, respectively, minimum and 'ET' sized cores (these are kind of the opposite extreme cases of the current design trade-space that have referenced above).

The blue line is for the short core (lower-end example) but, this time, with several additional 'tweaks' (complexity added...) on SSME / LRB burn profiles (examples: LRB down to 47% vs 60% on Excel file or with 2 of the SSME OFF – if remembering well, that is the third 'pike' -  before LRB sep!, which would be the fourth pike, etc) in a very crude attempt to study the maximum effect on performance loss vs maximum tweaks for a maximum acceleration control to less than 3g for eventual crewed applications (haven't really concluded the study, could have gone for a bit of extra thrust in several places, etc... this would also need completely new ascent guidance, which haven't really implemented...). Please note that this kind of tweaks could introduce non-trivial performance losses (on top of the already lower performance of the shorter core... eventually entering in the realm of top enhanced HLV capabilities...)... Again, extra and much more careful study needed!


… Please then having in mind that the blue line is an example of extreme g control case for an also extreme lower-end core variant, there is the need to put such 'tweaks' (desire to have more or less g control on launch vs aborts, etc) in perspective against, for example, the loads that astronauts feel/would feel when in return scenarios from LEO, the Moon and Beyond... Once more, this is also related with a number of other factors such as launcher / payload structural loads... ascent ground rules formulation too...


Without writing the extra comments that would be required to give a proper complete context to all the details seen in the shared graphic or without additional and very careful simulation work, I have also added, for rough comparison / historical context, T/W curves for STS / Apollo...




V. Final Comments / Summary

If there is the wish to take this informal brainstorm somehow moving forward, then a more solid decision needs to be made regarding the core parameters and, at least, some extra discussion / guidance is needed regarding maximum accelerations for AJAX... At least this is what I feel that is needed for a bit extra of more careful simulation work... A better core definition would help on better definition of LRB integration, payload fairings, etc... all of which would improve trajectory/performance/CFD outputs...


Would also like to note that this kind of things requires quite a bit of time both for research / study and also to properly share results and comments in written form (it would be nice if a new NSF forum teleport feature into a room with a nice and big black board for face-to-face brainstorm meetings was a reality!), time that could be used for other things :) . Please do not take this in the wrong way but I'm a bit reticent about continuing to 'study' the topic – even if in a very informal way and only for the 'sake of amusement' - when knowing that there is something that could eventually become a 'show-stopper' (liftoff T/W) and when the trade-space to solve such issue in a clear conservative way seems to be (artificially or not) very restrictive (independently if such specific hardware choices seem to be somehow attractive in a generic way... but the devil is always in the details...).

So, for the moment, and if I decide to continue participating – when possible - in the brainstorm, I will probably focus my research directions on the search for papers, analysis, etc that might provide good reading material about liftoff requirements for launchers, in particular heavy lift vehicles for crewed and non-crewed use. Not sure if makes sense to continue the brainstorm and study later parts of the ascent until having a better understanding of eventual requirements and constraints to launch vehicle design that affect the vehicle in those very early and important first few seconds of the ascent.


In case of doubt and if no specific professional input is then available, probably better to aim for very close or even greater than 1.2 T/W at liftoff... But if that means the assumption of a shorter core (like the lower end extreme case) then, depending of ground rules and other more careful feasibility analysis, that might bring some consequences (or not) to crewed uses of AJAX-44X and, independently of crewed use considerations, it also will almost surely mean an impact on conceptual final performance, that is, when comparing with the opposite extreme case -  the ET sized core – IF assuming that a lower T/W at liftoff of ~1.1 would end up by being acceptable (or when comparing with a middle sized core, IF assuming that a T/W value of about 1.15 would be acceptable at liftoff).

Thanks,
António
Title: Re: AJAX Launcher
Post by: Downix on 07/29/2010 04:39 pm
Doing a bit more study on my semi-shrunk core:

Every time a pair of CCBs are added, the extra thrust given dovetails with the extra lift capacity of the design, so it remains around that 1.15 T/W ratio.  Also, the necessary tank would have the interstage lining up with the CCB's a bit smoother as well it seems.

It is a lot smoother than the drop-engine idea, anyways.
Title: Re: AJAX Launcher
Post by: simcosmos on 07/29/2010 04:48 pm
Quick comment only to clarify that the meaning of the expression '2 SSME OFF' (on my previous long post and also on the attached graphic) is a reference to the shutdown of half of the SSME engines, at a given MET, and not a reference to dropping the SSME from the launch vehicle.

António
Title: Re: AJAX Launcher
Post by: Downix on 07/29/2010 04:58 pm
Quick comment only to clarify that the meaning of the expression '2 SSME OFF' (on my previous long post and also on the attached graphic) is a reference to the shutdown of half of the SSME engines, at a given MET, and not a reference to dropping the SSME from the launch vehicle.

António
Understood.  I was more thinking out loud for some of the more outrageous bits suggested, like dropping, as in actually dropping an engine or two, a la Atlas.
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/29/2010 07:46 pm
By the way, like I mentioned before, here's an example of why the Russians have skewed cones on top of most (all?) of their boosters instead of the regular cones the Americans like:

Notice there is virtually no shock on the "top" part where the cone would attach to the core. Granted, this is a wedge and not a cone, but the same principal would apply.

I plan to try to reproduce this with freecfd once I get that up and running.

EDIT: from here: http://lobbia.org/waveriders-03.html
Title: Re: AJAX Launcher
Post by: Downix on 07/29/2010 07:52 pm
By the way, like I mentioned before, here's an example of why the Russians have skewed cones on top of most (all?) of their boosters instead of the regular cones the Americans like:

Notice there is virtually no shock on the "top" part where the cone would attach to the core. Granted, this is a wedge and not a cone, but the same principal would apply.

I plan to try to reproduce this with freecfd once I get that up and running.

EDIT: from here: http://lobbia.org/waveriders-03.html
I am figuring on a skewed cone as well, the aerodynamics are right, plus, they look sexy.  8)
Title: Re: AJAX Launcher
Post by: Jim on 07/29/2010 08:05 pm
Look at the Atlas V SRB's
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/29/2010 08:12 pm
Look at the Atlas V SRB's
From here:
http://www.lockheedmartin.com/ssc/commercial_launch_services/launch_vehicles/AtlasV500Series.html
Title: Re: AJAX Launcher
Post by: Downix on 07/29/2010 10:43 pm
Look at the Atlas V SRB's
From here:
http://www.lockheedmartin.com/ssc/commercial_launch_services/launch_vehicles/AtlasV500Series.html
Very similar to the design I have.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/30/2010 12:12 am
I see no problem, in fact it seem there are advantages to using this nose cone design on the CCBS instead of a standard design.
Title: Re: AJAX Launcher
Post by: douglas100 on 07/30/2010 08:39 am
From Jim

Quote
Look at the Atlas V SRB's

Or the Ariane 5 SRB's.
Title: Re: AJAX Launcher
Post by: simcosmos on 07/30/2010 11:03 am
Another quick comment:

I might have somewhere on my archives an interesting pdf about the shape of Ariane5 SRB (EAP) 'cone' (at least I think that it was the topic of that pdf / paper(?)... might also have downloaded something closer related with AtlasV SRB nose shape... might try to search those files on a later occasion, if someone is interested about reading them (?)).

Without specific AJAX analysis and thinking in more generic terms, these kind of shapes do seem to be an optimal technical choice but the topic should  also be seen from a wider perspective with questions like:

- would such LRB cone shape really be needed for AJAX?

- what would be the cost difference, added production complexity (and other differences) of such shape versus a simpler cone?

Being that one of the objectives of AJAX brainstorm would be to use the LRB from AtlasV Heavy with as little changes as possible, and with such AtlasV LRB being apparently represented, on official documents, with a simpler / more standard nose shape, these kind of things need to be taken in account (remember that AtlasV Heavy stopped at CDR and the mentioned time for it to be ready from GO order might be in the order of 30-36 months).

Would also like to note that not all Russian vehicles seem to assume such kind of more complex shape for its boosters (and because this is a conceptual brainstorm, see the example of the ongoing development work for Angara or for Rus-M, although those are different configurations in what regards central core diameter, etc). Launchers like Soyuz and Proton are slightly different cases on their own too (Soyuz boosters shape / integration, Proton has external tanks, not boosters).

Energia / Energia-M and its boosters are the probable main 'references' for something like AJAX-44X (with the conceptual Vulkan as a reference for the 8 boosters placement for a conceptual AJAX-48X).

But again, independently of Energia, Ariane5 or several conceptual Heavy Lift designs around (there are quite a few at novosti-kosmonavtiki forums), in what regards AtlasV LRB cone for AJAX, a trade needs to be done about the technical aspects vs production vs costs vs commonality with eventual AtlasV Heavy, etc.

Without such careful trade done it might be better to baseline a more standard cone for now (?)...

António

PS: once details such as T/W issue vs core properties (prop. load, thrust structure / engine pod design) and baseline payload fairing shape / dimensions mass are more firmly decided I could share a very small zip for Orbiter simulation purposes... I could also share (by email request) a non-distributable zip with some 3D models for AJAX CFD purposes (but before doing that it would be nice to have a more solid baseline as well would need first to make a number of questions regarding the requirements of such models for CFD purposes... depending of the answers, those CFD models might need to be slightly different, in some aspects, from the simulation models... but, on my opinion, we are not there yet)... ok, back to lurker mode
Title: Re: AJAX Launcher
Post by: Downix on 07/30/2010 03:16 pm
As there is no AVH as of yet, technically we'd be buying CCB's, no cone.  So we will have to provide a nose cone in this scenario that I had in my head.  The slanted nosecone could also be of an advantage for the AVH, so it could migrate backwards for such a scenario. 

Now, if ULA is producing cones, it's not a game-stopper to use them.  I just see an advantage to the slanted.  Plus, then the CCB's would better mate up to the core tanks interstage.  I have the core tank mounts all plotted out now for it, but it is not difficult to swap out while on the paper-stage still.
Title: Re: AJAX Launcher
Post by: Downix on 08/02/2010 05:05 pm
I've finished crunching the #'s for the slightly shrunk core.  At every weight class (4, 6 and 8 CCB) it comes in over a T/W of 1.15, and is still within spitting distance of the larger cores throw capacity.  I think it is the right size.  It will be approximately the same size as the DIRECT core, with a different "top" and "Bottom" to the internal fuel tanks making the difference in fuel loads.
Title: Re: AJAX Launcher
Post by: sdsds on 08/02/2010 08:31 pm
Some criticism of DIRECT (and potentially even more criticism of AJAX) revolves around the accusation that we (the supporters) don't really know what we're talking about when we say, "Core derived from Shuttle ET."  My personal temptation if questioned on this would be to say, "Same as ET materials; same as ET diameter; same as ET tooling; same as ET worker skills; same as ET production location; same as ET transport infrastructure."  I would then mention something about "Michoud hook height," wave my hands and say, "Pay no attention to that man behind the curtain!"

I'm curious though:  what really is behind the curtain of "ET commonality"?  What are the materials?  What are the forming processes?  Milling processes?  Materials handling processes?  How do we really know that what works for an external tank will work for a rocket body?
Title: Re: AJAX Launcher
Post by: FinalFrontier on 08/08/2010 07:08 pm
Some criticism of DIRECT (and potentially even more criticism of AJAX) revolves around the accusation that we (the supporters) don't really know what we're talking about when we say, "Core derived from Shuttle ET."  My personal temptation if questioned on this would be to say, "Same as ET materials; same as ET diameter; same as ET tooling; same as ET worker skills; same as ET production location; same as ET transport infrastructure."  I would then mention something about "Michoud hook height," wave my hands and say, "Pay no attention to that man behind the curtain!"

I'm curious though:  what really is behind the curtain of "ET commonality"?  What are the materials?  What are the forming processes?  Milling processes?  Materials handling processes?  How do we really know that what works for an external tank will work for a rocket body?

Because DIRECT and people at MSFC and people at Areospace corp and other undisclosed groups EXTENSIVLEY researched this and have been doing so since 05' and they found that yes, it will work.

Its not as hard as many think, the ET is quite strong as it is. Process for the core milling are essentially the same as for ET milling, only difference is added material for more strength (example: Extra layer of grid paneling around the entier et, inside and/or outside for needed strengthening).
Only new part are: Thrust structure, faring, (and in our case CCB attach points.)


On another note: We should continue looking at this concept. I don;t think we ever "finished" with it really. And even though it might not ever be used, we should determine if its fully viable. :)
Title: Re: AJAX Launcher
Post by: Jim on 08/08/2010 07:28 pm


I'm curious though:  what really is behind the curtain of "ET commonality"?  What are the materials?  What are the forming processes?  Milling processes?  Materials handling processes?  How do we really know that what works for an external tank will work for a rocket body?

The ET is already a rocket body.  There is no difference in the fundamental design between the two.  There are only local nuisances.
Title: Re: AJAX Launcher
Post by: Downix on 08/08/2010 08:08 pm
Some criticism of DIRECT (and potentially even more criticism of AJAX) revolves around the accusation that we (the supporters) don't really know what we're talking about when we say, "Core derived from Shuttle ET."  My personal temptation if questioned on this would be to say, "Same as ET materials; same as ET diameter; same as ET tooling; same as ET worker skills; same as ET production location; same as ET transport infrastructure."  I would then mention something about "Michoud hook height," wave my hands and say, "Pay no attention to that man behind the curtain!"

I'm curious though:  what really is behind the curtain of "ET commonality"?  What are the materials?  What are the forming processes?  Milling processes?  Materials handling processes?  How do we really know that what works for an external tank will work for a rocket body?

Because DIRECT and people at MSFC and people at Areospace corp and other undisclosed groups EXTENSIVLEY researched this and have been doing so since 05' and they found that yes, it will work.

Its not as hard as many think, the ET is quite strong as it is. Process for the core milling are essentially the same as for ET milling, only difference is added material for more strength (example: Extra layer of grid paneling around the entier et, inside and/or outside for needed strengthening).
Only new part are: Thrust structure, faring, (and in our case CCB attach points.)


On another note: We should continue looking at this concept. I don;t think we ever "finished" with it really. And even though it might not ever be used, we should determine if its fully viable. :)
It is also not as if the CCB connection points would be all new either, they would be adapted from the shuttles connection system. 
Title: Re: AJAX Launcher
Post by: clongton on 08/08/2010 09:32 pm
In my opinion I do not see the SRB's as remaining *forever*. Right now they are a political necessity and will therefore be baselined.

However, eventually they will be replaced by LRB's and when they do, then we have AJAX and not Jupiter. That is actually what I personally hope to one day see. The LRB's allow an even more flexible launcher than the SRB's because they mass so much less. That means that while the Jupiter is what we started with, it will never be as capable as it could be because it is hamstrung by the SRB's. Once these are replaced with LRB's, then the potential IMLEO range is quite spectacular.

Going from the smallest configuration of the AJAX-440 with no upper stage to the mighty AJAX-486 with an upper stage, we cover the full range of 60mT medium lift to well in excess of 200mT Ultra Heavy Lift to LEO with a single launch system. We can easily spend decades doing appropriate or necessary incremental upgrades to this system and spend our money on missions in lieu of booster development. While the Jupiter is the very best that is possible in the current political climate, and we are *very* pleased that it looks to be actually happening, there is nothing wrong with thinking about where this can go from here.

I personally wish to see this thread continued, even as we witness the Jupiter come online and become the mainstay of the new SLS. AJAX is the next step from Jupiter and we started it right here. :)
Title: Re: AJAX Launcher
Post by: cro-magnon gramps on 08/08/2010 11:27 pm
In my opinion I do not see the SRB's as remaining *forever*. Right now they are a political necessity and will therefore be baselined.

However, eventually they will be replaced by LRB's and when they do, then we have AJAX and not Jupiter. That is actually what I personally hope to one day see.

<snip>

I  personally wish to see this thread continued, even as we witness the Jupiter come online and become the mainstay of the new SLS. AJAX is the next step from Jupiter and we started it right here. :)

I made this statement at an earlier time in the pre-AJAX discussion; This study is important for the same reason that the NLS study was important, if forms the core rationalization for a new launch vehicle, built around existing infrastructure and technologies, while allowing optimization with new technologies at the time it is needed (20-30 years from now);
    I know I have kept harping on the fact that the economic and political situations will not always be the same and there will be change as my generation passes on, and younger people come to their maturity, but that is ever the case with society; from Socrates to von Braun, and others, the youth's imaginations are captured by the impossible made possible;
     At some time in the not too distant future, some bright rocket scientist will want to have this study in their back pocket to pull out, when the question comes up, what do we do after the SRBs are defunded; then he can pull this out and point to the possibilities;
      There is, at this point in time, a group of people, capable people, who have been drawn together because of their interest in Space Exploration, and the vehicles that have been, and are being used; just like the Direct Team, 5 years ago, they have seen a problem and attempted a study of the solution; I would hate to see this study be stillborn because of the pessimistic attitude prevalent in society today; 30 years ago, I could have contributed mathematically, but that is not possible today; so all I can do is give encouragement, and suggestions;
 
     Gramps
Title: Re: AJAX Launcher
Post by: Downix on 08/08/2010 11:38 pm
In my opinion I do not see the SRB's as remaining *forever*. Right now they are a political necessity and will therefore be baselined.

However, eventually they will be replaced by LRB's and when they do, then we have AJAX and not Jupiter. That is actually what I personally hope to one day see.

<snip>

I  personally wish to see this thread continued, even as we witness the Jupiter come online and become the mainstay of the new SLS. AJAX is the next step from Jupiter and we started it right here. :)

I made this statement at an earlier time in the pre-AJAX discussion; This study is important for the same reason that the NLS study was important, if forms the core rationalization for a new launch vehicle, built around existing infrastructure and technologies, while allowing optimization with new technologies at the time it is needed (20-30 years from now);
    I know I have kept harping on the fact that the economic and political situations will not always be the same and there will be change as my generation passes on, and younger people come to their maturity, but that is ever the case with society; from Socrates to von Braun, and others, the youth's imaginations are captured by the impossible made possible;
     At some time in the not too distant future, some bright rocket scientist will want to have this study in their back pocket to pull out, when the question comes up, what do we do after the SRBs are defunded; then he can pull this out and point to the possibilities;
      There is, at this point in time, a group of people, capable people, who have been drawn together because of their interest in Space Exploration, and the vehicles that have been, and are being used; just like the Direct Team, 5 years ago, they have seen a problem and attempted a study of the solution; I would hate to see this study be stillborn because of the pessimistic attitude prevalent in society today; 30 years ago, I could have contributed mathematically, but that is not possible today; so all I can do is give encouragement, and suggestions;
 
     Gramps
Every previous LRB study has relied on new, custom LRB's.  Which is why AJAX is different, it stuck to the DIRECT methodology of minimum development cost. 

I'd like to make sure that our final core design can use either the current CCB or Phase II CCB and to do that, I am keeping the connection points on a spar, like how the shuttles front bipod is now.  If there is a change of current CCB to Phase II, we do not require a tank redesign, only a spar redesign.  By the same token, can swap out to CBC, Taurus II, or Falcon 9.  That being said, we are sticking to the CCB as the baseline, knowing that should it become politically expedient, we have the ability to change.

Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.
Title: Re: AJAX Launcher
Post by: clongton on 08/08/2010 11:48 pm
Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.

Which one?
Title: Re: AJAX Launcher
Post by: Downix on 08/09/2010 12:25 am
Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.

Which one?
Trying out a few.  Right now messing with BlenderCAD.
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/09/2010 01:20 am
Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.

Which one?
Trying out a few.  Right now messing with BlenderCAD.
And meanwhile, I've switched from freeCFD to FUN3D. Although FUN3D is harder to get a hold of, it should be much more powerful.
Title: Re: AJAX Launcher
Post by: cro-magnon gramps on 08/09/2010 02:44 am
Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.

Which one?
Trying out a few.  Right now messing with BlenderCAD.
And meanwhile, I've switched from freeCFD to FUN3D. Although FUN3D is harder to get a hold of, it should be much more powerful.

Would this be the Fun3D your looking for

Home / Development site -
http://code.google.com/p/fun3d/

http://www.freewarefiles.com/Fun3D_program_50437.html

Gramps
Title: Re: AJAX Launcher
Post by: HappyMartian on 08/09/2010 05:21 am
In my opinion I do not see the SRB's as remaining *forever*. Right now they are a political necessity and will therefore be baselined.

However, eventually they will be replaced by LRB's and when they do, then we have AJAX and not Jupiter. That is actually what I personally hope to one day see.

<snip>

I  personally wish to see this thread continued, even as we witness the Jupiter come online and become the mainstay of the new SLS. AJAX is the next step from Jupiter and we started it right here. :)

I made this statement at an earlier time in the pre-AJAX discussion; This study is important for the same reason that the NLS study was important, if forms the core rationalization for a new launch vehicle, built around existing infrastructure and technologies, while allowing optimization with new technologies at the time it is needed (20-30 years from now);
    I know I have kept harping on the fact that the economic and political situations will not always be the same and there will be change as my generation passes on, and younger people come to their maturity, but that is ever the case with society; from Socrates to von Braun, and others, the youth's imaginations are captured by the impossible made possible;
     At some time in the not too distant future, some bright rocket scientist will want to have this study in their back pocket to pull out, when the question comes up, what do we do after the SRBs are defunded; then he can pull this out and point to the possibilities;
      There is, at this point in time, a group of people, capable people, who have been drawn together because of their interest in Space Exploration, and the vehicles that have been, and are being used; just like the Direct Team, 5 years ago, they have seen a problem and attempted a study of the solution; I would hate to see this study be stillborn because of the pessimistic attitude prevalent in society today; 30 years ago, I could have contributed mathematically, but that is not possible today; so all I can do is give encouragement, and suggestions;
 
     Gramps


Gramps and Clongton hit the nail on the head. Great job!

It is likely that, in a decade or two, a dramatic  increase in the annual Jupiter flight rate is going to force the environmental issues of using the SRBs into the political arena. It is essential to the long-term success of the J-130, and its family, that alternatives to the SRBs be available and well understood.

A TAN version of the SSME or RD-180 could add to the AJAX launcher capabilities and eliminate the J-130's need for the SRBs. If the White House folks are interested in the environment and "game changing technology," a TAN version of the SSME or RD-180, or TAN versions of both engines, should be seriously considered.

But for now, the AJAX launcher team should stick with using what is available. That should work out pretty good.

Cheers!

Edited.
Title: Re: AJAX Launcher
Post by: luke strawwalker on 08/09/2010 05:35 am
In my opinion I do not see the SRB's as remaining *forever*. Right now they are a political necessity and will therefore be baselined.

However, eventually they will be replaced by LRB's and when they do, then we have AJAX and not Jupiter. That is actually what I personally hope to one day see. The LRB's allow an even more flexible launcher than the SRB's because they mass so much less. That means that while the Jupiter is what we started with, it will never be as capable as it could be because it is hamstrung by the SRB's. Once these are replaced with LRB's, then the potential IMLEO range is quite spectacular.

Going from the smallest configuration of the AJAX-440 with no upper stage to the mighty AJAX-486 with an upper stage, we cover the full range of 60mT medium lift to well in excess of 200mT Ultra Heavy Lift to LEO with a single launch system. We can easily spend decades doing appropriate or necessary incremental upgrades to this system and spend our money on missions in lieu of booster development. While the Jupiter is the very best that is possible in the current political climate, and we are *very* pleased that it looks to be actually happening, there is nothing wrong with thinking about where this can go from here.

I personally wish to see this thread continued, even as we witness the Jupiter come online and become the mainstay of the new SLS. AJAX is the next step from Jupiter and we started it right here. :)

I agree clongton that this would be "the best of both worlds".  I don't know that I'm as optimistic about the SRB's going away anytime in the foreseeable future though, or even if that's necessarily a good idea, at least not until we have a little more development on the LRB side of things (building the Atlas on Delta tooling (Phase I?) so only TWO LRB's instead of FOUR would be a great start, along with indigenous engine production, of whatever type or flavor).   The SRB's DO bring some HD thrust to the table, despite their obvious shortcomings...

One thing that's occurring to me that I've wondered about is, what would a HYBRID design be capable of??  One using, say, four segment SRB's as-is, with say a pair of Atlas V LRB's opposite them.  Seems like that'd get you some SERIOUSLY heavy lift capability to LEO. 

Yeah, I know, innumerable problems including certifying the combination, major bucks, and all that, but hypothetically speaking... have you guys looked at that??  Just thinking out loud...

Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: sdsds on 08/09/2010 06:03 am
Improbable as it once seemed, it does now look like something similar to Jupiter will pass through the wickets of Congressional authorization and funds appropriation.  It seems equally improbable, but perhaps it will also pass through the wickets of NASA "design", manufacturing and test, and emerge as a flyable system.

If that happens it will mean ATK once again begins production of large, segmented solid rocket motors.  We know where they're going to go with that!  They may give it a different name next time but they won't be able to resist the temptation of once again proposing a large solid as a first stage.

This is where the AJAX "CCB as LRB" approach really shines:  the booster is already a proven first stage with a matched, proven, second stage.  Hopefully by the time ATK turns its gaze again towards a crew launch vehicle, Atlas will already have become a proven crew launcher.  So long as there is even a peripheral awareness of AJAX, future decision makers will be able to "connect the dots" and move crewed spaceflight away from large solids entirely.
Title: Re: AJAX Launcher
Post by: clongton on 08/09/2010 12:02 pm
I think we need to write a paper that details this architecture and its many benefits and options. That paper is what will preserve for the future what we have done and are still doing here, just like the NLS papers did for DIRECT.
Title: Re: AJAX Launcher
Post by: simcosmos on 08/09/2010 12:14 pm
In my opinion I do not see the SRB's as remaining *forever*. Right now they are a political necessity and will therefore be baselined.

However, eventually they will be replaced by LRB's and when they do, then we have AJAX and not Jupiter. That is actually what I personally hope to one day see. The LRB's allow an even more flexible launcher than the SRB's because they mass so much less. That means that while the Jupiter is what we started with, it will never be as capable as it could be because it is hamstrung by the SRB's. Once these are replaced with LRB's, then the potential IMLEO range is quite spectacular.

( ... )

I personally wish to see this thread continued, even as we witness the Jupiter come online and become the mainstay of the new SLS. AJAX is the next step from Jupiter and we started it right here. :)

Hi,

Not sure if understood your comment Chuck but, at least at a first reading, the way you wrote it  seems a bit too much simplistic way of putting the things...  :D

Please someone correct me but it seems that the current brainstorm direction is to use something like a 65t core for a prop load of about 645t or so in order to allow for ~1.15 T/W at lift-off... and this under the key assumption that such T/W value is safe enough not only for conceptual brainstorm purposes but also for  the specific operational configurations (and eventual related constraints) being considered for AJAX...

...Although I do need to stress out (yet again!) that this T/W issue (and the impact of such issue not only on liftoff – where there might exist some 'lack' of T/W - but also on other, later moments of the ascent, where more or less power level control might be required depending of payload and ground rules for the launcher, etc...) would really need a professional and very careful analysis about the control authority of the launcher configurations during those very first seconds of the ascent, when clearing the MLP, tower, lightning towers vs different launch conditions vs other launchpad interactions...

Going to a lighter core solves the T/W issue but might make things more challenging on other moments of the ascent (and also means less payload). The mentioned above core might be in the middle of the allowable design trade-space (between lower-end and STS ET load cases) but there are still some questions that need further analysis...


This all to say that Jupiter assumes, as baseline, a core with STS ET load... Other SDLV and also other non-baseline DIRECT brainstorms, assume a stretched  core... We really do not know what will emerge from the ongoing context...


Although probably not impossible (depending of a good number of extra considerations), the current direction of AJAX brainstorm seems to mean that if something like a Jupiter STS sized core (or a stretched core like ESAS CaLV) would be fielded then, if wishing to later replace the 4 segment or the 5 segment, the liquid boosters assumptions would probably be different, in a good number of ways, than current AJAX  key assumptions... Again, depending of additional considerations and also of the intention of the quoted phrases, without further  qualification of that statement I do not quite agree with: 

"However, eventually they [SRB] will be replaced by LRB's and when they do, then we have AJAX and not Jupiter."





Regarding 3D / simulation stuff...

As I noted on another post, once a more clear baseline is properly assumed for...

- T/W: at liftoff (1.15 assumption then, despite all concerns...?); and how about Max. g for the ascent? 3g? 4g? 4.5g?

- the core (65t core for 645t propellants load? And what about the engine pod details? Assumption of an optimised engine pod length/design – similar to Energia assumptions - which raised some criticism on DIRECT v1.X, or go for something more 'standard', read, with more length and slightly more massive?)...

- the boosters (AtlasV LRB with 5% extra margin on inert mass – standard practice for adapted designs with high heritage, in this case - stated on AtlasV Users Guide and with modified nose cones? Nose cones similar to Energia? Or closer to AtlasV SRB assumptions?)

- Payload Fairing (2 parts? 4 parts?, 8.4m diameter? Barrel length? Shape of the Ogive?  Total length? Total mass?)... I have been using something like 12000 kg up to 15000 kg for the PLF mass (8.4m diameter)...

I have shared a few simulation ground rules, specs, etc of past simulation work on the Excel file and also on some past AJAX imagery that have attached on my participation on the current thread...

… I would be happy to share - within my possibilities – a set of further refined simulation files for Orbiter Simulator, where something like AJAX-44X (on a first preliminary set) could be displayed and could have a full rough/preliminary automatic guidance file (all the user would have to do would be to press a key to see the vehicle's ascent... then the user could also try to tweak the guidance file itself, as long as being perfectly aware of what to do...)...

In the same way, depending of the requirements for the 3D models to be used for CFD purposes, I could try to produce / adapt those Orbiter simulation 3D models for eventual specific CFD requirements and then selectively share a probably specific non-distributable zip containing those modified versions of the 3D models to interested people (such as Robotbeat)...

… However, as I also stated somewhere on a previous post, before even thinking more seriously about doing all that I would prefer to see a slightly stronger commitment to a baseline design definition for AJAX (and also for some ground rules formulation), in particular for something like the entry level capability, the AJAX-44X...

A good way to start building such baseline, at very least to have a more solid point of departure for some extra simulation (trajectory, ascent events, performance assessment) and CFD  work would be to further brainstorm and provide clear answers to the kind of topics I mentioned above... Then, I could produce and share some simulation related stuff... For CFD purposes would prefer email contact to share eventual resources and also because would need to know first a number of details regarding eventual 3D models requirements for such specific purpose (I guess that there is no need to clutter the forums with those questions). Depending of the answers I might (or not) need to adapt or even rebuild the models for better CFD analysis compatibility...

But again, without such stronger commitment regarding essential information / discussion needed for a better baseline definition to be used as point of departure for several types of refined extra work, I do not see, from this side of the Net,  much purpose on spending time to continue simulation / 3D work, etc, at least not at the current moment   8)

Thanks,
António
Title: Re: AJAX Launcher
Post by: cro-magnon gramps on 08/09/2010 12:36 pm
Quote>
But again, without such stronger commitment regarding essential information needed for a better baseline definition to be used as point of departure for several types of refined extra work, I do not see much purpose on spend time to continue simulation / 3D work, etc, at least not at the current moment.

Thanks,
António
<quote

Chuck, this came in while I was preparing to write a response to your suggestion for a paper; this last paragraph points up the need for some kind of paper that sums up what has already agreed upon, and is baselined, ie a Mark 1 Ajax 44x that forms a discussion point for future research; the rational behind the choices as well as the simulations and problems to work on;

I wasn't aware that this was still brainstorming and hadn't gone into a vs #  yet; I would not suggest putting a vs # on it yet, until a firmer foundation is reached for the LV; at that point the architecture would be appropriately brought into the picture ie the launch pad mods and the space infrastructure possibilities; right now it appears from Antonio's reading of the situation, that the LV is the issue at hand;

Gramps
Title: Re: AJAX Launcher
Post by: nooneofconsequence on 08/09/2010 08:13 pm
There are legal,  health and safety, "national security" issues that are markedly different than in the 1970's. The segmented  solids were difficult to get through then, the fiat of "national security" in the holdover of the lunar program forced the situation.

That may not be the case this time. Reasonable legal challenges likely won't be overridden. When the Shuttle stands down, the past rubric leaves with it.
Everything needs to be justified from the ground on up.

One should also consider the schedule threat to any SLS. What if you can't legally use the RSRM's, except perhaps a few times for transition thru a development program? Then you'd need a "plan B".

"National security" may not hold here. Name me the single strategic weapon we need at this moment that retaining segmented solid boosters of this size allows? King sized mortars in Pakistan?

Can we maintain strategic lift capability with clusters of EELV boosters alone? If a court finds "yes", doesn't matter what Congress says ... we call this 'balance of power' ... keeps this country from becoming a kleptocracy that loses sight of actual needs of national security, instead of devious ones.

Back with the cold war, it was different.
Title: Re: AJAX Launcher
Post by: clongton on 08/09/2010 08:15 pm
Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.

Which one?

Trying out a few.  Right now messing with BlenderCAD.

There are three (3) main things to look for when deciding what cad software to use.

1. file format compatibility
2. cost
3. ease of learning/use

Obviously you don't want to invest a lot of money (#2), but at the same time cheap or free software that can't communicate with any of the analysis software that will be needed (#1) is useless. Consideration #3 must play second fiddle to the first 2.

1. You need to first determine what software will be used for analysis, find out what file formats they can either natively open or import, and then narrow down the list of candidates to ones that will create design files that the analysis software can either open directly or that are easily translated into the format the analysis software needs. Eliminate everything that doesn't meet this requirement, regardless of how slick or fun it looks.

2. From those remaining, look at the costs and eliminate anything that you can't afford. What's left is a list of several candidates all capable of getting the job done, some costing more than others but you know you can afford any of them.

3. THEN: From the list that remains, examine each one for how difficult it is to learn and or use and make your selection from there. Remember, sometimes, but not always, the cost of something is not an indicator as to its value so ignore cost at this point because you know you can afford any of them. I have seen really expensive software that couldn't do half what a less expensive competitor could, and vice versa. Some expensive software is junk, and some cheap software is too. You have to look carefully at each one individually. You really need to just make a list of several candidates you know can do the job and that you can afford and then make the selection from them based on utility and use, without regard for which one costs less.

4. But above all else, do step #1 first – make sure that your cad files can be used by the analysis software, either natively or easily translated.
Title: Re: AJAX Launcher
Post by: clongton on 08/09/2010 08:26 pm
"National security" may not hold here. Name me the single strategic weapon we need at this moment that retaining segmented solid boosters of this size allows? King sized mortars in Pakistan?

Unfortunately we still must maintain our strategic nuclear deterrence. As long as "potential" adversaries possess nuclear weapons with the means to deliver them intercontinentally, then we must maintain our own icbm force as a deterrent. All our icbm's are solids.

Quote
Can we maintain strategic lift capability with clusters of EELV boosters alone? If a court finds "yes", doesn't matter what Congress says ... we call this 'balance of power' ... keeps this country from becoming a kleptocracy that loses sight of actual needs of national security, instead of devious ones.

No. Our stratigic lift capability is intrinsically tied to our national defense, like it or not. It's still about the icbm's. Liquid icbm's will not work. It takes too long to fuel and launch them. We need to be able to respond *literally* within seconds of the President's order to do so.

Quote
Back with the cold war, it was different.

Don't kid yourself - it's still going on. It's the presence of the nuclear deterrence that has cooled it down but the fire is not out. There are some out there who would nuke us in a heartbeat if they thought they could get away with it. Trust me on this.

Having said that, now back on topic please.
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/09/2010 08:36 pm
...

There are three (3) main things to look for when deciding what cad software to use.

1. file format compatibility
2. cost
3. ease of learning/use
...
Number 1 isn't necessarily a show-stopper. You can always write the conversion program yourself.  EDIT:As long as both sides are documented (ASCII helps, too).
Title: Re: AJAX Launcher
Post by: clongton on 08/09/2010 08:41 pm
...

There are three (3) main things to look for when deciding what cad software to use.

1. file format compatibility
2. cost
3. ease of learning/use
...
Number 1 isn't necessarily a show-stopper. You can always write the conversion program yourself.  EDIT:As long as both sides are documented (ASCII helps, too).

That's way too much effort for what we're doing here.
I've done a fair amount of programming and it can be very time consuming.

Just when you think you're done, there's an update to what you're using and now you have compatability issues to deal with. This happenes every year with every new upgrade to software.
It's a never ending story.
So you have to ask yourself the question:
Do you want to design software or rockets?
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/09/2010 08:45 pm
...

There are three (3) main things to look for when deciding what cad software to use.

1. file format compatibility
2. cost
3. ease of learning/use
...
Number 1 isn't necessarily a show-stopper. You can always write the conversion program yourself.  EDIT:As long as both sides are documented (ASCII helps, too).

That's way too much effort for what we're doing here.
I've done a fair amount of programming and it can be very time consuming.

Just when you think you're done, there's an update to what you're using and now you have compatability issues to deal with.
This happenes every year with every new upgrade to software.
It's a never ending story.
So you have to ask yourself the question:
Do you want to design software or rockets?
I had to write a conversion program for a 3d file format before. It was in ASCII, and I was sick of trying to tackle the problem using MATLAB code, so I taught myself enough PERL to do the conversion, and what was taking about 2 pages of code then took only a few lines of PERL. Right tool for the right job (sort of). If the input is in text and the output needs to be in text, then PERL is pretty awesome.

Then again, it was a relatively simple format, but I'm just saying it's not necessarily a show stopper.
Title: Re: AJAX Launcher
Post by: Downix on 08/09/2010 09:21 pm
In my opinion I do not see the SRB's as remaining *forever*. Right now they are a political necessity and will therefore be baselined.

However, eventually they will be replaced by LRB's and when they do, then we have AJAX and not Jupiter. That is actually what I personally hope to one day see. The LRB's allow an even more flexible launcher than the SRB's because they mass so much less. That means that while the Jupiter is what we started with, it will never be as capable as it could be because it is hamstrung by the SRB's. Once these are replaced with LRB's, then the potential IMLEO range is quite spectacular.

( ... )

I personally wish to see this thread continued, even as we witness the Jupiter come online and become the mainstay of the new SLS. AJAX is the next step from Jupiter and we started it right here. :)

Hi,

Not sure if understood your comment Chuck but, at least at a first reading, the way you wrote it  seems a bit too much simplistic way of putting the things...  :D

Please someone correct me but it seems that the current brainstorm direction is to use something like a 65t core for a prop load of about 645t or so in order to allow for ~1.15 T/W at lift-off... and this under the key assumption that such T/W value is safe enough not only for conceptual brainstorm purposes but also for  the specific operational configurations (and eventual related constraints) being considered for AJAX...
I've checked, and there are several lifters which are around this target, the most notable being the Atlas V itself (401 has a T/W of 1.152).  At this point, with both EELV's running at this T/W ratio (Delta IV Medium is 1.17) it looks to be settled to me
Quote
...Although I do need to stress out (yet again!) that this T/W issue (and the impact of such issue not only on liftoff – where there might exist some 'lack' of T/W - but also on other, later moments of the ascent, where more or less power level control might be required depending of payload and ground rules for the launcher, etc...) would really need a professional and very careful analysis about the control authority of the launcher configurations during those very first seconds of the ascent, when clearing the MLP, tower, lightning towers vs different launch conditions vs other launchpad interactions...
Agreed here.  I think once we have the T/W and core length calculated out, this is the next piece of the puzzle to focus on.
Quote
Going to a lighter core solves the T/W issue but might make things more challenging on other moments of the ascent (and also means less payload). The mentioned above core might be in the middle of the allowable design trade-space (between lower-end and STS ET load cases) but there are still some questions that need further analysis...


This all to say that Jupiter assumes, as baseline, a core with STS ET load... Other SDLV and also other non-baseline DIRECT brainstorms, assume a stretched  core... We really do not know what will emerge from the ongoing context...


Although probably not impossible (depending of a good number of extra considerations), the current direction of AJAX brainstorm seems to mean that if something like a Jupiter STS sized core (or a stretched core like ESAS CaLV) would be fielded then, if wishing to later replace the 4 segment or the 5 segment, the liquid boosters assumptions would probably be different, in a good number of ways, than current AJAX  key assumptions... Again, depending of additional considerations and also of the intention of the quoted phrases, without further  qualification of that statement I do not quite agree with: 

"However, eventually they [SRB] will be replaced by LRB's and when they do, then we have AJAX and not Jupiter."





Regarding 3D / simulation stuff...

As I noted on another post, once a more clear baseline is properly assumed for...

- T/W: at liftoff (1.15 assumption then, despite all concerns...?); and how about Max. g for the ascent? 3g? 4g? 4.5g?
Keeping the 1.15 assumption, it matches the EELV's so fits in our needs
Quote
- the core (65t core for 645t propellants load? And what about the engine pod details? Assumption of an optimised engine pod length/design – similar to Energia assumptions - which raised some criticism on DIRECT v1.X, or go for something more 'standard', read, with more length and slightly more massive?)...
I was figuring on sticking closer to the DIRECT and NLS methodology here, despite Energia being a better assumption.
Quote
- the boosters (AtlasV LRB with 5% extra margin on inert mass – standard practice for adapted designs with high heritage, in this case - stated on AtlasV Users Guide and with modified nose cones? Nose cones similar to Energia? Or closer to AtlasV SRB assumptions?)
Due to the core length, I will still voice my preference for the Energia nose cone variety.
Quote
- Payload Fairing (2 parts? 4 parts?, 8.4m diameter? Barrel length? Shape of the Ogive?  Total length? Total mass?)... I have been using something like 12000 kg up to 15000 kg for the PLF mass (8.4m diameter)...
I assumed to use the DIRECT fairings.
Quote
I have shared a few simulation ground rules, specs, etc of past simulation work on the Excel file and also on some past AJAX imagery that have attached on my participation on the current thread...

… I would be happy to share - within my possibilities – a set of further refined simulation files for Orbiter Simulator, where something like AJAX-44X (on a first preliminary set) could be displayed and could have a full rough/preliminary automatic guidance file (all the user would have to do would be to press a key to see the vehicle's ascent... then the user could also try to tweak the guidance file itself, as long as being perfectly aware of what to do...)...

In the same way, depending of the requirements for the 3D models to be used for CFD purposes, I could try to produce / adapt those Orbiter simulation 3D models for eventual specific CFD requirements and then selectively share a probably specific non-distributable zip containing those modified versions of the 3D models to interested people (such as Robotbeat)...

… However, as I also stated somewhere on a previous post, before even thinking more seriously about doing all that I would prefer to see a slightly stronger commitment to a baseline design definition for AJAX (and also for some ground rules formulation), in particular for something like the entry level capability, the AJAX-44X...

A good way to start building such baseline, at very least to have a more solid point of departure for some extra simulation (trajectory, ascent events, performance assessment) and CFD  work would be to further brainstorm and provide clear answers to the kind of topics I mentioned above... Then, I could produce and share some simulation related stuff... For CFD purposes would prefer email contact to share eventual resources and also because would need to know first a number of details regarding eventual 3D models requirements for such specific purpose (I guess that there is no need to clutter the forums with those questions). Depending of the answers I might (or not) need to adapt or even rebuild the models for better CFD analysis compatibility...

But again, without such stronger commitment regarding essential information / discussion needed for a better baseline definition to be used as point of departure for several types of refined extra work, I do not see, from this side of the Net,  much purpose on spending time to continue simulation / 3D work, etc, at least not at the current moment   8)

Thanks,
António

Understandable.
Title: Re: AJAX Launcher
Post by: simcosmos on 08/10/2010 11:23 am
Only for completeness and given that it took much less time than expected (!!!) to adapt previous configuration and guidance files to prepare a simulation run for a core with an inert mass of ~65500 kg for a prop. load of ~646000 kg (at SSME ignition sequence start), will soon share (in this post) an attachment with a preliminary update to the T/W picture that have previously shared (http://forum.nasaspaceflight.com/index.php?topic=22266.msg623135#msg623135) (where compared short core – with two power level programs - vs ET core vs STS vs Apollo).

In this update, the 65.5t / 646t core is represented by a brown line. T/W at lift-off is ~1.15 for launcher properties (LRB, PLF) and ascent ground rules equal to the ones that have shared on the '20100720-AJAX-44X' Excel file (http://forum.nasaspaceflight.com/index.php?topic=22266.msg620464#msg620464) (example: FPR / Residuals less than 1%, aiming for ~0.25% for LRB, ~1% initial prop. load for core; PLF away at ~125km up to 130 km alt., etc).



In what concerns T/W vs Ascent Timeline, these were the assumptions for the 65.5t / 646t core update:

- 4 x SSME ignition start / verification up to 109% taking ~6s, staying at such power level during extra 2.7s of the LRB start and verification sequence to 100%

- T/W of about 1.15, launcher taking ~11s or so to clear the lightning towers cage

- SSME throttle down at 110s, from 109% to 67% (with all 4 SSME then staying at 67% until MECO)

- RD-180 throttle down at 120s, from 100% to 75% EDIT: my mistake: RD-180 at 100%, no throttle assumed (shutdown command – sent at about 230s or so - while keeping less than 1% initial LRB prop. load, might try to aim for 0.25% on another run or leave it like this to account for simulation imprecision / margin; LRB separation at ~240s, separation being currently simulated with each LRB pair staying together, extra discussion needed)

- PLF released at ~305s (note: 8.4m diameter / 15t mass PLF being used as placeholder and also to better compare with my previous simulation runs)

- Core impact probably somewhere on the middle of Pacific Ocean (extra study required).


There might exist better possibilities for the ascent pitch program or RD-180 / SSME throttle settings for these updated core assumptions but, for the moment and given time constraints, this was probably the simplest way I managed to implement the described launcher without messing around too much with the power levels and while protecting performance... This to say that, with these settings, there does not seem to exist much impact on performance: the gross payload mass (adapter+payload+margins = +/- 83t or so) is just a few tons less than what I have shared on the STS ET sized core (~85t)... But again, would still need to make a better implementation to see if that is the case or not as well would need to properly verify the new implementation.
 
'Max g' was slightly above 4g (before LRB shutdown) and slightly above 3.5g at MECO (if keeping all 4 SSME going at 67%).

To improve the performance assessment for specific applications (such as crewed flights or specific non-crewed applications), it would be required to make additional also specific assumptions: for the moment the very generic approach I'm taking is to assume a generic / undefined gross payload mass on top of the core and divided by adapter + payload + margins and either fully enclosed within a 15t PLF or else something similar to Skylab (partially enclosed). The payload is being assumed as able to make orbital insertion (from sub orbital injection by the core), else some mass needs to be reserved for some kind of propulsion capability (perhaps built-in on the launcher adapter itself)... Again, this is just for preliminary purposes: this is part of the many other details that need to be discussed, refined and then documented.

 

Summary:

If something like this core (~65.5t inert mass for ~646t prop. load) would then be the direction to pursue for AJAX brainstorm please let me know. I could then try to adapt 3D models that would roughly represent the core dimensions as well the LRB (although can't advance dates for when will be able to focus again on the topic).

About the payload fairing: Downix, you wrote that you were assuming DIRECT PLF. Could you please be more specific? If making a reference to the 10m diameter PLF, wouldn't it be better to make an AJAX specific brainstorm (also with updated context) to then decide what could be the properties of AJAX-44X baseline PLF/SLA properties?

Another thing that might be interesting to discuss and agree about for AJAX simulations is related with the SSME thrust / ISP settings, for example, for the 104.5% power level at vacuum and sea level... I'm writing this because from DIRECT materials to Boeing's SDLV papers to recent NASA HLV Assessments to other sources I have seen, for example, the SSME 104.5% at vacuum being referenced from 2181794.8754 N up to 2185847.072 N. I understand the reasons for such dispersions, just saying that this is another detail that might need to be further discussed and, after such discussion, properly standardized for AJAX's brainstorm.


All for now, will then soon attach the updated graphic (might also share an updated Excel file focused on 'new' core and also on other updated assumptions, on an undefined later moment, once a few extra details – like the ones I have been suggesting - are discussed)

António
 
EDIT: graphic now attached
Title: Re: AJAX Launcher
Post by: Lobo on 08/10/2010 04:45 pm
I think we need to write a paper that details this architecture and its many benefits and options. That paper is what will preserve for the future what we have done and are still doing here, just like the NLS papers did for DIRECT.

Cool,

I like that I helped come up with the name (since I don't know enough about rocket science to have done much else.  :)  )

Although, if AJAX ever does fly, I'm sure it'll be called something else since SLS probably won't call the LV "Jupiter".  So you won't have the "J" in the name. 
But for now, I'll take it.  And I agree with all, it's always good to have the "next thing" in your back procket for the time down the road when it's called for.  Hopefully in about 20 years or so...
Title: Re: AJAX Launcher
Post by: nooneofconsequence on 08/10/2010 07:39 pm
"National security" may not hold here. Name me the single strategic weapon we need at this moment that retaining segmented solid boosters of this size allows? King sized mortars in Pakistan?

Unfortunately we still must maintain our strategic nuclear deterrence. As long as "potential" adversaries possess nuclear weapons with the means to deliver them intercontinentally, then we must maintain our own icbm force as a deterrent. All our icbm's are solids.

You're putting ATK's words in my mouth - never said what you claim.

We did Minuteman without solids in HSF WHILE DOING SATURN.

Conflating non-segmented solids(military purpose) with segmented solids(no military purpose) is simply a shyster lawyer trick - even the chemical/physical composition is different.

Not a strategic issue but a kleptocracy issue. Another TARP bailout for ATK so you can pursue DIRECT? Seems "two bit" to me.

Quote
Can we maintain strategic lift capability with clusters of EELV boosters alone? If a court finds "yes", doesn't matter what Congress says ... we call this 'balance of power' ... keeps this country from becoming a kleptocracy that loses sight of actual needs of national security, instead of devious ones.

No. Our stratigic lift capability is intrinsically tied to our national defense, like it or not. It's still about the icbm's. Liquid icbm's will not work. It takes too long to fuel and launch them. We need to be able to respond *literally* within seconds of the President's order to do so.
Didn't argue about solids, haven't since the 60's Minuteman I.

The Shuttle represented a different kind of strategic lift threat - takes months to fly. Yet it indirectly bankrupted them in addressing it.

For that, wouldn't have mattered solids vs liquids. As you know too.

Quote
Back with the cold war, it was different.

Don't kid yourself - it's still going on. It's the presence of the nuclear deterrence that has cooled it down but the fire is not out. There are some out there who would nuke us in a heartbeat if they thought they could get away with it. Trust me on this.
Stop putting words I don't say into my posts.

Or perhaps this is intentional.

If you truly believe the insanity of linkage between the two DIFFERENT business activities, then you are a)arguing to reduce our strategic effectiveness and b) dooming SLS to being another Cx redux/cancellation.

If you buy the wrong 'guns' with the money otherwise to be used for 'butter', then you have to spend more money to buy the right 'guns' again so you damage things because of insufficient 'butter'.

The cold war economy with 'guns' worked based on symmetrical 'guns' from both sides driving demand for 'butter' to support eventual 'guns'.

In a globalized economy (cold war was 'compartmentalized' economies in contrast), it's the reverse - 'butter' (or GDP) drives spending on 'guns'.
So you lose the race economically if you spend unwisely on any 'guns'.

'guns' as in non-segmented solids predated Shuttle by decades. The gimmick with the Shuttle solids was part of a strategic game unique to the cold war. It's poison this time around.

Think really, really hard about this. Otherwise kiss off HSF, given the devil you let in by the front door.

add: There's an interesting legal precedent from the civil war that perfectly demonstrates this. Lincoln indicated how much it cost to the country back then. A reference to it is still in major federal contracts including DOD/NASA to this day. It is where such a lawsuit will start.
Title: Re: AJAX Launcher
Post by: Proponent on 08/11/2010 02:28 am
"National security" may not hold here. Name me the single strategic weapon we need at this moment that retaining segmented solid boosters of this size allows? King sized mortars in Pakistan?

Unfortunately we still must maintain our strategic nuclear deterrence. As long as "potential" adversaries possess nuclear weapons with the means to deliver them intercontinentally, then we must maintain our own icbm force as a deterrent. All our icbm's are solids.

Deputy Secretary of Defense for Space Launch Gary Payton has said (http://www.defensenews.com/story.php?i=4628372&c=FEA&s=INT)

Quote from: Gary Payton
We've come to find out that it has a trivial impact on space launch because we don't use the big 3½-meter segmented solids on our EELVs; we use solids that are about 1½ meters in diameter.

Although Payton was speaking of space launch, America's ICBMs are also non-segmented and about 1.5 meters in diameter (Minuteman is 1.7 m; even Peacekeeper was just 2.3 m).  Termination of the production of Shuttle SRBs will affect overheads in missile programs to some extent (touched on in this thread (http://forum.nasaspaceflight.com/index.php?topic=21657.msg591194#msg591194)), but that's no reason to keep using them for space launch.

To look at it from another perspective, if keeping large, segmented SRBs in production were important and compatible with space launch, wouldn't DoD have insisted, as an insurance policy against the Shuttle's termination, that at least one of the EELVs use segmented SRBs?  After all, it was DoD that invented them and used them on its heavy Titans for decades.
Title: Re: AJAX Launcher
Post by: 2552 on 08/11/2010 03:50 am
Question, does using CCBs instead of SRBs affect/remove the Base Heating issue? If so, could a human-rated (non-regen) RS-68A be used instead of SSME?
Title: Re: AJAX Launcher
Post by: Downix on 08/11/2010 04:14 am
Question, does using CCBs instead of SRBs affect/remove the Base Heating issue? If so, could a human-rated (non-regen) RS-68A be used instead of SSME?
In theory yes.  However, no such engine at this time exists.  It would also require a larger tank, due to the isp issues, or an upper stage on every payload.  Part of the reason this design works at all is due to the SSME's efficiency.
Title: Re: AJAX Launcher
Post by: kkattula on 08/11/2010 08:17 am
"National security" may not hold here. Name me the single strategic weapon we need at this moment that retaining segmented solid boosters of this size allows? King sized mortars in Pakistan?

Unfortunately we still must maintain our strategic nuclear deterrence. As long as "potential" adversaries possess nuclear weapons with the means to deliver them intercontinentally, then we must maintain our own icbm force as a deterrent. All our icbm's are solids.

Deputy Secretary of Defense for Space Launch Gary Payton has said (http://www.defensenews.com/story.php?i=4628372&c=FEA&s=INT)

Quote from: Gary Payton
We've come to find out that it has a trivial impact on space launch because we don't use the big 3½-meter segmented solids on our EELVs; we use solids that are about 1½ meters in diameter.

Although Payton was speaking of space launch, America's ICBMs are also non-segmented and about 1.5 meters in diameter (Minuteman is 1.7 m; even Peacekeeper was just 2.3 m).  Termination of the production of Shuttle SRBs will affect overheads in missile programs to some extent (touched on in this thread (http://forum.nasaspaceflight.com/index.php?topic=21657.msg591194#msg591194)), but that's no reason to keep using them for space launch.

To look at it from another perspective, if keeping large, segmented SRBs in production were important and compatible with space launch, wouldn't DoD have insisted, as an insurance policy against the Shuttle's termination, that at least one of the EELVs use segmented SRBs?  After all, it was DoD that invented them and used them on its heavy Titans for decades.

FYI, it's the AP (ammonium perchlorate) that's the common factor between military, ELV and Shuttle solids.  Segmented or not doesn't matter.

Something like 70% of annual US AP production is used by the Shuttle SRBs.  Stop using those, and the other users have to pay the full cost of maintaining the production facility. Apparently it wouldn't save money to reduce capacity either.

So there's maybe a $100 million or two that gets passed on to other AP users if SRBs are retired.  Not unmanageable, but not insignificant.
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/11/2010 04:53 pm
Not exactly a bad thing to get rid of ammonium perchlorate: http://www.youtube.com/watch?v=HJVOUgCm5Jk
http://en.wikipedia.org/wiki/PEPCON_disaster
It claimed two lives and injured hundreds of people.
4 kilotons of it exploded.

They relocated the plant, and nine years later, they had another explosion that killed someone.

It's very dangerous stuff. Might as well be nuclear... In fact, I'm sure there's SUBSTANTIALLY less risk of that kind of explosion with nuclear material.
Title: Re: AJAX Launcher
Post by: clongton on 08/11/2010 06:39 pm
Here is a perfect example of why you MUST approach anything written up on Wikipedia with caution. There is only one place in that entire article which states *clearly* what Ammonium perchlorate actually is: it is an *oxidizer*, not a fuel. As such *it does not and cannot "explode"* . What it DOES do, and does it extremely efficiently, is *support* combustion or explosion by allowing any fuel in its presence to combust or flagerate. Those plastic drums were *FUEL*, and so was everything else there once that intense fire got started. It was really stupid to store AP in plastic drums. HOWEVER, I will hasten to say that if those drums had been full of pure oxygen instead of AP the initial result would have been exactly the same; with the exception that it would have been over sooner because the oxygen would have been more quickly consumed. But once the fires started, supported by an oxidizer as dense and as energetic as AP, there was no stopping it so long as any kind of fuel existed anywhere near enough the fire to be ignited. And don't forget the ruptured 16" gas pipeline that was dumping fuel directly into the fire!

I personally handle AP on an almost daily basis and I can say with absolute certainty that AP, in and of itself, is *NOT* an explosive; it cannot explode! And I am not the only one. The BATFE has recently settled in a lawsuit with the NAR and Tripoli Associations where it was scientifically demonstrated beyond any conceivable doubt that AP, in and of itself, cannot explode. Hell it can't even burn on its own! You have to either mix it with or wrap it with a propellant of some kind. THEN you have something on your hands that is dangerous, not before. The issue with AP-based propellants is that once you ignite them the fire cannot be extinguished. But without mixing propellant with the AP there is no danger. Unfortunately for those who died, the company effectively wrapped the AP in propellant by encasing it in plastic drums. But AP by itself is not dangerous. I have witnessed a state policeman shooting a container of AP with a rifle, over 10 times in rapid succession, and the only thing that happened was that there were 20 new holes in the containers; 10 entry holes and 10 exit holes. NO FIRE or EXPLOSION! Just holes. AP functions in exactly the same way as Oxygen or Nitrous Oxide, except that being in solid form it is far denser and allows far more intense fire. But without fuel for it to mix with it is not dangerous. You can pick it up in your hands and toss it around, hell even play tennis with a ball of the stuff if you want to.

Please note that any fire which is being supported by AP oxidation, is nearly impossible to extinguish, and THAT is what happened in Utah and that is the safety issue with using SRB's and is also the reason the fires and explosions continued for so long at that Utah location. The fuel that was made available to the fire and supported by AP was totally uncontrolled in its makeup and quantity – a pure recipe for disaster.

Do you think for one minute that NASA would strap its astronauts into a vehicle that would explode? Of course not. The propellant formulation used in conjunction with the AP is such that explosions cannot occur. It is carefully controlled so that it is safe to handle and ride on. The propellant burns at an extremely rapid rate, with the shock wave propagating just below the subsonic level. If the SRB's could actually undergo an uncontrolled detonation the Space Shuttle would never – ever use them.

It was not AP that caused the disaster – it was pure stupidity that did that.

The environmental impacts of using AP for an oxydizer is an entirely different matter.
Title: Re: AJAX Launcher
Post by: nooneofconsequence on 08/11/2010 06:41 pm
FYI, it's the AP (ammonium perchlorate) that's the common factor between military, ELV and Shuttle solids.  Segmented or not doesn't matter.

Something like 70% of annual US AP production is used by the Shuttle SRBs.  Stop using those, and the other users have to pay the full cost of maintaining the production facility. Apparently it wouldn't save money to reduce capacity either.

So there's maybe a $100 million or two that gets passed on to other AP users if SRBs are retired.  Not unmanageable, but not insignificant.
This is a common fallacy. Producing the base chemical is a tiny fraction of the industry base. The real costs come in manufacturing the components, as is true with *any* weapons. Such components are highly specialized and are assembled at great risk - there is NO such commonality to offset a industrial base which MUST have commonality in PRODUCTION for this to work for national security *cost sharing*. Just paying off same pockets is no different than a SUBSIDY or a BRIBE.

Not to mention the active / planned increase in weapons components. In the 70's with MX, we had an arms race that was concurrent so there was a strategic NEED then.

What is happening now is economic competition which we need to win.

Segmented solids are UNECONOMIC and destroy our ability to economically compete as they are a SUBSTANDARD technology compared to liquids. We are subsidizing a buggy whip manufacturer WHERE WE ARE THE ONLY CUSTOMER. IF WE ARE TO REDUCE OUR LAUNCH COSTS, WE CAN'T USE THEM!

If you want to pay off ATK, fine, pay them to do business development finding other/safer uses of this stuff as a side project. Or have them modernize the ICBM force. As it was with Minuteman during the era that preceded Shuttle.

It's incredibly ironic to me that the AF STOPPED USING SEGMENTED SOLIDS YEARS AGO for UNMANNED payloads, while NASA continues to use them for MANNED, FRAGILE, RLV spacecraft. AF also found they INCREASED LAUNCH COSTS and lowered flight readiness - why they were "evolved away" - EELV was originally have NO solids of any kind.

So lets return to Saturn-V days and  process solids like with Minuteman. You want to subsidize solids for weapons - THEN DO so by modernizing ICBMs. Knock yourself out. Want to evolve solids into other areas? Fine too.

But don't talk about this as a scam that does space and weapons at the same time. They are different. AF has said so repeatedly.

Lets really keep to national security, not use it as a excuse to horse trade ourselves into a less secure situation in the big picture.

Stay focused on reducing launch costs  & increasing flight rate and competing economically.
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/11/2010 06:54 pm
Clongton, that's fine, but a solid rocket motor is essentially oxidizer mixed with fuel... it is inherently dangerous, and once combustion starts, it's VERY difficult (almost impossible) to stop.

And Ammonium Perchlorate can decompose if heated, which oxygen doesn't. As such, ammonium perchlorate is classed as an explosive if it has large grain sizes, even when not mixed with fuel. Many oxidizers are dangerous in this way, and many can decompose explosively without another fuel under the right conditions.

I'm not saying it's impossible to make it safe enough, only that there are substantial precautions one must take.
Title: Re: AJAX Launcher
Post by: clongton on 08/11/2010 07:10 pm
Please don't get me wrong - I am *not* advocating for the continued use of solids. I personally wish to see them go away. Their continued use on the SLS is a political necessity, not a technical one, one that I am not enthused with but one that I accept as necessary if we're going to get back into space - post shuttle.

One day we will succeed in getting rid of the solids. I will be a happy camper on that day. That's one of the reasons I am such a staunch advocate of THIS thread.
Title: Re: AJAX Launcher
Post by: nooneofconsequence on 08/11/2010 08:01 pm
My issue is getting by the 30 year "distraction" of segmented solids.

Under the "color of authority" of "national security", it has injured national efforts *repeatedly* and in a disingenuous way. Many smart, thoughtful person has gotten trapped in this minefield. It is too easy to "drink the kool aid".

And I'm personally sick of seeing the greatness of the US diminished by a petty, pointless, avariciousness. When we are in a world of pain. And need every bit of the Yankee inventiveness that can argue for (and prove!) the best way forward without lying to ourselves about it.

All along I've been wary of anything that smacks of HLV because of the way it is easily "jerrymandered". Had no issue with 4 seg for critical path to an 'all up' flight test soonest. Then do cost reduction to kerolox replacement with future capacity phase-in.

But given this thread I'm beginning to see that may be way too optimistic. Given no interest in a "balls out" effort to do a soonest "all up" test, and the fact that key pumpers of DIRECT have sipped the kool-aid ... I'm going to have to admit I've been roodled again.

You do solids then you are stuck with solids. "Once you pay the Dane geld, then you are never free of the Dane".

So I'm afraid only doing off the shelf ELV's is sane anymore. HLV is too perilous - and the politics of the situation are going to be:

"We are repeating HLV failure over and over again because political earmarks too much dominate for success to be viable. Plan on your seat being taken with "I told you so's"."

Which is sad but true.
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/12/2010 05:50 am
I'm still working on this, BTW... I have a mesh, but need it in CGNS format, since that is what my solver uses... I'm trying to compile my mesh generator with CGNS support right now...

Paraview seems to work pretty well for visualization, by the way.
Title: Re: AJAX Launcher
Post by: clongton on 08/12/2010 10:02 am
Re: Solids
We are in a situation, like it or not, where the choice is not driven by what is technically best. If we could decide based on that alone we would have a totally different government-funded space program. The people who control the money and who have the *final* say-so about what flies and what does not are the same ones that are saying that if we want to fly at all it will be with solids. I do not like that any more than you do but there it is - the pure, naked unadulterated truth. If we want to fly it will be with solids - or - we don't get to fly at all. Arguing that that is not the best way to go is like shoveling dust into a headwind - not going to happen.

Given that unbendable situation I choose to fly. At least with the solid-augmented inline Jupiter we have the things in place to upgrade away from the solids at a later date. But you cannot substitute LRB's for SRB's if there are no SRB's flying.

Better to fly for a while with solids than to not fly at all. And that my friend is the *only* government-funded game in town.
Title: Re: AJAX Launcher
Post by: simcosmos on 08/12/2010 11:52 am
Chuck, what you wrote above is something that I'm having some 'issues' (in lack of better word) in fitting in the context of the current AJAX brainstorm / puzzle (and this, must confess, from some time now). Maybe you, Downix or others can help to further clarify some things at the light of the current political context... which seems to be something that AJAX is sometimes just ignoring in a number of ways (but I might having an incorrect impression!)


I mean, as I have tried to hint in several related posts - here or in another threads (for example when tried to write very generic considerations about the modular approach vs optimised liquid boosters approach for an SDLV derived core (http://forum.nasaspaceflight.com/index.php?topic=22122.msg616003#msg616003)) -  I'm not yet sure about what is the context of the current AJAX brainstorm at the light (this is very important!!!) of the apparent consensus building-up in the political world for the fielding  of an SRB powered HLV capability...


This to say that the current AJAX considerations for the core properties (which seems to be heading to a core with about 646t prop. load or so? Yes? No? Maybe?), independently of assuming AtlasV LRB or other boosters (from other providers), as was saying those AJAX brainstorm considerations do not seem to be very compatible with the eventual adoption, in 'real life', of something like a Jupiter-130 or an equivalent capability parallel SDLV... and this to not talk about a stretched core (with a prop. load from 950t up to ~1000t or so...), if that is the final development direction in 'real life'...

What I mean is that if an equal or greater than ET sized core is fielded, then we might have again the liftoff T/W issue lurking around... Even more if a stretched core is fielded... Under those circumstances, if somehow in the future there is the wish to replace 4 or 5 seg. SRB by liquid boosters I would think that such liquid boosters design would try to minimize as much as possible changes to the dimensions and properties of the other launch components (equal to say, no dimensional core changes... else it would be like building a whole new launch vehicle from start)... Such move, depending of extra considerations and depending of what ends up by being fielded 'now', might mean that the new liquid booster might be less common, at least in the sense of the conceptual idea of using AtlasV LRB (or other providers) across lower than HLV capabilities and across modular HLV capabilities, which seems to be one of the most attractive points of current AJAX brainstorms...


What I'm trying to say is that if a large SRB powered HLV is 'soon' decided to be fielded then I do not see the relevance of the current brainstorm, at least not in the current format... If the large solid boosters would be replaced somewhere in the future – and that future could not be so near – then the liquid booster designs at that time would probably be +/- 'direct' replacements (perhaps with a little increment in performance, depending of design choices) of the lost (large SRB) capability where I'm using the term 'direct' to mean that the number of boosters would probably not increase / be variable and would perhaps be slightly less 'flexible' in the interval of payload masses that could support (this to say that such boosters might probably be oriented more for HLV / Super-HLV than to less heavier payloads... Flyback boosters and/or ~40t to 50t or so payload range vehicles could still be additional applications tough (in addition to / beyond the side-booster application for the HLV)


I'm just not sure where exactly AJAX fits in the current context... Unless wishing to use AJAX designation to define something a LOT more generic than what has been brainstormed until now... But, if that would be the case, I do not also see what would be the point... with a little more freedom, virtually everything not using solids could be called AJAX then!

Not sure if I'm being successful in describing my doubts...

António
Title: Re: AJAX Launcher
Post by: JohnFornaro on 08/12/2010 03:20 pm
Quote
Where do I get a 3' x 5' scanner?
Our local printshop will scan a 30 x 42 to TIFF.  See who the A&E shops use in your area.  I'd like to see it....

Quote
There are three (3) main things to look for when deciding what cad software to use.
What are you guys using?

Quote
Do you want to design software or rockets?
My answer?  Don't upgrade.  If you can design your first rocket with it, you can design your second and third.  Yeah, they'll kick you out of the discount upgrade path, but several years later, they may not be the appropriate choice.  YMMV.

If the program output is in ASCII format, conversion should be relatively simple.  DXF is a well known ASCII format, for example.  If there are aspects of the program that are not supported by the ASCII export feature of the software, that's not good.  In other words, is there a CAD attribute which is not translated to ASCII?  That's not good.

As to the second version of AJAX?  That would be BEJAX.   Very interesting thread.
Title: Re: AJAX Launcher
Post by: clongton on 08/12/2010 04:44 pm

Quote
There are three (3) main things to look for when deciding what cad software to use.
What are you guys using?

If you mean in my day job, I use mostly CATIA, but also SolidWorks, Pro-E and AutoCAD.
We are in the process of switching from CATIA to NX.
Title: Re: AJAX Launcher
Post by: JohnFornaro on 08/12/2010 05:03 pm
I was gonna gues CATIA.  That's pricey.  How much is a seat?  Also, I tried a SolidWorks demo, and that seemed affordable and powerful enough for a guy like me.
Title: Re: AJAX Launcher
Post by: sdsds on 08/12/2010 06:59 pm
I'm just not sure where exactly AJAX fits in the current context...
Your concerns are reasonable, and thinking ahead is usually a good thing, but you ask about the current context.  Currently the United States does not have a launcher for "space exploration" missions.  This year NASA is funding development of a two-stage crew launch vehicle using a solid first stage and a liquid second stage.  That's the current context.

It is possible that in a few months when the next fiscal year starts NASA could begin the process of shifting to development of a different launcher.  We hope it will be a shift towards something vaguely like Jupiter.  If it is, we do not know what process NASA will use to implement the shift from CLV development to HLV development.  For example, will there be bids on new contracts?  Will there be negotiations about prices with manufacturers currently operating under CLV contracts?

We don't know, but it is in that (relatively near future) context that AJAX might first be really useful.  With AJAX in the picture, ATK might be less able to command monopoly prices for its solid boosters.  (Also, the justification for spending on J2-X might be reconsidered.)  I suggest we refer to the AJAX proposal during this time frame as AJAX 1.0.  AJAX 1.0 needs to look highly competitive from cost, schedule and performance perspectives.  Thus, AJAX 1.0 should specify the optimal core length to use with existing CCBs.

As you correctly suggest, though, it is highly unlikely NASA will proceed with a design like AJAX.  Once NASA has specified new core dimensions for a Jupiter-like vehicle, and has begun ramping up for actual production, it will be time to consider an AJAX 2.0 that is adjusted to accommodate that new reality.  But that is way beyond the "current context!"
Title: Re: AJAX Launcher
Post by: HappyMartian on 08/13/2010 12:52 pm
Part of an earlier post may provide a long-term solution with the Atlas Phase II switch to 5 m core with 2 RD-180's. There are several possible versions of AJAX.



it's not just that, however.  the shrunk tank was not a major redesign, it was removing a ring out of both the LOX and LH2 tank.  A stretched tank, for comparison, would be adding another ring.

We're still utilizing the parts of the ET, so we do need to keep that in mind.

We can discuss growth options as well in here, set a long distance goal, and figure out the steps to get there.

The other thread had one discussion topic, how would AJAX impact EELV evolution.

It helps to understand Atlas evolution:

Phase I, new upper stage, called ACES

Phase II switch to 5 m core with 2 RD-180.

Phase III new 8.4m core.

AJAX would still be using the ACES for it's upper stage, so this would be funneling the resources for that.

AJAX would also get a huge benefit from the Phase II, as the 5m core w/ two RD-180 would get the better T/W ratio.

So, I see this as being a shot in the arm for EELV evolution as well.  But we're not counting on it, only putting on the table that so we can ponder the Block I, II, III, etc when it comes to it.

Part of the process will be in the use of Atlas as the crew launcher.




The two current SRBs are most likely just a temporary tool. If SRBs are to remain relevant for the long-term, they will have to become much more environmentally benign. ATK can decide what they can or want to do about that.

If something like the AJAX Launcher is going to actually be built, then it should have three theoretical versions, with one version being based on the assumptions you are currently using.

The second version should be based on the NASA decided core tank size and number of SSMEs for the SLS. The Senate has clearly indicated its support for the SLS.  This second version of the AJAX Launcher should be two pairs of three Atlas cores. These Atlas triplet boosters for AJAX would be doable today. Something similar has been noted previously as an AJAX growth option.

The third version would have four of the proposed Atlas Phase II cores. Each Atlas core would have 2 RD-180's. The four cores would work as two pairs in the SRBs current positions.

Both the four Atlas Phase II cores in the form of two doublet boosters and the two standard Atlas core triplet booster versions of AJAX, would make the AJAX T/W ratio much less of a concern despite whatever J-130, J-130H, J-130SH, J-140, J-140H, J-140SH, or similar HLV launcher, is chosen by NASA for the SLS.

One major issue is the crossfeed of fuel between the standard Atlas cores or the possible Atlas Phase II cores. With four, six, or eight RD-180 engines running hard, dealing with potential engine out concerns should be an early design issue.

Would crossfeeding propellant between the standard two Atlas cores in the doublet booster be difficult?

Would crossfeeding propellant between the standard three Atlas cores in the triplet booster be difficult?

Would there be any issues with doing crossfeed between the cores of proposed Atlas Phase II doublet?

Is this propellant crossfeed a feature that can be added to the standard Atlas cores as they are joined together?

Would retaining to one of the two Atlas based boosters for an extra minute or two, due to an engine out issue, be unworkable?

In the long-term, there should be several powerful options to use as liquid propellant boosters, or booster pairs, or booster triplets, so the core weight of the new SLS shouldn't be a show stopper for the AJAX Launcher. 

The RD-180 and the SSME are both highly efficient and very valuable leftovers from the Cold War. If we are wise, we will use both of them for a long time to come. The DIRECT philosophy is to use what you already have to get the human species out exploring space. We have the RD-180 and the SSME, so we should continue to use them with all three versions of the AJAX Launcher.


Cheers!
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 08/13/2010 01:39 pm

Quote
There are three (3) main things to look for when deciding what cad software to use.
What are you guys using?

If you mean in my day job, I use mostly CATIA, but also SolidWorks, Pro-E and AutoCAD.
We are in the process of switching from CATIA to NX.

CATIA to NX???  Have you used NX or their data managment package?
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 08/13/2010 01:42 pm
My preference for AJAX type booster would be to add TAN as part of new nozzle development for RS25e instead..  do away with boosters altogether.. at least for the 50-70T missions.. I could see using several Atlas cores, attached sans RD-180s, as drop tanking for the TAN part of the flight.
Title: Re: AJAX Launcher
Post by: orbitjunkie on 08/13/2010 02:08 pm
One major issue is the crossfeed of fuel between the standard Atlas cores or the possible Atlas Phase II cores. With four, six, or eight RD-180 engines running hard, dealing with potential engine out concerns should be an early design issue.

I've been reading the AJAX threads with interest for a while now.

Regardless of the feasibility of cross-feed, if and how you could handle an RD-180 engine out should be a subject of some study. Issues that come to my mind would be
 - Loss of 50% of the thrust way out on one side of the stack would generate a notable torque imbalance. Can the TVC of the core and other boosters handle this? Through all parts of ascent?
 - Even if you could cross-feed, what kinds of abort-to-orbit options do you have? Can you throttle down the working engines on the opposite side and just keep going under reduced power? What ATO options does that leave you?
 - Are there situations where it is better to simply stage the broken booster, and possibly the working booster opposite to it?

This just seems like a pretty complex engine out scenario to deal with. Maybe it's not that much worse than any other engine out on ascent scenario, I dunno.

Also, how much does adding cross-feed add to the weight? Unless the ability to cross-feed somehow really enhances your abort-to-orbit options, which I'm not sure is obvious, then don't bother. The main benefit of cross-feed, at least on the DIVH, is so that the commonly sized boosters could give some of their propellant to the core and then stage eariler while leaving the core fully fueled at that point, which gave a mass-to-orbit increase. See http://www.ulalaunch.com/site/docs/publications/DeltaIVLaunchVehicle%20GrowthOptionstoSupportNASA%27sSpaceExplorationVision.pdf (http://www.ulalaunch.com/site/docs/publications/DeltaIVLaunchVehicle%20GrowthOptionstoSupportNASA%27sSpaceExplorationVision.pdf)

You won't get that advantage with AJAX since the core is a different propellant.

Though it does occur to me that if you had cross-feed when one engine when out, you might shut down the opposite working engine anyway, turn on cross-feed for both, and just burn the two remaining RD-180s until all the propellant was gone. How long can a single RD-180 burn for? Sounds like simcosmos has his sim work cut out for him here.

My preference for AJAX type booster would be to add TAN as part of new nozzle development for RS25e instead..  do away with boosters altogether.. at least for the 50-70T missions.. I could see using several Atlas cores, attached sans RD-180s, as drop tanking for the TAN part of the flight.

I agree a TAN augmented RS25e would be a pretty sweet thing to see, but I don't think it fits well within the design concept of AJAX, which is basically DIRECT's "use what you have today" philosophy, but in a world where SRBs are somehow off the table. I'd rather see that money spent on payloads for an HLV. Maybe you could  pony up a few million per year for "HLV enhancement research" over the next 10 years to look into it and reduce risk or cost, and then try it.
Title: Re: AJAX Launcher
Post by: HappyMartian on 08/13/2010 02:21 pm
My preference for AJAX type booster would be to add TAN as part of new nozzle development for RS25e instead..  do away with boosters altogether.. at least for the 50-70T missions.. I could see using several Atlas cores, attached sans RD-180s, as drop tanking for the TAN part of the flight.


Yep. Some TAN RS25es and Atlas cores, attached sans RD-180s, make a lot of sense. Someday soon would be nice.

Cheers!
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 08/13/2010 02:29 pm
My preference for AJAX type booster would be to add TAN as part of new nozzle development for RS25e instead..  do away with boosters altogether.. at least for the 50-70T missions.. I could see using several Atlas cores, attached sans RD-180s, as drop tanking for the TAN part of the flight.

I agree a TAN augmented RS25e would be a pretty sweet thing to see, but I don't think it fits well within the design concept of AJAX, which is basically DIRECT's "use what you have today" philosophy, but in a world where SRBs are somehow off the table. I'd rather see that money spent on payloads for an HLV. Maybe you could  pony up a few million per year for "HLV enhancement research" over the next 10 years to look into it and reduce risk or cost, and then try it.

RS-25e development has always been part of at least the mid-term plan for DIRECT(as a major piece cost savings)..

If you're going to spend all the money to develop a new cheaper nozzle anyway... why not at least do a few trade studies looking at adding TAN capability in the process?  TAN can also be done using LH2/LOX.. although then you would probably need stretched tanking.

Can a TAN augmented RS-25e reach 1Mlbf?   1.5Mlbf?  How much thrust do you need to make a core only(or core with drop tanks) viable for HLV?

Title: Re: AJAX Launcher
Post by: sdsds on 08/13/2010 07:29 pm
a TAN augmented RS25e would be a pretty sweet thing to see, but I don't think it fits well within the design concept of AJAX, which is basically DIRECT's "use what you have today" philosophy

Precisely correct, and it will be difficult for NASA to maintain the discipline this philosophy requires.  NASA culture reveres projects that are the "First to do this" or "First to do that."  But being the first to use a technology adds dollar cost, adds schedule time, and adds cost and schedule uncertainty.


One major issue is the crossfeed of fuel between the standard Atlas cores or the possible Atlas Phase II cores. With four, six, or eight RD-180 engines running hard, dealing with potential engine out concerns should be an early design issue.

if you had cross-feed when one engine when out, you might shut down the opposite working engine anyway, turn on cross-feed for both, and just burn the two remaining RD-180s until all the propellant was gone.

I love cross-feed designs, and this is a clever use of the concept, but the same logic that applies to TAN probably applies here as well.  Some other effort, not AJAX, needs to carry the costs associated with developing the technology.
Title: Re: AJAX Launcher
Post by: clongton on 08/13/2010 09:39 pm
Cross feeding runs counter to a fundamental principle of AJAX; namely that the Atlas-V CCB must be unchanged whether it flies alone as an EELV, alone as a crew/cargo launcher or in pairs as the HLV LRB. It's an unnecessary complication.

There are lots of things that are "nice to do's", but that are not really value-added when you consider the system-wide impact.
Title: Re: AJAX Launcher
Post by: MP99 on 08/14/2010 08:42 am
My preference for AJAX type booster would be to add TAN as part of new nozzle development for RS25e instead..  do away with boosters altogether.. at least for the 50-70T missions.. I could see using several Atlas cores, attached sans RD-180s, as drop tanking for the TAN part of the flight.

If you assume that we'll start with an SRB-boosted SDLV, ISTM that replacing the SRB's with TAN + kero drop tanks would be an alternative to AJAX.

However, it sounds like this might be an expensive option to develop (although presumably cheap to operate):-

Aerojet has done the work to demonstrate the feasibility of providing a TAN for the RS-68. I am not at liberty to discuss results except to say categorically that the results were very, very good. The application would be to have a LH2/LOX core, ground ignited, with RP-1/LOX burning in the nozzle to provide the same advantage as having side-mounted RP-1/LOX LRB's, however without the additional mass of the RP-1 engines. The RP-1 would be carried in side mounted tanks with the LOX being provided by the core LOX tank. When the RP-1 is depleted, the side-mounted tanks would be jettisoned just as if they were actual LRB stages when in reality they are only drop tanks. Meanwhile the LH2/LOX core continues upward on its own. Very efficient.

Does that also imply that TAN might be equally applicable to SSME?

cheers, Martin

Theoretically yes, but that would be expensive to implement.
IMO it would probably cost less to create an engine from scratch than to modify the SSME for TAN.

cheers, Martin
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 08/14/2010 02:41 pm
My preference for AJAX type booster would be to add TAN as part of new nozzle development for RS25e instead..  do away with boosters altogether.. at least for the 50-70T missions.. I could see using several Atlas cores, attached sans RD-180s, as drop tanking for the TAN part of the flight.

If you assume that we'll start with an SRB-boosted SDLV, ISTM that replacing the SRB's with TAN + kero drop tanks would be an alternative to AJAX.

However, it sounds like this might be an expensive option to develop (although presumably cheap to operate):-

Aerojet has done the work to demonstrate the feasibility of providing a TAN for the RS-68. I am not at liberty to discuss results except to say categorically that the results were very, very good. The application would be to have a LH2/LOX core, ground ignited, with RP-1/LOX burning in the nozzle to provide the same advantage as having side-mounted RP-1/LOX LRB's, however without the additional mass of the RP-1 engines. The RP-1 would be carried in side mounted tanks with the LOX being provided by the core LOX tank. When the RP-1 is depleted, the side-mounted tanks would be jettisoned just as if they were actual LRB stages when in reality they are only drop tanks. Meanwhile the LH2/LOX core continues upward on its own. Very efficient.

Does that also imply that TAN might be equally applicable to SSME?

cheers, Martin

Theoretically yes, but that would be expensive to implement.
IMO it would probably cost less to create an engine from scratch than to modify the SSME for TAN.

cheers, Martin

Appreciate the quote although I heartily disagree with the logic.. How much would it cost to develop a brand new SSME class(ISP) rocket motor even w/o TAN much less with it???  RS25e already will get brand new nozzle..and other parts..  so why not design it with TAN in mind?   

Also thinking.. doesn't F9 or taurus II tanking have better mass fraction than Atlas.. so much for the A part of AJAX
Title: Re: AJAX Launcher
Post by: clongton on 08/14/2010 03:53 pm
Also thinking.. doesn't F9 or Taurus II tanking have better mass fraction than Atlas.. so much for the A part of AJAX

TrueBlue;
Think about it.
1. Elon isn't going to let his competition use the F9.
2. The Taurus is essentially an American assembled foreign rocket.
I don't believe either the F9 or the Taurus is viable for this application.
It's going to be either the Atlas or the Delta, and the Atlas is the better choice from a system perspective.
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 08/14/2010 07:34 pm
Also thinking.. doesn't F9 or Taurus II tanking have better mass fraction than Atlas.. so much for the A part of AJAX

TrueBlue;
Think about it.
1. Elon isn't going to let his competition use the F9.
2. The Taurus is essentially an American assembled foreign rocket.
I don't believe either the F9 or the Taurus is viable for this application.
It's going to be either the Atlas or the Delta, and the Atlas is the better choice from a system perspective.

For AJAX as boosters I totally agree. May have been a misunderstanding.  I was speaking of using the cores as drop tanks for a TAN configuration. Is taurus core tanking made in the US? Price and mass fraction vs atlas core?
Title: Re: AJAX Launcher
Post by: Jim on 08/14/2010 08:16 pm
   
Also thinking.. doesn't F9 or taurus II tanking have better mass fraction than Atlas.. so much for the A part of AJAX

Because it was designed to be generic, it can fly solo, with 1-5 solids and as a LRB, with no mods.
Title: Re: AJAX Launcher
Post by: nooneofconsequence on 08/15/2010 06:38 pm
The people who control the money and who have the *final* say-so about what flies and what does not are the same ones that are saying that if we want to fly at all it will be with solids.
As was "last time". This lead to an overreach. New overreach is due to fixed cost (RSRB's) and development cost (J-2X) issues. In trying to do a launcher on the cheap, "Cx lite" will again overspend (Orion + other costs will be much, much, much higher).

Getting ahead of the current political crisis, this will be the next one.

Then we'll face another cancellation or design accomodation or launcher "shrink". (add: core becomes just  4 seg solids aka SRB-X  :D  If you liked Ares -I, you're just going to love SRB-X! Don't let the House know - they'd do it ...)

The House is still wrestling with the loss of 5 seg and budget expansion. The potential for 4-segs endangering the core is coming on its heels.

Anyone who doesn't see this coming is also unrealistic about "choosing to fly". They are simply choosing another debacle.

I think the political accommodations are running past the breaking point. The results of breaking is an even more drastic loss of jobs/talent.
(http://www.flightglobal.com/assets/getAsset.aspx?ItemID=18348)
Title: Re: AJAX Launcher
Post by: Downix on 08/15/2010 08:12 pm
As a cheap to develop proof-of-concept you can do one other thing as well, bolt some CCB to a framework which then mates up to the ET the same way the SRBs do.  (this is assuming that DIRECT or DIRECT-like wins)  The T/W would be worse, so this will have to be a partial-load of the core to compensate for the worse core weight.
Title: Re: AJAX Launcher
Post by: sdsds on 08/16/2010 12:43 am
bolt some CCB to a framework which then mates up to the ET the same way the SRBs do.  (this is assuming that DIRECT or DIRECT-like wins)

Yes, once DIRECT-like wins and a ET-based core has been designed, that will be the time for an AJAX 2.0 design.  Certainly one step would be the proof-of-concept you describe, i.e. plug-in replacements for the SRBs.  As you indicate these must transfer thrust to the core at the same attach points as the SRBs. 

Are you imagining long brackets running up the side of the LH2 tank for this, or something else?
Title: Re: AJAX Launcher
Post by: Downix on 08/16/2010 06:07 am
bolt some CCB to a framework which then mates up to the ET the same way the SRBs do.  (this is assuming that DIRECT or DIRECT-like wins)

Yes, once DIRECT-like wins and a ET-based core has been designed, that will be the time for an AJAX 2.0 design.  Certainly one step would be the proof-of-concept you describe, i.e. plug-in replacements for the SRBs.  As you indicate these must transfer thrust to the core at the same attach points as the SRBs. 

Are you imagining long brackets running up the side of the LH2 tank for this, or something else?
Actually a framework between the two CCB's which then attach to the SRB pointing points.  So two CCB's would attach to each other, and then that pair would mate up to the SRB mounting points.

This is getting, of course, a bit ahead until there is the SLS, but it does need to be kept in the back-mind.
Title: Re: AJAX Launcher
Post by: StuffOfInterest on 08/16/2010 12:28 pm
Actually a framework between the two CCB's which then attach to the SRB pointing points.  So two CCB's would attach to each other, and then that pair would mate up to the SRB mounting points.

I thought there was a difference in loading between the SRB (top) vs. the LRB (bottom) which would make ET changes necessary?
Title: Re: AJAX Launcher
Post by: Jim on 08/16/2010 01:45 pm
bolt some CCB to a framework which then mates up to the ET the same way the SRBs do.  (this is assuming that DIRECT or DIRECT-like wins)

Yes, once DIRECT-like wins and a ET-based core has been designed, that will be the time for an AJAX 2.0 design.  Certainly one step would be the proof-of-concept you describe, i.e. plug-in replacements for the SRBs.  As you indicate these must transfer thrust to the core at the same attach points as the SRBs. 

Are you imagining long brackets running up the side of the LH2 tank for this, or something else?
Actually a framework between the two CCB's which then attach to the SRB pointing points.  So two CCB's would attach to each other, and then that pair would mate up to the SRB mounting points.

This is getting, of course, a bit ahead until there is the SLS, but it does need to be kept in the back-mind.

Not that simple.  It probably require changes to the CCB skin thickness.  There are differences in loads for a strapon vs lifting an upperstage with payload.
Title: Re: AJAX Launcher
Post by: clongton on 08/16/2010 03:44 pm
Actually a framework between the two CCB's which then attach to the SRB pointing points.  So two CCB's would attach to each other, and then that pair would mate up to the SRB mounting points.

It's better to just attach them individually to the Core Thrust Structure using the same interface that Atlas has for it's 3-core heavy. Remember that the goal is to keep the CCB unchanged from it's native configuration.
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/16/2010 05:10 pm
Actually a framework between the two CCB's which then attach to the SRB pointing points.  So two CCB's would attach to each other, and then that pair would mate up to the SRB mounting points.

It's better to just attach them individually to the Core Thrust Structure using the same interface that Atlas has for it's 3-core heavy. Remember that the goal is to keep the CCB unchanged from it's native configuration.
I think Downix's idea was to keep both the CCBs and the Core (as it is in J-130) almost entirely unchanged, if possible.
Title: Re: AJAX Launcher
Post by: nooneofconsequence on 08/16/2010 05:55 pm
I think Downix's idea was to keep both the CCBs and the Core (as it is in J-130) almost entirely unchanged, if possible.
No changes to CCB. Change the ET/core as much as you like. Economies of scale and flight proven history dominates here.

Any changes to ET at this point will go through the same rigorous process. Do not plan to "optimize" this cost - it is not possible and unwise.
Title: Re: AJAX Launcher
Post by: Downix on 08/16/2010 06:27 pm
Actually a framework between the two CCB's which then attach to the SRB pointing points.  So two CCB's would attach to each other, and then that pair would mate up to the SRB mounting points.

It's better to just attach them individually to the Core Thrust Structure using the same interface that Atlas has for it's 3-core heavy. Remember that the goal is to keep the CCB unchanged from it's native configuration.
I think Downix's idea was to keep both the CCBs and the Core (as it is in J-130) almost entirely unchanged, if possible.
Semi, it's a proof-of-concept idea only, a la "AJAX-X".  For production, a modified core is the only way to go.  But for taking an existing ET or Jupiter Core for a one-off flight, this may work.  (Being a one-off could use RS-68's for the cores engines, the extra thrust would be more than sufficient to deal with the weight issues)  Once proven that the CCB's can be used as boosters, can then begin the core redeux.  (this is of course assuming the SLS is an in-line)

Because you know, once the SLS is going, moving to another booster will be a major headache, "it's unproven" "it violates the laws of physics" the usual argument.  So you need an argument to "prove the pudding".  But this is getting far ahead of ourselves.

Title: Re: AJAX Launcher
Post by: clongton on 08/16/2010 11:21 pm
For all the usual reasons, if you want the final design to use the SSME then start with the SSME, not the RS-68. Possession is 9/10's of the law, and the design. Whatever you start with is what you'll always fly with.
Title: Re: AJAX Launcher
Post by: Downix on 08/17/2010 01:43 am
For all the usual reasons, if you want the final design to use the SSME then start with the SSME, not the RS-68. Possession is 9/10's of the law, and the design. Whatever you start with is what you'll always fly with.
Good point.

back to nailing down Ajax, not discussing interim steps for now.

Has anyone done a study of core length vs stress on it, would a slightly shorter core undergo more stress than a longer?
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/17/2010 03:13 pm
For all the usual reasons, if you want the final design to use the SSME then start with the SSME, not the RS-68. Possession is 9/10's of the law, and the design. Whatever you start with is what you'll always fly with.
Good point.

back to nailing down Ajax, not discussing interim steps for now.

Has anyone done a study of core length vs stress on it, would a slightly shorter core undergo more stress than a longer?
I would guess that a shorter core would have less stress... lower bending moment.
Title: Re: AJAX Launcher
Post by: clongton on 08/17/2010 03:33 pm
For all the usual reasons, if you want the final design to use the SSME then start with the SSME, not the RS-68. Possession is 9/10's of the law, and the design. Whatever you start with is what you'll always fly with.
Good point.

Back to nailing down Ajax, not discussing interim steps for now.

Has anyone done a study of core length vs. stress on it, would a slightly shorter core undergo more stress than a longer?
I would guess that a shorter core would have less stress... lower bending moment.

The core needs to be shortened by 1 barrel section. Remember that the CCB's have their structural attachment at the core thrust structure, not a cross beam up high. That crossbeam is eliminated and we shorten the core to eliminate the space normally taken up by that beam.

Of course, we could always leave the core the standard length and extend the LH2 and LOX tanks to fill it, providing more propellant for the launch. I don't think offhand that that would mass much more than the crossbeam. So mass-wise it would be close to a wash but may increase the IMLEO somewhat. We'll have to do a trade to see.
Title: Re: AJAX Launcher
Post by: MP99 on 08/17/2010 04:10 pm
For all the usual reasons, if you want the final design to use the SSME then start with the SSME, not the RS-68. Possession is 9/10's of the law, and the design. Whatever you start with is what you'll always fly with.
Good point.

Back to nailing down Ajax, not discussing interim steps for now.

Has anyone done a study of core length vs. stress on it, would a slightly shorter core undergo more stress than a longer?
I would guess that a shorter core would have less stress... lower bending moment.

The core needs to be shortened by 1 barrel section. Remember that the CCB's have their structural attachment at the core thrust structure, not a cross beam up high. That crossbeam is eliminated and we shorten the core to eliminate the space normally taken up by that beam.

Of course, we could always leave the core the standard length and extend the LH2 and LOX tanks to fill it, providing more propellant for the launch. I don't think offhand that that would mass much more than the crossbeam. So mass-wise it would be close to a wash but may increase the IMLEO somewhat. We'll have to do a trade to see.


Surely any reduction in GLOW by eliminating the beam & shortening the intertank would be welcome as a way to improve T/W whilst maintaining a large core prop load.

Increasing the tank size / prop load would seem to be conterproductive.

cheers, Martin
Title: Re: AJAX Launcher
Post by: Downix on 08/18/2010 05:09 pm
For all the usual reasons, if you want the final design to use the SSME then start with the SSME, not the RS-68. Possession is 9/10's of the law, and the design. Whatever you start with is what you'll always fly with.
Good point.

Back to nailing down Ajax, not discussing interim steps for now.

Has anyone done a study of core length vs. stress on it, would a slightly shorter core undergo more stress than a longer?
I would guess that a shorter core would have less stress... lower bending moment.

The core needs to be shortened by 1 barrel section. Remember that the CCB's have their structural attachment at the core thrust structure, not a cross beam up high. That crossbeam is eliminated and we shorten the core to eliminate the space normally taken up by that beam.

Of course, we could always leave the core the standard length and extend the LH2 and LOX tanks to fill it, providing more propellant for the launch. I don't think offhand that that would mass much more than the crossbeam. So mass-wise it would be close to a wash but may increase the IMLEO somewhat. We'll have to do a trade to see.


Surely any reduction in GLOW by eliminating the beam & shortening the intertank would be welcome as a way to improve T/W whilst maintaining a large core prop load.

Increasing the tank size / prop load would seem to be conterproductive.

cheers, Martin
Unless you added a 5th SSME, but then we get into Ares V issues.

Removing a segment while also reducing the space between the LH2/LOX tanks seems the smartest move.
Title: Re: AJAX Launcher
Post by: luke strawwalker on 08/19/2010 06:31 pm
"National security" may not hold here. Name me the single strategic weapon we need at this moment that retaining segmented solid boosters of this size allows? King sized mortars in Pakistan?

Unfortunately we still must maintain our strategic nuclear deterrence. As long as "potential" adversaries possess nuclear weapons with the means to deliver them intercontinentally, then we must maintain our own icbm force as a deterrent. All our icbm's are solids.

You're putting ATK's words in my mouth - never said what you claim.

We did Minuteman without solids in HSF WHILE DOING SATURN.

Conflating non-segmented solids(military purpose) with segmented solids(no military purpose) is simply a shyster lawyer trick - even the chemical/physical composition is different.

Not a strategic issue but a kleptocracy issue. Another TARP bailout for ATK so you can pursue DIRECT? Seems "two bit" to me.

Quote
Can we maintain strategic lift capability with clusters of EELV boosters alone? If a court finds "yes", doesn't matter what Congress says ... we call this 'balance of power' ... keeps this country from becoming a kleptocracy that loses sight of actual needs of national security, instead of devious ones.

No. Our stratigic lift capability is intrinsically tied to our national defense, like it or not. It's still about the icbm's. Liquid icbm's will not work. It takes too long to fuel and launch them. We need to be able to respond *literally* within seconds of the President's order to do so.
Didn't argue about solids, haven't since the 60's Minuteman I.

The Shuttle represented a different kind of strategic lift threat - takes months to fly. Yet it indirectly bankrupted them in addressing it.

For that, wouldn't have mattered solids vs liquids. As you know too.

Quote
Back with the cold war, it was different.

Don't kid yourself - it's still going on. It's the presence of the nuclear deterrence that has cooled it down but the fire is not out. There are some out there who would nuke us in a heartbeat if they thought they could get away with it. Trust me on this.
Stop putting words I don't say into my posts.

Or perhaps this is intentional.

If you truly believe the insanity of linkage between the two DIFFERENT business activities, then you are a)arguing to reduce our strategic effectiveness and b) dooming SLS to being another Cx redux/cancellation.

If you buy the wrong 'guns' with the money otherwise to be used for 'butter', then you have to spend more money to buy the right 'guns' again so you damage things because of insufficient 'butter'.

The cold war economy with 'guns' worked based on symmetrical 'guns' from both sides driving demand for 'butter' to support eventual 'guns'.

In a globalized economy (cold war was 'compartmentalized' economies in contrast), it's the reverse - 'butter' (or GDP) drives spending on 'guns'.
So you lose the race economically if you spend unwisely on any 'guns'.

'guns' as in non-segmented solids predated Shuttle by decades. The gimmick with the Shuttle solids was part of a strategic game unique to the cold war. It's poison this time around.

Think really, really hard about this. Otherwise kiss off HSF, given the devil you let in by the front door.

add: There's an interesting legal precedent from the civil war that perfectly demonstrates this. Lincoln indicated how much it cost to the country back then. A reference to it is still in major federal contracts including DOD/NASA to this day. It is where such a lawsuit will start.

"We did Minuteman without solids in HSF WHILE DOING SATURN." 

What is that supposed to mean??  Makes no sense whatsoever. 
1) Minuteman IS a solid propellant missile.  All subsequent missiles have been solid propellant because A) it's indefinitely storable (for all intents and purposes) B) completely fuelled at all times  C) ready to launch nearly instantaneously. 

2) The last liquid propellant ICBM was the Titan II... which used storable but highly toxic and dangerous propellants (due to the hypergolic nature of the propellants)  This led to at least one BAD accident when a dropped socket bounced off a silo wall and punctured the skin of the missile, creating a toxic propellant leak, which subsequently led to an explosion that killed some workers and blew the lid off the silo, ejecting the thermonuclear warhead some 800 feet from the silo, IIRC.  Titan II was a leap forward in capability and response time due to the hypergolic storable propellants, giving it very short response times compared to the 45 minute minimum response time required for previous kerosene/LOX fuelled nuclear missiles like Atlas and Titan I...  but the Titan II's were finally retired under START.

3) Saturn was a TOTALLY different program.  Though it had it's genesis in the ARPA project when Von Braun and his team still worked for the military, it was a seperate project from the 'mainstream' missile programs like Atlas, Titan, Minuteman, and Polaris.  The Saturn was an 'ad-hoc' project to meet a requirement for a US booster capable of 1 million pounds of thrust, to restore 'parity' between US and Soviet capabilities.  US intelligence had "reverse calculated" the capabilities of Soviet missiles of the time from observed payloads and orbits and the energy requirements and booster size believed necessary to achieve the observed performance, and decided the Soviets were ahead in missile development and had a booster capable of a million pounds of thrust, and that the US had a strategic need to develop a similar performance booster ASAP.  Of course this completely ignored several important facts-- 1) the Soviets couldn't produce them in quantity; in fact only 6 Sapwood missiles were ever fielded strategically,  2) the Soviets needed larger missiles to lift their heavy and bulky warhead designs, problems the US was rapidly overcoming with lighter miniaturized nuclear warhead designs that the Soviets were having trouble matching, and 3) the superior accuracy of the US missile guidance, which was leading to lower yield requirements of the warhead to destroy the designated target, since the greater accuracy negated the need for huge warhead yields to assure the destruction of the target, to overcome the poor accuracy of the warhead "missing" the target by a considerable distance, which made the warheads lighter and smaller since lower yield warheads ARE somewhat smaller (and quite a bit lighter) than higher-yielding warheads, though they don't scale linearly...

The 1 million pound Saturn soon found itself without a strategic purpose, but perfect for the new space program that could use the lift capabilities for a lunar program.  The strategic situation drove missile development into the 'fast response' requirement over lift capacity, especially with the improvement in accuracy and the proving of miniaturized warheads through the nuclear test program conducted in the Pacific and in Nevada.  The Navy as well wanted ballistic missiles for their submarines, but the dangers posed by hypergolic propellants, with their toxic nature and risk of spontaneous combustion from leaks leading to a fire or explosion, which is EXTREMELY dangerous in a submarine, led to the drive for solid propellants, which were much safer.  Hence the development of Polaris. 

The Soviets, meanwhile, also realized the benefits of solid propulsion, but lagged behind considerably in the development of solid propulsion... they did field the problematical SS-13, but never in very great numbers and it was retired by superior designs.  The Soviet Navy also raced for SLBM's, but had to settle on hypergolic propulsion with it's attendant dangers for a LONG time, until Soviet solid propulsion capabilities were perfected.   The Russians still have some liquid hypergolic propellant ICBM's but, like the US and China, focus most of their efforts on solid propellant ICBM's due to their considerable advantages...

The idea of using solid propellant boosters is certainly nothing new and not the 'boogy-man' you make it out to be.  Some of the earliest proposals for increasing the performance of Saturn I's involved strapping a number of Minuteman motors to the first stage of the Saturn I, and several proposals for various SRM boosters for Saturn V, most of which culminated in the monolithic 260 inch SRM tests in Florida, but which were ultimately abandoned in favor of segmented SRM's, as used on Titan III/IV. 

The main reason segmented solids never found their way into the ICBM program was that they were not necessary... the warhead miniaturization program coupled with greater accuracy led to the Minuteman being a quite small missile compared to it's predecessors like Atlas, Titan I, and Titan II, all of which had to loft large, heavy, high yield thermonuclear weapons to intercontinental ranges, and did well to get the warhead within a mile of the target, which is basically a "miss" when it comes to hardened targets like silos and underground bunkers.  SO, with small, lightweight warheads capable of doing the job, there was no need for a huge solid propellant ICBM that would be better built from segmented solids, rather than a lightweight solid propellant ICBM that could be cast monolithically. 

I agree that NASA WOULD probably do better to move away from solid propellant SRB's, but politically that's a tough nut to crack.  The issue of SRB production lowering costs for SRM technology for the military is certainly part of the issue, despite the fact that the military would be better able to afford the increased costs for solid propellant out of 'pocket change' than NASA does out of it's paltry budgets.  Look at the EELV program-- primarily designed incidentally for the boosting of strategic military/intelligence assets to orbit-- and what do you see?? Liquid propulsion, with only small SRM boosters as needed-- NO HUGE segmented SRM's like the Titan III/IV used.  Clearly if there were an advantage for large segmented SRM's the Air Force would have pushed for their inclusion in the EELV programs as boosters.  They did not, and for good reason-- to cut costs and streamline operations.  The Air Force didn't seem too concerned about increased SRM costs for other military systems due to THEIR reduction in the use of segmented solid propellant boosters!   Yet this cost issue for the military is a BIG DEAL when NASA suddenly thinks of dropping SRB's... despite the fact that the military could EASILY afford the added costs for solid propellants without SRB's, out of petty cash, while NASA can ill afford the expensive infrastructure and procedures necessary to support SRB operations from it's paltry budget.  SO, that argument doesn't wash with me. 

Then there's the strawman about 'maintaining our SRB technical prowess for future US strategic program needs'.  Like what??  Some mythical new ICBM??  The US hasn't developed a new ICBM since MX/Peacekeeper, which is retired.  There's nothing more than dreamy talk of replacing the Minuteman, upon which we now entirely depend, for land based strategic capabilities... certainly NO serious funding has materialized!  All that despite the fact that serious concerns about the capability and reliability of the long-serving Minuteman has been raised, and the fact that our strategic opponents in Russia and China are developing and fielding advanced next-generation solid propellant ICBM's....  SO, the argument that NASA must buy SRB's to 'keep the lights on' in the SRM factories, just in case we need an advanced solid propellant ICBM in the next decade, sounds rather hollow to me. 

Of course if we had the Atlas on Delta tooling option, we probably would be having a very different conversation right now...

Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: clongton on 08/20/2010 01:41 am
Ok, while it started as a side comment wrt SRB's, we are now getting *way* off topic so I'm going to ask everyone to just stop following this off topic idea, at least on the AJAX thread. It's got *nothing* to do with AJAX. Can we all do that please? The moderator's button is only a small push away. It's been used both on me and by me and I have no qualms about doing it again.

Everyone - please return to the topic of the AJAX Jupiter alternative design.
Title: Re: AJAX Launcher
Post by: Downix on 08/21/2010 01:07 am
Not counting the SSME's, the reduced core is coming up at 44.4 m.  (I wish I was kidding, but it actually did come to this)  The mounting for the base of the CCB's is being integrated into the boat tail.  The advantage here is, the boat tail now has to take the weight, rather than the SSME supporting some weight, and the SRB's other.  This will allow likely even more weight reduction over the Jupiter in time, but for now we are keeping the extra weight in order to maintain some margin for reductions in the future. 
Title: Re: AJAX Launcher
Post by: sdsds on 08/21/2010 02:07 am
Not counting the SSME's, the reduced core is coming up at 44.4 m.

Versus 46.9 m for the ET?  94.67%

Do you have projected dry and wet masses yet, or can we simply multiply ET values by 0.9467 to get an approximation?
Title: Re: AJAX Launcher
Post by: Downix on 08/21/2010 02:30 am
Not counting the SSME's, the reduced core is coming up at 44.4 m.

Versus 46.9 m for the ET?  94.67%

Do you have projected dry and wet masses yet, or can we simply multiply ET values by 0.9467 to get an approximation?

yes, they are posted a bit earlier in the thread, but they are less than that.  Part of the length is in the boattail, which the ET does not have. 
Title: Re: AJAX Launcher
Post by: Downix on 08/23/2010 06:47 pm
Not counting the SSME's, the reduced core is coming up at 44.4 m.

Versus 46.9 m for the ET?  94.67%

Do you have projected dry and wet masses yet, or can we simply multiply ET values by 0.9467 to get an approximation?
dry core: 64,103 kg
fuel: 629,721 kg

Part of the weight loss without the massive length loss is due to the merging of the SRB support with the SSME support systems.  (since CCB's lift from the bottom, just as the SSME's do, seems logical to unite their support structures)
Title: Re: AJAX Launcher
Post by: martin hegedus on 08/27/2010 09:42 pm
I'm still working on this, BTW... I have a mesh, but need it in CGNS format, since that is what my solver uses... I'm trying to compile my mesh generator with CGNS support right now...

Paraview seems to work pretty well for visualization, by the way.

Any luck with FreeCFD?  I saw your post on the FreeCFD forum and replied by asking if you have choked the flow.  I "think" FreeCFD should work for supersonic flow (Euler) as long as the shock does not touch the boundaries specified as "inlet."  FreeCFD may (it should!) work even when that happens, but I'm not confident if that is true and haven't tested it.  I'm having problems running steady state subsonic cases since the solution is "piling up" at the inlet boundary conditions. :P  I'm also having trouble with the turbulence model, but that may be my problem.  I'm testing FreeCFD with a NACA 0012 airfoil case, and so far, all that works is supersonic Euler.

BTW, Fun3D, http://fun3d.larc.nasa.gov, is ITAR.

Out of curiosity, what CFD code was used by the DIRECT team to analyze subsonic and supersonic compressible flow for Jupiter?  Is the code (and thus results) ITAR?
Title: Re: AJAX Launcher
Post by: martin hegedus on 08/28/2010 12:00 am
I'm still working on this, BTW... I have a mesh, but need it in CGNS format, since that is what my solver uses... I'm trying to compile my mesh generator with CGNS support right now...

Paraview seems to work pretty well for visualization, by the way.

Any luck with FreeCFD?  I saw your post on the FreeCFD forum and replied by asking if you have choked the flow.  I "think" FreeCFD should work for supersonic flow (Euler) as long as the shock does not touch the boundaries specified as "inlet."  FreeCFD may (it should!) work even when that happens, but I'm not confident if that is true and haven't tested it.  I'm having problems running steady state subsonic cases since the solution is "piling up" at the inlet boundary conditions. :P  I'm also having trouble with the turbulence model, but that may be my problem.  I'm testing FreeCFD with a NACA 0012 airfoil case, and so far, all that works is supersonic Euler.

BTW, Fun3D, http://fun3d.larc.nasa.gov, is ITAR.

Out of curiosity, what CFD code was used by the DIRECT team to analyze subsonic and supersonic compressible flow for Jupiter?  Is the code (and thus results) ITAR?


I got my subsonic wedge case working by dropping the pressure from the inlet boundary condition and adding it to the outlet condition.
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/28/2010 12:06 am
I'm still working on this, BTW... I have a mesh, but need it in CGNS format, since that is what my solver uses... I'm trying to compile my mesh generator with CGNS support right now...

Paraview seems to work pretty well for visualization, by the way.

Any luck with FreeCFD?  I saw your post on the FreeCFD forum and replied by asking if you have choked the flow.  I "think" FreeCFD should work for supersonic flow (Euler) as long as the shock does not touch the boundaries specified as "inlet."  FreeCFD may (it should!) work even when that happens, but I'm not confident if that is true and haven't tested it.  I'm having problems running steady state subsonic cases since the solution is "piling up" at the inlet boundary conditions. :P  I'm also having trouble with the turbulence model, but that may be my problem.  I'm testing FreeCFD with a NACA 0012 airfoil case, and so far, all that works is supersonic Euler.

BTW, Fun3D, http://fun3d.larc.nasa.gov, is ITAR.

Out of curiosity, what CFD code was used by the DIRECT team to analyze subsonic and supersonic compressible flow for Jupiter?  Is the code (and thus results) ITAR?


I got my subsonic wedge case working by dropping the pressure from the inlet boundary condition and adding it to the outlet condition.

Thank you! I'll give it a try soon.
Title: Re: AJAX Launcher
Post by: 93143 on 08/30/2010 12:13 am
There are three linearly-independent variables in the 1-D Euler equations.  The characteristic wavespeeds are the flow velocity (the advection wave) and the flow velocity plus and minus the sound speed (the acoustic waves).  Therefore, a uniformly subsonic case needs two variables specified at the inlet and one at the outlet, while a uniformly supersonic case needs all three at the inlet and none at the outlet, since all three waves are travelling downstream and no information propagates upstream.
Title: Re: AJAX Launcher
Post by: martin hegedus on 08/30/2010 08:11 am
There are three linearly-independent variables in the 1-D Euler equations.  The characteristic wavespeeds are the flow velocity (the advection wave) and the flow velocity plus and minus the sound speed (the acoustic waves).  Therefore, a uniformly subsonic case needs two variables specified at the inlet and one at the outlet, while a uniformly supersonic case needs all three at the inlet and none at the outlet, since all three waves are travelling downstream and no information propagates upstream.

That is well understood by me.  However, my main question is will FreeCFD work for the purpose of analyzing AJAX or is there another freely available CFD program better suited?  Any thoughts?
Title: Re: AJAX Launcher
Post by: 93143 on 08/30/2010 08:42 am
<elementary CFD delivered in a self-important and patronizing manner>

That is well understood by me.  However, my main question is will FreeCFD work for the purpose of analyzing AJAX or is there another freely available CFD program better suited?  Any thoughts?


Sorry.  Our research group's code is technically open-source, but in terms of actual availability, ease-of-use, and a reasonable level of certainty that someone hasn't just broken one of the modules trying to fix a bug or add a feature, you're probably better off using something else.

I'm not actually familiar with FreeCFD, though I'd heard of it, but the description on the website looks like it covers the basics fairly well.  It won't let you analyze the interior of a hybrid rocket motor like our code...  doesn't yet (I'm working on it)...  but it should be fine for supersonic aerodynamics if you can feed it a sufficiently accurate mesh and have access to sufficient computing resources.

Other options?  No idea.
Title: Re: AJAX Launcher
Post by: martin hegedus on 08/30/2010 03:59 pm

... a reasonable level of certainty that someone hasn't just broken one of the modules trying to fix a bug or add a feature, you're probably better off using something else.


LOL  :)  Sssssh, you shouldn't mention that little CFD "secret!"  All the aerodynamic prediction codes (engineering, intermediate, and high fidelity) are like this.
Title: Re: AJAX Launcher
Post by: Robotbeat on 08/30/2010 04:13 pm

... a reasonable level of certainty that someone hasn't just broken one of the modules trying to fix a bug or add a feature, you're probably better off using something else.


LOL  :)  Sssssh, you shouldn't mention that little CFD "secret!"  All the aerodynamic prediction codes (engineering, intermediate, and high fidelity) are like this.

That's why they call it "Colorful Fluid Dynamics." ;) The important part is the pretty pictures! (Just kidding, of course...)
Title: Re: AJAX Launcher
Post by: martin hegedus on 08/30/2010 04:35 pm
The important part is the pretty pictures! (Just kidding, of course...)

Haha, I've been at this long enough to know you are not kidding!  The stories I could tell...
Title: Re: AJAX Launcher
Post by: Downix on 09/08/2010 02:23 pm
I think I have the bottom done redesign just about finished for the fuel tank.  As the original DIRECT engine layout has changed slightly, due to the load-bearing structure now at the base, this was necessary to ensure fuel flow to the engines while still being able to maintain should it become necessary. 
Title: Re: AJAX Launcher
Post by: simcosmos on 09/11/2010 09:38 am
Hi all,

Sharing yet another quick preliminary render test of something like AJAX-440/44X?... I have done the rendering of this picture quite a few time ago and, running the risk of repeating myself:

- it does not precisely include several details (updates to thrust structure design – although did make it +/- equivalent in length to other SDLV for extra space for SSME integration -  other details also missing, etc)

- as well not sure if represents or not the current (?) propellant load assumption (?) for the core: in this image the core is sized for about 646t prop. amount at liftoff, which was the propellant amount that I have 'tested' on my simulations and for which shared specific considerations regarding preliminary performance results vs ascent procedures (I saw the mention to ~630t prop. load but haven't done simulation work on that)

- neither not sure about eventual updates regarding PLF study / analysis considerations specific to AJAX and to several updated context information (not just a copy+paste of older DIRECT / other assumptions...): in the lack of such study or, at least, further discussion on this thread, I have simply continued to use a 'generic' 8.4m diameter  / long PLF for this first iteration representation.

- eventually needed kick stage / propulsion system (integrated on payload adapter?) is not represented (this assuming that baseline for AJAX would be sub-orbital injection of payload?... yes? / no?... yet another important thing that really think that would need extra discussion on the current thread in order to further advance the conceptual design, if there is the wish to do so)

Despite the apparent slow down / missing details / active discussion (unless it is being done on other thread / places?) about this kind of specific AJAX considerations regarding also slightly more specific components designs, preciser requirements and mission procedures (at least to build a more solid baseline / departure point case) I decided to share the current clumsy render: at least it shows the AtlasV boosters with a more aerodynamic nose integrated on a smaller than ET prop. load core.  8)

Back to 'away mode',
António
Title: Re: AJAX Launcher
Post by: Halidon on 09/12/2010 05:22 am
Impressive, simcosmos, very impressive. Not to add to your workload, but do you have plans for a render using Merlin-2 Falcon cores in place of Atlas CCBs?
Title: Re: AJAX Launcher
Post by: StuffOfInterest on 09/12/2010 12:18 pm
Impressive, simcosmos, very impressive. Not to add to your workload, but do you have plans for a render using Merlin-2 Falcon cores in place of Atlas CCBs?

I'm sorry but this would make no sense as the whole concept of AJAX is to use as much existing, unmodified technology out there as possible.  Merlin-2 is still on the drawing board and Falcon 9 using Merlin-2 will require some significant changes to the back end.

The rendering does look nice but I still have a vision of Energia when I see it.  Not that this is bad.  I'd love to see that thing lifting off the pad.
Title: Re: AJAX Launcher
Post by: clongton on 09/12/2010 12:57 pm
Impressive, simcosmos, very impressive. Not to add to your workload, but do you have plans for a render using Merlin-2 Falcon cores in place of Atlas CCBs?

I'm sorry but this would make no sense as the whole concept of AJAX is to use as much existing, unmodified technology out there as possible.  Merlin-2 is still on the drawing board and Falcon 9 using Merlin-2 will require some significant changes to the back end.

The rendering does look nice but I still have a vision of Energia when I see it.  Not that this is bad.  I'd love to see that thing lifting off the pad.

I have no problem with seeing images of an American Energya in the AJAX concept. The thought is really quite elegant. By mixing and matching pairs of the Atlas-V CCB as strap-on LRB's, this vehicle would cost effectively cover the full IMLEO range of performance from 50mT to nearly 200mT, all without an upper stage, in a *single* launch vehicle design. In addition to that, the Atlas-V would also be the system's default crew launch vehicle. Of course the HLV would be man rated so that it wouldn't be *necessary* to fly the Atlas CLV in addition to the HLV, but mission planners would have both options available and be free to decide which crew launch option made the most sense for *that* mission. For example if the mission required the full capacity of the HLV plus crew, then the Atlas CLV would lift the crew separately. On the other hand, if the mission could lift the crew and all the mission requirements on the AJAX, then they would be free to launch the crew atop the AJAX. Mission flexibility is the name of the game.

If NASA were to adopt the AJAX as the SLS lifter in lieu of DIRECT's Jupiter it would be the best of both worlds (Commercial EELV and SDHLV) wrapped into one. Although the political realities appear to be dictating otherwise, at least for now (SRB's vs. LRB's), The AJAX concept is more cost effective and flexible than even DIRECT's Jupiter HLV because the Jupiter does not employ a CLV as it's booster. In addition, the AJAX is more capable in the area of super heavy lift - and all without the expense of developing an upper stage. The AJAX-48x can match the best that the Jupiter-246 can do without using an upper stage at all. Add an upper stage to the AJAX-48x and your lift performance is off the charts above anything that NASA has ever even considered possible before; all in a single cost effective and extremely flexible LV design.

I really like the AJAX - very much.
Title: Re: AJAX Launcher
Post by: HappyMartian on 09/12/2010 01:27 pm
The AJAX launcher looks good. Keep on trucking! :)

Cheers!
Title: Re: AJAX Launcher
Post by: Ronsmytheiii on 09/12/2010 09:15 pm
This was probably mentioned earlier, but could the Atlas CCB's still use a limited number of SRB's for cargo flights?  I know that Delta IV Heavy has growth options to use boosters on the core, although the Atlas CCB would have another CCB right beside it as well as the Et-core.
Title: Re: AJAX Launcher
Post by: clongton on 09/12/2010 11:21 pm
This was probably mentioned earlier, but could the Atlas CCB's still use a limited number of SRB's for cargo flights?  I know that Delta IV Heavy has growth options to use boosters on the core, although the Atlas CCB would have another CCB right beside it as well as the Et-core.

Not likely Ron. Sorry.
Title: Re: AJAX Launcher
Post by: martin hegedus on 09/13/2010 12:48 am
Hi all,

Sharing yet another quick preliminary render test of something like AJAX-440/44X?... I have done the rendering of this picture quite a few time ago and, running the risk of repeating myself:

...

Back to 'away mode',
António


António, wonderful job both now and previously.

In regards to your rendering, one issue that comes to mind is the outer angle of the nose cone to the body for the CCB.  Seems large, i.e. the height of the nose may need to be lengthened.  You should maybe keep the angle the same as it is with the current CCB, i.e. lengthen the nose to match it, or copy the angle from a preexisting vehicle, such as Ariane 5.  For me, It is hard to tell what your angle is since the image is not a side view so I may have misjudged this.

The reason for my suggestion is that at the shoulder, the junction of the nose and body, the flow is probably separated, i.e. the beginning of a separation bubble.  At transonic speeds a shock may try to ride the bubble.  This causes unsteady aerodynamics since, in general, when the shock interacts with bubble, the bubble disappears or bursts, then the shock moves away from the bubble region or decreases in strength, and the bubble reappears, and the shock then moves back toward the bubble or increases in strength, and the process continues.  This unsteady process tends to rip the rocket apart, and I'm not exaggerating.  Unfortunately, this class of aerodynamics is extremely difficult to predict.  RANS CFD codes, because of the high level of damping provided by the eddy viscosity terms, tend to come up with a steady solutions where the shock is steady and it does ride the bubble.  Of course, this is a totally incorrect result.  Also, Wind Tunnel predictions can be considerably off because of the effects of the slots in the WT.  So, for the time being, maybe it's best to imitate what works.  Just a suggestion.

A question for the group, how will the trajectory for the vehicle be determined?  So far it seems that delta v calculations and trajectory integration program have been used.  Will a trajectory optimization program be used?  I don't know of any trajectory optimization program which is not ITAR so I doubt the license agreement will allow the program to be used on this project.  POST (2D, 3D, and II) (https://post2.larc.nasa.gov/) and  OTIS (http://technology.grc.nasa.gov/tech-detail-coded.php?cid=GR-0021#benefits) are ITAR and Astros (http://www.astos.de/products/astos) is restricted.

Title: Re: AJAX Launcher
Post by: martin hegedus on 09/13/2010 01:20 am
Hi all,

...

António


Hi António,

Can you do me a favor and post the dimensions you are using for the CCB?  What I'm looking for is very simple, nose cap radius, height of nose (from shoulder to nose tip, or whatever is convenient for you), body radius, and length of body (from shoulder to base of nozzle).  So no frills.  I'll try to grid it up.  I know I can get the dimensions from other web sites but I think it would be good practice to be on the same page as you.

Thanks,

Martin
Title: Re: AJAX Launcher
Post by: Ronsmytheiii on 09/13/2010 03:05 am

Not likely Ron. Sorry.

No big deal, rather shoot down an improbable idea.

Could the payload interface use the EELV interface, or borrow parts?
Title: Re: AJAX Launcher
Post by: simcosmos on 09/13/2010 05:57 pm
Thanks all,
A few comments / answers next:


I. LRB Details: nose cone, core integration, etc

In regards to your rendering, one issue that comes to mind is the outer angle of the nose cone to the body for the CCB.  Seems large, i.e. the height of the nose may need to be lengthened.  You should maybe keep the angle the same as it is with the current CCB, i.e. lengthen the nose to match it, or copy the angle from a preexisting vehicle, such as Ariane 5.  For me, It is hard to tell what your angle is since the image is not a side view so I may have misjudged this.
(...)


Thanks for the input Martin: please note that, for the moment, I have only used a very generic shape for the LRB nose cones, mostly for quick render purposes (same valid for the representation of a few other details, being that other details aren't even represented yet).


On a later moment my plan would be to use / adapt reference images, probably from Energia's boosters, which might be a closer reference for AJAX than Ariane5 (although I think that have a little more information about the geometric shape of Ariane5  EAP's cone).

Note: in a similar way (again to Energia), in the lack of professional analysis and only (at least for the moment) to make the performance implementation / simulation something a bit 'easier' / straightforward here, I' have been also considering that the AJAX-44x LRBs would stage in pairs (both LRB of each side connected to each other during staging): in the render that I previously shared, the boosters would need to be slightly closer to each other to represent such staging method (this assuming that, after extra study, such method would have advantages over separating each LRB in a separated way and also assuming that the main AJAX configurations would be 4 or 8 boosters, extra study required about a number of considerations related with this topic, but again, for the moment, I'm going with what is easier to setup here: independent / non-connected LRB staging is something slightly more complex and time intensive to implement at this very preliminary phase)...



II. 3D Models / Dimensions

Can you do me a favor and post the dimensions you are using for the CCB?  What I'm looking for is very simple, nose cap radius, height of nose (from shoulder to nose tip, or whatever is convenient for you), body radius, and length of body (from shoulder to base of nozzle).  So no frills.  I'll try to grid it up.  I know I can get the dimensions from other web sites but I think it would be good practice to be on the same page as you.

Thanks,

Martin


Sure Martin, but I will need a little of extra time to check some dimensions and to prepare at least a commented rendering (perhaps showing cross sections or something like that). Not sure when will be able to do it though, perhaps next weekend (?), depending of how goes some other non-related 'stuff' here.

Note: in addition, as have mentioned on several past posts in this and other AJAX related threads, and depending of a few constraints, I could also selectively prepare / share (by email) non-textured versions of AJAX 3D components specifically produced for CFD purposes although currently have some doubts about eventual requirements for such utilization; there are a number of questions that would wish to ask first and, depending of the answers, the current 3D models might need to be adapted / rebuilt in order for them to be more 'compatible' for a more efficient CFD utilization (when comparing with these wip/dev versions of such 3D models which are more aimed for implementation on a space flight simulator / other render objectives and which might have a slightly different set of 'construction philosophy' parameters than models built for CFD)... If wishing to further continue this specific line of thought maybe better to contact me via PM / email (but please do not strange if I take a little to answer)



3. Simulation / Trajectory / Performance Optimization

A question for the group, how will the trajectory for the vehicle be determined?  So far it seems that delta v calculations and trajectory integration program have been used.  Will a trajectory optimization program be used?  I don't know of any trajectory optimization program which is not ITAR so I doubt the license agreement will allow the program to be used on this project.  POST (2D, 3D, and II) (https://post2.larc.nasa.gov/) and  OTIS (http://technology.grc.nasa.gov/tech-detail-coded.php?cid=GR-0021#benefits) are ITAR and Astros (http://www.astos.de/products/astos) is restricted.

I started writing something about this topic (basically writing some considerations about the method I'm using for performance simulation - http://orbit.medphys.ucl.ac.uk/home.php / www.orbitersim.com + http://users.swing.be/vinka/, ground rules clarification / summary, etc) but the text was starting to get a bit too long... Maybe on another time (it would also help if I could find an opportunity to clean / release the AJAX simulation that have here but my plate is full with other things). For the moment will only write that if this brainstorm is to be taken into a next level then the performance results (including optimizations) might need to either use an accepted tool or, if using some kind of other tool(s) / method(s), such tool(s) / method(s) need to be professionally compared with an accepted tool in order to properly validate results (which could be, by itself, a separated project!...). I could have extra thoughts about this topic but every time that start writing about this the text seems to get 'out of control' - in terms of length - and probably a bit off-topic for the thread (maybe subject for a separated thread).  8)

António
Title: Re: AJAX Launcher
Post by: martin hegedus on 09/15/2010 09:47 pm
I thought I would expand a little on the cone angle thought since it
demonstrates some things about analysis/design, aerodynamics, and CFD.
 And pretty pictures will be included since they are worth a thousand
words and are cool.

I ran blunt nose/body shapes with the CFD code I wrote (Aero Troll
CFD, http://www.hegedusaero.com/software.html).  The code is RANS
(Reynolds averaged Navier Stokes) with a Spalart-Allmaras turbulence
model.  The results shown below are axisymmetric (to save CPU time)
and for a Reynolds number/per inch approximating the value for the
Shuttle at Max Q (300000.0/inch).  The Mach number I'm running is 0.9
and the angle of attack is 0.  Granted the Reynolds number was
calculated at Mach 1.5 and I'm running the Mach number lower.  This
won't affect the results in regards to this post.

The first case I ran was for a blunt nose approximating the Atlas CCB
nose.  I call this the long nose.  For this case I marched the
solution with local time stepping (CFL = 5.0).  This is standard
procedure for obtaining steady state results since it converges the
solution faster than a constant time step.  However, one must use
care, as will be seen later.  So, the first image is of the Mach
number plot for the long nose geometry with local time stepping.

Next, I changed the angle (by shortening the nose) on the nose cone to
match the maximum cone angle that would result if the nose tip was
moved sideways so one side of the nose cone was parallel to the body.
I call this the short nose.  I did this (instead of shifting the nose
tip sideways) to keep the geometry axisymmetric.  But the result
should still be illustrative.  The nose length is approximately 40%
shorter than the nose length for the previous "long nose" example.
The problem was converged with the same local time stepping approach
as above.  The Mach number plot for the short nose geometry with local
time stepping is the second image below and is qualitatively similar
to the first.  This is were the fun begins.  So, from this plot one
might think what I said earlier about a separation bubble doesn't
apply.  Haha, wrong.  The key is that I used a local time stepping
method.  With the local time stepping approach each grid cell is
marched by a local time step which is a function of the grid cell
size.  The bigger the cell, the larger the time step.  This is non
physical.

After seeing the result, I was skeptical of the solution so I re-ran
the case with a constant time step.  Unfortunately, this takes more
CPU time since the time step is constrained by the smallest cell size.
 These are the cells next to the body which are required to have a
very small height to properly capture the boundary layer.  For
example, the outer surface of the grid is about 4000 inches out and
the cells next to the body have a height of 1.0E-4 inches.  Also, for
these examples I placed the outer boundary closer to the body than it
should be.  My rule of thumb for a 3D shape is about 20 times the
longest dimension to quantitatively capture the loads.  Since the body
is about 1400 inches long, the outer grid should be 28000 inches.
Sorry, the resources are just not available for this qualitative
example.  So I ran the case, and waited, and waited.  It took about 20
times longer than the local time stepping approach.

The short nose geometry with constant time step results are shown in
the third image.  You can't miss the separation bubble.  Also notice
that the "shock" is riding on top of the bubble.  Also note that it's
not a shock.  The separation bubble adapts so that the flow can slow
down without a shock.  In the real world, outside of the lab, this
does not happen.  However, I've been told, that this phenomenon can be
reproduced in the lab.

The fourth image is the long nose geometry re-run with a constant time
step.  Notice it is very very close to the result obtained with the local
time stepping approach.  I did not converge it all the way.

Notes:  1)  Currently my CFD code (a structured solver) can not handle
overlapping grids, therefore it can not solve multi body problems
(However, I'm working on it...); 2) If design choices are made which
require a constant dt to be used for an analysis then CFD results
become more expensive and therefore harder to obtain,  3) Structured
solvers tend to be appreciatively faster than unstructured solvers
such as FreeCFD.

Martin
Title: Re: AJAX Launcher
Post by: Robotbeat on 09/15/2010 10:39 pm
Well, as you say, structured doesn't usually work with multiple bodies.

FreeCFD isn't necessarily the best choice, but it can work as a stand-in until better tools are available. To be honest, I'm mostly just trying to get comfortable using CFD tools again.

As you mentioned, CFD can't completely replace supersonic/hypersonic testing. They need to be used together, to try to paint as complete a picture as possible of what your rocket will actually do when launched, before you launch the multimillion dollar craft.
Title: Re: AJAX Launcher
Post by: martin hegedus on 09/15/2010 11:46 pm
FreeCFD isn't necessarily the best choice, but it can work as a stand-in until better tools are available. To be honest, I'm mostly just trying to get comfortable using CFD tools again.

Personally, I don't know of a best choice, even including commercial and government codes.  Each has it's strengths and weaknesses.  For example, my code is a finite difference method with artificial dissipation, therefore, it will not convect vorticity as well as AUSM or HLLC.  However, it is robust and converges all the way better.  (Note, it is very important to converge some runs all the way since one never knows what, when, and how non linearities "express" themselves.)  And, it should be assumed all codes have bugs hiding somewhere.  Therefore, ideally, more than one code should be used.

Quote
As you mentioned, CFD can't completely replace supersonic/hypersonic testing. They need to be used together, to try to paint as complete a picture as possible of what your rocket will actually do when launched, before you launch the multimillion dollar craft.

TOTALLY AGREE!!!

BTW, and this is not directed at you Chris, this is true for all codes and methods, GN&C, trajectories, structures, thermodynamics, costs, etc.  The non linearities involved with rocket engineering can sure mess things up.  This is why I think it is bad form when people/groups do not clearly state what analysis and design codes they are using for their design.
Title: Re: AJAX Launcher
Post by: martin hegedus on 09/16/2010 12:18 am
I. LRB Details: nose cone, core integration, etc
...


Another item to consider is that the nose cap radius may need to be reduced to move the nose closer to the ET.  The reason is that a horse shoe vortex may form around the paired CCBs.  The vortex will start at the nose region of the paired boosters and travel down the outer sides of the boosters, like a rope draping over the CCBs.  The vortex is caused by the flow separating ahead of the booster.  And, if a vortex does form, it will probably burst somewhere along the sides of the boosters, creating very unsteady flow.  The trade off is that a smaller nose cap radius affects the thermodynamics of the nose cap.  Notice how the nose cap is probably getting heavier...

edit:
The horse shoe vortex is a function of the number of boosters next to each other.  One booster is probably not an issue, two boosters paired together probably more of an issue, three boosters paired together probably an issue, four boosters (i.e. 8 boosters total forming a ring around the ET) may have a ring vortex wrapped around the ET ahead of the CCBs.
end of edit:

Quote
II. 3D Models / Dimensions
...


Don't worry, if you can do it, do it at your convenience.  I gather the overall pace of this topic is, um, "measured".  And since it doesn't seem like structures or thermodynamics analysis and design member(s) are associated with this topic, the analysis may not get very far.
Title: Re: AJAX Launcher
Post by: Downix on 09/16/2010 07:33 pm
Studying these, it seems that the longer nose has some advantages for this application.  However, when considering the fact that we have two CCB's paired up, the front-side trapped air should create a kind of air dam, preventing the corkscrewing of air in between the two.
Title: Re: AJAX Launcher
Post by: orbitjunkie on 09/16/2010 07:35 pm
I'm sorry but this would make no sense as the whole concept of AJAX is to use as much existing, unmodified technology out there as possible.  Merlin-2 is still on the drawing board and Falcon 9 using Merlin-2 will require some significant changes to the back end.
<snip>
If NASA were to adopt the AJAX as the SLS lifter in lieu of DIRECT's Jupiter it would be the best of both worlds (Commercial EELV and SDHLV) wrapped into one. Although the political realities appear to be dictating otherwise, at least for now (SRB's vs. LRB's), The AJAX concept is more cost effective and flexible than even DIRECT's Jupiter HLV because the Jupiter does not employ a CLV as it's booster. In addition, the AJAX is more capable in the area of super heavy lift - and all without the expense of developing an upper stage. The AJAX-48x can match the best that the Jupiter-246 can do without using an upper stage at all. Add an upper stage to the AJAX-48x and your lift performance is off the charts above anything that NASA has ever even considered possible before; all in a single cost effective and extremely flexible LV design.

I really like the AJAX - very much.

Chuck, I think I may have just become more of an AJAX fan than a DIRECT fan (current political feasibility not withstanding). A recent post (http://forum.nasaspaceflight.com/index.php?topic=22381.msg636950#msg636950) by alexw highlighted how expensive the SRBs are. Not new information, but I've never seen it broken down that way before. Using that with another nice cost-summarizing post (http://forum.nasaspaceflight.com/index.php?topic=22122.msg619377#msg619377) of his, I come up with the following for booster costs only:

SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that

AJAX 44x (starting anytime)
$160-360/flight anytime, including through 2017

Even with a couple of AJAX test flights, that's a savings of ~$2.5B up front and $160-360M per flight from then on.

Can these numbers be backed up? Well, the up front savings might be a wash since presumably you'd have some notable infrastructure changes at KSC. (Btw, has anyone thought about this for AJAX?)

Besides cost, there are other "intangibles" like:
- SRB ground difficulties (toxicity, handling, cleanup, integration, can't do pure clean pad)
- SRB environmental nastiness - see the recent DM-2 test fallout
- SRB vs LRB failure mode danger issues
- Commonality with commercial crew launches, which look very likely to happen regardless of HLV
- Quality, safety, and cost efficiencies from greater # of boosters, especially in concert with commercial crew
- Potential for future re-competition of booster services (e.g. Falcon, Taurus, Atlas evolution many years from now, which may have other incentives to happen anyway)

I used to think the SRBs were a necessary but cost-effective evil. Now I don't think so. Regarding the political necessity, I realize ATK wields some power and influence in Congress right now. It's also seems impossible that an AJAX concept would supplant the current SD-HLV thinking today. However, I could see some potential for the political equation changing. Utah's senators won't be in office forever, ULA is in AL after all (though they've got a lot of work to do on that front), lean times are coming and the savings are not pocket change, it would benefit commercial crew, etc. I am certainly no expert but it seems that the benefits to the anti-STS-heritage crowd are equal to or greater than the damage to the pro-STS-heritage crowd.

I think DIRECT was a clear winner 2-5 years ago. This year? Next year? Suffice to say, I really like the AJAX - very much!
Title: Re: AJAX Launcher
Post by: martin hegedus on 09/16/2010 07:55 pm
Studying these, it seems that the longer nose has some advantages for this application.  However, when considering the fact that we have two CCB's paired up, the front-side trapped air should create a kind of air dam, preventing the corkscrewing of air in between the two.

The corkscrewing of the air does not occur between the two, rather the two legs of the horseshoe vortex go down the outer sides of the pair of boosters (by pair, I mean the two which are next to each other).  It is the air dam which causes this effect.  Consider it this way, the air dam creates a separation point (due to the increasing pressure) ahead of the CCBs and at this point the flow leaves the surface thus creating a vortex.  Think of how an aerospike creates a vortex in front of the nose (not referring to engines, rather, the spikes that are added to high speed noses to reduce their drag).
Title: Re: AJAX Launcher
Post by: alexw on 09/16/2010 10:30 pm
Chuck, I think I may have just become more of an AJAX fan than a DIRECT fan (current political feasibility not withstanding). A recent post (http://forum.nasaspaceflight.com/index.php?topic=22381.msg636950#msg636950) by alexw highlighted how expensive the SRBs are. Not new information, but I've never seen it broken down that way before. Using that with another nice cost-summarizing post (http://forum.nasaspaceflight.com/index.php?topic=22122.msg619377#msg619377) of his, I come up with the following for booster costs only:
SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that
    To be fair, ATK costs are mostly fixed costs. The prices drop precipitously after that -- by my eye, 8 segments is $65 million/segment, 16 segments is ~$34 million/segment, 24 segments ~ $23 million/segment. Dig up Ross's curve (sorry, I don't have a post-link handy.) The raw materials for casting the PBAN obviously cost little, but the infrastructure costs for ATK to maintain all the necessary personnel are substantial.
    Thus, the SRBs were seen as a very good deal at high projected flight rates, but terribly expensive just to keep around.
   -Alex
Title: Re: AJAX Launcher
Post by: martin hegedus on 09/16/2010 11:20 pm
I've attached some images to help illustrate the effects of blocked
flow at supersonic speeds.  The case was run at Mach 1.5 and Mach 0.6.
 The geometry is an axisymmetric representation of AJAX with CCBs
going all the way around (i.e. eight of them).  The cases were run
with local time stepping.  The first three plots are for a freestream
Mach number of 1.5.  In the first plot, the cyan color embedded within
the recirculation region in front of the CCB nose (the flat vertical
wall) represents the flow going upstream.  So there is a vortex within
that region.  The first plot is with the Mach contour limits
unconstrained.  Notice the interaction between the shock and
separation bubble.  The second image is with the Mach contour levels
constrained to be between 0 and 0.5, to better illustrate what is
occurring within the separation bubble.  The next image is a zoomed
out view with the contour levels unconstrained.  I've included it
solely because I think it looks cool.  The next image (and last) is at Mach 0.6
to illustrate the difference between subsonic and supersonic flow.  Of
course there is a vortex embedded in the region ahead of the CCB
model, but it is not as prominent as the supersonic one.
Title: Re: AJAX Launcher
Post by: Robotbeat on 09/17/2010 02:21 am
Excellent!
Title: Re: AJAX Launcher
Post by: aquanaut99 on 09/17/2010 09:40 am
Chuck, I think I may have just become more of an AJAX fan than a DIRECT fan (current political feasibility not withstanding). A recent post (http://forum.nasaspaceflight.com/index.php?topic=22381.msg636950#msg636950) by alexw highlighted how expensive the SRBs are. Not new information, but I've never seen it broken down that way before. Using that with another nice cost-summarizing post (http://forum.nasaspaceflight.com/index.php?topic=22122.msg619377#msg619377) of his, I come up with the following for booster costs only:
SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that
 
Being thoroughly disappointed with SLS/DIRECT since the HEFT disaster, I, too, come back to the AJAX thread. I always thought EELV/AJAX were the way to go but accepted DIRECT as the politically feasible alternative that was still affordable. Since the HEFT study I've completely changed my tune and now believe that SLS will destroy NASA's HSF. All EELV is the way to go, with AJAX as an alternative to please the pro-HLV crowd.

AJAX is certainly impressive. I like it as much as I can like any HLV.
Title: Re: AJAX Launcher
Post by: EE Scott on 09/17/2010 10:44 am
Chuck, I think I may have just become more of an AJAX fan than a DIRECT fan (current political feasibility not withstanding). A recent post (http://forum.nasaspaceflight.com/index.php?topic=22381.msg636950#msg636950) by alexw highlighted how expensive the SRBs are. Not new information, but I've never seen it broken down that way before. Using that with another nice cost-summarizing post (http://forum.nasaspaceflight.com/index.php?topic=22122.msg619377#msg619377) of his, I come up with the following for booster costs only:
SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that
 
Being thoroughly disappointed with SLS/DIRECT since the HEFT disaster, I, too, come back to the AJAX thread. I always thought EELV/AJAX were the way to go but accepted DIRECT as the politically feasible alternative that was still affordable. Since the HEFT study I've completely changed my tune and now believe that SLS will destroy NASA's HSF. All EELV is the way to go, with AJAX as an alternative to please the pro-HLV crowd.

AJAX is certainly impressive. I like it as much as I can like any HLV.

I am begining to think the same thing.
Title: Re: AJAX Launcher
Post by: simcosmos on 09/17/2010 06:56 pm
Interesting text / images Martin: regarding CFD, I could have a few questions that would like to do but do not know if / when will be able to make such questions.

For the moment, this (attachment) is what was possible to share  8)

… Before continuing, the disclaimer: please note that these 3D models are part of my archives of development / work-in-progress parts which were / are being created mostly with the eventual objective of being used as visual place-holders for performance implementations inside  Orbiter Space Flight Simulator and / or for other 'eye-candy' purposes (renders). This to say that although I always try to be the most accurate as possible in what regards generic dimensions, shapes, etc, people need to have 'in the back of the mind' that these models are not as detailed as they could in theory be (in order to optimize a little the performance on the simulated reality and also due to other constraints)... Just to give a few examples, sometimes details are transferred to textures, geometries are simplified, other details might not have been yet added, non-visible stuff isn't modelled (although for these specific images I have included a very dummy representation of the main tanks domes locations)...


Disclaimer made, a few extra notes:

- AtlasV LRB nose cone: as described on the previous participation I have implemented something closer to the shape used on Energia boosters (except recovery hardware), which was also basically the main nose shape for the conceptual mighty Vulkan too.

- As also written in the latest post, the core that have represented here is sized for a prop. amount of about 646t or so. The intertank has been shortened a bit (when comparing with STS ET case) EDIT1: this kind of shorter intertank could require a new design for the LO2 routing... probably should be of more length if not wishing to spend development resources on that part but, in order to not delay more the sharing of this image, I kept that shorter length for the current render /EDIT1; EDIT2: on another hand, the top LH2 dome should probably be located on a slightly lower position and the bottom LO2 dome on a slightly higher position than what I represented >> as mentioned above, I did not take much time with preciser render / location of internal components also because those 3D parts are deleted on the final 3D model (for simulation optimization); the information about tanks sizes is given by the external texture; if having extra time, I might try to do a better match between such external texture and the clumsy internal 3D render of the tanks, on an eventual next occasion /EDIT2


Ho, also added one or two 'extras' in the background (quick semi-transparent copy+paste of some older images from my flickr space): on a later moment might produce an image with a better display of multiple AtlasV CCB utilizations vs AJAX.

Hope that haven't made any major typo on key dimensions (will only be able to double-check on a later occasion). Until next time,

António
Title: Re: AJAX Launcher
Post by: orbitjunkie on 09/21/2010 03:15 am
Chuck, I think I may have just become more of an AJAX fan than a DIRECT fan (current political feasibility not withstanding). A recent post (http://forum.nasaspaceflight.com/index.php?topic=22381.msg636950#msg636950) by alexw highlighted how expensive the SRBs are. Not new information, but I've never seen it broken down that way before. Using that with another nice cost-summarizing post (http://forum.nasaspaceflight.com/index.php?topic=22122.msg619377#msg619377) of his, I come up with the following for booster costs only:
SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that
    To be fair, ATK costs are mostly fixed costs. The prices drop precipitously after that -- by my eye, 8 segments is $65 million/segment, 16 segments is ~$34 million/segment, 24 segments ~ $23 million/segment. Dig up Ross's curve...
Ah, that is a key fact that I didn't know! I will look for that curve. But, taking your word for it, it seems clear that AJAX definitely is the favorite for lower launch rates but the situation probably reverses for any flight rate that I would call "decent". There are a lot of variables here, but it certainly seems like there is a scenario in which AJAX would be the clear winner for all the reasons I mentioned earlier. However, the real trick is to determine if we are actually going to be in that scenario or another one...
Title: Re: AJAX Launcher
Post by: clongton on 09/21/2010 10:17 am
Chuck, I think I may have just become more of an AJAX fan than a DIRECT fan (current political feasibility not withstanding). A recent post (http://forum.nasaspaceflight.com/index.php?topic=22381.msg636950#msg636950) by alexw highlighted how expensive the SRBs are. Not new information, but I've never seen it broken down that way before. Using that with another nice cost-summarizing post (http://forum.nasaspaceflight.com/index.php?topic=22122.msg619377#msg619377) of his, I come up with the following for booster costs only:
SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that
    To be fair, ATK costs are mostly fixed costs. The prices drop precipitously after that -- by my eye, 8 segments is $65 million/segment, 16 segments is ~$34 million/segment, 24 segments ~ $23 million/segment. Dig up Ross's curve...
Ah, that is a key fact that I didn't know! I will look for that curve. But, taking your word for it, it seems clear that AJAX definitely is the favorite for lower launch rates but the situation probably reverses for any flight rate that I would call "decent". There are a lot of variables here, but it certainly seems like there is a scenario in which AJAX would be the clear winner for all the reasons I mentioned earlier. However, the real trick is to determine if we are actually going to be in that scenario or another one...

What I really like is the hard link between NASA's HLV and Commercial crew. Under DIRECT, or its SLS equivalent, nothing of the HLV system flies unless it is a NASA HLV flight. But under AJAX, every time there is a commercial crew flight of any kind using the Atlas CLV, to any destination, ISS, Bigelow, anywhere, then part of the HLV system is also flying; the Atlas-V CCB LRB. That helps to keep the cost of the HLV system down by it not being static. And every time the HLV flies, that's four(4) more Atlas-V CCB's being used. That increases the Atlas business by a considerable amount, driving the cost of the Atlas commercial CLV down even more. So the 2 complement each other, NASA's HLV and Commercial's CLV, each one contributing to lower the cost of the other.
Title: Re: AJAX Launcher
Post by: alexw on 09/21/2010 10:35 am
What I really like is the hard link between NASA's HLV and Commercial crew. Under DIRECT, or its SLS equivalent, nothing of the HLV system flies unless it is a NASA HLV flight. But under AJAX, every time there is a commercial crew flight of any kind using the Atlas CLV, to any destination, ISS, Bigelow, anywhere, then part of the HLV system is also flying; the Atlas-V CCB LRB. That helps to keep the cost of the HLV system down by it not being static. And every time the HLV flies, that's four(4) more Atlas-V CCB's being used. That increases the Atlas business by a considerable amount, driving the cost of the Atlas commercial CLV down even more. So the 2 complement each other, NASA's HLV and Commercial's CLV, each one contributing to lower the cost of the other.
        It also increases the market for the US to develop a large kerolox engine, any of several possibilities, which (depending) could be helpful for many scenarios or users: SpaceX, Atlas CCB using domestic, Atlas Phase II-ish, the next-gen DOD program being discussed, or AJAX.
    -Alex
Title: Re: AJAX Launcher
Post by: alexw on 09/21/2010 02:08 pm
Silly question, all: does anyone remember the performance of something like a J-150 without SRBs? It was discussed a long while back on the DIRECT threads, and maybe around the time AJAX was first considered.

Running simple guesses through Schilling's calculator suggests it makes an ISS 30x100nmi @ 52deg orbit, but the uncertainty is large.

I've tried searched the boards, but the search engine doesn't like short strings like "J-150".

Thanks,
   -Alex
Title: Re: AJAX Launcher
Post by: HappyMartian on 09/21/2010 02:48 pm
What I really like is the hard link between NASA's HLV and Commercial crew. Under DIRECT, or its SLS equivalent, nothing of the HLV system flies unless it is a NASA HLV flight. But under AJAX, every time there is a commercial crew flight of any kind using the Atlas CLV, to any destination, ISS, Bigelow, anywhere, then part of the HLV system is also flying; the Atlas-V CCB LRB. That helps to keep the cost of the HLV system down by it not being static. And every time the HLV flies, that's four(4) more Atlas-V CCB's being used. That increases the Atlas business by a considerable amount, driving the cost of the Atlas commercial CLV down even more. So the 2 complement each other, NASA's HLV and Commercial's CLV, each one contributing to lower the cost of the other.
        It also increases the market for the US to develop a large kerolox engine, any of several possibilities, which (depending) could be helpful for many scenarios or users: SpaceX, Atlas CCB using domestic, Atlas Phase II-ish, the next-gen DOD program being discussed, or AJAX.
    -Alex


Yep. It certainly does sound good. But when should we try selling it to the political powers that be? My WAG was in about ten years, but I am open to a much closer time frame... Hey! It should even make Jim pretty happy! With Jim supporting AJAX, it should be doable much sooner...

Cheers! 
Title: Re: AJAX Launcher
Post by: clongton on 09/21/2010 03:52 pm
What I really like is the hard link between NASA's HLV and Commercial crew. Under DIRECT, or its SLS equivalent, nothing of the HLV system flies unless it is a NASA HLV flight. But under AJAX, every time there is a commercial crew flight of any kind using the Atlas CLV, to any destination, ISS, Bigelow, anywhere, then part of the HLV system is also flying; the Atlas-V CCB LRB. That helps to keep the cost of the HLV system down by it not being static. And every time the HLV flies, that's four(4) more Atlas-V CCB's being used. That increases the Atlas business by a considerable amount, driving the cost of the Atlas commercial CLV down even more. So the 2 complement each other, NASA's HLV and Commercial's CLV, each one contributing to lower the cost of the other.
        It also increases the market for the US to develop a large kerolox engine, any of several possibilities, which (depending) could be helpful for many scenarios or users: SpaceX, Atlas CCB using domestic, Atlas Phase II-ish, the next-gen DOD program being discussed, or AJAX.
    -Alex


Yep. It certainly does sound good. But when should we try selling it to the political powers that be? My WAG was in about ten years, but I am open to a much closer time frame... Hey! It should even make Jim pretty happy! With Jim supporting AJAX, it should be doable much sooner...

Cheers! 

I would think ~10 years would be right. Let the environmentalists have some time to campaign against solids, let the Atlas-V CLV gain some experience, and then introduce a "X-Program" to see how Commercial Crew and NASA HLV might work together.
Title: Re: AJAX Launcher
Post by: orbitjunkie on 09/21/2010 05:05 pm
<snip> it seems clear that AJAX definitely is the favorite for lower launch rates but the situation probably reverses for any flight rate that I would call "decent". There are a lot of variables here, but it certainly seems like there is a scenario in which AJAX would be the clear winner for all the reasons I mentioned earlier. However, the real trick is to determine if we are actually going to be in that scenario or another one...

<snip>And every time the HLV flies, that's four(4) more Atlas-V CCB's being used. That increases the Atlas business by a considerable amount, driving the cost of the Atlas commercial CLV down even more. <snip>

Yes, that is certainly a great possibility which would have many benefits outside of considering HLV costs in isolation. And those could sway the decision makers. However - I've looked but still not found that graph - it does seems obvious that even high volume purchases of Atlas cores is probably not likely to get below the cost of SRBs at, maybe 4+ HLV flights per year. What we'd need to do is find the graph of Atlas cores $/unit vs # of units and see where those graphs intersect. And does such a graph exist with any level of credibility? Has ULA stated you get a volume discount for Atlas buys? Or just that above some production rate they need new facilities?

Assuming some kind of SD-HLV actually continues, 10 years sounds like a reasonable time frame for a potential synergy. But if one HLV is almost ready to go, I don't forsee a lot of willingness to pay for redeveloping it right away - unless the synergy somehow creates really substantial total cost savings to NASA (enough to pay for redevelopment) or it's just mandated from above.

Has anybody thought how much it would cost to modfiy KSC AJAX? And how much, if any, an operational AJAX system would save for those kinds of assembly/integration/pad costs over the current solid system? I know that "solids have tons of issues" but how about quantifying them in $?
Title: Re: AJAX Launcher
Post by: luke strawwalker on 09/21/2010 05:12 pm
Chuck, I think I may have just become more of an AJAX fan than a DIRECT fan (current political feasibility not withstanding). A recent post (http://forum.nasaspaceflight.com/index.php?topic=22381.msg636950#msg636950) by alexw highlighted how expensive the SRBs are. Not new information, but I've never seen it broken down that way before. Using that with another nice cost-summarizing post (http://forum.nasaspaceflight.com/index.php?topic=22122.msg619377#msg619377) of his, I come up with the following for booster costs only:
SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that
 
Being thoroughly disappointed with SLS/DIRECT since the HEFT disaster, I, too, come back to the AJAX thread. I always thought EELV/AJAX were the way to go but accepted DIRECT as the politically feasible alternative that was still affordable. Since the HEFT study I've completely changed my tune and now believe that SLS will destroy NASA's HSF. All EELV is the way to go, with AJAX as an alternative to please the pro-HLV crowd.

AJAX is certainly impressive. I like it as much as I can like any HLV.

I am begining to think the same thing.

Yeah, me too...

NASA has GOT to find more inventive ways to conduct missions or there will be NO BEO HSF.  AJAX really shows the way in this respect...

LateR!  OL JR :)
Title: Re: AJAX Launcher
Post by: Robotbeat on 09/22/2010 12:22 am
<snip> it seems clear that AJAX definitely is the favorite for lower launch rates but the situation probably reverses for any flight rate that I would call "decent". There are a lot of variables here, but it certainly seems like there is a scenario in which AJAX would be the clear winner for all the reasons I mentioned earlier. However, the real trick is to determine if we are actually going to be in that scenario or another one...

<snip>And every time the HLV flies, that's four(4) more Atlas-V CCB's being used. That increases the Atlas business by a considerable amount, driving the cost of the Atlas commercial CLV down even more. <snip>

Yes, that is certainly a great possibility which would have many benefits outside of considering HLV costs in isolation. And those could sway the decision makers. However - I've looked but still not found that graph - it does seems obvious that even high volume purchases of Atlas cores is probably not likely to get below the cost of SRBs at, maybe 4+ HLV flights per year. What we'd need to do is find the graph of Atlas cores $/unit vs # of units and see where those graphs intersect. And does such a graph exist with any level of credibility? Has ULA stated you get a volume discount for Atlas buys? Or just that above some production rate they need new facilities?

Assuming some kind of SD-HLV actually continues, 10 years sounds like a reasonable time frame for a potential synergy. But if one HLV is almost ready to go, I don't forsee a lot of willingness to pay for redeveloping it right away - unless the synergy somehow creates really substantial total cost savings to NASA (enough to pay for redevelopment) or it's just mandated from above.

Has anybody thought how much it would cost to modfiy KSC AJAX? And how much, if any, an operational AJAX system would save for those kinds of assembly/integration/pad costs over the current solid system? I know that "solids have tons of issues" but how about quantifying them in $?
A solid is roughly $80-100 million each, right? I heard Atlas V CCBs cost roughly $30-50 million, right? So, they're about even right now.

Solids aren't cheap. Even just to restack them is expensive since they're so darned heavy (and you have to be really careful with them).
Title: Re: AJAX Launcher
Post by: orbitjunkie on 09/22/2010 03:12 pm
A solid is roughly $80-100 million each, right? I heard Atlas V CCBs cost roughly $30-50 million, right? So, they're about even right now.

Solids aren't cheap. Even just to restack them is expensive since they're so darned heavy (and you have to be really careful with them).

Just at the top of this page I was discussing Ross' SRB cost curve that alexw reminded us of. Read back a few posts. The argument is that almost all of the SRB costs are fixed, not variable; whereas probably all of the Atlas costs to NASA are variable.

But the processing difficulty and expense of SRB vs AtlasV cores is a discussion I haven't seen many details on.
Title: Re: AJAX Launcher
Post by: alexw on 09/23/2010 10:38 am
Silly question, all: does anyone remember the performance of something like a J-150 without SRBs? It was discussed a long while back on the DIRECT threads, and maybe around the time AJAX was first considered.

Running simple guesses through Schilling's calculator suggests it makes an ISS 30x100nmi @ 52deg orbit, but the uncertainty is large.

I've tried searched the boards, but the search engine doesn't like short strings like "J-150".

Thanks,
   -Alex
  Anyone?  Schilling's calc. gives me anything from 10-40mT performance; wasn't this fellow discussed a while back, or could someone point to a better tool for simulations? I've got an idea, which might be relevent to AJAX.

 Thanks,
   -Alex
Title: Re: AJAX Launcher
Post by: sdsds on 09/23/2010 11:36 am
the performance of something like a J-150 without SRBs? [...]
Running simple guesses through Schilling's calculator suggests it makes an ISS 30x100nmi @ 52deg orbit, but the uncertainty is large.

  Anyone? 


What assumptions are you using?  Hypothetically if you had a core that was 70 t dry and carried 750 t of propellant, using 1% for residuals and FPR yields a spent core mass of 77.5 t.  With an 8 t payload and 5 SSME at 109%, the initial T/W is 1.15 and there's sufficient delta-v to reach orbit.  More payload than that and the initial T/W drops below 1.15.

Your mileage may vary.
Title: Re: AJAX Launcher
Post by: MP99 on 09/23/2010 12:19 pm
Silly question, all: does anyone remember the performance of something like a J-150 without SRBs? It was discussed a long while back on the DIRECT threads, and maybe around the time AJAX was first considered.

Running simple guesses through Schilling's calculator suggests it makes an ISS 30x100nmi @ 52deg orbit, but the uncertainty is large.

I've tried searched the boards, but the search engine doesn't like short strings like "J-150".

Thanks,
   -Alex
  Anyone?  Schilling's calc. gives me anything from 10-40mT performance; wasn't this fellow discussed a while back, or could someone point to a better tool for simulations? I've got an idea, which might be relevent to AJAX.

 Thanks,
   -Alex

It's OK, apparently, but the results are utterly meaningless for a perigee below 100nmi (EG Jupiter still reaches orbit if you replace 3xSSME with 1xRL-10 !!!!). There's a warning on the screen, but frankly it should just refuse to calculate.

cheers, Martin
Title: Re: AJAX Launcher
Post by: EE Scott on 09/24/2010 01:11 am
A solid is roughly $80-100 million each, right? I heard Atlas V CCBs cost roughly $30-50 million, right? So, they're about even right now.

Solids aren't cheap. Even just to restack them is expensive since they're so darned heavy (and you have to be really careful with them).

Just at the top of this page I was discussing Ross' SRB cost curve that alexw reminded us of. Read back a few posts. The argument is that almost all of the SRB costs are fixed, not variable; whereas probably all of the Atlas costs to NASA are variable.

But the processing difficulty and expense of SRB vs AtlasV cores is a discussion I haven't seen many details on.

This fact recommends AJAX, since c'mon guys, are we really going to see more than 2 - 4 missions per year?  Some years we may just be lucky to get one mission launched, due to funding or mission opportunities, etc.





Title: Re: AJAX Launcher
Post by: martin hegedus on 09/28/2010 06:37 pm
Interesting text / images Martin: regarding CFD, I could have a few questions that would like to do but do not know if / when will be able to make such questions.

For the moment, this (attachment) is what was possible to share  8)

...

António

Thanks for the dimensions.  Long story short, it turns out my code is not up to the multiple geometries for this case.  So I'm working on it and we'll see where it goes.  But the road is long.

Some thoughts.  There are, at least, three points of interest along a trajectory, max Q, max heating rate, and max heating load.  The point where max heating rate/load occurs during a trajectory is the uncertain one to determine.  But, I'm not a thermodynamicist.  One camp uses density*V*V*V.  Another camp will use the heating on a unit sphere.  It may be important to insure that the CCBs on the AJAX see the same thermal environment as the Atlas at these trajectory points, otherwise modifications may need to be done.  And I gather modifications are out.

Another concern, as always, is base heating.  One key point is to minimize the recirculation of air.  Of course, that is extremely hard to determine analytically.  (BTW, I find the base of Jupiter very interesting.  My belief is that, at supersonic speeds, there is going to be separation at the junction of the body and boat tail.  This recirculation region will extend all the way down to the nozzles and bring up hot gases.  Needless to say, I believe the entire end will cook.  But, from what I gather, the base heating issue was looked at, so I don't know what's up there.)

Take care,
Martin
Title: Re: AJAX Launcher
Post by: Downix on 09/29/2010 03:00 pm
Interesting text / images Martin: regarding CFD, I could have a few questions that would like to do but do not know if / when will be able to make such questions.

For the moment, this (attachment) is what was possible to share  8)

...

António

Thanks for the dimensions.  Long story short, it turns out my code is not up to the multiple geometries for this case.  So I'm working on it and we'll see where it goes.  But the road is long.

Some thoughts.  There are, at least, three points of interest along a trajectory, max Q, max heating rate, and max heating load.  The point where max heating rate/load occurs during a trajectory is the uncertain one to determine.  But, I'm not a thermodynamicist.  One camp uses density*V*V*V.  Another camp will use the heating on a unit sphere.  It may be important to insure that the CCBs on the AJAX see the same thermal environment as the Atlas at these trajectory points, otherwise modifications may need to be done.  And I gather modifications are out.

Another concern, as always, is base heating.  One key point is to minimize the recirculation of air.  Of course, that is extremely hard to determine analytically.  (BTW, I find the base of Jupiter very interesting.  My belief is that, at supersonic speeds, there is going to be separation at the junction of the body and boat tail.  This recirculation region will extend all the way down to the nozzles and bring up hot gases.  Needless to say, I believe the entire end will cook.  But, from what I gather, the base heating issue was looked at, so I don't know what's up there.)

Take care,
Martin

Base Heating is not going to be much of an issue here.  All engines are regen to begin with, and the time it will take for the base to heat up is not enough.  Remember, the boosters are attached only until their fuel is burned up, during which time the core engines are not running at max. And none of the engines pumps out the BTU's of the SRB's either.

If there is a heat issue on the Atlas itself, either at the top connector or the base, and I am perfectly willing to test and see if there would be, this can be addressed thankfully with thermal wrap.  It would look a bit silly, putting a "rocket-sock" on the bottom of the CCB's, but I don't see a deal breaker there.  As all of the engines used in this are more than capable of handling the heat, the only heat issue would be for the CCBs themselves, so no repeat of the Ares V base heating problem, where the engines were the failpoints.
Title: Re: AJAX Launcher
Post by: martin hegedus on 09/29/2010 04:09 pm

Base Heating is not going to be much of an issue here.  All engines are regen to begin with, and the time it will take for the base to heat up is not enough.  Remember, the boosters are attached only until their fuel is burned up, during which time the core engines are not running at max. And none of the engines pumps out the BTU's of the SRB's either.

If there is a heat issue on the Atlas itself, either at the top connector or the base, and I am perfectly willing to test and see if there would be, this can be addressed thankfully with thermal wrap.  It would look a bit silly, putting a "rocket-sock" on the bottom of the CCB's, but I don't see a deal breaker there.  As all of the engines used in this are more than capable of handling the heat, the only heat issue would be for the CCBs themselves, so no repeat of the Ares V base heating problem, where the engines were the failpoints.

Of the three types of heat transfer possibilities (Conduction, Convection, and Radiation) are you referring to radiation?  My point was the recirculation of air, i.e. convection.  I'm not an expert in regards to the ins and outs of rocket engines, rocket plumes, and thermodynamics.  So what follows is basically a summary of what I know in regards to recirculation and base heating.  Rocket engines are non ideal so the sides of the plumes are subsonic and turbulent and this provides the opening for heat within the plume to transfer to the surrounding air.  When there is a separation point ahead of the plume there is the possibility for air to recirculate, i.e. the air actually travels up the side of the plume and gathers heat along the way.  This heat is then transferred to the rocket.  Some of this is quite wild.  There are cases were the separation point occurs on the side of the rocket, well ahead of the base, and the heat from the plume wraps around the base and is pulled up onto the side of the rocket, all the way up to the separation point.  As far as I know, care must be taken to minimize the possibilities of this, or at least, account for it.

For example, take Jupiter.  Just because the end of the main tank (the boat tail portion) has been streamlined and the base area has been minimized does not mean that base heating has been mitigated.  Unfortunately, the boat tail portion could become the base.

So, I guess my question is, is the heat within the plume (after exit from the rocket engine bell) for a regen engine much different than a non-regen engine?  I thought regenerative cooling just kept the rocket engine bell cool.  Granted it cools the plume boundary layer too, but I would assume that the boundary layer is turbulent so it should pick up heat from the inner flow quickly.  And the engine is generally not running at it's design point so the plume either expands out when it exits, or there will be a shock within the nozzle, or etc., so this adds to the mess which probably helps transfer heat within the plume to the surrounding air and thus allows it to be convected up to the rocket.
Title: Re: AJAX Launcher
Post by: martin hegedus on 09/29/2010 05:04 pm
Here is an interesting question(s), at least in my opinion.  How much does throttling the engine back affect the convection portion of base heating?  How much does throttling back the engine affect the temperature of the plume?  Granted, the density, pressure, and total amount of energy stored changes.  The plume will cool quicker.  And, of course, the recirculation region will be cooler.  But, lets assume one throttles back on the order of 30%, is it significantly cooler?
Title: Re: AJAX Launcher
Post by: Downix on 09/30/2010 02:48 am
Here is an interesting question(s), at least in my opinion.  How much does throttling the engine back affect the convection portion of base heating?  How much does throttling back the engine affect the temperature of the plume?  Granted, the density, pressure, and total amount of energy stored changes.  The plume will cool quicker.  And, of course, the recirculation region will be cooler.  But, lets assume one throttles back on the order of 30%, is it significantly cooler?

Heat is from energy expended, so if the engines are throttled back, less energy generated, hence, less heat produced.

And Convection is less of an issue as there are new gasses being introduced into the area, and existing gasses being taken away by the thrust.  AJAX, like Jupiter, does not have a large, flat, base surrounded by engines, creating a kind of gas-trap, which leads to convection activity.  Simply put, there will not be enough gasses by the time the pressure could build to create a convection motion.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 09/30/2010 05:13 am
SLS was offically passed today under the house vote. Thats great news. Would really like to continue work on the AJAX vehicle as its certainly an evolution/alternative option for the future (or for if ATK was to fail).

Title: Re: AJAX Launcher
Post by: Downix on 09/30/2010 05:21 am
SLS was offically passed today under the house vote. Thats great news. Would really like to continue work on the AJAX vehicle as its certainly an evolution/alternative option for the future (or for if ATK was to fail).


Indeed, altho now the pressure to rush it is not there now.  Still, I see a serious advantage in the long term, so as the SLS comes together AJAX will be adjusted accordingly, to be a future evolutionary path.  The solids will eventually fade, and I want AJAX there when the political pressure increases to the point that it is the time to strike.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 09/30/2010 05:28 am
SLS was offically passed today under the house vote. Thats great news. Would really like to continue work on the AJAX vehicle as its certainly an evolution/alternative option for the future (or for if ATK was to fail).


Indeed, altho now the pressure to rush it is not there now.  Still, I see a serious advantage in the long term, so as the SLS comes together AJAX will be adjusted accordingly, to be a future evolutionary path.  The solids will eventually fade, and I want AJAX there when the political pressure increases to the point that it is the time to strike.
My thoughts exactly. Are we still planning to use AV boosters?
Title: Re: AJAX Launcher
Post by: Downix on 09/30/2010 05:32 am
SLS was offically passed today under the house vote. Thats great news. Would really like to continue work on the AJAX vehicle as its certainly an evolution/alternative option for the future (or for if ATK was to fail).


Indeed, altho now the pressure to rush it is not there now.  Still, I see a serious advantage in the long term, so as the SLS comes together AJAX will be adjusted accordingly, to be a future evolutionary path.  The solids will eventually fade, and I want AJAX there when the political pressure increases to the point that it is the time to strike.
My thoughts exactly. Are we still planning to use AV boosters?
The Synergy is too good, especially with the bill passed.  Atlas V is getting the last bits for man-rating under the private launch sections of the bill, so that eliminates that worry.  So, the bill actually made our jobs here easier.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 09/30/2010 05:35 am
SLS was offically passed today under the house vote. Thats great news. Would really like to continue work on the AJAX vehicle as its certainly an evolution/alternative option for the future (or for if ATK was to fail).


Indeed, altho now the pressure to rush it is not there now.  Still, I see a serious advantage in the long term, so as the SLS comes together AJAX will be adjusted accordingly, to be a future evolutionary path.  The solids will eventually fade, and I want AJAX there when the political pressure increases to the point that it is the time to strike.
My thoughts exactly. Are we still planning to use AV boosters?
The Synergy is too good, especially with the bill passed.  Atlas V is getting the last bits for man-rating under the private launch sections of the bill, so that eliminates that worry.  So, the bill actually made our jobs here easier.
Awesome :D A double win :D :D
Title: Re: AJAX Launcher
Post by: aquanaut99 on 09/30/2010 06:06 am

Awesome :D A double win :D :D

Great! I still don't like SLS/DIRECT, for reasons I've made clear often enough (I'm more pro-EELV; not necessarily ant-HLV, but the HEFT study made me doubt SLS). I do appreciate the effort hard work and dedication of the DIRECT team, though, and have a huge respect for the people there.

I really like AJAX. Very much. And now it just got better. SLS will now get started, some infrastructure and knowledge will be preseved (for good or ill) and commercial does get more money. If a future Congress/administration/NASA leadership decides to cancel SRBs for environmental or economic reasons, we have a solution ready in the form of the AJAX.

Keep up the good work!
Title: Re: AJAX Launcher
Post by: clongton on 09/30/2010 12:20 pm
The win for DIRECT/SLS is a win for AJAX! :)
Title: Re: AJAX Launcher
Post by: orbitjunkie on 09/30/2010 02:17 pm
I would be excited to see SLS fly with SRBs for many years! However, I agree the AJAX concept has some distinct advantages and there may come a time when it is just what's needed. Perhaps even sooner than we think, if it can be shown to have serious cost advantages over an SRB solution. So I'd be in favor of continuing to work on and evolve the concept. Besides, let's not kid ourselves, this is fun stuff for space nerds like us!

I also think it would a wise move to use the SLS core as the starting point for the AJAX core, as soon as we start seeing some details about it emerge. Even if there's not much technical difference or if the magnitude of redesign effort is not really any different, just using the appropriate name would be a valuable step and send the right message. Same goes for other details about everything that comes out of SLS.
Title: Re: AJAX Launcher
Post by: martin hegedus on 09/30/2010 06:07 pm
In this case there are two meanings for base. There is the geometrical base, and, in the case of Jupiter, this area is small since the boat tail has tapered down the cross sectional area.  Then there is the aerodynamic base, and that is more uncertain in the case of boat tails.  It is a function of boat tail angle, Reynolds number, and Mach number.  There is information in literature in regards to boat tails and projectiles.

For subsonic flow, I will quote Hoerner's Fluid Dynamic Drag bible.  (BTW, to an extent, it applies to transonic and supersonic flows.  However, the physics of transonic/supersonic flows which promote flow separation and recirculation are different than subsonic aero)

On page 3-20 "Effect of Boat-Tailing. ... , the effect of "boat-tailing" the rear end of projectiles, depends upon the boundary-layer thickness and the employed shape of taper.  By means of a boat tail, moderate in size (d_b/d=0.9) and in angle of taper (in the order of 5 degrees as against axis) it is possible somewhat to reduce the drag of projectiles.  Reference (46,b) shows in such a case a reduction in the order of delta CD0=-0.07.  For larger taper angles, or in cases where drag and boundary-layer thickness of the forebody are much larger, rather the maximum cross section area of the body must be considered as "base" and the base drag be determined for the corresponding CfB value (based upon the larger area)."  (I emphasized maximum)

In the case of Jupiter, the angle of taper of the boat tail is about 22 degrees.  For subsonic speeds it is probable that the majority of the boat-tail sees separated flow.  The separated flow is the gas bucket.

What about supersonic flow?  With supersonic flow the increase of pressure which induces separation comes from the end of the boat tail when the flow must turn by means of a shock.  The unknown is how far up the boat tail this separation point travels.  This is a function of Mach number, and, unfortunately from an analysis perspective, the plumes.  The plumes force the flow to turn more thus the shocks increase in strength and the flow backs up more.  In fact, if AJAX has a rear end similar to Jupiter, shocks will probably exist between the CCB plumes and main rocket engine plumes.  If these shocks cause the flow to go subsonic (i.e. localized choking) one should anticipate a good sized gas bucket and flow issues.

Can this be analyzed with CFD?  With a RANS solver, successfully predicting separation from the boat tail (without plumes) of an axisymmetricish body can be a challenging task and does require experience.  And, assuming you get a separation point, it may not be in the correct location.  As for predicting flows with plumes, that's difficult because of the need to model the plume.  And the fact that plume shape is sensitive to altitude adds to the challenge.

As a side, I Googled images of Ariane V for night launches.  Couldn't find a good shot that would tell me if recirculation at the base is an issue and if hot gases made their way up or not.
Title: Re: AJAX Launcher
Post by: simcosmos on 09/30/2010 10:49 pm
( . . . )

As a side, I Googled images of Ariane V for night launches.  Couldn't find a good shot that would tell me if recirculation at the base is an issue and if hot gases made their way up or not.


Martin, I'm a bit out of my 'area' but have a pdf on the archives (stuff that hunt and download from Internet for bedtime reading :) ) which might be relevant, at least in part, for what you seek (?). In any case, here goes the original download link:

FLUID STRUCTURE INTERACTION AT THE ARIANE-5 NOZZLE SECTION BY ADVANCED TURBULENCE MODELS
http://proceedings.fyper.com/eccomascfd2006/documents/106.pdf
( http://proceedings.fyper.com/eccomascfd2006/ )
 


About the future of AJAX brainstorm:

I would be excited to see SLS fly with SRBs for many years! However, I agree the AJAX concept has some distinct advantages and there may come a time when it is just what's needed. Perhaps even sooner than we think, if it can be shown to have serious cost advantages over an SRB solution. So I'd be in favor of continuing to work on and evolve the concept. Besides, let's not kid ourselves, this is fun stuff for space nerds like us!

I also think it would a wise move to use the SLS core as the starting point for the AJAX core, as soon as we start seeing some details about it emerge. Even if there's not much technical difference or if the magnitude of redesign effort is not really any different, just using the appropriate name would be a valuable step and send the right message. Same goes for other details about everything that comes out of SLS.


As sometimes discussed in previous posts (in this or other related threads, for example here (http://forum.nasaspaceflight.com/index.php?topic=22266.msg627873#msg627873)), if 'AJAX' designation evolves to mean a liquid booster configuration for the core to be used on SLS  (which, unless something significantly changes(!), will probably use a pair of 4 seg. or 5 seg. SRB) then, depending also of the specific path forward regarding such SLS core properties (STS ET load or stretched core, assuming that it will be an inline configuration if not wishing to complicate the brainstorm) it might be necessary for 'AJAX' to assume a completely new liquid booster design effort (instead of utilization of existing liquid boosters) as well it might be necessary to loose some modularity (in terms of minimum payload ranges).

What I have just written is much more evident if NASA choice is to go for the 'maximum' approach of  a  stretched core (with prop. load from 950t up to ~1000t and 4 to 5 SSME) + pair of 5 seg. SRB... (although I have some reserves regarding if going much beyond the STS ET load + 4 seg. SRB for SLS will be something 'feasible'... unless the proper money is made available to support all the implications of that choice).

What I want to write (and again, as also wrote in past occasions) is that depending of what 'AJAX' designation means in more generic terms, what is being discussed 'today' as being 'AJAX' (sdsds suggested (http://forum.nasaspaceflight.com/index.php?topic=22266.msg627971#msg627971) to call the current brainstorm as AJAX 1.0)  might mean something a bit different depending if the wish is or not to adapt to whatever ends up by being 'SLS' core properties (for an eventual AJAX 2.0 musing).

Only remembering about this again because of the step taken yesterday (http://forum.nasaspaceflight.com/index.php?topic=22850.0) and which starts to place NASA a 'little' closer to the SLS reality than when some of the past posts were written (preciser details about SLS will still take time to 'emerge', just doings an heads-up if wishing to think on what could AJAX 2.0 brainstorm constraints be vs the most plausible outcomes for NASA's HLV core / SRB properties vs conceptual liquid boosters design properties vs HLV application and other 'stand-alone' applications of such boosters ... but that would require a new thread).

António
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/01/2010 12:16 am


FLUID STRUCTURE INTERACTION AT THE ARIANE-5 NOZZLE SECTION BY ADVANCED TURBULENCE MODELS
http://proceedings.fyper.com/eccomascfd2006/documents/106.pdf
( http://proceedings.fyper.com/eccomascfd2006/ )
 

António

LOL, AWESOME!  Thanks António.

For those interested, check it out.  Totally beautiful.  From the figures one can get an idea of what the flow at the back end of a rocket is like.  What a mess.  From Figure 1 you see the low Mach number "gas bucket" (The blue region).  One can also get an idea of how the plumes block the flow.  And keep in mind that this is "only" supercritical flow.  It is not full supersonic.  (The authors probably picked this transonic Mach number since this is typically one of the areas where buffet occurs)

In Figure 9 it can been seen how the stream lines separate from the back end of the body (i.e. the junction of the constant radius body and the cylindrical conical "boat tail" segment (the slope is so steep I wouldn't really call it a boat tail, but I'm at a loss for words)).  Notice how some of the stream lines then reattach themselves to the nozzle and travel back up.  There is nothing that says under different freestream conditions that the stream lines can not reattach on the plume and then travel up.

Also, assuming I understand this correctly, the pressure within the center plume is lower than freestream.  I guess this analysis was done at a lower altitude, as Mach=0.8 would suggest.  And it does look like the stream lines running down the center plume are coming together.  As the rocket goes up in altitude the center plume seen in Figure 9 will expand out, thus obstructing more flow.  Also, I think it looks as if the flow within the center nozzle has separated within the bell.  That would make sense.  However that is hard to tell.

Personally, after seeing this, I believe the Ariane V is a candidate for pulling up hot gases at supersonic speeds and higher altitudes.

I am not saying that I think heating is a show stopper with AJAX.  It just needs to be analyzed and then accounted for in TPS, structures, etc. and, of course, a mass margin needs to be attached to it.  HOWEVER, if buffet is an issue with AJAX, that is a major problem.

Again, thanks António.
Title: Re: AJAX Launcher
Post by: Downix on 10/01/2010 06:07 pm
Antonio is right, that if the SLS becomes the stretched-tank, then we will have to re-evaluate into an AJAX 2.0, considering such things as Delta boosters, new boosters, etc.  However, if it remains the same-size tank, then the modifications to reduce the fuel-size is still more than viable, so we are good.

Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/04/2010 03:42 am
Antonio is right, that if the SLS becomes the stretched-tank, then we will have to re-evaluate into an AJAX 2.0, considering such things as Delta boosters, new boosters, etc.  However, if it remains the same-size tank, then the modifications to reduce the fuel-size is still more than viable, so we are good.


I don't think it will become stretched although I second what you said in the event that it did. In the mean time it is of interest to know where we are at. What did we decide for the fuel level issue? Is the baseline still 4 CCBS? How quickly could we introduce the first AJAX rocket config if need be? These are questions that still need to be answered. The fuel issue doesn't seem like a show stopper at all and I believe that we may already have solutions for it.
Title: Re: AJAX Launcher
Post by: Downix on 10/04/2010 05:20 am
Antonio is right, that if the SLS becomes the stretched-tank, then we will have to re-evaluate into an AJAX 2.0, considering such things as Delta boosters, new boosters, etc.  However, if it remains the same-size tank, then the modifications to reduce the fuel-size is still more than viable, so we are good.


I don't think it will become stretched although I second what you said in the event that it did. In the mean time it is of interest to know where we are at. What did we decide for the fuel level issue? Is the baseline still 4 CCBS? How quickly could we introduce the first AJAX rocket config if need be? These are questions that still need to be answered. The fuel issue doesn't seem like a show stopper at all and I believe that we may already have solutions for it.
So long as we keep in mind the changes that they're doing to the ET for the SLS, it should not be a dramatic time difference.  I've kept it as close to DIRECT as I could, keeping in mind the differences, so as to keep the time to shift down.

From all studies, the slightly shorter core is proving to be the best overall design, from both a T/W and performance standing.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/04/2010 05:39 am
Antonio is right, that if the SLS becomes the stretched-tank, then we will have to re-evaluate into an AJAX 2.0, considering such things as Delta boosters, new boosters, etc.  However, if it remains the same-size tank, then the modifications to reduce the fuel-size is still more than viable, so we are good.


I don't think it will become stretched although I second what you said in the event that it did. In the mean time it is of interest to know where we are at. What did we decide for the fuel level issue? Is the baseline still 4 CCBS? How quickly could we introduce the first AJAX rocket config if need be? These are questions that still need to be answered. The fuel issue doesn't seem like a show stopper at all and I believe that we may already have solutions for it.
So long as we keep in mind the changes that they're doing to the ET for the SLS, it should not be a dramatic time difference.  I've kept it as close to DIRECT as I could, keeping in mind the differences, so as to keep the time to shift down.

From all studies, the slightly shorter core is proving to be the best overall design, from both a T/W and performance standing.

Greatly appreciate all the work and glad to know that the shortened core will work best, this solves our fuel issues!
Title: Re: AJAX Launcher
Post by: alexw on 10/13/2010 05:47 am
I'm making a big plot of all the launch vehicle options for the polls:
http://forum.nasaspaceflight.com/index.php?topic=22993.msg647766#msg647766

If someone could re-summarize all the known LEO performance figures for the whole AJAX performance range, I could better present them on the plot. 3/4/5 SSME + 2/4/6 CCB, or whatever's at hand? Also, are such figures with or without the extra 10% performance reserve (to compare apples to apples)?
  -Alex
Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/13/2010 05:57 am
The current preferred option for AJAX to my knowledge was: Shortened length same diameter(as SLS/STS) core, 3-4 SSME (not sure if we decided on that though 3 seems more logical given the core change), 4 Atlas CCB (as is no engine upgrades).

If its not on this thread you should check the previous All liquid SDHLV options thread. Should be somewhere in the heavy lift section.
Title: Re: AJAX Launcher
Post by: Downix on 10/13/2010 09:34 pm
The current preferred option for AJAX to my knowledge was: Shortened length same diameter(as SLS/STS) core, 3-4 SSME (not sure if we decided on that though 3 seems more logical given the core change), 4 Atlas CCB (as is no engine upgrades).

If its not on this thread you should check the previous All liquid SDHLV options thread. Should be somewhere in the heavy lift section.
Actually we settled on 4 SSME.  The reasons were:
1) we needed the thrust on liftoff
2) cut-out capability, can loose an engine after 12 seconds and still make it to orbit.
Title: Re: AJAX Launcher
Post by: alexw on 10/13/2010 10:50 pm
Are these (Chuck, early July) (http://forum.nasaspaceflight.com/index.php?topic=22122.msg616465#msg616465) performance figures for AJAX-440/460/480 the most recent results?
   -Alex
Title: Re: AJAX Launcher
Post by: Downix on 10/14/2010 03:02 am
Are these (Chuck, early July) (http://forum.nasaspaceflight.com/index.php?topic=22122.msg616465#msg616465) performance figures for AJAX-440/460/480 the most recent results?
   -Alex
No, those are with the Jupiter ET, not the adjusted core. 

http://forum.nasaspaceflight.com/index.php?topic=22266.msg620300#msg620300
here's the adjusted core.

But here we go:
420: 47mT
440: 71mT
460: 92mT
480: 109mT
Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/14/2010 04:13 pm
The current preferred option for AJAX to my knowledge was: Shortened length same diameter(as SLS/STS) core, 3-4 SSME (not sure if we decided on that though 3 seems more logical given the core change), 4 Atlas CCB (as is no engine upgrades).

If its not on this thread you should check the previous All liquid SDHLV options thread. Should be somewhere in the heavy lift section.
Actually we settled on 4 SSME.  The reasons were:
1) we needed the thrust on liftoff
2) cut-out capability, can loose an engine after 12 seconds and still make it to orbit.
Alright glad to hear it :) Sorry I forgot about that change. Been incredibly busy lately.
Title: Re: AJAX Launcher
Post by: orbitjunkie on 10/14/2010 08:01 pm
420: 47mT
440: 71mT
460: 92mT
480: 109mT

These are all WITHOUT an upper stage, right? That's some pretty hot performance! Has anyone plugged in the numbers with some candidate upper stages? Man, what could this do with a JUS on top of it?
Title: Re: AJAX Launcher
Post by: clongton on 10/14/2010 08:39 pm
For starters it would have *NO* trouble getting us to the moon. :)
Title: Re: AJAX Launcher
Post by: Downix on 10/14/2010 09:00 pm
420: 47mT
440: 71mT
460: 92mT
480: 109mT

These are all WITHOUT an upper stage, right? That's some pretty hot performance! Has anyone plugged in the numbers with some candidate upper stages? Man, what could this do with a JUS on top of it?
With a JUS (RL-10-B2 version) I got over 150mT.  Ares V territory.  The T/W on liftoff tho dropped however.
Title: Re: AJAX Launcher
Post by: Lars_J on 10/14/2010 09:03 pm
Without adding a core engine, won't the upper stage mass mostly subtract from the existing payload capability?
Title: Re: AJAX Launcher
Post by: Downix on 10/14/2010 09:44 pm
Without adding a core engine, won't the upper stage mass mostly subtract from the existing payload capability?
Only if it is an EDS, and is orbited only by the first stage + boosters.  If, instead, it is an US, and does the orbital insertion itself, then no.

Incidentally, I did do the math on a 586 (5 core engine + 8 CCB + 6 RL-10-B2 JUS) and it lost performance, the same a the engine added to the core weight.  The worry then was T/W, but with the 8 CCB, it still kept it going in the right direction.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/15/2010 02:43 am
Since there is renewed interest I just wanted to go ahead and post these in this thread. Seems like they never were posted here, just in the AJAX thread's predecessor:

The vehicle:

Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/15/2010 02:46 am
Without adding a core engine, won't the upper stage mass mostly subtract from the existing payload capability?
Only if it is an EDS, and is orbited only by the first stage + boosters.  If, instead, it is an US, and does the orbital insertion itself, then no.

Incidentally, I did do the math on a 586 (5 core engine + 8 CCB + 6 RL-10-B2 JUS) and it lost performance, the same a the engine added to the core weight.  The worry then was T/W, but with the 8 CCB, it still kept it going in the right direction.
How well would it fly? Any idea on the MT? Would really like to discuss some of the configurations for this vehicle in more detail, especial now that SLS passed. Lets see how much is possible with this design :)
BTW thanks Downix for the MT numbers from earlier :D
Title: Re: AJAX Launcher
Post by: Downix on 10/15/2010 04:31 am
Without adding a core engine, won't the upper stage mass mostly subtract from the existing payload capability?
Only if it is an EDS, and is orbited only by the first stage + boosters.  If, instead, it is an US, and does the orbital insertion itself, then no.

Incidentally, I did do the math on a 586 (5 core engine + 8 CCB + 6 RL-10-B2 JUS) and it lost performance, the same a the engine added to the core weight.  The worry then was T/W, but with the 8 CCB, it still kept it going in the right direction.
How well would it fly? Any idea on the MT? Would really like to discuss some of the configurations for this vehicle in more detail, especial now that SLS passed. Lets see how much is possible with this design :)
BTW thanks Downix for the MT numbers from earlier :D
A 486 would be weak on T/W, about 1.1.  The 586 would boost that to 1.4, still a hair under the 1.5.
486 - 152mT
586 - 144mT

And this is with a JUS.  Another upper stage would give different results.
Title: Re: AJAX Launcher
Post by: alexw on 10/15/2010 10:32 pm
But here we go:
420: 47mT
440: 71mT
460: 92mT
480: 109mT
   BTW, thanks Downix for those numbers; added to the chart.
 
   I'm glad I asked Chris to add AJAX to the poll options -- it actually polled a bit better than the stretch-heavy classic vehicles, which seems unexpected! A testament to y'all's detailed work at demonstrating preliminary viability of the concept.
   -Alex
Title: Re: AJAX Launcher
Post by: clongton on 10/16/2010 12:22 am
But here we go:
420: 47mT
440: 71mT
460: 92mT
480: 109mT
   BTW, thanks Downix for those numbers; added to the chart.
 
   I'm glad I asked Chris to add AJAX to the poll options -- it actually polled a bit better than the stretch-heavy classic vehicles, which seems unexpected! A testament to y'all's detailed work at demonstrating preliminary viability of the concept.
   -Alex

I very much wish to see the AJAX kept going, even after SLS is flying because I do believe that there will come a day when the solids are no longer viable. At that point NASA will have to answer the question: "Do we start over from scratch or can we adapt what we have (SLS) to use LRB's?" And we'll have that answer for them, right at hand - AJAX.

In order to do that the AJAX will need to remain in lock-step with SLS, staying as close as it can to the operational LV, just like we did with DIRECT by staying as close to Ares as possible. That allows an apples-to-apples comparison almost "on demand". The Jupiter and the Ares didn't part company until it was realized that the ablative RS-68 would not survive an SRB-powered flight. Jupiter immediately went to the SSME and actually solved that problem while the champions of Ares apparently stuck their heads in the sand, hoping the problem would go away.
Title: Re: AJAX Launcher
Post by: HappyMartian on 10/16/2010 06:07 am
One very important thing that the Direct Team did was to maintain the distribution of work on the Jupiter that is somewhat similar to that of the Space Shuttles. The involvement of many states in the production, launching, and monitoring of the Orion/J-130/SLS is good for stimulating the public's interest in space exploration across the country. The alternative is to have your space exploration systems in a few areas of the country and stimulate an awareness of space in those limited number of places and leave the rest of the country as a kind of intellectual space exploration ghetto...

Creating or maintaining ghettos of any kind will not get us the planetary-wide resources that will be needed to explore and colonize the inner Solar System. We need to find many ways to directly involve all of America in space exploration, and also integrate the whole world in our efforts in LEO and BLEO. International cooperation working with commercial activities should be a very powerful combination that can make space exploration a sustainable activity for every country on the planet.

More specifically, try to find a role for ATK in building the AJAX launcher. You could have them build the RD-180. There are some other possibilities, such as a strap-on kit for the Atlas core that would enable it to be recovered. 

Cheers!

Edited.
Title: Re: AJAX Launcher
Post by: Robotbeat on 10/16/2010 06:19 am
ATK doesn't know how to make engines like the RD-180. They know solids, which aren't really optimal for manned spaceflight.

ATK can build solar arrays. They have a rather high-performance array called the UltraFlex array which has a very high specific power. They also have coilable boom technology for being able to make truly giant solar arrays that are also very lightweight, relatively stiff, and able to be deployed from a smaller volume. ATK can help make the SEP tug/transfer vehicle.
Title: Re: AJAX Launcher
Post by: simcosmos on 10/16/2010 03:28 pm
Hi all

I. AJAX Imagery

Since there is renewed interest I just wanted to go ahead and post these in this thread. Seems like they never were posted here, just in the AJAX thread's predecessor:

The vehicle:

Would like to note that, as mentioned in the above quote, those 3D renders of AJAX 'family' were earlier representations mostly done to provide a (very generic) visual reference for the ongoing brainstorm (which started on other previous threads).

In particular, would like to precise that such AJAX 'family' representation image shows different assumptions than the ones being used on more recent conceptual design talks, in particular it shows:

-  the boosters with a more 'standard' nose cone vs current assumption (baseline?) of a nose cone shape similar to Energia / Ariane5 boosters (?)
- the core with an STS ET prop. load vs the current 'less than ET load 'baseline' (?)
- minimal / 'optimized' cylindrical thrust structure vs current lengthier thrust structure (being that the thrust structure shape and other properties wasn't further brainstormed about yet)
- (other differences)

For a better perception of some of these differences please compare the AJAX-44X on the image quoted above with the one (and related text) that I have 'recently' shared at:
http://forum.nasaspaceflight.com/index.php?topic=22266.msg637815#msg637815




II. About AJAX Performance Numbers

Please (all) take what will write next as a constructive criticism but, on my humble opinion, I do not see much sense (for collective brainstorm purposes) on presenting performance numbers without also presenting further context...

… I mean, performance numbers have very little meaning if, when sharing them, there is no reference about what method was used to study that performance or about what was the specific starting / input data or about what were some of the ascent ground rules or about what were the injection targets, etc, etc, etc...

This to write that in the current or other related threads, whenever I shared performance / trajectory data from (admittedly) very preliminary simulations, for example, like what have shared at...

http://forum.nasaspaceflight.com/index.php?topic=22266.msg626811#msg626811
or
http://forum.nasaspaceflight.com/index.php?topic=22266.msg620464#msg620464
(or in several other moments)

… I have tried to roughly link to / identify some things (like what just have described above), in order to at least allow eventual interested readers to use their own tools and methods (with the same or as similar as possible launcher configuration input numbers / ascent ground rules, etc) to obtain their own performance outputs / results that could then be minimally comparable across different methods of performance assessment for the same or as similar as possible launch vehicle / injection targets and also with other vehicles...

What I'm saying (and this from quite some time and across several AJAX threads) is that without that extra effort for some minimal standardization I do not see how this brainstorm can advance in a more coordinated and meaningful way (if wishing to further advance it in an organized way, that is).

So, if there is the wish to advance the conceptual brainstorm to new levels, I would suggest that it might be close the time in which a more solid baseline / departure point set of assumptions are agreed upon and documented...




III. Towards building a more solid AJAX (v1.0?, v2.0?) baseline / departure point:

In what relates to the current brainstorm (v1.0?) this could pass by the discussion, justification and final agreement of things as 'trivial' as (perhaps in the following order, one item at a time before moving to a next item):

- the boosters properties, like what I have tried to do (and justify) here:
http://forum.nasaspaceflight.com/index.php?topic=22122.msg616689#msg616689

- core properties (including SSME numbers to be used and justification?), for example, regarding SSME specs, see my comment in the bottom part of the following post (summary):
http://forum.nasaspaceflight.com/index.php?topic=22266.msg626811#msg626811

- ground rules (I have already shared a number of rules suggestions on my posts ranging from engines starting sequence to lift-off, pitch program constraints, separation events, intended injection targets, etc)... I do not mind on collecting all that (from my past written interventions or from related images and excel files that have also shared) in a single structured post on an eventual future moment but would like to do so only if knowing that such work would be used as a starting point for discussion, agreement and for a commitment regarding the implementation of those 'rules' (as best as possible given different performance analysis methods) on future performance assessments... else that would kind of be 'wasted' time!


I then leave the question to all and, in particular, to the readers whom have more actively participated in technical aspects of the discussion: do you agree with what have written or have additional perspectives about the topic?

Assuming there is agreement, I suggest that the focus could first be on a conceptual baseline definition of the AtlasV LRB properties to be used on AJAX, then on the vehicle's core specs, then on a 'generic'  adapter /  PLF, then on ground rules... then on performance assessments / comparisons for AJAX-44X with multiple tools as possible and for well identified injection targets...

… Only after that done (and somehow documented), which is the same to say, with a more solid 'baseline' / departure point, I would think that the conditions would be gathered for moving into something like further specification and differentiation of payloads / upper stages and into brainstorms related with other 'more complicated' AJAX configurations...




IV. AJAX: v1.0 (AtlasV LRB + optimized SDLV core) vs v2.0 (boosters?, core?)

To end – and apologies for the insistence – but as I have also previously noted a number of times, if SLS core ends up by being something different from an STS ET prop. load then this brainstorm would probably have to be  transformed in a number of ways regarding current assumptions...


I very much wish to see the AJAX kept going, even after SLS is flying because I do believe that there will come a day when the solids are no longer viable. At that point NASA will have to answer the question: "Do we start over from scratch or can we adapt what we have (SLS) to use LRB's?" And we'll have that answer for them, right at hand - AJAX.

In order to do that the AJAX will need to remain in lock-step with SLS, staying as close as it can to the operational LV, just like we did with DIRECT by staying as close to Ares as possible. That allows an apples-to-apples comparison almost "on demand". ( . . . )

Chuck, yes, I agree but would like to note again that with AJAX current assumption of using AtlasV cores as LRB, one core with STS ET prop. load would mean low liftoff T/W... The STS ET prop. load case is probably the maximum in what regards design plausibility... and even then it might require non-consensual work arounds to deal with some issues... (and that was one of the reasons why recent iterations of AJAX brainstorm when to lower core sizes...).

Greater (than STS ET prop. load) cores, for example, a stretched core (if that is the outcome of SLS trade studies) would need something different – in a number of ways - for the boosters configuration... loosing some of the current advantages of using existing hardware and probably transforming the brainstorm into something even more conceptual...

This all to say that with a stretched SLS core (or, depending of extra considerations even with a core with STS ET prop. load), the direction of the brainstorm would most probably evolve into considerations about a 'new booster' (and not AtlasV CCB, not Taurus II first stage, etc)... This could bring both disadvantages and advantages but the final result would not be as 'direct' as current 'v1.0' line of thought...


I know that what wrote above is nothing new but would then like to (re)ask what should / could be the forward path for 'AJAX' conceptual musing:

IV.a) continuation of 'AJAX v1.0':  assumption of an optimized SDLV 'short' core with 4 SSME, AtlasV CCB modifications for AJAX's LRB role, synergies between Heavy Lift and current (or Phase1)  AtlasV / EELV configurations?

IV.b) or would people prefer to wait for a better definition of SLS heading and then look at the brainstorm from a perspective of a new liquid booster, I mean, something that could still use existing engines and tanks building facilities but which would not be something 'existing' today, at least not as an AtlasV CCB (?)...


I have been saying since the start of these considerations that the second option might be where we might end up simply because the constraint of LRB choice to AtlasV CCB, although could have advantages, also ends up by seriously constraint some of the core properties...

Something like what has been discussed so far and which can be loosely called of 'AJAX v1.0' seems to be more an SLS candidate / competitor design... Something like an 'AJAX 2.0' forward discussion (when knowing what SLS might be) would be something more like an evolution / upgrade plan very similar to a number of past studies regarding, for example, replacing the solids on STS by liquid boosters (which could also have stand-alone applications / ramifications as first stages for other launch vehicle configurations or derivatives such as flyback boosters, etc)

All this to conclude by writing that if wishing to have something 'on demand' to act as an eventual future replacement of solid boosters on SLS (if that will really end up by being the reality...), the path forward will most probably be 'AJAX 2.0', which might have less points of contact with 'AJAX 1.0'...


The questions on my mind are if it is 'worth' (in lack of better word) to continue this brainstorm in the current 'v1.0' conceptual design space constraints and, independently of the answer (continue with 'v1.0' vs updated context leading to 'v2.0'), what could be the steps (already suggested some) to further move the brainstorm into slightly 'new' levels of higher definition, independently of the 'very informal' state of current musings.

Thanks,
António
Title: Re: AJAX Launcher
Post by: MP99 on 10/16/2010 04:46 pm

A 486 would be weak on T/W, about 1.1.  The 586 would boost that to 1.4, still a hair under the 1.5.
486 - 152mT
586 - 144mT

The Boeing proposal contains the comment:-

Quote
Launch T/W at liftoff >1.2 for controllability off the pad

That presumably includes TVC on the SRB's?

cheers, Martin
Title: Re: AJAX Launcher
Post by: sdsds on 10/16/2010 07:39 pm
IV. AJAX: v1.0 (AtlasV LRB + optimized SDLV core) vs v2.0 (boosters?, core?)

Ninety days from now, When NASA presents to Congress its SLS design, it would be great to have a "shadow" presentation for AJAX 1.0.  I feel that should present a vehicle with Atlas V LRBs and a core optimized for use with them, and the vehicle configurations should have lift-off T/W high even at the expense of overall performance.

Only then, and really only if Congress gives NASA the green light for its design, should the AJAX 2.0 effort begin.
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/18/2010 04:37 am
Hi all

II. About AJAX Performance Numbers

Please (all) take what will write next as a constructive criticism but, on my humble opinion, I do not see much sense (for collective brainstorm purposes) on presenting performance numbers without also presenting further context...

...

What I'm saying (and this from quite some time and across several AJAX threads) is that without that extra effort for some minimal standardization I do not see how this brainstorm can advance in a more coordinated and meaningful way (if wishing to further advance it in an organized way, that is).


I agree.  To insure quality, context, understanding, clarity, integrity, and reproducibility it is important to present methodology and inputs (independent variables) along with analysis results.

Quote

I then leave the question to all and, in particular, to the readers whom have more actively participated in technical aspects of the discussion: do you agree with what have written or have additional perspectives about the topic?

....


Thanks,
António

António
First, I need to apologize if I have read your post incorrectly and if that error on my part has given me an incorrect perception.

Here is my perspective on the topic of AJAX design.  You seem to be one of those individuals who may be interested in the actual in depth engineering and design (i.e. technical design aspects) of launch vehicles.  And, therefore, you may not be in sync with the capabilities that exist or that people are willing to share on this site.  Sorry.  And, I wish I could help out more with the AJAX design.  But, as an aerodynamicist, my role is just one of many roles in the overall design process.  And, if I step outside of that role I'm doing more arm waving than I would like to do.  I may do more harm than good.

I'm not sure how many people are working on the technical aspects of AJAX.  There may be a group of people working behind the scenes on this.  I'm not aware of them.  And to all, I'm sorry but I don't consider delta v calculations anything other than basic back of the envelope engineering level calculations.  I personally would not rely on the methodology to down select a design unless the methodology was proven and documented to have strong predictive capabilities for the given set of choices.

Which leads me to trajectory optimization.  POST, OTIS, and ASTOS are restricted.  Therefore, the data that comes out of these codes are probably also restricted.  However, the methodologies these codes use, especially POST, are very well understood, are clearly in the public domain, and are even taught at the university level.  One can freely pick up the formulation manual for POST from ntrs (NASA-CR-132689)  The physical equations (atmosphere, gravity, coordinate systems, vehicle) are spelled out and one can either use the optimization method presented in the document or find one on the net.  The methodology is not difficult to program and there are much more difficult dynamic optimization problems than trajectory optimization to LEO.  In fact, if gravity is assumed constant and aerodynamics is neglected, it becomes a graduate, if not undergraduate, home work problem.  Therefore, trajectory optimization to LEO is probably not ITAR (only a concern for those in USA).  Furthermore, the optimized trajectory data for a launch vehicle placed in the public domain and obtained from an public domain trajectory optimization methodology is also probably not regulated by ITAR.  And "public domain" is key in regards to ITAR.  If it is not in the public domain, ITAR may apply.  (i.e. the ITAR regulations focus on the topics of "data" and "public domain" may be due to First Amendment rights)  Again, this is only of relevance to those in the USA.  (If one wants to follow up on ITAR in regards to traj. opt. one can freely contact the Response Team at the Department of State.)  So where am I going with this?  Trajectory optimization is a corner stone of the launch vehicle design process.  If there is a "grass roots" launch vehicle design group interested and/or capable of the technical aspects of designing a launch vehicle I would assume there is a public domain trajectory optimization code.  But, I have done a lot of searching on the web and asking around, and I have not been able to find a trajectory optimization method.  I even placed this post on nsf
and the only reply pointed to a software package called "Orekit" which doesn't seem to do optimization.  Granted the DIRECT team seems, to me, to be projecting the image that they can design a launch vehicle, but, sorry, some of the dots are just not connecting for me.

I'll admit I wanted to write a trajectory optimization method and even began programming it up.  I think it would be cool and fun.  But I don't have the time.  I'm up to my eyeballs in CFD and GUI coding.  If someone is interested in programing one up, I used the POST formulation manual and "Applied Optimal Control, Optimization, Estimation, and Control" by Arthur E. Bryson, Jr., and Yu-Chi Ho as my foundation.  "Applied Optimal Control" can be a difficult book if one has a certain mind set or expectation.  Dr. Bryson's personal approach, from my experience, is more "engineering."  By this I mean that he tells you how to do it but doesn't go into details of explaining why it works or how the methodology came about, unless you explicitly ask him.  So, if you are looking for "understanding," you may not get it from this book.  Thus, I know, the book is aggravating to some.  And it is a graduate level text.  So maybe there is a better text.  However, Dr. Bryson is considered one of the pioneers of control theory and his contributions to "minimum-time-to-climb," which began in the 50s, was significant.  The "minimum-time-to-climb", or in this case "minimum-fuel-to-climb", objective is central to trajectory optimization, and some of the examples in the text are clearly tied to that.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/18/2010 05:05 am
Antonio, thanks for the info appreciate the hard work :D

Appreciate the insight Martin :D
Title: Re: AJAX Launcher
Post by: M_Puckett on 10/19/2010 06:07 pm
Let me propose something heretical.

Since we are stuck with SRB's and the crawlerway cannot handle much more weight, could we augment the current Direct launcher with a couple of atlas cores in addition to the 2 SRBs?


Obviously, this would be a monster but would it be feasable?  Mabey the T/W would be high enough till you could 100% fill both Atlas cores?
Title: Re: AJAX Launcher
Post by: 93143 on 10/19/2010 07:06 pm
If there is a "grass roots" launch vehicle design group interested and/or capable of the technical aspects of designing a launch vehicle I would assume there is a public domain trajectory optimization code.
...
Granted the DIRECT team seems, to me, to be projecting the image that they can design a launch vehicle, but, sorry, some of the dots are just not connecting for me.

Most of DIRECT is NASA and contractor engineers.  They have access to the proprietary stuff.

simcosmos is the guy behind Orbiter (http://simcosmos.planetaclix.pt/), which means he has significant capability himself.

EDIT:  Actually he's not; it just looked that way to me. (http://forum.nasaspaceflight.com/index.php?topic=22266.msg650186#msg650186)  Either way, it's something.

There's also Schilling's performance estimator, but it's not really as accurate as you'd probably like...
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/19/2010 07:33 pm
If there is a "grass roots" launch vehicle design group interested and/or capable of the technical aspects of designing a launch vehicle I would assume there is a public domain trajectory optimization code.
...
Granted the DIRECT team seems, to me, to be projecting the image that they can design a launch vehicle, but, sorry, some of the dots are just not connecting for me.

Most of DIRECT is NASA and contractor engineers.  They have access to the proprietary stuff.

I have no true knowledge of the license for POST since I have not seen it.  At the least it is restricted and from the POST web page it is claimed to be ITAR.  Why it is ITAR I do not know.  I am skeptical it is because of technology or what it can do, it may be because somewhere along the line DoD added funding.  Regardless, it is definitely not up to me to question it's restrictions.  It is restricted.  Which also means that the data coming out of the code may also be restricted and may require approval to be released into the public.  I do not understand why people are tying theirs hands with POST.

Quote
simcosmos is the guy behind Orbiter (http://simcosmos.planetaclix.pt/), which means he has significant capability himself.

There's also Schilling's performance estimator, but it's not really as accurate as you'd probably like...

Sorry, I'm just scratching my head.  I had Prof. Bryson's class at Stanford in 1992.  At the time, we were doing these types of optimization problems with Matlab on Mac's.


Edit:  BTW, I'm not implying that simcosmos or anyone else is not able to handle this problem.  I am actually very convinced that they can.  Which confuses me all the more.  I just don't understand why it hasn't been done.
Title: Re: AJAX Launcher
Post by: Lars_J on 10/19/2010 08:11 pm
Let me propose something heretical.

Since we are stuck with SRB's and the crawlerway cannot handle much more weight, could we augment the current Direct launcher with a couple of atlas cores in addition to the 2 SRBs?


Obviously, this would be a monster but would it be feasable?  Mabey the T/W would be high enough till you could 100% fill both Atlas cores?


It certainly would not be worth the added complexity. The added performance would be minuscule, and for that small gain you'd have to completely redesign the pad and the core.
Title: Re: AJAX Launcher
Post by: jml on 10/19/2010 09:25 pm
Obligatory CEPE plug required here:

CEPE is a great macro-based Excel or OpenOffice spreadsheet that is really simple for armchair rocket scientists to model what-ifs without needing to build a matlab model, or have access to POST.

created by NSF member PaulL

http://www.paul.enutrofal.com/
Title: Re: AJAX Launcher
Post by: sdsds on 10/19/2010 09:30 pm
I'm not implying that simcosmos or anyone else is not able to handle this problem.  I am actually very convinced that they can.  Which confuses me all the more.  I just don't understand why it hasn't been done.

This very good question deserves some attention, particularly in the AJAX context.  I believe the reason may be that it is not strictly necessary to do trajectory optimization when trajectory simulation is sufficient to show the vehicle has (at least) the claimed capability.
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/19/2010 11:07 pm
I'm not implying that simcosmos or anyone else is not able to handle this problem.  I am actually very convinced that they can.  Which confuses me all the more.  I just don't understand why it hasn't been done.

This very good question deserves some attention, particularly in the AJAX context.  I believe the reason may be that it is not strictly necessary to do trajectory optimization when trajectory simulation is sufficient to show the vehicle has (at least) the claimed capability.

Yes, trajectory simulation is sufficient to show that a system has a certain capability.  However, a trajectory optimization tool brings constraint sensitivities to the table.  It also helps to show margins.  Granted one can do what an optimization tool does with a trajectory simulation tool by tweaking the knobs.  But, for me, trajectory simulation alone is not a sufficient design/analysis tool.

And, in general, people are less willing to spend the resources on high fidelity methods for a trajectory point which was not "designed", i.e. optimized, for some specific purpose.  One needs to get the most bang for the buck.

Just my two cents.

However, you are correct and it boils down to what one is after and whether one wants to spend resources now or even more resources down the road.
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/19/2010 11:49 pm
OK, let me back up a little.  Just so everyone is on the same page and I apologize if writing something that is not required.

For a trajectory there are constraints and margins.  Well, more complicated than that.  So lets assume a vehicle is constrained to have a certain load.  Of course there are more constraints than that.  The trajectory is then developed.  An output is then various margins.  For example, the guidance and control margins.  So, the next question is, "What is the sensitivity of the margins to changes in the trajectory?"  A successful trajectory may have been determined with a trajectory simulation, however, you may be an epsilon away from voiding a margin.  OK, it may be dramatic, but maybe not as dramatic as one thinks.  The unfortunate thing about trajectories is that "errors" (for lack of a better term) can accumulate .  One may find themselves going through door A when the need was to go through door B.
Title: Re: AJAX Launcher
Post by: simcosmos on 10/20/2010 03:49 pm
Hi Martin, sdsds, all

I was trying to wait for the next weekend to make it possible / give a little of extra time for eventual extra participation (from other AJAX thread members) and to also better prepare this post but, given the contents of recent messages, I will then write some comments next (my apologies if sometimes the text might result less clear or seems 'rushed'...)


First of all, would like to thank you for the comments Martin ;) Your posts perfectly fit in the kind of feedback / additional perspectives which are very good reading for this thread's context (and other similar threads). The current heading of the discussion is kind of generic, not exclusive to AJAX and could perhaps deserve a separated thread similar to the one you opened (http://forum.nasaspaceflight.com/index.php?topic=22140) (or some links there pointing to this discussion)... but, for now, I guess that it is OK to continue here.



I. The Constraints of an Informal Brainstorm

Only for clarification, one of the things that I wanted to evidence with my previous looooong post (http://forum.nasaspaceflight.com/index.php?topic=22266.msg649034#msg649034)  was the  nature of the ongoing brainstorm and how such nature obviously impacts on the time, resources and in several other things that each one of us can bring to the table of this highly conceptual informal musing (being that all efforts and interventions are greatly appreciated!).

Another of the things that I wanted to note was that despite what wrote in the above paragraph, I believe that some extra steps could perhaps be taken in order to - still within these informal brainstorm constraints -  in order to at least try to slightly standardize some aspects of the discussion and maybe advance it a little further in a few selected areas or, at least, in order to document some things to form an easier to read 'baseline case' so that it would also be easier for others to eventually improve on the 'work' made until now...

… In any case, will use this opportunity to ask the 'casual' readers (not the usual participants) to please do not take the idea that a launch vehicle is being 'developed' here, ready for assembly!!! Please do not take this or similar forum brainstorms for something that it isn't!



Martin, as I believe you also wished to point in one of your past interesting posts (http://forum.nasaspaceflight.com/index.php?topic=22266.msg649359#msg649359) (and please correct me as needed if that was not the case):

- I agree that this kind of informal musing (with all its constraints) does lack in several very important fields, there isn't enough critical mass (either under the form of extra participants with specialized background and know-how on different needed fields or under the form of readily available 'tools') to further advance this kind of forum brainstorms much beyond some more or less well identifiable levels in some areas (at least not without some selected extra 'development effort')...

- The above point to say that there are several essential areas / disciplines which are not represented at all and which are completely in the 'dark' - and will probably stay that way - disciplines which might hide those kind of 'unknowns-unknowns' that might even make a given baseline 'choice' (which is not really a 'choice' when several key parts of knowledge are missing!) or overall concept formulation to eventually result in something non viable in the end... Something similar could be written even for the disciplines which are represented... I guess that the important is to not loose focus about what can and can not be done – and how realistic something can be done – for a given current context or for eventual future perspectives...




II. About my (Simulation) Contribute



simcosmos is the guy behind Orbiter (http://simcosmos.planetaclix.pt/), which means he has significant capability himself.

Before I continue, some extra clarifications are needed next:

I'm not the “guy behind Orbiter”: Orbiter Space Flight Simulator is the product of the hard work of Dr. Martin Schweiger: www.orbitersim.com (http://orbit.medphys.ucl.ac.uk/home.php).

What I do – like many other developers in Orbiter Community - is to use Orbiter simulator to implement launch vehicles, spacecraft, rovers, etc and also mission designs (either they be based on historical, current on conceptual stuff)...  Some other developers also provide essential work on expanding Orbiter simulator features beyond these examples...

On my specific case, and although do have some programming knowledge (many years ago started with BASIC, FORTRAN and then ended up with IDL for late University works) and, in theory, could program C++ to build custom dlls, what I'm using are already developed dlls – called Vinka's spacecraft / multistage generic dlls ( http://users.swing.be/vinka/ )... These generic dlls act as a kind of 'bridge' between Orbiter simulator and structured INI files containing input parameters for the launch vehicle / spacecraft configurations and related properties or for ascent guidance information, etc...

This specific method of implementation (generic dlls) has the advantage of allowing somehow fast 'development' (by simply using notepad to 'build' the vehicles properties) and has good results (as long as the developer knows what is doing and as well knows what are the limitations, constraints and even one or another well identified 'bug' of the current version of the generic dlls... all that vs free time vs final intended audience)... Would also like to note that despite all their nice features, generic dlls are just the tip of the iceberg in what regards what can be done with Orbiter simulator, both in terms of vehicles simulation or of things such as trajectory simulation and even trajectory optimization too... We have 'C++' examples in Orbiter Community of, just to give two, of Apollo and Shuttle related stuff which are pure gold...



So, with the above in mind, and continuing to talk only for myself and about part of my contributes to this series of threads (beyond the obvious 3D 'eye-candy'): although my University background was in Physics / Applied Mathematics / Astronomy I'm not a 'rocket scientist' (in the sense of being an hand-on-the-metal / conceptual 'specialist' in any of the intended disciplines required for rocket design, far from that) and I'm the first to admit that the simulations and methodology that have been using as well the 'results' that have shared until the moment are not perfect:

- the work can be further refined although, as in any simulation, the ultimate simulation is a real life ascent

- going a little back, the input numbers of such very preliminary simulations (for example, estimation of masses for launch vehicle components, additional aspects related with ascent environments vs trajectory analysis, etc) would require not only extra work from my side but, more importantly, would require a much more professional look (across different disciplines - focusing on some technical - ranging  from structural, thermal, control, aerodynamics, also probability analysis of several types,  etc, etc perspectives) than what seems to have been possible to do until now...

… Despite the above points, the methodology I'm using (Orbiter Space Flight Simulator + 'conscientious' use of Vinka's multistage2.dll features, etc) seems to be, in 'first order', in accordance – in terms of simulation of the ascent and of performance outputs – with historical or current vehicle results cases or when comparing with conceptual results (from papers, reports, etc) which used accepted professional tools.


The last comment could lead again to the importance of ground rules definition and the related simulation refinement...  Once that done, eventual extra simulation files / methodology could probably be shared from my side of the Net / World and, as always, within personal time constraints...


In any case, I would also ask the readers to please do not look at my simulations as unique data point / 'analysis' work in which to solidly make and base 'choices' regarding things such as specific launcher configurations, trajectory shaping, etc...


Trying to be slightly more explicit, some of my objectives, until the moment, in this or similar conceptual threads, was mostly to loosely and preliminarily study:

a) the 'impact' of some 'choices' / input data into eventual final performance results and other ascent constraints

b) to study, at first in a separated incremental way, segmented portions of an ascent story which are then later unified under a common ascent guidance; such guidance would still need further optimizations; such guidance tries to obey to some ground rules (for example, related with pitch profile / AOA in particular while in the lower atmosphere, maxQ, max g, separation events / staging / disposal constraints, etc, etc...)

c) last but not least, another objective was to share the assumptions being made so that others could eventually try to verify at least parts of the ascent story, or of the input data, etc although I'm aware that such extra tools and verifications might be not 'shareable' or even be currently very feasible (another reason why a 'new level' of the brainstorm could be to try to agree about some things and then try to document such things... more about this later).


Only to be extra clear (and running the risk of being repetitive / obvious): please do NOT take my simulations as sole / unique base for conceptual 'decision' making but more as preliminary study / hints for further specialized study... being that such specialized study might be something off the limits of the constraints of this thread or, at least, require further 'development' effort of some kind, either on existing tools or in the creation of new tools or in a better representation of some disciplines (if wishing to minimize  the utilization of 'analogue' concepts as point of reference... although I'm aware that such would probably be beyond the limit of what can be done on a forum brainstorm).




III. Conclusions

The above paragraphs were written to express (or at least try to express) that I have the conscience of the several limitations of this kind of brainstorm, even more when what is being done here is not a conceptual brainstorm about 'generic' mission design aspects / payloads riding on top of an existing vehicle (which, without wishing to be 'simplistic', could somehow 'facilitate' some aspects of these kind of  brainstorms) but it is about playing 'Lego' with some parts to idealize in a very, very, very rough and incomplete way (with several important specific areas in the 'dark'), some kind of conceptual vehicle...


Despite all those constraints, and without wishing to be perceived as doing arm waving myself, and going back to what wrote in the start, I think that at least some 'work' done until the moment might be interesting enough so that could be slightly further discussed and documented, if there would be the wish to do so, at least to have a centralized reference for eventual future study: I write this fully conscientious of the informal nature of this musing (and very appreciative of the time everyone is able to spend on more technical posts) and of its constraints...

… If such further study would be possible at all and in what format could it be done is certainly a very, very good discussion topic but the key idea that I wanted to bring to the table is that, before such step and despite all limitations, a good as any place to eventually start could be to standardize and agree in some things we have now – even if they might be far from perfect or far from completed regarding several disciplines analysis – and then somehow document it (pdf?) so that at least other eventual interested persons do not have to read the whole series of threads to have a clearer idea of what is the basic 'concept' and what are some of the analysis difficulties or the perceived advantages, disadvantages, etc of such 'concept'. 


By the way, and to end, I'm also not aware of anyone 'working' on AJAX 'behind the scenes' neither of how many exact persons are 'brainstorming' about it and with which regularity or with which background / tools, etc, in these forums.

Yet another reason for the wish to bring some extra standardization to the table and to try to gather what has been done until the moment...  But to even do that there would be, on my opinion, the need to talk first a bit  about these kind of topics (like I have tried to do and like Martin and others also did, thanks!)

Hope that was able to slightly clarify my position and provide a few extra loose thoughts about the topic, which isn't something easy to do given the range of interlinked 'sub-topics'.

Thanks,
António
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/20/2010 06:04 pm
Hi António


… In any case, will use this opportunity to ask the 'casual' readers (not the usual participants) to please do not take the idea that a launch vehicle is being 'developed' here, ready for assembly!!! Please do not take this or similar forum brainstorms for something that it isn't!

Exactly, a launch vehicle is not being developed!!  I realize that to a novice that it may seem that way.  However, regardless of how technical some of these discussion might get, they are just a small part of the iceberg.  These technical topics are taught at the graduate level and to a lesser degree at the undergraduate degree.  They are old news.  If people have doubts they can check out the online course catalogs for Stanford, MIT, Georgia Tech, etc.  Also, no blueprints are being made and no metal is being bent.  Furthermore, and I can only speak for myself, I do not have the desire nor the resources to dwell into the details required to ensure that this "project" works.  Hey, that's a job and I'm in this for the fun!  :)

Quote
- I agree that this kind of informal musing (with all its constraints) does lack in several very important fields, there isn't enough critical mass (either under the form of extra participants with specialized background and know-how on different needed fields or under the form of readily available 'tools') to further advance this kind of forum brainstorms much beyond some more or less well identifiable levels in some areas (at least not without some selected extra 'development effort')...

This is the one area that my brain hasn't been able to align on.  On one hand Ross indicates there is a technical "team" (nasa, contractors, etc.) and on the other hand I don't see their technical foot prints.  Maybe these people are non technical (or they think they are technical and they are not.)  I don't know.

Quote

Trying to be slightly more explicit, some of my objectives, until the moment, in this or similar conceptual threads, was mostly to loosely and preliminarily study:

a) the 'impact' of some 'choices' / input data into eventual final performance results and other ascent constraints

b) to study, at first in a separated incremental way, segmented portions of an ascent story which are then later unified under a common ascent guidance; such guidance would still need further optimizations; such guidance tries to obey to some ground rules (for example, related with pitch profile / AOA in particular while in the lower atmosphere, maxQ, max g, separation events / staging / disposal constraints, etc, etc...)

c) last but not least, another objective was to share the assumptions being made so that others could eventually try to verify at least parts of the ascent story, or of the input data, etc although I'm aware that such extra tools and verifications might be not 'shareable' or even be currently very feasible (another reason why a 'new level' of the brainstorm could be to try to agree about some things and then try to document such things... more about this later).

...

Thanks,
António

I'll follow up on the quoted passage above later today.
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/20/2010 06:13 pm
 ???  I'm confused.  The chain of posts (i.e. trajectory optimization coding) from Niels Stchedroff, Chuck, and then myself, have been deleted.  Please, can a moderator explain why they were deleted so the same mistake is not made again?   :'(
Title: Re: AJAX Launcher
Post by: clongton on 10/20/2010 06:45 pm
This is the one area that my brain hasn't been able to align on.  On one hand Ross indicates there is a technical "team" (nasa, contractors, etc.) and on the other hand I don't see their technical foot prints.  Maybe these people are non technical (or they think they are technical and they are not.)  I don't know.

The technical team was engaged on DIRECT. That team is not functioning at this time on AJAX. They are otherwise engaged. That's the difference.
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/20/2010 07:07 pm
Hi Martin, sdsds, all

...

Thanks,
António

Hi António,

Not sure what's going on.  Posts are being deleted and Chuck is claiming representation for people who I thought were volunteers.  Maybe they all quit and joined C-star.

António, not sure if you read my earlier post.  As you probably know, more and more physics based technology is making it's way down to the video game level.  The coming years (well in 5+ years) have the possibility of being fun in regards to adding "nature" into the strategy experience!

As far as my involvement in AJAX, I may stay on the sidelines for a while and see where things go.
Title: Re: AJAX Launcher
Post by: clongton on 10/20/2010 07:30 pm
... and Chuck is claiming representation for people who I thought were volunteers.

Hi Martin
Just want to make sure we're on the same page.
We assembled an impressive team that volunteered their time on DIRECT.
That "team" is not and never was similarly engaged on AJAX.
Just want to make certain that we all understand that.
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/20/2010 07:44 pm
... and Chuck is claiming representation for people who I thought were volunteers.

Hi Martin
Just want to make sure we're on the same page.
We assembled an impressive team that volunteered their time on DIRECT.
That "team" is not and never was similarly engaged on AJAX.
Just want to make certain that we all understand that.

Got it.  It's an issue of terminology.  The DIRECT "team" is not engaged on AJAX however the individuals who comprise the "team" could be if they wanted to be.
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/21/2010 12:52 am

LOL, the state of the art in this subject is not really clear to me.  And there has been a lot of work over the last few years with Adjoint methods in regards to CFD shape optimization.  And we used Adjoint methods for trajectory analysis back in the grad school days.  So maybe some of that work applies.

BTW, I'm assuming that your use of "objective" refers to constraints.  For example, trying to get to so and so is a constraint.  Whereas fuel would be the "cost" or "objective" function.  Granted, with some optimization formulations the constraints are wrapped up into the cost function.

Anyway, in the "old days" it took quite a few iterations to reach an optimized solution.  These are non linear systems.  And each iteration is, if I remember correctly, a complete simulation run.  So changing a constraint would require additional iterations.  At least in the "old days"  However, after each simulation one does have the sensitivities, i.e. how the trajectory would change if constraints would change an epsilon.

Not sure if I helped.
Title: Re: AJAX Launcher
Post by: sdsds on 10/21/2010 01:51 am
Not sure if I helped.

Yes, your reply helped.  (It helped me at least.  So, "Thank you!")

It may seem like a total non-sequitur, but this question of optimization versus mere simulation points to some fundamental characteristics of the AJAX effort as I understand it.  These are stated below as if they were consensus beliefs, whereas in fact they are merely propositions.

Proposition 1:  We understand the plan for the NASA Space Launch System (SLS) is to use segmented solid rocket boosters (SRBs), and this effort is not in opposition to that plan.

Proposition 2:  We claim the technical approach underlying SLS (i.e. an inline vehicle using a core stage derived from the Shuttle external tank) does not absolutely require SRBs, and we wish to demonstrate that claim.

Proposition 3:  We assert the AJAX effort is supportive of SLS as currently planned, because it demonstrates the robustness of the underlying SLS approach. 

Proposition 4:  We further assert AJAX provides an alternative for a contingency where SLS vehicles using SRBs are deemed "not viable." 

Proposition 5:  We see little value in dwelling on the reasons why SRBs might become not viable.  We accept that others will perceive this to be the "central conceit" of the AJAX effort.

In that context many aspects of the AJAX design which would otherwise be seen as variables which we could optimize, such as the core propellant tank sizes or the LRB propellant tank sizes, might instead be dictated by circumstances beyond our control, i.e. they might be constrained to exact values.  Indeed there might be many constraints, i.e. we might impose an Atlas-like "zero angle of attack" flight profile on much of the atmospheric ascent simply because that guidance control law presents such a low risk of unanticipated events.

Imposing these simplified constraints almost guarantees sub-optimal performance.  Nonetheless, experienced engineers -- of all disciplines -- are often comfortable with imposing design constraints like these.  That's why they love to use phrases like, "Perfect is the enemy of good enough."
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/21/2010 03:44 am
Not sure if I helped.

Yes, your reply helped.  (It helped me at least.  So, "Thank you!")

It may seem like a total non-sequitur, but this question of optimization versus mere simulation points to some fundamental characteristics of the AJAX effort as I understand it.  These are stated below as if they were consensus beliefs, whereas in fact they are merely propositions.

Proposition 1:  We understand the plan for the NASA Space Launch System (SLS) is to use segmented solid rocket boosters (SRBs), and this effort is not in opposition to that plan.

Proposition 2:  We claim the technical approach underlying SLS (i.e. an inline vehicle using a core stage derived from the Shuttle external tank) does not absolutely require SRBs, and we wish to demonstrate that claim.

Proposition 3:  We assert the AJAX effort is supportive of SLS as currently planned, because it demonstrates the robustness of the underlying SLS approach. 

Proposition 4:  We further assert AJAX provides an alternative for a contingency where SLS vehicles using SRBs are deemed "not viable." 

Proposition 5:  We see little value in dwelling on the reasons why SRBs might become not viable.  We accept that others will perceive this to be the "central conceit" of the AJAX effort.

In that context many aspects of the AJAX design which would otherwise be seen as variables which we could optimize, such as the core propellant tank sizes or the LRB propellant tank sizes, might instead be dictated by circumstances beyond our control, i.e. they might be constrained to exact values.  Indeed there might be many constraints, i.e. we might impose an Atlas-like "zero angle of attack" flight profile on much of the atmospheric ascent simply because that guidance control law presents such a low risk of unanticipated events.

Imposing these simplified constraints almost guarantees sub-optimal performance.  Nonetheless, experienced engineers -- of all disciplines -- are often comfortable with imposing design constraints like these.  That's why the love to use phrases like, "Perfect is the enemy of good enough."

Given your propositions, you are correct.  It depends on constraints and margins.  The SLS has constraints and AJAX has constraints.  At this point, I gather, the constraints are basically unknown.  And, some, if not most of them, will probably continue to remain unknown, at least to us.  Putting that aside, the desire for a trajectory optimization methodology would possibly increase if it was determined that a constraint for the SLS exceeded a constraint for AJAX (due to the usage of CCB)  However, a trajectory can be "optimized" by hand through intelligent trial and error.  I assume it will be a pain and one probably doesn't want to do it too often.  It is all about defining good enough.
Title: Re: AJAX Launcher
Post by: Downix on 10/21/2010 05:35 am
The attempt to use a JUS and it's low T/W has me pondering a bit more.  Crunching more numbers, may have something later tomorrow.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/21/2010 06:13 am
Very cool Downix. IDK that we ever evaluated the upper stage options for AJAX. Seems like the big issue in the room until recently was the T/W on the first stage.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/21/2010 06:27 am
DIVUS would have even lower T/W. I would suggest taking a look at ACES, but I think DIVUS is more realistic (given that it exists now). Not really clear at this point if ULA will actually build ACES.
Title: Re: AJAX Launcher
Post by: Downix on 10/22/2010 06:07 am
The problem is, once you add the US, you get the T/W back below the magic number.

I looked back at the stubby-core, as I call it, to study it for T/W, and found it may, actually, be able to do the job if given even a basic US.  It would marry us to requiring an upper-stage (even a basic Centaur), no cool J-130 like "look ma, no US".  But it's still preliminary study. 

I was so focused on the basic config, I ignored the future growth.
Title: Re: AJAX Launcher
Post by: Lars_J on 10/22/2010 07:37 am
That seems to be the eternal issue with the AJAX approach. T/W at liftoff. You keep having to compensate for the fact that Atlas V cores just don't have enough thrust to be very good boosters. You need too many of them to be practical if you add a sizable US with heavy payload.

If you want to replace the SRB's, you need boosters with F-1 class engines to be very practical. IMO. I realize you are trying to work with what we have... But it seems like you'll have to reduce the payload capacity as a trade-off for losing the SRBs.
Title: Re: AJAX Launcher
Post by: clongton on 10/22/2010 01:00 pm
That seems to be the eternal issue with the AJAX approach. T/W at liftoff. You keep having to compensate for the fact that Atlas V cores just don't have enough thrust to be very good boosters. You need too many of them to be practical if you add a sizable US with heavy payload.

If you want to replace the SRB's, you need boosters with F-1 class engines to be very practical. IMO. I realize you are trying to work with what we have... But it seems like you'll have to reduce the payload capacity as a trade-off for losing the SRBs.

You're assuming that we *need* to use an upper stage. Remember that the 6 and 8 CCB configurations easily exceed 100mT to LEO without an upper stage. It may be that the key to heavy lift with AJAX is NO upper stage; just increase the CCB count from 4 to 6 or 8. Let any upper stage actually be a *mission* stage that does not contrubute to the ride to orbit. 100mT delivered to LEO can easily be a massive spacecraft with fuel load, or an even bigger spacecraft if it then tanks up at a depot. 100mT to LEO is no sneezing matter. Who says we *have* to use an upper stage to do that?
Title: Re: AJAX Launcher
Post by: sdsds on 10/22/2010 01:45 pm
It may be that the key to heavy lift with AJAX is NO upper stage; just increase the CCB count from 4 to 6 or 8.

Right!  In exchange for the ability to add another SSME to the core to support an upper stage (as Jupiter does going from J-130 to J-24x), AJAX provides the ability to add more LRBs.  This should be touted as increasing assurance of mission success:  all the engines are ground lit and verified before lift-off, so there is no risk of an engine failing to start at altitude.
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/22/2010 02:25 pm
Sorry, I'm working off memory and, for me, that's not the best thing sometimes.

I believe the T/W of a CCB is about 1.2?  So the more you add the closer to 1.2 you get.  In that case, the T/W of the Atlas Heavy can't be more than 1.2.  I'd need to due the math.
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/22/2010 02:55 pm
Over at http://www.grc.nasa.gov/WWW/K-12/rocket/ienzl.html there is a rocket thrust calculator.  What I like about it is that it gives values for Isp vs. altitude.  This may be useful for a trajectory simulation.  However, some code modifications may be required since the graphical user interface (GUI) is limited on the amount of chamber pressure and temperature.  I *think* the chamber pressure for the RD-180, and possibly the SSME, is higher than what the GUI allows.  The "engine" behind the GUI may not have that limitation.  So the limit may be a "feature" of the GUI only.  Anyway you can run the applet at the above web site to check it out.  You can also download the applet from the web site, uncompresse the .zip file, and check out the source code.  The license for the source code is presented at the top of Rnoz.java.

The first paragraph of the license states,
****
"This software is in the Public Domain.  It may be freely copied and used in non-commercial products, assuming proper credit to the author is given.  IT MAY NOT BE RESOLD.  If you want to use the software for commercial products, contact the author."
*****

After that it is the typical no warranty, etc. stuff.  So, PLEASE abide by the license.  And I'll emphasize this part even further to ALL who are reading this, IF YOU USE IT - GIVE CREDIT!

I also contacted Tom Benson, the author, at the email given on the web site above.  (In general I don't like posting email addresses because of email "scrapers")

Here is my email
****
Dear Mr. Benson,

There may be an interest to use the Interactive Rocket Thrust Program
for a launch vehicle brainstorming session at
http://forum.nasaspaceflight.com/index.php?topic=22266.0.  (Creating a
launch vehicle from the Shuttle ET+SSME+Atlas CCBs) We may need to do
some modifications to the program, i.e. Rnoz.java, to model the Atlas
CCB's RD-180 and the SSME to, at the current time, obtain the
variation of Isp vs. Altitude for a trajectory simulation.  This is
not a commercial venture.  I've read the License and realize the
program is in the public domain.   However, I would like to ask you if
this is OK out of courtesy and just in case.

Sincerely,
Martin Hegedus
****

And this is Mr. Benson's response
****
Martin,

For studies like this .... have at it!.

If you download the program from

http://www.grc.nasa.gov/WWW/K-12/rocket/ienzl.html

and unzip it .. the source is Rnoz.java  ... (looks like you already figured that out!)  You'll need to download the Java developer's kit (JDK) that you get from Sun Microsystems for free.  Then as you mod .. you can compile using  javac ... or I suppose you could create a jar file (I never do this .. but I have seen young interns use this)

Good luck on your studies.

Tom
****
Title: Re: AJAX Launcher
Post by: Lars_J on 10/22/2010 03:27 pm
That seems to be the eternal issue with the AJAX approach. T/W at liftoff. You keep having to compensate for the fact that Atlas V cores just don't have enough thrust to be very good boosters. You need too many of them to be practical if you add a sizable US with heavy payload.

If you want to replace the SRB's, you need boosters with F-1 class engines to be very practical. IMO. I realize you are trying to work with what we have... But it seems like you'll have to reduce the payload capacity as a trade-off for losing the SRBs.

You're assuming that we *need* to use an upper stage....

I am assuming no such thing... I was just commenting in Downix's post about upper stage discussion. Perhaps I should have quoted for context, but I did not believe it was necessary.
Title: Re: AJAX Launcher
Post by: Downix on 10/22/2010 04:07 pm
That seems to be the eternal issue with the AJAX approach. T/W at liftoff. You keep having to compensate for the fact that Atlas V cores just don't have enough thrust to be very good boosters. You need too many of them to be practical if you add a sizable US with heavy payload.

If you want to replace the SRB's, you need boosters with F-1 class engines to be very practical. IMO. I realize you are trying to work with what we have... But it seems like you'll have to reduce the payload capacity as a trade-off for losing the SRBs.
Not really.  The advantage to CCB's over SRB's is that we can throw more at the problem.  Remember, with 8 we can lift more than the SRB based Jupiter can with an upper stage.

Chuck is right in that we may not need an upper stage, and in all likelihood it looks like there won't be one, or if there is, it would be a Centaur, DIVUS or ACES, mission-specific one.  And with 8 CCB's, plenty of T/W for even the heaviest ACES.

I just did some comparisons of upper stages, and the 440 w/ DIVUS could easily launch Orion to the moon, with plenty to spare, performance-wise.
Title: Re: AJAX Launcher
Post by: simcosmos on 10/22/2010 06:24 pm
Hi all


( . . . ) António, not sure if you read my earlier post.  As you probably know, more and more physics based technology is making it's way down to the video game level.  The coming years (well in 5+ years) have the possibility of being fun in regards to adding "nature" into the strategy experience! ( . . . )

(Quick note only to write that I might not be fully aware of all deleted posts contents and some of the eventually valuable information - for this thread's topic - that might have been 'lost'.).


Moving on: I continue to think that it might not make much sense to start either differentiation and further specification of AJAX 44X payloads and, much less do it for more complicated variants – such as a core surrounded by 8 x Atlas V CCB and a heavier upper stage - without first discussing and agreeing about a number of things which I believe would be essential for a more organized brainstorm and collective data sharing...



AJAX-486 Super Heavy Lifter

… Despite that, and despite I do not particularly enjoy sharing non-completed / 'fresh' data will perhaps use this post to share a few loose thoughts about something like an AJAX (v1.0) 486 Super Heavy Lifter, as always, based on very preliminary simulation work done here (which I would really need more time to improve... and this is even more valid for the specific case of this super heavy lifter!!!...).

My apologies in advance for the current quality of the text / data sharing or if making typos.



I. Launch Facilities, yet again T/W at early moments, AtlasV LRB constraints to conceptual design trade-space, etc


Will start by a personal very rough estimation of the total mass for something like an AJAX-486:

3435527 kg (fully loaded)
~336827 kg (without prop. loaded on the core and on the 8 boosters)


I'm not sure if can start to imagine what that loaded mass could really represent in terms of launch facilities interactions and requirements vs available resources... Yes, the 'empty' mass is much more manageable to transport from the VAB to the Pad than a solid booster based HLV but, on the other hand, the loaded mass – at the pad (and prop. load requirements vs number of components, etc) - might starting to be a bit on the high side for this maximum AJAX v1.0 configuration, even if it could have a nice payload and mission modes...

In what regards T/W at lift-off, the start sequence that I have previously mentioned for something like an AJAX 44x (SSME taking about 6.6s to start and reach max. power level and staying there until the RD-180 powered LRB would do the same in about 2.7 extra seconds) would probably need to be slightly reviewed in what concerns the ignition of the 8 LRB configuration... Not sure if all 8 LRB would ignite at the same time or if it would be better to make some kind of phased LRB ignition / verification (example: 4 + 4)... As always this would require very careful analysis... which might be beyond this thread's constraints... Only to have a starting point I kept the same ignition sequence than AJAX 44X for AJAX-486 (with all 8 LRB starting at the same time)...

Depending of a number of further considerations (which will not write for the moment), and using 'my' mass assumptions and assuming the following thrust levels for SSME / RD-180...

SSME (SL, 109%)  : 1859325.5 N
RD-180 (SL, 100%): 3826961.7 N

…this might result on a lift-off T/W of at least ~1.14 (if the 4 x SSME at 109% and all 8 x LRB at 100% SL thrust and IF assuming some kind of ignition start / verification sequence for the core + boosters before launch commitment). With a little of tweak on some assumptions the liftoff T/W could perhaps approach the '1.15' value (or to be slightly greater) but that would really require the discussion about a number of extra considerations...

… Only to give an example, a value of about 1.16 could perhaps be achieved if assuming the AJAX-486 launching a lighter upper stage than what I have assumed on later parts of this post or if launching alone the upper stage that I have assumed.



I.a) More about Liftoff T/W and the '1.2 Magic Number':

On my opinion, there isn't much that can be done to improve the lift-off T/W situation for AJAX v1.0 (and this is more evident when considering the whole range of eventual vehicle configurations, mission modes, etc):

- yes, the core could be assumed to be even shorter than what I have assumed (at a cost of complexity in burn profiles for lower payload range HLV configurations)

- yes, there were several talks about some non-consensual 'workarounds' but...

… But there is a limit of plausibility regarding things that can be tweaked to make a design work... And I write this when we are only brainstorming at a very high first order conceptual level, imagine the *real life* brainstorms... Some of you might not agree with what I will write next but, independently of the comparison not being very good, if looking at this issue from a given set of perspectives this might not be very different than what happened with AresI case... (I mean, in terms of some strict constraints being 'imposed' to the design trade-space / starting assumptions which then affect other parts of the brainstorm)

The other option would be to somehow improve the engines thrust, at least at sea level... In any case, this all results of the AJAX v1.0 constraint of assuming an LRB design which would in essence – at least in theory - be an AtlasV CCB (yes, there are advantages but there are also disadvantages).


I do not see a consensual solution to achieve the 1.2 liftoff T/W 'magic' number for AJAX, at least not without entering in a 'game' of extra assumptions (which can be dangerous if such extra assumptions aren't later verified with professional analyses) or, at least, without further 'refining' some aspects of this brainstorm (for example related with ground rules, mission modes, etc)... but... *BEFORE* such steps we would probably really need to achieve a greater standardization regarding how this brainstorm could be moved forward in some selected areas (?).



II.b) Would also like to remember (as did in previous participations) that have seen such '1.2' T/W reference on:
- Boeing's HLV Assessment,
- on ESAS Report this also seemed to be a minimum lift-off T/W 'goal' (although a few vehicle designs were considered with T/W of about 1.17 or so, perhaps because of being +/- the same value as SaturnV, at least as stated on that report)
- also think that remember seeing that kind of '1.2' value on other past conceptual reports (pre-VSE, at NTRS) and, more recently, even saw a reference to it on SpaceX's conceptual HLV related materials...





III. AJAX-486 ('simcosmos' temp. version dev20101022A)

As mentioned above, I'm not very comfortable with sharing incomplete / 'fresh' stuff (when was not able to verify for gross mistakes / typos, etc)... so I ask the readers to please take all this with a larger grain of salt than usual... Anyway, these are the starting numbers being used here to 'simulate' something like an AJAX-486 ascent:

   183976.8 kg : 8 x LRB (8 x 21902 kg x (1 + 0.05): 5% margin added to AtlasV Guide LRB, March 2010)
 2272700.0 kg : 8 x LRB (8 x 284087.5 kg prop. load)
     65500.0 kg : AJAX Core (4 x SSME)
   646000.0 kg : AJAX Core Prop. Load (at SSME engine pre-start)
       4850.0 kg : interstage (including eventual separation motors; it might be lighter)
   180000.0 kg : upper stage prop. load (one of the options being studied here)
     17500.0 kg : upper stage dry mass (one of the options being studied here)
     55000.0 kg : gross payload, for a certain type of Exploration mission design (including adapter)
     10000.0 kg : PLF
---------------------------
 3435526.8 kg : total AJAX-486 'SCdev20101022A' mass at the pad, pre - SSME start


III.a) Very crude preliminary performance estimation:

     94762 kg : upper stage prop. load after (direct) insertion
     17500 kg : upper stage mass
     55000 kg : gross payload mass
-----------------------------
   167262 kg : 283 km x 236 km, 28.75 degrees inc. 

If adding the prop. load on the US to 'payload' definition (for example, for some kind of Exploration mission profile), the total payload would then be ~149762 kg, rounding up, ~150t.


Note: only to provide some kind of (very rough) comparison, again using stuff on my own simulation archives, something similar (not equal!) to an ESAS Report CaLV could have a total mass of about 2845463 kg (2 x 5 seg. SRB of some type + stretched core with 5 SSME at 109% and with prop. load from 950t up to 1000t + interstage + ~210t prop. load upper stage (with different than ESAS propulsion assumptions) + 50t or so of payload (including adapter) + 10t PLF) and a LEO (at least above 200km circ. orbit) gross payload (adapter + spacecraft + prop. load on upper stage after insertion) of about 130t...



III.b)Loose Ascent Notes:

Although very preliminary, this AJAX-486 ascent had some set of ground rules implementation / verifications in what regards pitch commands, max. accelerations, max. dynamic pressures, simulation of staging or separation events, etc, etc...

I will not (re)detail them here or, as usual, the post would become even greater than what will already be... (although I really think that this 'ground rules topic' might deserve discussion, standardization and commitment, probably on a separated thread?).

For the moment will only note that for the above specific launch vehicle configuration had a T/W of about 1.14 at liftoff and that the 8 x LRB could eventually take the vehicle to about 100 km altitude, PLF  could be separated at about 126 km altitude and that the core's MECO could happen at about 5800 m/s (while keeping ~1% of initial load) and at an altitude of about 172 km. From there, staging and upper stage ignition sequence had also some rules  simulation (it was not treated as instantaneous events, same valid for other previous launcher components ignition and separation events).

By the way, further optimization can de implemented in particular for the last parts of core's burn and for the upper stage portion of the ascent. On another hand, additional constraints verification might also be introduced on later simulation runs... Maybe on a later occasion, depending of how goes the discussion direction on this thread.




IV. AJAX-486 Upper Stage (Options) vs Mission Design Notes: 

I tried to be slightly conservative in what regards the upper stage dry mass and, to that effect, tried to aim for  some kind of middle-ground between more aggressive vs more conservative assumptions...

The upper stage could also probably have been assumed with a lighter prop. load (mission stage) but I have tried to not constraint too much eventual future 'enhanced' applications of the same basic stage design or eventual different mission modes, etc... and that is why went for a first 'guess' of an upper stage sized for a  ~180t prop. load... This to write that although AJAX-486 could virtually insert into LEO other kind of fully loaded upper stage + related payload such research direction would require extra study than what have tried to do in this set of simulation run(s) (and, once more, would probably require extra coordination and standardization of input data... for example, it might require extra considerations about PLF design and other integration aspects vs ascent events). 


Back to the numbers that shared, the 180t prop. load / 17.5t mass upper stage propulsion assumption was a cluster of 6 RL-10 derived engines which would be – in terms of thrust / ISP - something in-between the RL10A4-2 (~99.2 kN, 445s ISP) and the RL10B-2 (~110 kN, 459s ISP). The assumed vac. ISP was ~452s.


Being very simplistic with the math (and unless made some typo), this means that the above performance 'result' could allow the upper stage to achieve something like a dV budget of ~3187 m/s  for a gross payload of 55t (adapter + spacecraft) while keeping ~5% of the initial 180t prop. load inside the US...

I leave to the reader further brainstorm about what could those 9t of prop. be used for although would still note that part of those 9t would need to be kept for Flight Performance Reserves / Residuals... The rest  could allow for some extra LEO loiter time protection - depending of upper stage design assumptions and mission mode considerations - or allow for slightly extra payload mass for some mission modes or some mass growth on other components or partial protection for less favourable ascent cases, etc...

For the specific case of the numbers that have shared above, the mission concept was related with lunar missions and no LEO rendezvous was assumed: for such case, the insertion orbit could have been lower (and payload / prop. margins higher, etc) but I wanted to use this same set of simulation run(s) to, once more, study a middle-ground in what regards generic conceptual capabilities / performance...

In terms of enhanced mission modes (for example, AJAX-486 launching that upper stage alone + depots at start / ending places + longer duration kits added to the upper stage, etc) that upper stage could allow a dV of about 4200 m/s from LEO: this would be enough to do TMI of about 75t to 80t or to insert such kind of mass into low lunar orbit or to consider departure from EML2 (after refill) of  heavy payloads...

Last but not least, the launcher would look something close to the configuration seen on the right side of the image at http://forum.nasaspaceflight.com/index.php?topic=22266.msg648629#msg648629, while having in mind what I have written about that image at http://forum.nasaspaceflight.com/index.php?topic=22266.msg649034#msg649034 .

Further verifications, corrections and refinements to this AJAX-486 (or AJAX-44X) simulations are still possible but would need extra time as well a few extra individual (and probably collective) steps... Maybe on another time.

António
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/22/2010 07:16 pm

Moving on: I continue to think that it might not make much sense to start either differentiation and further specification of AJAX 44X payloads and, much less do it for more complicated variants – such as a core surrounded by 8 x Atlas V CCB and a heavier upper stage - without first discussing and agreeing about a number of things which I believe would be essential for a more organized brainstorm and collective data sharing...

...


Topic 1:
Personally, I view my contributions as just things brought to the table.  They may or may not get used.  As far as using more complicated variants, I see that work as scouting missions to see what is out there.  But that path may not be followed.  Afterall, it has not been shown that strapping 8 essentially unmodified CCBs together can be done.  Thermal and structural loading may squash that idea.  But that is probably far down the road.

Topic 2:
I do agree that somehow numbers and concepts need to get organized.  Digging through posts, for me, is a challenge.  Does someone have ideas on a good way of showing what the current snapshot of the data for the main trunk and branches are?  Some sort of versioning system.  ( :P, my mind is blanking on the name and acronym for the methodology/software to organize project data)

Topic 3:
Antonio, how did you account for varying thrust with altitude?

Edit:
Oh, now I remember, Product Data Management (PDM), Though something along the lines of CVS may be good enough.  I guess there are many ways.
Edit 2:
Or Content Management System (CMS)
Title: Re: AJAX Launcher
Post by: martin hegedus on 10/22/2010 08:34 pm
How well does the trajectory simulation run (i.e. payload into orbit) match the delta v calculations?
Title: Re: AJAX Launcher
Post by: simcosmos on 10/23/2010 05:54 pm
Hi Martin

(. . . )
Topic 3:
Antonio, how did you account for varying thrust with altitude?
( . . . )


To answer I will need to make a short introduction about the performance implementation method (Orbiter Simulator + Multistage2.dll) that I'm using (hope it isn't too much boring)

Some of the propulsion related parameters that are needed to be included in a stage definition inside a structured INI file being read by Vinka's multistage2.dll are 'Prop. Mass' , 'Thrust' and 'Burn Time':

- The 'Prop. Mass' should be the totality of the main propulsion system propellants contained on the stage (mission prop. + FPR + Residuals)

- The 'Thrust' number should be the maximum vacuum thrust of the stage (sum of the individual max. thrust of the stage engines).

- The 'Burn Time' can be approximated by playing with the rocket equation and should assume the max.  total 'Thrust' ( vac. ISP) burning all the 'Prop. Mass' (if the stage has a cluster of main propulsion engines of different type then the ISP needs to be approximated by a kind of 'weighted average' which can also be achieved by playing a little more with the rocket equation). This 'Burn Time', like the also described 'Prop. Mass' and 'Thrust' values are only some of the input parameters for stage definition / initialization purposes in the simulation environment, for example, the 'Burn Time' isn't necessarily equal to the operational burn time, I mean, the parameter 'Burn Time' is not equal to the time the stage actually burns on the simulation.

Continuing the logic: the operational burn time is the result of ground rules (cutoff command sent once intended injection target is achieved and/or in order to meet FPR / Residuals per ground rules on a nominal simulation case) and takes in account thrust level transitions (either due to sea level to vacuum transition, either related with ignition / cutoff transients simulation or related with power level transitions required to meet other ground rules, for example, such as to not let the vehicle be above maximum accelerations or maximum dynamic pressures limits, etc... emergency / non-100% nominal cases could also be simulated).

Such thrust transitions can be simulated with two multistage2.dll key features:

- Possibility of defining thrust curves for boosters definitions, independently if they are solid or liquid, with an array of  up to 10 points where each entry is composed by CURVEi_(MET (s), % 'Thrust'), i=1 to 10. 

- Another possibility (for central stages / upper stages) is to issue thrust variation commands on the associated guidance file (.txt file which contains the roll and pitch programs, commands for jettison / staging events, thrust commands, etc). 

Martin, the above is just a little of background about the method, there is some documentation at:
http://users.swing.be/vinka/
(for extra information please download the multistage2.dll *full* package zip which contains 'multistage.pdf')

Such multistage2.pdf also contains some of the limitations / constraints of multistage2.dll version although most of them can be worked around if the developer knows what he/she is doing and has some kind of experience with performance implementation methodologies / theory / Orbiter simulation... Will link next to extra information about generic dlls (both multistage and spacecraft dll) which might provide further interesting reading / perspectives:

http://orbiter-forum.com/showthread.php?t=16167
(Orbiter 2010 + spacecraft3.dll + multistage2.dll)

http://orbiter.dansteph.com/forum/read.php?f=5&i=19410&t=19410
(Multistage [3] en version d'essai)

http://orbiter.dansteph.com/forum/read.php?f=5&i=8075&t=7940&page=0
(suggestion pour Multistage3 de Vinka)

http://orbiter-forum.com/showthread.php?t=1755
(Vinka's spacecraft2/3.dll on Orbiter2006P1: payload mass bug on quick save (?))



Now, answering then to your question, about engine performance variation with altitude: a custom dll (I mean, if coding the needed vehicle parameters, guidance information, etc in a dll itself instead of using Vinka's generic dll to act as a bridge between structured INI files and the simulator), would ideally be programmed by coding, in this case, the SL and VAC. parameters of each stage's propulsion and then would call Orbiter's atmospheric model (pressure) to output the thrust values against constant checks / updates of altitude reading... Something like this seems to have been in the plans also for an upgrade to the generic multistage2.dll (multistage3.dll, as seen in some of the links above) but, like everything in Orbiter Community, these things are done in the free times and from quite some time that an update to the Vinka's generic dlls has been in the 'back burner'.

Independently of that, the already mentioned 'thrust curve' and 'guidance file' multistage2.dll features can be used to partially work around the issue. This might be a little hard to explain but, using some iterations, I get an approximation of the pitch profile that matches launcher properties (ex: propulsion / dimensions / mass properties) vs selected ground rules (related with start of pitch program, maxQ, max acc., limits to AOA excursions while in lower atmosphere, etc) which then results in an approximation about where (altitude) the launcher might be at a given MET: with some iterations a good degree of convergence can be achieved in the sense that a trajectory solution can be found which meets a given set of ground rules.  Going back a little, the 'thrust curve' feature and/or 'guidance file' are used to start the stage(s) engine(s) (core / boosters) from 0% up to the percentage corresponding to a selected  SL thrust (usually max. SL thrust) where the 100% of that scale is the maximum vacuum 'Thrust' (the parameter that I mentioned at the start of this post).

Quick example with round numbers:

RD-180 (100%, SL)   : 3827 kN ~  92.17% of multistage2.dll 'Thrust'
RD-180 (100% VAC)  : 4152 kN = 100% multistage2.dll 'Thrust'  = Max. Thrust Input on multistage2.dll INI


Due to time constraints, what I do is to keep a little the SL thrust levels (in the example above, for the RD-180, ~92.15%) while clearing the pad and then make a linear variation so that the 100% multistage2.dll 'Thrust' parameter is achieved higher in the atmosphere from which I assume vacuum conditions. This is the simplest case. Adaptations need to be introduced if assuming power levels changes while in the denser atmospheric flight.

Yes, I know, I know: this requires some previous iterations and it is not very perfect but to do something better would require a bit of extra work (and time)... Which is something I'm planning for other personal (non-released) Orbiter 'addons', where the development work is more stable in terms of 'project' definition,  components properties and, in what regards launch vehicles, ascent guidance pitch program vs ground rules formulation. To do such kind of work when things are fluid might be a  'waste' of time vs the perceived simulation quality gains. Still focusing only on launch vehicles, a custom dll could make some of this SL-to-VAC. transition something more 'automatic' but the generic dlls – as their name suggests – have a few advantages over custom dlls, at least regarding fast virtual prototyping / first order conceptual study (just by using notepad and structured INI  files; even some c++ coders use them before doing custom dlls).

There are a few presentations / white papers / online videos (for example, related with Mars For Less work) that also talk a little about this kind of topic of using Orbiter for various types of 'conceptual brainstorm / virtual prototyping purposes', for example:

http://video.google.com/videoplay?docid=-1246319804290931754#docid=-1792034508676879956







How well does the trajectory simulation run (i.e. payload into orbit) match the delta v calculations?

Not sure if understood the question: what I have presented on III.a) and III.b) of my previous post were simulation results (which again, are preliminary because, among other things, there are conceptual launch vehicle 'details' which need to be better 'coded' as well things related with the ascent guidance which is not yet fully adapted to AJAX-486).


Regarding the dV budgets talk that made on IV.: that was not the result of simulation work but just and only of pocket calculator math :)


Making a little more explicit the given examples:


Being very simplistic with the math (and unless made some typo), this means that the above performance 'result' could allow the upper stage to achieve something like a dV budget of ~3187 m/s  for a gross payload of 55t (adapter + spacecraft) while keeping ~5% of the initial 180t prop. load inside the US...


452*9.807*ln((17500+94762+55000)/(17500+55000+180000*0.05)) ~ 3187 m/s

The above assuming that the 5% margin on EDS would cover boil-off and other performance losses (T/W at TLI start would be ~0.4) while still keeping good FPR / residuals (~2% or so). The 55t could represent something like a 48t spacecraft with the rest being adapter + payload mass margins or, if assuming less / no payload margin (although still keeping FPR / Residuals), could represent ~1t adapter + 54t spacecraft.



In terms of enhanced mission modes (for example, AJAX-486 launching that upper stage alone + depots at start / ending places + longer duration kits added to the upper stage, etc) that upper stage could allow a dV of about 4200 m/s from LEO: this would be enough to do TMI of about 75t to 80t or to insert such kind of mass into low lunar orbit or to consider departure from EML2 (after refill) of  heavy payloads...

The above was assuming that the basic upper stage design of my previous post would be modified – with the addition of kits - for longer space endurance (low boil-off, EDIT: and other modifications on power, debris protection, etc) and to be filled by depots, where such extra kits mass + part of payload adapter  would be  represented by 10t:

452*9.807*ln((17500+10000+179000+75000)/(17500+10000+75000+180000*0.0223)) ~ 4303 m/s

With almost full tanks and a T/W at start of departure burn of ~0.23 the above ideal dV budget might be able to protect (better detail and simulation required!) TMI of about 4200 m/s or TLI of about 3200 m/s but again, these are just and only pocket calculator calculations. It would not make sense – at least not to me - to do more elaborated brainstorm at this moment and in this thread (although on my own personal musings do have extra research / calculations / simulations made about Exploration mission concepts, for example, one of my focus on such brainstorms is about a 10m diameter upper stage / EDS with about 10x Centaur Load on top of a SDLV  (with SRB or LRB) (http://forum.nasaspaceflight.com/index.php?topic=21938.msg604199#msg604199) but that would require a combination of engines with a little more thrust for the upper stage... exploring something like a 4 x RL-60 cluster around a single J-2S – not J-2X - seems to present a number of advantages for several different mission modes).

The comment about 4200 m/s budget being OK for either TMI or TLI+MCC+LOI (rough example: 3200+25+975) is based on reports / papers about dV requirements. 


To end, in what regards Orbiter Simulator Trajectory planning (not sure if it was this what was being asked?), there are some tools such as...

TransX:
http://www.orbitermars.co.uk/
http://orbiter.quorg.org/
http://flytandem.com/orbiter/tutorials/

or Interplanetary-MFD:
http://koti.mbnet.fi/jarmonik/Orbiter.html

… as well there are some other tools for ascent / landing 'autopilots' (both for bodies with and without atmosphere).

But this thread is more about AJAX launcher, which probably needs to be slightly better 'defined' (even if just in a very first order) in a number of aspects before, on my opinion, extra more detailed work focus could move to conceptual spacecraft / payloads and mission design with such kind of tools utilization (and that is why only used the pocket calculator on the quick examples above).

Martin, not sure if answered the questions (?).

António
Title: Re: AJAX Launcher
Post by: HappyMartian on 10/24/2010 01:22 pm
Heads up! This may also be relevant for the future of AJAX. Environmental protection is a very sensitive issue. Politics is a skittish animal.

Here's the original release.

Soot from space tourism rockets could spur climate change.

Rocket exhaust could become a significant contributor to global climate change in coming decades, according to a new study. The research finds that soot emitted by rockets — not their carbon dioxide emissions — has the greater potential to contribute to global climate change in coming decades.
.......

The research was funded by The Aerospace Corporation and NASA.

www.agu.org/news/press/pr_archives/2010/2010-34.shtml


Cheers!
Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/25/2010 02:21 pm
Heads up! This may also be relevant for the future of AJAX. Environmental protection is a very sensitive issue. Politics is a skittish animal.

Here's the original release.

Soot from space tourism rockets could spur climate change.

Rocket exhaust could become a significant contributor to global climate change in coming decades, according to a new study. The research finds that soot emitted by rockets — not their carbon dioxide emissions — has the greater potential to contribute to global climate change in coming decades.
.......

The research was funded by The Aerospace Corporation and NASA.

www.agu.org/news/press/pr_archives/2010/2010-34.shtml


Cheers!


Not interested, don't believe it has much bearing (see my comments on that thread). Turns out the person who wrote that thread presented the study all wrong. Also  turns out there are many questions regarding the study itself. So no, I don't think has any bearing especially since SRBS would be far worse, IMO, than liquid boosters.
Title: Re: AJAX Launcher
Post by: HappyMartian on 10/26/2010 01:02 pm
Heads up! This may also be relevant for the future of AJAX. Environmental protection is a very sensitive issue. Politics is a skittish animal.

Here's the original release.

Soot from space tourism rockets could spur climate change.

Rocket exhaust could become a significant contributor to global climate change in coming decades, according to a new study. The research finds that soot emitted by rockets — not their carbon dioxide emissions — has the greater potential to contribute to global climate change in coming decades.
.......

The research was funded by The Aerospace Corporation and NASA.

www.agu.org/news/press/pr_archives/2010/2010-34.shtml


Cheers!


Not interested, don't believe it has much bearing (see my comments on that thread). Turns out the person who wrote that thread presented the study all wrong. Also  turns out there are many questions regarding the study itself. So no, I don't think has any bearing especially since SRBS would be far worse, IMO, than liquid boosters.



What I want to know is who paid for this study?

That information would likely point towards the motivation behind it.

If it was an environmental group, then I would suppose that they are just beginning to ramp-up to make this an 'issue'.

If it was one of the rival companies who paid for this, then this is probably an attempt to scuttle a New.Space company before they get established in the marketplace as a rival.

Which is it?

Ross.

Strange. You know, in my twisted sense I was going over this in my head this weekend thinking along similar lines. Not saying this is so, but I have to wonder if this was done as a cover for the 'real' reason for such a study: the SRBs. What better way to shed bad light on a SD-HLV design, or get back at ATK, then to run a study to gain favour with liquid boosters (IE: AJAX design). Commercial just gets to be a pawn in all this, not surprising.

Again, not saying this is so, just a thought I had.


My thinking goes in a twisted direction similar to Robertross's wondering. Like I said, "Heads up! This may also be relevant for the future of AJAX. Environmental protection is a very sensitive issue. Politics is a skittish animal."

FinalFrontierour, your comment, "So no, I don't think has any bearing especially since SRBS would be far worse, IMO, than liquid boosters" hits the nail on the head. The research could have a direct bearing on the SLS or ALEX politics question. Or should I say the ALEX as SLS politics question.

Politics, like physics, should be based on reality. However politics is sometimes not just about a scientific reality. The elite's and general public's multiple perceptions or visceral interpretations of an issue can also be important. I like the ALEX Launcher. However, I see it as an evlolution of the J-130/J-140. Let's hope the Orion/SLS/J-130/J-140 is flying sooner rather than later. And once the SLS is defined, more work will be needed on the AJAX Launcher.

Cheers!

Edited.
Title: Re: AJAX Launcher
Post by: sdsds on 10/26/2010 06:06 pm
To answer I will need to make a short introduction about the performance implementation method (Orbiter Simulator + Multistage2.dll) that I'm using

Thanks for providing this.  Do I understand correctly that with multistage2.dll, the ascent guidance is largely open loop?  That is, ascent maneuvers are triggered at a given Mission Elapsed Time, and there isn't much (or any) provision for specifying maneuvers that are triggered at e.g. a given altitude?

I'm guessing this would be fine for AJAX simulations at this point in the effort.  Do others concur, or are there some aspects of ascent that can't be adequately captured that way?
Title: Re: AJAX Launcher
Post by: Downix on 10/26/2010 07:56 pm
Heads up! This may also be relevant for the future of AJAX. Environmental protection is a very sensitive issue. Politics is a skittish animal.

Here's the original release.

Soot from space tourism rockets could spur climate change.

Rocket exhaust could become a significant contributor to global climate change in coming decades, according to a new study. The research finds that soot emitted by rockets — not their carbon dioxide emissions — has the greater potential to contribute to global climate change in coming decades.
.......

The research was funded by The Aerospace Corporation and NASA.

www.agu.org/news/press/pr_archives/2010/2010-34.shtml


Cheers!


Not interested, don't believe it has much bearing (see my comments on that thread). Turns out the person who wrote that thread presented the study all wrong. Also  turns out there are many questions regarding the study itself. So no, I don't think has any bearing especially since SRBS would be far worse, IMO, than liquid boosters.



What I want to know is who paid for this study?

That information would likely point towards the motivation behind it.

If it was an environmental group, then I would suppose that they are just beginning to ramp-up to make this an 'issue'.

If it was one of the rival companies who paid for this, then this is probably an attempt to scuttle a New.Space company before they get established in the marketplace as a rival.

Which is it?

Ross.

Strange. You know, in my twisted sense I was going over this in my head this weekend thinking along similar lines. Not saying this is so, but I have to wonder if this was done as a cover for the 'real' reason for such a study: the SRBs. What better way to shed bad light on a SD-HLV design, or get back at ATK, then to run a study to gain favour with liquid boosters (IE: AJAX design). Commercial just gets to be a pawn in all this, not surprising.

Again, not saying this is so, just a thought I had.


My thinking goes in a twisted direction similar to Robertross's wondering. Like I said, "Heads up! This may also be relevant for the future of AJAX. Environmental protection is a very sensitive issue. Politics is a skittish animal."

FinalFrontierour, your comment, "So no, I don't think has any bearing especially since SRBS would be far worse, IMO, than liquid boosters" hits the nail on the head. The research could have a direct bearing on the SLS or ALEX politics question. Or should I say the ALEX as SLS politics question.

Politics, like physics, should be based on reality. However politics is sometimes not just about a scientific reality. The elite's and general public's multiple perceptions or visceral interpretations of an issue can also be important. I like the ALEX Launcher. However, I see it as an evlolution of the J-130/J-140. Let's hope the Orion/SLS/J-130/J-140 is flying sooner rather than later. And once the SLS is defined, more work will be needed on the AJAX Launcher.

Cheers!

Edited.

[/quote\]
If emissions do become the "must solve this nao" issue, we can switch from the Atlas V CCB to the Delta IV CBC, as this is still a paper rocket.  We loose payload, but the T/W problems all but vanish. Also it would take more time, as a man-rated Delta is not on the table, while a man-rated Atlas is.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 10/26/2010 11:53 pm
If this became an issue in future I think we would actually be better off as we are now. Reason being is that even though Atlas burns kerolox, it does not produce anywhere near the kind of pollution that the SRB does meaning that we would actually be in a perfectly fine position politically. If it was absolutely necessary we could, as Downix said, switch to the all hydrogen configuration. But right I think that we should not try to change our concept based on this *study* None of the information in that study is valid, IMO, because it has not been experimentally proven or quantified with an actual data collection experiment that actually flies lots of rockets and takes measurements to determine the effects, nor has a scaled down experiment been done to determine this. Now there should be further investigation into the matter of rockets and climate change, but that is not our concern, IMHO as this thread is dedicated to AJAX.

I would like to return to discussion on AJAX.
Regarding the delta 4 configuration. I would like to discuss that further, perhaps on a thread delegated to it because the primary configuration using Atlas is still not finished yet. Would also like to discuss how quickly that could be implemented, mainly because it does bring quite a few benefits in the way of T/W improvements.

Also, was wondering about the fuel/oxidizer configuration for the boosters. Since we are going to use a shortened core, would we then be operating at 100% full for the boosters? Regarding the core, was wondering if there is a rough estimate on how much shorter (in feet or meters) it would need to be to achieve the needed T/W ratio.
Title: Re: AJAX Launcher
Post by: Downix on 10/27/2010 01:00 am
If this became an issue in future I think we would actually be better off as we are now. Reason being is that even though Atlas burns kerolox, it does not produce anywhere near the kind of pollution that the SRB does meaning that we would actually be in a perfectly fine position politically. If it was absolutely necessary we could, as Downix said, switch to the all hydrogen configuration. But right I think that we should not try to change our concept based on this *study* None of the information in that study is valid, IMO, because it has not been experimentally proven or quantified with an actual data collection experiment that actually flies lots of rockets and takes measurements to determine the effects, nor has a scaled down experiment been done to determine this. Now there should be further investigation into the matter of rockets and climate change, but that is not our concern, IMHO as this thread is dedicated to AJAX.

I would like to return to discussion on AJAX.
Regarding the delta 4 configuration. I would like to discuss that further, perhaps on a thread delegated to it because the primary configuration using Atlas is still not finished yet. Would also like to discuss how quickly that could be implemented, mainly because it does bring quite a few benefits in the way of T/W improvements.

Also, was wondering about the fuel/oxidizer configuration for the boosters. Since we are going to use a shortened core, would we then be operating at 100% full for the boosters? Regarding the core, was wondering if there is a rough estimate on how much shorter (in feet or meters) it would need to be to achieve the needed T/W ratio.
Well a DIV based model, using the standard Jupiter core, not our shrunk AJAX core:
420: T/W 1.77  38 mT
440: T/W 1.23  66 mT
460: T/W 1.27  94 mT
480: T/W 1.29  115 mT
But again, no man-rated Delta IV, so this has an additional roadblock which the Atlas does not.
Title: Re: AJAX Launcher
Post by: Halidon on 10/27/2010 04:53 pm
Well a DIV based model, using the standard Jupiter core, not our shrunk AJAX core:
420: T/W 1.77  38 mT
440: T/W 1.23  66 mT
460: T/W 1.27  94 mT
480: T/W 1.29  115 mT
But again, no man-rated Delta IV, so this has an additional roadblock which the Atlas does not.
Not to go too far down the rabbit hole, what about Delta-diameter RP-1 (fat Atlas) boosters?
Title: Re: AJAX Launcher
Post by: Downix on 10/27/2010 06:35 pm
Well a DIV based model, using the standard Jupiter core, not our shrunk AJAX core:
420: T/W 1.77  38 mT
440: T/W 1.23  66 mT
460: T/W 1.27  94 mT
480: T/W 1.29  115 mT
But again, no man-rated Delta IV, so this has an additional roadblock which the Atlas does not.
Not to go too far down the rabbit hole, what about Delta-diameter RP-1 (fat Atlas) boosters?
Worse T/W, you'd have more weight for the same thrust. 

*however* if you pair that with two RD-180's, a la Atlas Phase II, then we're talking about a huge boost in T/W *and* payload.
Title: Re: AJAX Launcher
Post by: Halidon on 10/28/2010 05:40 am
Well a DIV based model, using the standard Jupiter core, not our shrunk AJAX core:
420: T/W 1.77  38 mT
440: T/W 1.23  66 mT
460: T/W 1.27  94 mT
480: T/W 1.29  115 mT
But again, no man-rated Delta IV, so this has an additional roadblock which the Atlas does not.
Not to go too far down the rabbit hole, what about Delta-diameter RP-1 (fat Atlas) boosters?
Worse T/W, you'd have more weight for the same thrust. 

*however* if you pair that with two RD-180's, a la Atlas Phase II, then we're talking about a huge boost in T/W *and* payload.
That's indeed what I intended, sorry for the oversight of not listing dual 180s.
Title: Re: AJAX Launcher
Post by: Downix on 10/28/2010 05:57 pm
Well a DIV based model, using the standard Jupiter core, not our shrunk AJAX core:
420: T/W 1.77  38 mT
440: T/W 1.23  66 mT
460: T/W 1.27  94 mT
480: T/W 1.29  115 mT
But again, no man-rated Delta IV, so this has an additional roadblock which the Atlas does not.
Not to go too far down the rabbit hole, what about Delta-diameter RP-1 (fat Atlas) boosters?
Worse T/W, you'd have more weight for the same thrust. 

*however* if you pair that with two RD-180's, a la Atlas Phase II, then we're talking about a huge boost in T/W *and* payload.
That's indeed what I intended, sorry for the oversight of not listing dual 180s.
Part of the idea with AJAX is that this would be the push.  ULA wants Phase II, but cannot validate the funding without a customer to pay for the R&D.  AJAX would enable NASA to be that customer without stepping on toes or violating mandates.  However, first we'd need a working AJAX model using the existing CCB's, before any Phase II work has begun, as a bridge and proof of concept.  Phase II would improve the performance dramatically.  In addition, I could see it getting Phase I handled as well, by paying for ACES development.  It would be a win-win for both NASA and ULA, giving the necessary development without the gap.

If Phase II were pushed immediately, there would be a gap, uncertainty, and a likely cancellation of project, too many new things.  By instead starting off with a minimal R&D approach, just the new core, we get the system on-line.  THEN we start with upgrades.  First an upper stage, if not a JUS then the same ACES as Delta IV and Atlas V.  Unified upper stages would be a huge improvement, and help develop orbital refueling.  Once that is accomplished, Phase II work starts.  All of the meantime, we still have a fully operational vehicle.  It becomes a smooth transition, and a solid space platform.
Title: Re: AJAX Launcher
Post by: simcosmos on 10/29/2010 11:54 am
I. Multistage2.dll Guidance and Extra Notes About Performance Implementation in Orbiter Simulator

To answer I will need to make a short introduction about the performance implementation method (Orbiter Simulator + Multistage2.dll) that I'm using

Thanks for providing this.  Do I understand correctly that with multistage2.dll, the ascent guidance is largely open loop?  That is, ascent maneuvers are triggered at a given Mission Elapsed Time, and there isn't much (or any) provision for specifying maneuvers that are triggered at e.g. a given altitude?

I'm guessing this would be fine for AJAX simulations at this point in the effort.  Do others concur, or are there some aspects of ascent that can't be adequately captured that way?

Yes, in multistage2.dll the commands contained on the guidance file are triggered by mission elapsed time, with the minor 'exception' of one command that, once triggered, then seeks for apogee values to cut-off the engine(s), although must write  that until now I think that haven't used such command on my files (I prefer to use other cut-off methods).

What I will write next can be applied to multistage2.dll or to other methods of implementation in Orbiter simulator (for example, by coding a custom dll) or to other simulation software / tools:

The realism / assessment detail of an ascent simulation passes (among several other things related with the methodology of implementation of the launcher's input parameters and related with simulation 'environment' ) by defining and obeying to realistic ground rules, such as, for example, to build an ascent profile within some constraints related with limits to AOA maximum excursions (in particular while in the lower atmosphere), pitch rates, eventual maximum accelerations limits and – again regarding lower atmosphere – also keeping an eye at aerodynamic loads protection, etc, or to only send the payload fairing jettison command at a proper set of conditions, things like that.


I.a) Eventual future versions of Vinka's generic dlls or a custom made dll or other external 'addons' / plug-ins / tools interactions can provide more advanced features / algorithms related with any of the following items:

- more advanced vehicle parameters (including payload integration advanced features)
- guidance / ascent optimization (including giving extra 'brains' to the vehicle for closed loop guidance)
- advanced systems simulation
- related with the above, failure modes / dispersions / off-nominal situations (by assigning some probabilistic model)
- related with the above, damage simulation
- (other, for example, weather simulation...)

 
That is why I wrote, on previous post, that multistage2.dll / Vinka's nice generic dlls are only the tip of the iceberg of what can be done in and with Orbiter Simulator... The beauty of Vinka's generic dlls (both multistage and spacecraft dlls) is that they are generic enough to be adapted to a wide range of launch vehicle and spacecraft configurations and all that just by using a simple text editor... On the other hand, this requires the user to know what he/she is doing being that the amount of effort the developer puts into a given multistage.dll (or spacecraft.dll) .INI implementation is also dependent of the target audience, specific objectives of the 'exercise' and, as always, is dependent of available free time (but all this is also valid if choosing to use c++ to code a custom dll)...

In any case, despite being essential for the developer and users to be perfectly aware of what are the constraints of a given implementation method would also like to note that, with a little of imagination, some of such constraints can be 'worked around', using already provided features. Beyond that, other tools can also be used *together* with the generic dlls or with custom dlls (for example, to try some further optimisation of trajectory instead aiming for convergence by doing a kind of iterative 'manual' procedure or to implement some of the advanced features referenced above)... Such additional tools do not necessarily need to be closely related with Orbiter Community work... For a better perception of Orbiter Simulator capabilities I recommend a visit to the related media page (and the download of a few documents available there, for example, the older 2004/2006 ESTEC presentations):
http://orbit.medphys.ucl.ac.uk/media.php

Another thing that also helps is to study / read a 'few' things about the theory behind what is being done (in this particular case, related with performance implementation, guidance and trajectory optimization) as well to make some 'hands-on' virtual experimentation of ascent strategies ;)


I.b) In what relates to open-loop vs closed-loop guidance, I seem to remember some papers - in particular one paper (?) / study (?) - where that kind of topic was analysed (for several launcher configurations, based on NLS). Do not remember the year (would need to check the download archives to see if can find the reference) but, as far as remember, the conclusion seemed to be that open-loop, or better,  optimized open-loop might be preferable for the lower atmosphere (although the variation with MET was the most sensitive to dispersion of results when comparing with commands sent vs altitude or velocity... on the other hand, on a 'nominal' Orbiter simulation session case there aren't many dispersions being introduced... unless using extra resources to implement such... that kind of statistical analyses is probably better made with other software).

After maxQ and when higher in the atmosphere (usually on the later burn portion of boosters / first stage, depending also of specific launch vehicle), something like a closed-loop guidance might have several advantages but an optimized open-loop guidance solution might also be competitive (although requiring extra 'ground' effort, even more for extra analysis if the launch vehicle is to be crewed...). If also remembering well – would need to check – SaturnV was open-loop for the lower atmosphere / first stage then closed-loop for the second stage / third stage then again partially open-loop, at least for the later part of the third stage (but again, would need to double check that and other related things, for example about STS and about EELV, meanwhile someone please feel free to correct or add input about the topic, thanks!).


I.c) Transposing all this to multistage2.dll, in a first instance, the ascent guidance optimisation might depend of an iterative procedure where the trajectory is optimised by parts before such parts being 'glued' together (I personally try to not 'mess up' too much while in the lower atmosphere, for example, if aiming for 'safer' quality simulation,  by trying to keep AOA excursions within ~2 degrees or so or by making some assumptions for the pitch variation rate, etc).

The above paragraph to write that with a given set of several ground rules plus the early 'flight' properties of a given launcher  it is possible to constraint the trajectory in what regards conditions for the start / implementation of pith program and that has then an effect in keeping the trajectory within a specific 'envelope' (this is also related with some extra considerations related with payload 'type'...): once higher in the atmosphere I then try to do what a closed-loop guidance would do, for example, allowing an higher limit for AOA variations... it is a bit hard to explain... Some study of other launch vehicles ascent trajectories (historical, contemporary or conceptual) might also help to find a solution convergence. Beyond this there could also exist a few other options (such as using other addons / plug-ins available in Orbiter Community) to guide the vehicle vs intended injection goals but I usually try to avoid external requisites (when releasing stuff) and do all with multistage2.dll... This do not necessarily means that other tools might not be used during the development phase of a multistage2.dll guidance file...





II. Multistage2.dll: still about SL-to-VAC transition

Following my last post I would also perhaps like to go back to the topic of SL-to-VAC simulation with multistage2.dll and add a few extra comments in what regards eventually slightly better way(s) to implement such transition.

For example, what I have done until now for AJAX is not (not yet) one of those 'slightly better' ways, due to time constraints... One of the alternative strategies that I'm using in other (non-released) projects might also not be perfect but it might be slightly more 'advanced': like have hinted on the previous post, it is all about using the atmospheric model to extract pressure values vs altitude and then use such data points as one of the input parameters (other parameters are related with engine specs) of a function that outputs the thrust for a given altitude... In a custom programmed dll such kind of function (or stuff such as active guidance 'brains')  could  work in a more 'automatic' way (contained and making the calculations in 'real time' within the dll itself)... In multistage2.dll / generic dlls - as is the case if wishing to implement features not directly supported by default on a given version of the generic dll - things sometimes need to be slightly more 'manual', I mean, the implementation of such kind of function requires previous 'out-of-the-simulation' work on a spreadsheet software with the product of such work then being implemented on multistage2.dll via input parameters on the already mentioned thrust curve and/or guidance file supported features (not sure if was able to explain?).

That thrust function - with an exponential factor containing parameters related with engine specs, pressure - can be approximated with about 3 or 4 linear functions of 'Thrust vs MET' (to be implemented on thrust curve  and guidance file). Such function might not be exactly what really happens in real world... it might be more a mathematical expression... but at least results in SL and VAC. thrust in the extreme intervals and the variation seems to be in accordance with pressure variation in the atmosphere. It might be good enough for first order simulations, in particular if already having some previous optimization work done on the guidance file (which is also not really the case for the AJAX 'stuff' that, at least from my side, I have shared until now, much less for the AJAX-486! 'example' recently shared!).





III. Final Comments (Generic Thoughts about AJAX Brainstorm)

As always, extra work / study would be required although - as mentioned on another occasion - I'm currently slightly 'reluctant' to further think about doing that vs time that could be used for other things vs slightly better definition of current AJAX brainstorm goals (v1.0 = AtlasV LRB(?)), for example, about if there is the wish or not to strictly protect for liftoff T/W of at least 1.17 up to 1.2 while only assuming nominal start and verification engine sequences vs the impact of such 'strict protection' choice on several other things, for example, related with aspects of the simulation / ascent work or related with comparing the resulting conceptual design assumptions with other launch vehicle / architecture alternatives... all that vs eventual future changes in AJAX brainstorm direction / goals (v2.0?) which might happen in the relatively near-time (once extra SLS details are known).

I also continue to have some doubts about the relation of something like AJAX 'v1.0' with something like what can become AJAX 'v2.0': have seen some interpretations / comments on this thread which, on my opinion, offer perspectives about this topic which might not be exactly 'compatible' in terms of opinions about what should be 'v1.0' and what could be 'v2.0' vs eventual  'transition' / relations between 'v1.0' and 'v2.X'...

Meanwhile, and independently of some currently existing less defined topics related with performance assessment comparisons (discussion, common definition and agreement about several key input / verification / goals data for everybody to use and be on the same page, for example, regarding components mass and performance specs, agreement on ground rules and injection targets or related with further specification of different methods being used for performance estimation in order to allow for better comparisons across methods) I have then been writing these looooong comments and development notes to share a little more about the input parameters / ground rules / method that I'm using here to roughly estimate first order performances as well have been sharing some very preliminary (non finished / non optimised) related simulation outputs, within the possibilities. Assuming that there might exist a collective wish to slightly improve some things of the current AJAX v1.0 (?) brainstorm, the time might be close to reach some agreement on a number of topics. Without such kind of agreement towards the definition of what I would call of a consolidated 'departure point' it might become harder to try to slightly improve the quality of some selected aspects of the discussion (at least from my side of the Net).

Thanks,
António
(back to lurker mode)

Title: Re: AJAX Launcher
Post by: Downix on 10/30/2010 07:12 am
A random thought just hit me, reading up on the Soyuz-1 and how the inclusion of steering engines also helps T/W....

What if we included 4 RL-10's as steering engines, with the added benefit of the extra thrust for takeoff *and* they can restart for orbital insertion and de-orbiting as well.

Just random thinking.
Title: Re: AJAX Launcher
Post by: sdsds on 10/30/2010 07:52 pm
In my view, the difficulty AJAX designers seem to face right now is in providing well-supported values for the burnout mass of a "short" AJAX core and boosters.  For the boosters, only the nose cones are of uncertain mass; all else can come from ULA specs for the Atlas CCB.  For the core, we need mass targets for the tanks themselves, the thrust structure and plumbing, the payload fairing, the spacecraft adapter, propellant residuals and miscellany such as avionics.

We need mass targets for these that are achievable, and for which the design efforts needed to achieve the targets are well understood.

With those masses, and with agreed upon values for engine maximum thrust and Isp, we can fairly easily (i.e. via Schilling) get a payload mass which the vehicle could with good confidence loft to 185x185km LEO.

Then using that payload mass and the other mass targets we can simulate (e.g. using Orbiter multistage2.dll) an actual ascent trajectory that demonstrates the vehicle could reach that orbit while staying within all trajectory constraints.

Each step is dependent on those that come before.  Have we yet achieved the first step, i.e. agreed on defensible mass targets?
Title: Re: AJAX Launcher
Post by: FinalFrontier on 11/02/2010 02:46 am
Hello everyone. Glad to see that things are going well with the AJAX concept :) I would like discuss setting up a new thread, to be associate with AJAX. This thread would be dedicated to discuss the "Delta 4+ SDLV core" option which we have talked about several times but never gotten into in detail. The main reason is that it appears nearly certain that AJAX would be the quickest, cheapest, all liquid SDLV considering the extra cost of modifying delta 4 and man rating it. That said, I would still like to open discussion into that concept, but on a separate thread so as not to gum up discussion on the primary concept, AJAX.

Thoughts on this idea?
Title: Re: AJAX Launcher
Post by: FinalFrontier on 11/02/2010 03:07 am
In my view, the difficulty AJAX designers seem to face right now is in providing well-supported values for the burnout mass of a "short" AJAX core and boosters.  For the boosters, only the nose cones are of uncertain mass; all else can come from ULA specs for the Atlas CCB.  For the core, we need mass targets for the tanks themselves, the thrust structure and plumbing, the payload fairing, the spacecraft adapter, propellant residuals and miscellany such as avionics.

We need mass targets for these that are achievable, and for which the design efforts needed to achieve the targets are well understood.

With those masses, and with agreed upon values for engine maximum thrust and Isp, we can fairly easily (i.e. via Schilling) get a payload mass which the vehicle could with good confidence loft to 185x185km LEO.

Then using that payload mass and the other mass targets we can simulate (e.g. using Orbiter multistage2.dll) an actual ascent trajectory that demonstrates the vehicle could reach that orbit while staying within all trajectory constraints.

Each step is dependent on those that come before.  Have we yet achieved the first step, i.e. agreed on defensible mass targets?
Very true. We do have some targets, mainly STS and DIRECT based. But you are correct that we need to generate our own.
Title: Re: AJAX Launcher
Post by: sdsds on 11/02/2010 05:06 am
Two questions:

1. DIRECT must have examined the 4 SSME configuration for J-24x.  Were the STS propellant feedlines (17 inch) deemed sufficient?

2. The AJAX intertank should be markedly less massive than that of STS or Jupiter, because the crossbeam is deleted but also because the other SRB-related strengthening in that area can be deleted.  As a first-order estimate, though, AJAX takes that mass back in additional strengthening lower in the core, to carry the loads from the LRBs.  The major reduction in dry mass for the AJAX core thus comes from the shortening.  Over the range of tank sizes which might be considered, is a 2:1 percentage ratio an appropriate estimate, i.e. for every 2% of propellant reduction is the dry mass reduced by about 1%?
Title: Re: AJAX Launcher
Post by: FinalFrontier on 11/02/2010 05:29 am
Two questions:

1. DIRECT must have examined the 4 SSME configuration for J-24x.  Were the STS propellant feedlines (17 inch) deemed sufficient?

2. The AJAX intertank should be markedly less massive than that of STS or Jupiter, because the crossbeam is deleted but also because the other SRB-related strengthening in that area can be deleted.  As a first-order estimate, though, AJAX takes that mass back in additional strengthening lower in the core, to carry the loads from the LRBs.  The major reduction in dry mass for the AJAX core thus comes from the shortening.  Over the range of tank sizes which might be considered, is a 2:1 percentage ratio an appropriate estimate, i.e. for every 2% of propellant reduction is the dry mass reduced by about 1%?
1. Yes believe it was sufficient.
2. Not sure, need to ask Antonio and DIRECT about that.
Title: Re: AJAX Launcher
Post by: sdsds on 11/02/2010 08:26 am
Thanks for those responses!

To encourage further discussion of details I'm attaching a snapshot of my current delta-v based ascent performance analysis for AJAX-440.  It should be self-explanatory ;) but I'll provide a narrative description here anyway.

The target orbit is 130x130nmi (240x240km) at 30deg.  Orbital velocity at that altitude is 7,761 m/s.  The planned ascent duration is less than 8.5 minutes, so a delta-v penalty for atmospheric and gravity losses of 2,000 m/s is assumed.  The ascent thus requires 9,761 m/s of performance.

This performance is achieved for a 70 t (metric ton) payload using a core with a 670 t gross propellant capacity.  This is 91% of the capacity of the J-130 core.  The dry mass of the AJAX core is assumed to be 96% of the J-130 core dry mass, or just under 61 t.  Residual propellant left in the core at MECO is assumed to be 1.25% of the total.

Propellant requirements for engine startup are approximated by 5 seconds of combustion which provide no delta-v.  The SSMEs are then ramped up to 109% thrust, providing a thrust/weight ratio of 1.15.  This thrust level is maintained for 45 seconds at which point SSME thrust is throttled back to 67%, which is now sufficient to provide a T/W ratio of 1.2.  These engine settings are maintained for an additional 135 seconds at which point vacuum engine characteristics are assumed.  The RD-180s are throttled to 62% and they burn at that level for 84 seconds before being shut down and jettisoned.  Just prior to shutdown the T/W ratio has risen to 2.9.  After LRB jettison the SSMEs are ramped up to 100% thrust and continue to burn at that level for 90 seconds, with T/W again returning to almost 3.0.  That triggers partial MECO, after which two SSMEs continue to burn for another 155 seconds.  Total time from ignition to orbit is 515 seconds and the 7,761 m/s orbital velocity is reached.

Schilling's online calculator estimates the vehicle could loft a payload of 77,902 kg (including fairing etc.) to this orbit.
Title: Re: AJAX Launcher
Post by: HappyMartian on 11/02/2010 09:24 am
Hello everyone. Glad to see that things are going well with the AJAX concept :) I would like discuss setting up a new thread, to be associate with AJAX. This thread would be dedicated to discuss the "Delta 4+ SDLV core" option which we have talked about several times but never gotten into in detail. The main reason is that it appears nearly certain that AJAX would be the quickest, cheapest, all liquid SDLV considering the extra cost of modifying delta 4 and man rating it. That said, I would still like to open discussion into that concept, but on a separate thread so as not to gum up discussion on the primary concept, AJAX.

Thoughts on this idea?

We should keep the "Delta 4+ SDLV core" option in our minds, but for now concentrate on AJAX in order to not distract our brainpower. We also need to keep our collective eyes open for environmental issues with the SRBs.

Cheers!
Title: Re: AJAX Launcher
Post by: martin hegedus on 11/03/2010 04:57 pm
1)  Any recommendations for a Free and/or Open Source FEM package?  I thought if would be fun to gain a little experience with FEA by applying it to AJAX.  Granted, my analysis won't be a "real" analysis (i.e. structure will be very simplified) but it is one step ahead of a stick analysis in regards to fun factor, and cool looking pictures.  The package I'm looking into at the moment is Elmer (http://www.csc.fi/english/pages/elmer).  If there is something better in regards to ease of use and/or analysis capability, please let me know.

2)
Quote
2. The AJAX intertank should be markedly less massive than that of STS or Jupiter, because the crossbeam is deleted but also because the other SRB-related strengthening in that area can be deleted.  As a first-order estimate, though, AJAX takes that mass back in additional strengthening lower in the core, to carry the loads from the LRBs.  The major reduction in dry mass for the AJAX core thus comes from the shortening.  Over the range of tank sizes which might be considered, is a 2:1 percentage ratio an appropriate estimate, i.e. for every 2% of propellant reduction is the dry mass reduced by about 1%?
I don't know the answer but it doesn't seem unreasonable if the dry mass you are referring to is the Shuttle ET rather than the dry mass of the Jupiter core (with engines, thrust structure, etc).

3)  Antonio, thanks for all the information.  It was helpful and someday I hope to try my hand at my own trajectory.  Seems like it takes a bit of time to get a trajectory right.
Title: Re: AJAX Launcher
Post by: clongton on 11/03/2010 06:43 pm
Sorry guys, 17 inch feedline is not sufficient for 4xSSME - it would starve the engines. The Jupiter-246 used 22 inch diameter feedlines.
Title: Re: AJAX Launcher
Post by: gin455res on 11/03/2010 09:49 pm
Seeing as eventually the SLS will be using disposable SSMEs, is there any point re-analysing what the optimum expansion ratio for this modded engine would be in the three stage configuration? And how difficult or easy would it be to alter this?

Perhaps, sacrificing a little vacuum isp for greater thrust at sea level would improve system performance. So it might be worth taking a hit while using up the lower thrust shuttle engines (or in the interim use small solid augmentation), to benefit from improved payload down the line.
Title: Re: AJAX Launcher
Post by: sdsds on 11/03/2010 10:29 pm
eventually the SLS will be using disposable SSMEs [...] this modded engine [...] greater thrust at sea level

In a word, "Yes."

But there's more, including "modifications" that don't require changes to the hardware!  AJAX needs the 109% thrust level from four SSMEs, but only for the first 45 seconds of flight.  Thereafter it could pretty much get to orbit with one engine out.  So really why restrict the engines to "only" 109% thrust?  Given the level of instrumentation already on the engines why not crank them up even further, knowing that if one were heading towards early failure it would be detected and could be shut down without compromising the mission?

I see AJAX keeping all these possibilities as "pocket reserves."  In the hypothetical situation where the notion was granted authorization to proceed but then a detailed analysis showed a performance shortfall, these reserves could be called upon to assure design "closure."
Title: Re: AJAX Launcher
Post by: FinalFrontier on 11/04/2010 04:02 am
Sorry guys, 17 inch feedline is not sufficient for 4xSSME - it would starve the engines. The Jupiter-246 used 22 inch diameter feedlines.
So we would need the upgraded feed line as well since we are using a Common Core. Will need to factor this in to mass target/ T/W calcs. Shouldn't make too much of a difference, but then again we gotta be sure.
Title: Re: AJAX Launcher
Post by: Downix on 11/06/2010 08:36 pm
The development on the all-liquid SDLV thread, with a 6-engine SSME core, got me to thinking.  With 6 SSME, the core if properly done can lift itself, and a payload of up to 30mT.  If you add CCB's, you then get a seriously powerful lifter.  Add a JUS to a 686, and we're looking at almost 200mT, and that's with the JUS burning only half of it's fuel, retaining the left for use as EDS.
Title: Re: AJAX Launcher
Post by: Patchouli on 11/07/2010 12:58 am
The development on the all-liquid SDLV thread, with a 6-engine SSME core, got me to thinking.  With 6 SSME, the core if properly done can lift itself, and a payload of up to 30mT.  If you add CCB's, you then get a seriously powerful lifter.  Add a JUS to a 686, and we're looking at almost 200mT, and that's with the JUS burning only half of it's fuel, retaining the left for use as EDS.

You just reinvented Energia Vulkan which is a take you to Mars type of LV.
http://www.k26.com/buran/Info/Hercules/vulkan.html

I think if that vehicle configuration is chosen it should be designed with that kind of expansion in mind from the start the block I able to handle at least four Atlas CCBs or F9 cores and the block II being able to accept eight of them.

Not sure it it would be possible to design it to accept either LRB but it would be nice to have two LRB suppliers.

Attachment points and electrical connections would be different and the F9 core esp the proposed Merlin 2 variant is higher thrust to weight which means a different burn profile.
Title: Re: AJAX Launcher
Post by: Downix on 11/07/2010 03:57 am
It could also be a compromise design this way.  I did some checking, and with the shrunken core of AJAX, we can liftoff with 6 engines and deliver 36 mT in a 600 config.  Now the CCBs are gravy.
Title: Re: AJAX Launcher
Post by: Patchouli on 11/07/2010 06:26 am
It could also be a compromise design this way.  I did some checking, and with the shrunken core of AJAX, we can liftoff with 6 engines and deliver 36 mT in a 600 config.  Now the CCBs are gravy.

I still prefer the four SSME four CCB vehicle as there is no need for a 36MT configuration it's too close to planned Delta IV-H upgrades and F9-H with Raptor to justify it's cost.

Some very smart people came to a very similar design to AJAX on Energia and it could scale to 175MT in a 51 degree orbit which means pretty much equal to Ares V.

A cut down Energia core probably could reach orbit with six RD-0120s but they did not do this for good reason it would be more expensive then Proton.

Instead they proposed replacing Proton eventually with Energia M a cut down core with one RD-0120 and two Zenits but then the USSR fell.
Energia M would have lifted 34MT.
http://www.buran-energia.com/energia/energia-M-desc.php
Title: Re: AJAX Launcher
Post by: clongton on 11/07/2010 11:34 am
Hmm. 36mT isn't too shabby. Think of it this way. USAF wanted two EELV's to ensure rides to orbit in the 20-25mT range. They got them in the Atlas-V and Delta-IV. If this All Liquid configuration were available, where the core by itself would fly 36mT to LEO, and was totally scalable to meet all the medium and heavy lift requirements of NASA, then I think one of the EELV's would likely become extinct. My prediction would be that Delta would be phased out, leaving Atlas-V and SLS as the LV capabilities of the US gov. DoD obviously has no problem using the RD-180 for it's payloads, but I'd be willing to bet that the President's plans to do new engine development would eventually lead to a new kerolox engine on the Atlas - all American. At that point there'd be no problem adapting the Atlas as the US CLV and also as the CCB on an AJAX-style configuration of the All Liquid launcher.

Just musing here.
Title: Re: AJAX Launcher
Post by: Downix on 11/07/2010 05:00 pm
The advantage here is that, in the 6-engine core config, we don't have to install all 6.  So we can have the 440, or 640, or install two RL-10's in the middle for orbital insertion post-burn, whatever we needed.  The configuration has advantages.
Title: Re: AJAX Launcher
Post by: sdsds on 11/07/2010 05:58 pm
How far out do the engines extend beyond the core?
Title: Re: AJAX Launcher
Post by: clongton on 11/07/2010 07:29 pm
How far out do the engines extend beyond the core?

A good rule of thumb is for the centers of the engines to be 1.5 nozzle diameters apart. This is needed for gimbling. Depending on the thermal environment that may or may not be enough. Remember that in a cluster configuration the engines in the center tend to have their efficiency choked by plume impingement. When that happens you will *not* get the thrust/isp out of that engine that it is rated at. The center engine on the Saturn-V suffered this condition for the same reason.
Title: Re: AJAX Launcher
Post by: sdsds on 11/08/2010 05:13 am
A good rule of thumb is for the centers of the engines to be 1.5 nozzle diameters apart.

It's difficult to make 1.5x look right, but here's the appearance of 1.33x.  With the outer ring of engines equally spaced, it sure looks like there would be room for Atlas CCB pairs between them.
Title: Re: AJAX Launcher
Post by: Dappa on 11/08/2010 10:57 am
Why not put the two center engines on the outside? It would place all engines around the edge, so no engine has to extend beyond the core, or maybe just a minimal amount. I don't if that works for booster placement though.
Title: Re: AJAX Launcher
Post by: Downix on 11/08/2010 05:30 pm
Why not put the two center engines on the outside? It would place all engines around the edge, so no engine has to extend beyond the core, or maybe just a minimal amount. I don't if that works for booster placement though.

Then you get air trapped in the middle, with the resulting heat being trapped with it.  That is one of the issues Ares V had.
Title: Re: AJAX Launcher
Post by: douglas100 on 11/08/2010 08:28 pm
From Downix:

Quote
Then you get air trapped in the middle, with the resulting heat being trapped with it.  That is one of the issues Ares V had.

But it can be done. Look at the arrangement of the six engines on the first stage of the Proton.
Title: Re: AJAX Launcher
Post by: Dappa on 11/08/2010 10:17 pm
Why not put the two center engines on the outside? It would place all engines around the edge, so no engine has to extend beyond the core, or maybe just a minimal amount. I don't if that works for booster placement though.

Then you get air trapped in the middle, with the resulting heat being trapped with it.  That is one of the issues Ares V had.
I wasn't aware of that, thank you for explaining.
Title: Re: AJAX Launcher
Post by: Downix on 11/08/2010 10:20 pm
From Downix:

Quote
Then you get air trapped in the middle, with the resulting heat being trapped with it.  That is one of the issues Ares V had.

But it can be done. Look at the arrangement of the six engines on the first stage of the Proton.
wider base, and cryo fuel.  Proton is a unique beast, and if we were running non-cryo fuel, I'd look into it.
Title: Re: AJAX Launcher
Post by: Downix on 12/06/2010 03:14 pm
Ok, been mulling this a bit, the idea of costs.

What R&D money there is has to be split, a few ways.  A way to "grease the wheels" may be to enable longer R&D cycles, through the ability to use Atlas boosters, as well as the funding of Atlas Phase II work, which I believe ULA would be quite pleased over.  Being able to match the SLS requirement w/o an upper stage means that we could, in theory, ignore US entirely and funnel that money into Atlas.  That would make plenty of people on the hill happy.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 12/16/2010 08:02 pm
Been wondering if work on AJAX will continue with the idea merge underway.
Title: Re: AJAX Launcher
Post by: Downix on 12/16/2010 08:56 pm
Been wondering if work on AJAX will continue with the idea merge underway.
It will, I am just assessing the whole package, however.  The RS-68 core w/ CCB booster concept, for instance, has gotten me interested.
Title: Re: AJAX Launcher
Post by: Downix on 12/17/2010 02:31 am
After some soul searching, while I like the idea of a unified fuel system as offered by the CBC's, the AJAX, with it's kerolox nature seems to have the real oomph. 

So, studying 5 and 6 engine cores, we can return to the full-sized tank core.  This gives us some advantage as well.

I have been tinkering on a 6-engine core version w/ CCB:

620 - 58 mT
640 - 84 mT
660 - 108 mT
680 - 131 mT

This is with a return of the full-sized Jupiter core.  Doing a bit of study, I've figured out how to mount the CCB's to fit around the "core-bulges".  I still think US focus needs to be for orbital maneuvering and EDS functions, not for lift.  This limits staging issues, a good feature in my opinion.  And yes, ACES for the upper stage.
Title: Re: AJAX Launcher
Post by: alexw on 12/17/2010 02:59 am
After some soul searching, while I like the idea of a unified fuel system as offered by the CBC's, the AJAX, with it's kerolox nature seems to have the real oomph. 
So, studying 5 and 6 engine cores, we can return to the full-sized tank core.  This gives us some advantage as well.
I have been tinkering on a 6-engine core version w/ CCB:
620 - 58 mT
640 - 84 mT
660 - 108 mT
680 - 131 mT
This is with a return of the full-sized Jupiter core.  Doing a bit of study, I've figured out how to mount the CCB's to fit around the "core-bulges".  I still think US focus needs to be for orbital maneuvering and EDS functions, not for lift.  This limits staging issues, a good feature in my opinion.  And yes, ACES for the upper stage.
   Somehow, I have a nasty feeling that the 4,6,8 LRB configs will be eliminated as unfeasible; can anyone offer a substantive reason?

    But it seems there might actually be a (NASA) business case for Phase II as an LRB. Consider this scenario: NASA builds the 600 as the cheapest, quickest core, and flies it. It can be flown as a 620 (dual CCBs) also this decade. Meanwhile, the costs to develop the Phase II booster -- let's say $3 billion (discussion elsewhere) -- is paid back from the SRB budget within, oh, 6-8 years. (Using dual RD-180 or new kerolox, or alternatively, Falcon X, using new kerolox), and comes online sometime around 2020 or thereabouts -- which the technology roadmaps indicate roughly when they would figure Atlas transitioning to domestic kerolox. That's the performance equivalent of your nominal 640, using only two boosters.

    Just a guess, but how does the 620 and 640 do with a 40mT or 70mT 100klb or 150klb ACES? Who crosses the magic 118mT boundary first?

    -Alex

Title: Re: AJAX Launcher
Post by: Downix on 12/17/2010 03:40 am
After some soul searching, while I like the idea of a unified fuel system as offered by the CBC's, the AJAX, with it's kerolox nature seems to have the real oomph. 
So, studying 5 and 6 engine cores, we can return to the full-sized tank core.  This gives us some advantage as well.
I have been tinkering on a 6-engine core version w/ CCB:
620 - 58 mT
640 - 84 mT
660 - 108 mT
680 - 131 mT
This is with a return of the full-sized Jupiter core.  Doing a bit of study, I've figured out how to mount the CCB's to fit around the "core-bulges".  I still think US focus needs to be for orbital maneuvering and EDS functions, not for lift.  This limits staging issues, a good feature in my opinion.  And yes, ACES for the upper stage.
   Somehow, I have a nasty feeling that the 4,6,8 LRB configs will be eliminated as unfeasible; can anyone offer a substantive reason?

    But it seems there might actually be a (NASA) business case for Phase II as an LRB. Consider this scenario: NASA builds the 600 as the cheapest, quickest core, and flies it. It can be flown as a 620 (dual CCBs) also this decade. Meanwhile, the costs to develop the Phase II booster -- let's say $3 billion (discussion elsewhere) -- is paid back from the SRB budget within, oh, 6-8 years. (Using dual RD-180 or new kerolox, or alternatively, Falcon X, using new kerolox), and comes online sometime around 2020 or thereabouts -- which the technology roadmaps indicate roughly when they would figure Atlas transitioning to domestic kerolox. That's the performance equivalent of your nominal 640, using only two boosters.

    Just a guess, but how does the 620 and 640 do with a 40mT or 70mT 100klb or 150klb ACES? Who crosses the magic 118mT boundary first?

    -Alex


Ok, 624 first:
ACES41 - 71mT
ACES71 - 84mT
ACES101 - 80mT

Now let's do the 644 now:
ACES41 - 86mT
ACES71 - 99mT
ACES101 - 114mT

And for fun: JUS - 126mT

Now, a long term plan would be a focus on Atlas Phase II, as it would be a better booster, and such development would better enhance ULA's bottom line.  ACES first (aka Phase I) then Phase II with it's 5m tank and twin RD-180's. But for now, getting the first steps locked down.
Title: Re: AJAX Launcher
Post by: alexw on 12/17/2010 03:52 am
    Just a guess, but how does the 620 and 640 do with a 40mT or 70mT 100klb or 150klb ACES? Who crosses the magic 118mT boundary first?
Ok, 624 first:
ACES41 - 71mT
ACES71 - 84mT
ACES101 - 80mT

Now let's do the 644 now:
ACES41 - 86mT
ACES71 - 99mT
ACES101 - 114mT

And for fun: JUS - 126mT
   The 624 is clearly under-thrusted in the upper stage. ULA is looking (BK2010) at 70mT ACES using 6xRL-10 (hence my 150klbf comment above), in the 5m diameter -- ie, the ACES that can certainly still be shared with Phase I.

     But they're also looking at 120mT/6xRL-10, which I *think* they think they could also manage as the limit of a barrel stretch of the 5m, without going wider. So don't bother with 71 or 101 in the 4xRL-10 config.

     BTW, what core propellant load and dry mass are you using here?
   -Alex
Title: Re: AJAX Launcher
Post by: A_M_Swallow on 12/17/2010 04:16 am
Ok, 624 first:
ACES41 - 71mT
ACES71 - 84mT
ACES101 - 80mT
Check
Title: Re: AJAX Launcher
Post by: Downix on 12/17/2010 04:47 am
    Just a guess, but how does the 620 and 640 do with a 40mT or 70mT 100klb or 150klb ACES? Who crosses the magic 118mT boundary first?
Ok, 624 first:
ACES41 - 71mT
ACES71 - 84mT
ACES101 - 80mT

Now let's do the 644 now:
ACES41 - 86mT
ACES71 - 99mT
ACES101 - 114mT

And for fun: JUS - 126mT
   The 624 is clearly under-thrusted in the upper stage. ULA is looking (BK2010) at 70mT ACES using 6xRL-10 (hence my 150klbf comment above), in the 5m diameter -- ie, the ACES that can certainly still be shared with Phase I.

     But they're also looking at 120mT/6xRL-10, which I *think* they think they could also manage as the limit of a barrel stretch of the 5m, without going wider. So don't bother with 71 or 101 in the 4xRL-10 config.

     BTW, what core propellant load and dry mass are you using here?
   -Alex

As no hard numbers for ACES have been posted, so I've been using the closest thing I could, the DIVUS, removing the weight of the RL-10 and adjusting for fuel size then adding the RL-10's back.

I, too, think the 4 and 2 CCB's would be the ones most likely to be utilized.  I want to keep 6 and 8 as developed, so that in case that "ZOMG SUPER MASSIVE IT'S TOO HEAVY" stuff shows up, we have a lifter.

I did one more test, I took my ACES 71, and swapped in a J-2X for the RL-10 cluster:

641 - 117mT

There you go. Now, could one take the ACES and develop it in such a way so as to allow such an option?  Off the shelf ACES, with a customized engine configuration?
Title: Re: AJAX Launcher
Post by: alexw on 12/17/2010 09:22 am
As no hard numbers for ACES have been posted, so I've been using the closest thing I could, the DIVUS, removing the weight of the RL-10 and adjusting for fuel size then adding the RL-10's back.
    [ZKB2009] "A Commercially Based Lunar Architecture", pg.11: ACES-41 5mT, ACES-71 (tanker) 5.5mT.  <--- note that that's the tanker, where the extra 30mT of prop /is/ the cargo. Dry mass for something with 70mT prop and cargo on top of that may be higher.

Quote
I, too, think the 4 and 2 CCB's would be the ones most likely to be utilized.  I want to keep 6 and 8 as developed, so that in case that "ZOMG SUPER MASSIVE IT'S TOO HEAVY" stuff shows up, we have a lifter.
   It's not the stuff, it's the people, but point taken :)

Quote
I did one more test, I took my ACES 71, and swapped in a J-2X for the RL-10 cluster:
641 - 117mT
There you go. Now, could one take the ACES and develop it in such a way so as to allow such an option?  Off the shelf ACES, with a customized engine configuration?
    You'd think that something sized for 12xRL-10 thrust loads would add too much dry weight, but obviously we'd love to know. [BK2010] is not amused ...  "Although ULA has received many inquiries on the compatibility of a J-2X upper stage on existing EELVs, it actually provides less performance, requires more booster modifications, and a stage less compatible with higher energy GTO and GEO missions (losing synergy with National Security Space) than the existing upper stages or the ACES stage."

Figure the options as 40mT/100klbf, 70mT/100klbf, and 120mT/150klbf, skipping the middle one as the least important for bracketing performance envelopes. I suspect that 35mT/50klbf is the only one we can reasonably hope to have by 2016.
  -Alex
Title: Re: AJAX Launcher
Post by: Downix on 12/17/2010 04:46 pm
As no hard numbers for ACES have been posted, so I've been using the closest thing I could, the DIVUS, removing the weight of the RL-10 and adjusting for fuel size then adding the RL-10's back.
    [ZKB2009] "A Commercially Based Lunar Architecture", pg.11: ACES-41 5mT, ACES-71 (tanker) 5.5mT.  <--- note that that's the tanker, where the extra 30mT of prop /is/ the cargo. Dry mass for something with 70mT prop and cargo on top of that may be higher.
Ok, so my estimates are heavier by a ton and a half.  So performance will be better, good.
Quote
Quote
I, too, think the 4 and 2 CCB's would be the ones most likely to be utilized.  I want to keep 6 and 8 as developed, so that in case that "ZOMG SUPER MASSIVE IT'S TOO HEAVY" stuff shows up, we have a lifter.
   It's not the stuff, it's the people, but point taken :)

Quote
I did one more test, I took my ACES 71, and swapped in a J-2X for the RL-10 cluster:
641 - 117mT
There you go. Now, could one take the ACES and develop it in such a way so as to allow such an option?  Off the shelf ACES, with a customized engine configuration?
    You'd think that something sized for 12xRL-10 thrust loads would add too much dry weight, but obviously we'd love to know. [BK2010] is not amused ...  "Although ULA has received many inquiries on the compatibility of a J-2X upper stage on existing EELVs, it actually provides less performance, requires more booster modifications, and a stage less compatible with higher energy GTO and GEO missions (losing synergy with National Security Space) than the existing upper stages or the ACES stage."

Figure the options as 40mT/100klbf, 70mT/100klbf, and 120mT/150klbf, skipping the middle one as the least important for bracketing performance envelopes. I suspect that 35mT/50klbf is the only one we can reasonably hope to have by 2016.
  -Alex
Quite true.  I don't see the need for J-2X.  If a new high-thrust US engine was to be developed, I'd push the RL-60 or if R&D money is lacking, AJ26-59 running hydrolox, both of which surpass the J-2X.

So, we would meet the SLS requirements, using the 664 ACES, but are now more scalable.  I am glad that the 620 is actually a usable system under this.  By my estimate, can get a lunar Orion launch with the 624, using only a fraction of the ACES fuel for final orbit burn and the majority for lunar trajectory.  This now is a very viable launch vehicle.
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 12/17/2010 04:53 pm
Quite true.  I don't see the need for J-2X.  If a new high-thrust US engine was to be developed, I'd push the RL-60 or if R&D money is lacking, AJ26-59 running hydrolox, both of which surpass the J-2X.


Or even Raptor if SpaceX gets that far.

I really like this overall concept.
Title: Re: AJAX Launcher
Post by: Downix on 12/18/2010 12:56 am
I just tried with the AJ26 upper stage engine, and with ACES package, got:

621 - 82mt
642 - 126mt

Note, specs on NK-33 hydrolox: 1960kN isp 440
Title: Re: AJAX Launcher
Post by: Downix on 12/21/2010 04:19 pm
Ok, enough of idle thinking, using the 6-SSME core.  Let us set down the goals here:

Stage 0: Functioning lifter using existing CCB's.
Stage 1: Funding for ACES to deliver a universal US/EDS/Depot
Stage 2: Funding for Atlas Phase II CCB's


It's much the same goals as under the merged thread, but brought back to AJAX. 

By my logic here, we get a functional launcher right off the bat.  Studying the cost breakdown between a 4-engine core and 6-engine core, at two launches per year the cost difference is actually not very much, and it's lifting capability is more.  And as the system grows we get more capability, both for AJAX and for Atlas.
Title: Re: AJAX Launcher
Post by: spacenut on 12/21/2010 04:36 pm
To me, the Atlas V Phase II is the most logical.  Two engines on a 5 or 5.5m core gives about 30 tons to LEO vs the Delta IV heavy with about 25 tons and 3 engines.  An Atlas V Phase II heavy can deliver 75 tons to LEO.  Then if you cross fed the Atlas V Phase II heavy, how much could you get to LEO?  Atlas V phase II does however, limit the diameter of payloads to 5-7m wide.  To me, it gives the most bang for the buck.  The Atlas V phase II would be a single core and eliminate the 3 core Delta IV heavy for the 20-30 ton market.  If you added some GEM type solids, you might could push 50 tons with a single core. 

Then if you attach it to the Ajax core, we can get a very heavy lifter if needed. 
Title: Re: AJAX Launcher
Post by: Downix on 12/21/2010 05:22 pm
To me, the Atlas V Phase II is the most logical.  Two engines on a 5 or 5.5m core gives about 30 tons to LEO vs the Delta IV heavy with about 25 tons and 3 engines.  An Atlas V Phase II heavy can deliver 75 tons to LEO.  Then if you cross fed the Atlas V Phase II heavy, how much could you get to LEO?  Atlas V phase II does however, limit the diameter of payloads to 5-7m wide.  To me, it gives the most bang for the buck.  The Atlas V phase II would be a single core and eliminate the 3 core Delta IV heavy for the 20-30 ton market.  If you added some GEM type solids, you might could push 50 tons with a single core. 

Then if you attach it to the Ajax core, we can get a very heavy lifter if needed. 
Right, but it is expensive to develop off the bat, which is why this staged development approach.  First get a quick and dirty launcher, add the Phase I upper stage, then develop the Phase II.  At all points, you've retained full capability, no gaps, and further your own non-SLS projects as well.  The development of ACES/Phase I alone will improve both Atlas and Delta, adding that to SLS gives us a full BEO system.
Title: Re: AJAX Launcher
Post by: Downix on 12/22/2010 08:07 am
After some serious number crunching, Even the 620 is hitting a T/W of 1.18 

Now, some have argued that the RS-25 is too expensive.  After some serious searching, they are right...

Unless we can get the production rate up.

By my calcs, the price advantage of the man-rated RS-68 evaporates once we can produce 10 RS-25e's a year. (12 RS-25e's to replace 8 RS-68's)  This is due to volume production.  We do not need as many RS-68's, so we'd need more launches to get the production quantity up.  Having more RS-25's, however, gives us an edge, we only need 2 launches to get the RS-25's cost down to the ballpark.  We'd need to launch 3 RS-68 based designs to beat it.  But, then, 3 RS-25 launches, we'd need 5 RS-68's to beat it....

So, our RS-25 core, full length, 6 engine core, paired with CCB's for boosting, is going to give us a scalable launcher, all the way into Ares V territory.  But, once it starts growing, over the next 10 years, we can see some serious performance gains.  A 680, running Phase II, surpasses Ares V + Ares I in a single, man-rated launch.  And unlike Ares, this is actually affordable.
Title: Re: AJAX Launcher
Post by: HappyMartian on 12/22/2010 11:38 am

So, our RS-25 core, full length, 6 engine core, paired with CCB's for boosting, is going to give us a scalable launcher, all the way into Ares V territory.  But, once it starts growing, over the next 10 years, we can see some serious performance gains.  A 680, running Phase II, surpasses Ares V + Ares I in a single, man-rated launch.  And unlike Ares, this is actually affordable.

"Affordable" sounds great! AJAX is a capable competitor for SLS. Keep up the excellent work.

Cheers!
Title: Re: AJAX Launcher
Post by: gospacex on 12/22/2010 11:51 am
   The 624 is clearly under-thrusted in the upper stage. ULA is looking (BK2010) at 70mT ACES using 6xRL-10 (hence my 150klbf comment above), in the 5m diameter -- ie, the ACES that can certainly still be shared with Phase I.

     But they're also looking at 120mT/6xRL-10, which I *think* they think they could also manage as the limit of a barrel stretch of the 5m, without going wider. So don't bother with 71 or 101 in the 4xRL-10 config.

How they are planning to fit six RL-10s under 5m stage? The nozzle diameter is 2.2m, six nozzles in hexagonal pattern will be 6.6m wide even if placed without gaps...
Title: Re: AJAX Launcher
Post by: simonbp on 12/22/2010 03:00 pm
Probably the same way that Douglas fit 6x RL-10s on the 5.5 m diameter S-IV... :p
Title: Re: AJAX Launcher
Post by: sandrot on 12/22/2010 03:33 pm
Probably the same way that Douglas fit 6x RL-10s on the 5.5 m diameter S-IV... :p

Oh, I love when I can post this!
Title: Re: AJAX Launcher
Post by: Downix on 12/22/2010 03:45 pm
   The 624 is clearly under-thrusted in the upper stage. ULA is looking (BK2010) at 70mT ACES using 6xRL-10 (hence my 150klbf comment above), in the 5m diameter -- ie, the ACES that can certainly still be shared with Phase I.

     But they're also looking at 120mT/6xRL-10, which I *think* they think they could also manage as the limit of a barrel stretch of the 5m, without going wider. So don't bother with 71 or 101 in the 4xRL-10 config.

How they are planning to fit six RL-10s under 5m stage? The nozzle diameter is 2.2m, six nozzles in hexagonal pattern will be 6.6m wide even if placed without gaps...
You are mistaken.  The RL-10 is a family of engines, with nozzles ranging from 0.92m to 2.2m.  The one being looked at for this application is 1.2m across, the RL-10-A2.
Title: Re: AJAX Launcher
Post by: Downix on 12/22/2010 03:47 pm
Probably the same way that Douglas fit 6x RL-10s on the 5.5 m diameter S-IV... :p

Oh, I love when I can post this!
I love that pic.  So the people can know what they are looking at, that is a S-IV stage, with six RL-10's, models from before any revisions.  They were 0.92m across.  Plenty of room.
Title: Re: AJAX Launcher
Post by: alexw on 12/22/2010 08:05 pm
   The 624 is clearly under-thrusted in the upper stage. ULA is looking (BK2010) at 70mT ACES using 6xRL-10 (hence my 150klbf comment above), in the 5m diameter -- ie, the ACES that can certainly still be shared with Phase I.
    But they're also looking at 120mT/6xRL-10, which I *think* they think they could also manage as the limit of a barrel stretch of the 5m, without going wider. So don't bother with 71 or 101 in the 4xRL-10 config.
How they are planning to fit six RL-10s under 5m stage? The nozzle diameter is 2.2m, six nozzles in hexagonal pattern will be 6.6m wide even if placed without gaps...
   Do the nozzles, whatever the RL-10 species, even need to fit within the 5m stage diameter? ACES would be built at 5m (5.1m?) because that's the existing DCUS tooling, but at the same time ULA would be consolidating their vast array of Atlas/Delta fairings -- and Atlas V's (larger) fairing is already 5.4m. Boeing and then ULA had long suggested migrating Delta to 6.5m, and ULA's said that even Atlas V could conceptually hammerhead to 7.2m. ACES performance (scaling down to 2xRL-10, not sure about 1x) buys back the extra fairing weight.
   -Alex
Title: Re: AJAX Launcher
Post by: simonbp on 12/22/2010 11:14 pm
Oh, I love when I can post this!

Personally, I prefer color. :)

Also show just how much room the RL-10s had; even with RL-10A-style fixed extensions, there would still be room under the interstage...
Title: Re: AJAX Launcher
Post by: MP99 on 12/23/2010 03:10 am
Probably the same way that Douglas fit 6x RL-10s on the 5.5 m diameter S-IV... :p

Oh, I love when I can post this!
I love that pic.  So the people can know what they are looking at, that is a S-IV stage, with four  RL-10's, models from before any revisions.  They were 0.92m across.  Plenty of room.

This must be the revision with one-and-a-half nozzles each.

cheers, Martin
Title: Re: AJAX Launcher
Post by: Proponent on 12/23/2010 03:21 am
Oh, I love when I can post this!

Personally, I prefer color. :)

Also show just how much room the RL-10s had; even with RL-10A-style fixed extensions, there would still be room under the interstage...

What's with the jagged interstage-looking thing attached to the aft end of this S-IV?  Is it protection for the nozzles during shipping?
Title: Re: AJAX Launcher
Post by: Downix on 12/23/2010 05:08 am
Probably the same way that Douglas fit 6x RL-10s on the 5.5 m diameter S-IV... :p

Oh, I love when I can post this!
I love that pic.  So the people can know what they are looking at, that is a S-IV stage, with four  RL-10's, models from before any revisions.  They were 0.92m across.  Plenty of room.

This must be the revision with one-and-a-half nozzles each.

cheers, Martin
Wrote that while still half asleep, my goof.  Fixed it above.
Title: Re: AJAX Launcher
Post by: Downix on 12/25/2010 07:15 pm
One thought this morning, as we were discussing on the Neptune idea, that is we used the RS-25 on the core we could launch crew on that and cargo with the full booster config.  Well, with AJAX, we can do the opposite, the boosters are already prepared for crew service, we don't actually need the full design to be man-rated.  If we used RS-68's for a cargo-only vehicle, and used Atlas for crew, as an alternative.  I'll compare performance, and cost, this weekend to see how this would work.
Title: Re: AJAX Launcher
Post by: Downix on 12/25/2010 09:42 pm
After doing calcs with the RS-68, definately not the right lifter.  With 4 RS-68A's I only got 40mT.  With 2, only lost 4mT.  Frankly, not worth it.  So, tried with 5 RS-68A's, and did not improve it dramatically.  The best configuration, a 581 running a J-2X JUS, I got 131mT.  Not worth it, the RS-25 just gives so much more capability, it's worth the extra cost in my estimate. (reminder, an RS-25 ACES 684 gives 141mT)

For an RS-68 core we'd be looking at a non-standardized US, and another engine production line anyways for the US to get enough performance.  If we need an engine production line, the RS-25e is the better choice, for performance and to reduce costs.
Title: Re: AJAX Launcher
Post by: 2552 on 12/26/2010 01:07 am
In the event NASA were to choose an AJAX-like SD-HLV for SLS, is there anything in the NASA Authorization Act of 2010 that would prevent using CCBs instead of SRBs?

Also, would an AJAX-like vehicle make a restart of the RD-180 co-production effort (http://forum.nasaspaceflight.com/index.php?topic=14224) likely (at least for political reasons)? If so, how much would it cost to finish establishing co-production capability, and how long would it take until the first American RD-180s became available? I asked this one in the Atlas V Q&A thread (http://forum.nasaspaceflight.com/index.php?topic=6479.msg672976#msg672976) a week ago but it wasn't answered.
Title: Re: AJAX Launcher
Post by: Downix on 12/26/2010 03:09 am
In the event NASA were to choose an AJAX-like SD-HLV for SLS, is there anything in the NASA Authorization Act of 2010 that would prevent using CCBs instead of SRBs?

Also, would an AJAX-like vehicle make a restart of the RD-180 co-production effort (http://forum.nasaspaceflight.com/index.php?topic=14224) likely (at least for political reasons)? If so, how much would it cost to finish establishing co-production capability, and how long would it take until the first American RD-180s became available? I asked this one in the Atlas V Q&A thread (http://forum.nasaspaceflight.com/index.php?topic=6479.msg672976#msg672976) a week ago but it wasn't answered.

There's nothing in the bill to prevent CCB over SRB.  As for domestic engine production, that is always a possibility, but I have no idea as to timetable.
Title: Re: AJAX Launcher
Post by: Downix on 12/26/2010 06:37 pm
Alright, should we start putting this into a presentation?  Just to get all of our ideas together and into a coherent design?
Title: Re: AJAX Launcher
Post by: kkattula on 12/26/2010 10:29 pm
There's nothing in the bill to prevent CCB over SRB. 
...

Where do you get that idea?  The bill says to use Shuttle components to the extent practicable. That means if they can use them, they must.

The only way AJAX gets done is if NASA shows SRBs won't work, (doubtful), or convinces Congress to change the law (unlikely).
Title: Re: AJAX Launcher
Post by: Downix on 12/26/2010 10:38 pm
There's nothing in the bill to prevent CCB over SRB. 
...

Where do you get that idea?  The bill says to use Shuttle components to the extent practicable. That means if they can use them, they must.

The only way AJAX gets done is if NASA shows SRBs won't work, (doubtful), or convinces Congress to change the law (unlikely).
ATK's shut down 4-seg production, you forget.  There are no SRB's *to* order right now, per the requirements of the SLS.  While the RS-25 line was mothballed, the SRB was converted to the new 5-seg design, which is not a shuttle component.
Title: Re: AJAX Launcher
Post by: 2552 on 12/26/2010 11:02 pm
There's that, but also this from November 18:

http://hatch.senate.gov/public/index.cfm?FuseAction=PressReleases.Detail&PressRelease_id=602f9c19-1b78-be3e-e07e-fb550421a64a&Month=11&Year=2010

Quote
The language Hatch was successful in getting inserted in the NASA Authorization Act does not require the new heavy-lift rocket to use solid rocket motors. But delegation members say the Utah experts they consulted say the legislation’s requirements for the heavy-lift rocket can only be realistically met by using solid rocket motors.

For example, the rocket must be designed from its inception to carry 130 tons. The heavier the payload the more likely the rocket will use solid rocket motors. The law also requires NASA to use, as much as practical, existing contracts, workforces and industries for the Space Shuttle and Ares rockets.

Title: Re: AJAX Launcher
Post by: Downix on 12/26/2010 11:21 pm
There's that, but also this from November 18:

http://hatch.senate.gov/public/index.cfm?FuseAction=PressReleases.Detail&PressRelease_id=602f9c19-1b78-be3e-e07e-fb550421a64a&Month=11&Year=2010

Quote
The language Hatch was successful in getting inserted in the NASA Authorization Act does not require the new heavy-lift rocket to use solid rocket motors. But delegation members say the Utah experts they consulted say the legislation’s requirements for the heavy-lift rocket can only be realistically met by using solid rocket motors.

For example, the rocket must be designed from its inception to carry 130 tons. The heavier the payload the more likely the rocket will use solid rocket motors. The law also requires NASA to use, as much as practical, existing contracts, workforces and industries for the Space Shuttle and Ares rockets.


That is based on ATK's own claims.  From an engineering standpoint, we've found with AJAX that it meets those requirements without the solids.  In short, ATK gambled that they'd be the only game in town.  We have to demonstrate that they are wrong.
Title: Re: AJAX Launcher
Post by: clongton on 12/26/2010 11:59 pm
There's nothing in the bill to prevent CCB over SRB. 
...

Where do you get that idea?  The bill says to use Shuttle components to the extent practicable. That means if they can use them, they must.

The only way AJAX gets done is if NASA shows SRBs won't work, (doubtful), or convinces Congress to change the law (unlikely).

According to 51D Mascot, who was intimately involved in actually writing the bill, the language was crafted in such a way that LRB's *are* allowed to be considered in the design of the SLS on equal footing with the SRB. While the SRB enjoys a lot of support, it is no longer a sure bet. To me, that means that ATK now has to demonstrate that they bring a superior product to the table.
Title: Re: AJAX Launcher
Post by: Downix on 12/27/2010 12:48 am
There's nothing in the bill to prevent CCB over SRB. 
...

Where do you get that idea?  The bill says to use Shuttle components to the extent practicable. That means if they can use them, they must.

The only way AJAX gets done is if NASA shows SRBs won't work, (doubtful), or convinces Congress to change the law (unlikely).

According to 51D Mascot, who was intimately involved in actually writing the bill, the language was crafted in such a way that LRB's *are* allowed to be considered in the design of the SLS on equal footing with the SRB. While the SRB enjoys a lot of support, it is no longer a sure bet. To me, that means that ATK now has to demonstrate that they bring a superior product to the table.
It is now ATK's spot to loose, for they are competing with ULA even if indirectly.  ULA has impressed me with their capability in the time I've observed them, not only for manufacturing but for political maneuvering.  They are the 800lbs gorilla in the room.  I figure, if you're looking to move something heavy, having a gorilla on your side is a good thing.
Title: Re: AJAX Launcher
Post by: 2552 on 12/27/2010 01:21 am
There's nothing in the bill to prevent CCB over SRB. 
...

Where do you get that idea?  The bill says to use Shuttle components to the extent practicable. That means if they can use them, they must.

The only way AJAX gets done is if NASA shows SRBs won't work, (doubtful), or convinces Congress to change the law (unlikely).

According to 51D Mascot, who was intimately involved in actually writing the bill, the language was crafted in such a way that LRB's *are* allowed to be considered in the design of the SLS on equal footing with the SRB. While the SRB enjoys a lot of support, it is no longer a sure bet. To me, that means that ATK now has to demonstrate that they bring a superior product to the table.

That I did not know. That would mean if NASA were to choose an AJAX-type vehicle, the chances of Congress responding by explicitly mandating SRBs are probably slim to none. I hope RAC-1 (http://www.nasaspaceflight.com/2010/12/heft-sls-hlv-design-decision-april-2011/) is in fact trading the Atlas V CCB as an LRB on the ET-derived core. I guess we'll find out if they are on January 10, when (according to 51D Mascot (http://forum.nasaspaceflight.com/index.php?topic=22991.msg674283#msg674283)) the Section 309 report will be released.
Title: Re: AJAX Launcher
Post by: 2552 on 12/27/2010 01:48 am
http://www.orlandosentinel.com/news/space/os-nasa-ares-rocket-constellation-20101227,0,2096166.story

Quote
But under a new NASA plan signed into law by President Barack Obama in October, there's no guarantee that the new rocket required by that plan will use solid-fuel propulsion. And, in fact, many in the agency say a liquid-fueled rocket would be cheaper, more powerful — and safer.

Quote
"To the best of our understanding, there has been no change in direction and we are aligning our resources and capabilities to support NASA in the development of a new heavy-lift capability," said Bryce Hallowell, spokesman for ATK of Minnesota.

Quote from: page2
The new NASA plan — developed after months of debate between Congress and the White House — favors an Ares I-type design by requiring use of "shuttle-derived" components, including solid-rocket motors. But some NASA engineers — and, reportedly, Shelby, reflecting the preferences of engineers at Marshall — favor a liquid-fueled rocket.

Interesting.. Richard Shelby and MSFC favor a "liquid-fueled rocket"? Article doesn't specify what kind of liquid-fueled design, though.
Title: Re: AJAX Launcher
Post by: Downix on 12/27/2010 01:58 am
http://www.orlandosentinel.com/news/space/os-zombie-rocket-lives-20101227,0,4846338.story

Quote
But under a new NASA plan signed into law by President Barack Obama in October, there's no guarantee that the new rocket required by that plan will use solid-fuel propulsion. And, in fact, many in the agency say a liquid-fueled rocket would be cheaper, more powerful — and safer.

Quote
"To the best of our understanding, there has been no change in direction and we are aligning our resources and capabilities to support NASA in the development of a new heavy-lift capability," said Bryce Hallowell, spokesman for ATK of Minnesota.

The new NASA plan — developed after months of debate between Congress and the White House — favors an Ares I-type design by requiring use of "shuttle-derived" components, including solid-rocket motors. But some NASA engineers — and, reportedly, Shelby, reflecting the preferences of engineers at Marshall — favor a liquid-fueled rocket.

Interesting.. Richard Shelby and MSFC favor a "liquid-fueled rocket"? Article doesn't specify what kind of liquid-fueled design, though.

There are 12 design submissions being worked on.  I would not be surprised if something like AJAX or Neptune is not included.
Title: Re: AJAX Launcher
Post by: MP99 on 12/27/2010 01:46 pm
According to 51D Mascot, who was intimately involved in actually writing the bill, the language was crafted in such a way that LRB's *are* allowed to be considered in the design of the SLS on equal footing with the SRB.

I follow 51D's posts very closely, but I'd missed that.

Do you have a link?

Thanks, Martin
Title: Re: AJAX Launcher
Post by: Jorge on 12/27/2010 05:49 pm
According to 51D Mascot, who was intimately involved in actually writing the bill, the language was crafted in such a way that LRB's *are* allowed to be considered in the design of the SLS on equal footing with the SRB.

I follow 51D's posts very closely, but I'd missed that.

Do you have a link?

Thanks, Martin

I missed that too and would also appreciate a link. My understanding was closer to kkatula's.
Title: Re: AJAX Launcher
Post by: Downix on 12/27/2010 05:57 pm
According to 51D Mascot, who was intimately involved in actually writing the bill, the language was crafted in such a way that LRB's *are* allowed to be considered in the design of the SLS on equal footing with the SRB.

I follow 51D's posts very closely, but I'd missed that.

Do you have a link?

Thanks, Martin

I missed that too and would also appreciate a link. My understanding was closer to kkatula's.
I missed it as well, but I did read the bill and studied the wording closely to be certain of what I read.  I even got my fathers old friends involved, and they were clear that the language is such that SRB's are not manditory.  If ATK was still manufacturing the 4-seg design, the argument could be made, but they're not, they are setup for the 5-seg, and 5-seg is not a shuttle utilized system.  Which means any solution which can match up to the requirements of 130 tonnes qualifies.  AJAX more than surpasses this, as does the DIV varient of it, Neptune.  Using SRB's you can only *just* make it.
Title: Re: AJAX Launcher
Post by: MP99 on 12/27/2010 08:02 pm
According to 51D Mascot, who was intimately involved in actually writing the bill, the language was crafted in such a way that LRB's *are* allowed to be considered in the design of the SLS on equal footing with the SRB.

I follow 51D's posts very closely, but I'd missed that.

Do you have a link?

Thanks, Martin

The first quote here (context: shortly after the ATK delegation kicked off) suggests solids to me. The second says to me that kerolox boosters aren't anticipated by the act, but might just be squeezed through over Utah's objections.

cheers, Martin


That would be great if common sense had anything to do with it. However, it looks to me now that Bolden & crew will do everything in their power to make SLS as far removed from STS as humanly possible and still stay (barely, maybe) within the law. We are seeing signs of that now, with the Utah delegation having to issue a press release about their meeting with B&G. Also rumors of EELV-derived and other RP-LOX options being floated. It seems that those in power are still fighting for a way around SDLV.

Which brings me to another thing that's been bothering me. In the language of the NASA Auth. Act of 2010, there are several passages that require NASA to use existing assets, contracts, etc, to the amount practicable. "To the amount practicable" means that if such a thing it is even possible that NASA must take that approach and not some other option, even if the other option is preferred or if it may be cheaper. But that is not how it is being reported. Everywhere that I see those passages (mis)quoted, the word used is "practical" and not "practicable". Those two words are not synonyms! "Practical" would give NASA much more leeway, they could decide what is practical and what is impractical. Whereas a "practicable" interpretation require them to take that approach whether it is practical or not, as long as it can be reduced into practice, i.e. made to happen.

So is the "practical" spin being promoted as part of an agenda, or is it a simple case of linguistic sloppiness?

Very perceptive comment. The choice of the word "practicable" in the law was deliberate and intended to be more prescriptive, precisely because of the anticipated reluctance on the part of "some" at NASA and at the other end of Pennsylvania Avenue to accept the direction provided by the Congress. Expect to see this issue batted back and forth often between now and final SLS definition.


You and several others seem to already have a pretty firm idea of just WHAT SLS is, in order to judge whether "it" has sufficient budget, time, or flexibility to be done within the law. The law actually gives NASA some time (90 days after enactment, or completion of initial conceptual design work--based, of course, on a lot of previous and ongoing work) to sort out what the basic elements and approach to SLS development would be to meet the requirements and provisions of the law.  So far I'm not aware anyone has seen what that is. And yet "it" is already being described as being "over budget", unable to meet schedule, etc., etc. How does that make sense, exactly? Do you have specific information on which that is based?

As for the "Budget", all anyone has are the current authorized numbers for FY 2011, 12 and 13, and some guesstimates on what might be expected in later years, but that's not a true "Budget," in the sense of a fully articulated long-term funding plan associated with a specific development plan for a specific vehicle or, in this case, "Space Launch System." No one yet knows what appropriation levels NASA will end up at even for the current fiscal year. And the US government appropriates funds annually, based on annual budget requests, so all that could change next year. And authorized levels can be modified by a subsequent Congress--even by the same people who wrote them the first time, if there is a demonstrated need to do so. So what is the foundation on which any of these judgment calls are being made about what can be done "on budget?"

So much of it can only be speculation and guesswork, and yet so much of it is presented as "fact." Frankly, it gets a bit tedious trying to know how to respond when so many assumptions are being made, but not clearly identified.

What "work" or "study" is it then that the Utah delegation is responding so negatively towards?

and

Can it at least be said that the funding for NASA and SLS will in the most positive terms be what the President asked for in his 2010 budget and in a more pessimistic context something less?



If you can bracket the budget constraints within that ballpark couldn't one accurately say that there isn't the money for a new Kerelox booster requiring new infrastructure and workforce. Furthermore couldn't you then also make some assertion about how such a proposed vehicle then would clearly violate the Authorization?

Hehe...yes, you "could" do all of the above; my point is that without a point design, or a pretty good idea of system content, it's premature to make judgments or reach hard conclusions.

Regarding Kerolox booster, I'd also suggest there are other requirements for the SLS other than budgetary issues that would appear to rule that out as an option, such as core component availability as a launcher for crew/cargo to LEO to provide an ISS access back-up capability by 2016. But I am not unwilling to be surprised.

And, yes, in the short-term, at least, FY 2010 funding levels "might" be the optimum funding for the rest of FY 2011, at least at the NASA top line funding level. That is a reasonable--but still not "safe"--assumption.

Regarding the Utah delegation, I think they are more specifically responding to comments recently made by, or attributed to, senior NASA management that suggest an HLV option sans SRBs of some description remains in the "trade space."
Title: Re: AJAX Launcher
Post by: Downix on 12/28/2010 04:46 am
So, on a topic of Ares I on Huffington, had someone call me Mr Ajax.  It actually made me smile, even as he was trying to use it in a mocking way.

I'm getting into the swing of things.  This is going to be a very good thing.  Almost have my Blender model of AJAX together.  Then, presentations.  What do we want in it?
Title: Re: AJAX Launcher
Post by: kkattula on 12/28/2010 09:36 am
I missed it as well, but I did read the bill and studied the wording closely to be certain of what I read.  I even got my fathers old friends involved, and they were clear that the language is such that SRB's are not manditory.  If ATK was still manufacturing the 4-seg design, the argument could be made, but they're not, they are setup for the 5-seg, and 5-seg is not a shuttle utilized system.  Which means any solution which can match up to the requirements of 130 tonnes qualifies.  AJAX more than surpasses this, as does the DIV varient of it, Neptune.  Using SRB's you can only *just* make it.

That's a slippery slope you're walking on.  By the same logic, there is no active RS-25 production line, so NASA doesn't have to use them. The ET line at Michoud is done, so NASA don't have to use them.

http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=111_cong_bills&docid=f:s3729es.txt.pdf

The law doesn't say to use Shuttle components still in production. It says:
Quote
... the Administrator shall, to the extent practicable utilize—

  (1) existing contracts, investments, workforce, industrial base, and capabilities from the Space Shuttle and Orion and Ares 1 projects, including—
...
    (B) Space Shuttle-derived components and Ares 1 components that use existing United States propulsion systems, including liquid fuel engines, external tank or tank-related capability, and solid rocket motor engines;
...

When there are still three Shuttle missions left to fly, you can't claim 4-seg SRB isn't an existing United States propulsion system, and be taken seriously. Especially since ATK has provided both 4 & 5 seg numbers to HEFT.

Also 5-seg is an Ares I component, and the law says they're definitely included.
Title: Re: AJAX Launcher
Post by: kkattula on 12/28/2010 09:45 am
BTW, I'm not saying AJAX isn't a good idea, just saying it can't be implemented without changing the law, and you ought to factor that in.
Title: Re: AJAX Launcher
Post by: Downix on 12/28/2010 03:00 pm
BTW, I'm not saying AJAX isn't a good idea, just saying it can't be implemented without changing the law, and you ought to factor that in.
Understood. With the posting above of atk's locations, and comparing, ULA still has more. As for the language, there are ways to solve that or interpret that out there as well.

What is needed is a draft paper. Get our ducks in a row as it were.
Title: Re: AJAX Launcher
Post by: sdsds on 12/28/2010 09:03 pm
Has there been a side-by-side presentation comparing AJAX-440 and AJAX-620?
Title: Re: AJAX Launcher
Post by: Downix on 12/28/2010 09:25 pm
Has there been a side-by-side presentation comparing AJAX-440 and AJAX-620?
No, how about I do that then?
Title: Re: AJAX Launcher
Post by: Downix on 12/28/2010 09:57 pm
Ok, with full sized core, running the SSME at an average of 80% over the whole flight (104% on takeoff, throttling back during CCB booster stage of flight, then back up, final flight average came to 80.01%):
620 : 64mT
640 : 91mT
660 : 115mT
680 : 135mT

Now, the reduced-core to enable T/W on 4 SSME.  I also did some calcs on optimization, and came to needing 109% on takeoff, throttling down then back up upon CCB seperation, with a final flight average of 87%:
420 : 58mT
440 : 87mt
460 : 110mT
480 : 131mT

So payload loss of between 4-6mT.  Both of these used the same payload shroud as the J241 of 3957kg
Title: Re: AJAX Launcher
Post by: sdsds on 12/28/2010 10:35 pm
So payload loss of between 4-6mT.

Depends on how you line them up for comparison.  If we compare configurations with equal numbers of engines:

  8 engines - 620 : 64mT   vs. 440 : 87mt
10 engines - 640 : 91mT   vs. 460 : 110mT
12 engines - 660 : 115mT vs. 480 : 131mT

Note I don't suggest counting engines because of cost; I don't believe liquid engine cost is a "make or break" factor in the design.  But I'm worried about the difficulty (cost in another way) of simultaneously starting 8 (much less a dozen) engines.  Shuttle has never seemed to have much problem starting three SSMEs, but I've read that getting a Delta IV-Heavy off the pad is nearly as difficult as simultaneously launching three Delta IV-Mediums.....
Title: Re: AJAX Launcher
Post by: Downix on 12/28/2010 10:43 pm
So payload loss of between 4-6mT.

Depends on how you line them up for comparison.  If we compare configurations with equal numbers of engines:

  8 engines - 620 : 64mT   vs. 440 : 87mt
10 engines - 640 : 91mT   vs. 460 : 110mT
12 engines - 660 : 115mT vs. 480 : 131mT

Note I don't suggest counting engines because of cost; I don't believe liquid engine cost is a "make or break" factor in the design.  But I'm worried about the difficulty (cost in another way) of simultaneously starting 8 (much less a dozen) engines.  Shuttle has never seemed to have much problem starting three SSMEs, but I've read that getting a Delta IV-Heavy off the pad is nearly as difficult as simultaneously launching three Delta IV-Mediums.....
Looking at it that way, the 4-engine stubby core looks to be the best bet when all is said and done.  Yes, it's T/W is not the best, but it is above Sat V and near Atlas V's own.  It would also use less propellant and two less RS-25's, so lower cost there as well.
Title: Re: AJAX Launcher
Post by: MP99 on 12/29/2010 07:44 am
So payload loss of between 4-6mT.  Both of these used the same payload shroud as the J241 of 3957kg

J-241 cargo PLF is 7219Kg.

J-241 crewed PLF is 5702Kg (+ LAS + BPC), and is retained to orbit.

The 3957Kg PLF is only used where launching a fully-fuelled EDS without any other payload.

cheers, Martin
Title: Re: AJAX Launcher
Post by: Downix on 12/29/2010 02:24 pm
So payload loss of between 4-6mT.  Both of these used the same payload shroud as the J241 of 3957kg

J-241 cargo PLF is 7219Kg.

J-241 crewed PLF is 5702Kg (+ LAS + BPC), and is retained to orbit.

The 3957Kg PLF is only used where launching a fully-fuelled EDS without any other payload.

cheers, Martin
Good catch.  But reminding you, any payload loss from a larger/heavier fairing would be equal on all vehicles, so as this was a study of the differences between these vehicles, the compare/contrast still is good.
Title: Re: AJAX Launcher
Post by: spacenut on 12/30/2010 12:29 pm
I think the 400 series is better due to fewer engines.  If we ever develop a larger more powerful kerolox engine, then this performance will improve even more. 
Title: Re: AJAX Launcher
Post by: clongton on 12/30/2010 12:33 pm
So payload loss of between 4-6mT.

Depends on how you line them up for comparison.  If we compare configurations with equal numbers of engines:

  8 engines - 620 : 64mT   vs. 440 : 87mt
10 engines - 640 : 91mT   vs. 460 : 110mT
12 engines - 660 : 115mT vs. 480 : 131mT

Note I don't suggest counting engines because of cost; I don't believe liquid engine cost is a "make or break" factor in the design.  But I'm worried about the difficulty (cost in another way) of simultaneously starting 8 (much less a dozen) engines.  Shuttle has never seemed to have much problem starting three SSMEs, but I've read that getting a Delta IV-Heavy off the pad is nearly as difficult as simultaneously launching three Delta IV-Mediums.....
Looking at it that way, the 4-engine stubby core looks to be the best bet when all is said and done.  Yes, it's T/W is not the best, but it is above Sat V and near Atlas V's own.  It would also use less propellant and two less RS-25's, so lower cost there as well.

We hit the sweet spot with that design.
Title: Re: AJAX Launcher
Post by: Downix on 12/30/2010 05:53 pm
So payload loss of between 4-6mT.

Depends on how you line them up for comparison.  If we compare configurations with equal numbers of engines:

  8 engines - 620 : 64mT   vs. 440 : 87mt
10 engines - 640 : 91mT   vs. 460 : 110mT
12 engines - 660 : 115mT vs. 480 : 131mT

Note I don't suggest counting engines because of cost; I don't believe liquid engine cost is a "make or break" factor in the design.  But I'm worried about the difficulty (cost in another way) of simultaneously starting 8 (much less a dozen) engines.  Shuttle has never seemed to have much problem starting three SSMEs, but I've read that getting a Delta IV-Heavy off the pad is nearly as difficult as simultaneously launching three Delta IV-Mediums.....
Looking at it that way, the 4-engine stubby core looks to be the best bet when all is said and done.  Yes, it's T/W is not the best, but it is above Sat V and near Atlas V's own.  It would also use less propellant and two less RS-25's, so lower cost there as well.

We hit the sweet spot with that design.
My concern is with engine cut-off.  If we loose an engine in flight.  Now, I do remember that there was a report that the RS-25 could be pushed to 115%.  If this is the case, or if the RS-25e could have that done, then an engine cut-off during flight would not be a loss of mission.  It would be tight, and require some in-orbit maneuvering, but it would work.
Title: Re: AJAX Launcher
Post by: clongton on 12/30/2010 07:40 pm
We hit the sweet spot with that design.
My concern is with engine cut-off.  If we loose an engine in flight.  Now, I do remember that there was a report that the RS-25 could be pushed to 115%.  If this is the case, or if the RS-25e could have that done, then an engine cut-off during flight would not be a loss of mission.  It would be tight, and require some in-orbit maneuvering, but it would work.

RS-25 is capable of being pushed to 115%. It is typically not done so on Shuttle because that engine would likely not be able to be used again. For the Shuttle program that's a big deal because they reuse the engines. For AJAX it's no problem because the engines are expendable.
Title: Re: AJAX Launcher
Post by: kraisee on 12/30/2010 08:01 pm
109% has been certified, but the expectation is that the engine has three times greater chance of failure than 104.5%.

115% has never been certified for anything -- not even as an emergency power setting.   A few tests have been run up to that level before, but nobody currently thinks that the engines could be relied upon to operate safely at that level.   The chances are that if you assume that level for a cluster of engines, you're asking for problems with at least one of them -- and a problem with an SSME, given how highly strung they are, is not something I would recommend.

AJAX should learn a valuable and difficult lesson from DIRECT:   Don't assume any more performance than you have right now.   If you can make the system close with what you have today, you know you can make it work.   If you rely upon advances, you open yourself up to layers of additional problems.

I strongly recommend you don't plan on baselining anything greater than 109%.

Just my end-of-year advice to y'all.   Take it for whatever its worth to ya.

Ross.
Title: Re: AJAX Launcher
Post by: clongton on 12/30/2010 08:14 pm
109% has been certified, but the expectation is that the engine has three times greater chance of failure than 104.5%.

115% has never been certified for anything -- not even as an emergency power setting.   A few tests have been run up to that level before, but nobody currently thinks that the engines could be relied upon to operate safely at that level.   The chances are that if you assume that level for a cluster of engines, you're asking for problems with at least one of them -- and a problem with an SSME, given how highly strung they are, is not something I would recommend.

AJAX should learn a valuable and difficult lesson from DIRECT:   Don't assume any more performance than you have right now.   If you can make the system close with what you have today, you know you can make it work.   If you rely upon advances, you open yourself up to layers of additional problems.

I strongly recommend you don't plan on baselining anything greater than 109%.

Just my end-of-year advice to y'all.   Take it for whatever its worth to ya.

Ross.

Didn't say anything about "baselining" 115%:
Quote
RS-25 is capable of being pushed to 115%.

You said:
Quote
A few tests have been run up to that level before, but nobody currently  thinks that the engines could be relied upon to operate safely at that  level.

Wasn't talking about safe or reliable operation at that level. A simple question was asked (there was a report that the RS-25 could be pushed to 115%). I provided a simple answer. Yes, it has been run at 115% (as you have confirmed).

Bottom line: in answer to the question, running the RS-25 at 115% is possible. Should that be done? That's an entirely different matter.
Title: Re: AJAX Launcher
Post by: Downix on 12/30/2010 09:56 pm
109% has been certified, but the expectation is that the engine has three times greater chance of failure than 104.5%.

115% has never been certified for anything -- not even as an emergency power setting.   A few tests have been run up to that level before, but nobody currently thinks that the engines could be relied upon to operate safely at that level.   The chances are that if you assume that level for a cluster of engines, you're asking for problems with at least one of them -- and a problem with an SSME, given how highly strung they are, is not something I would recommend.

AJAX should learn a valuable and difficult lesson from DIRECT:   Don't assume any more performance than you have right now.   If you can make the system close with what you have today, you know you can make it work.   If you rely upon advances, you open yourself up to layers of additional problems.

I strongly recommend you don't plan on baselining anything greater than 109%.

Just my end-of-year advice to y'all.   Take it for whatever its worth to ya.

Ross.
Was not thinking of it as a baseline, only in terms of absolute emergency.

For baseline was only considering 109% maximum option, and in the majority of flight it would be throttled down.

I am trying to consider every argument in this, even safety and LOM. The focus on long term spiral development to appease those who love R&D without holding the program hostage, for instance.
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 12/31/2010 01:43 am
109% has been certified, but the expectation is that the engine has three times greater chance of failure than 104.5%.

115% has never been certified for anything -- not even as an emergency power setting.   A few tests have been run up to that level before, but nobody currently thinks that the engines could be relied upon to operate safely at that level.   The chances are that if you assume that level for a cluster of engines, you're asking for problems with at least one of them -- and a problem with an SSME, given how highly strung they are, is not something I would recommend.

AJAX should learn a valuable and difficult lesson from DIRECT:   Don't assume any more performance than you have right now.   If you can make the system close with what you have today, you know you can make it work.   If you rely upon advances, you open yourself up to layers of additional problems.

I strongly recommend you don't plan on baselining anything greater than 109%.

Just my end-of-year advice to y'all.   Take it for whatever its worth to ya.

Ross.
Was not thinking of it as a baseline, only in terms of absolute emergency.

For baseline was only considering 109% maximum option, and in the majority of flight it would be throttled down.

I am trying to consider every argument in this, even safety and LOM. The focus on long term spiral development to appease those who love R&D without holding the program hostage, for instance.

For a non-crewed launch.. there is no reason not to throttle to 115% on other engines in LOM situation.. Even if there's 50% or more overall chance of SSME failure rate at 115% power.. it beats the HECK out of a guaranteed LOM at 109% power!

"I need more power Scotty!"
Title: Re: AJAX Launcher
Post by: Downix on 12/31/2010 11:32 pm
Ross, would you mind if I followed the DIRECT template for our presentation?
Title: Re: AJAX Launcher
Post by: Downix on 01/01/2011 12:06 am
Incidentally, with the reduced core #'s, T/W with full payloads:

420 - 1.18
440 - 1.19
460 - 1.20
480 - 1.20

Optimized the core around 1.2 and with the payload and optimized burn design, every configuration is resulting in ~1.2.
Title: Re: AJAX Launcher
Post by: MP99 on 01/01/2011 11:23 am
For a non-crewed launch.. there is no reason not to throttle to 115% on other engines in LOM situation.. Even if there's 50% or more overall chance of SSME failure rate at 115% power.. it beats the HECK out of a guaranteed LOM at 109% power!

"I need more power Scotty!"

Followed, shortly after, by "she cannae take much more of this, Captain".

cheers, Martin
Title: Re: AJAX Launcher
Post by: sdsds on 01/02/2011 04:00 am
Incidentally, with the reduced core #'s, T/W with full payloads:

420 - 1.18
440 - 1.19
460 - 1.20
480 - 1.20

Optimized the core around 1.2 and with the payload and optimized burn design, every configuration is resulting in ~1.2.

These values are really encouraging.  No critic will be able to assert these vehicles wouldn't be able to get off the pad with good speed.  On a related aspect of the system, does the plan call for full thrust hold-down before release?  What's the implication of that for the 480 configuration, i.e. just how much thrust is 0.2 times the mass of the beast?

Obviously the Falcon 9 and Falcon 1 launch systems have gotten huge benefit from their ability to hold the vehicle down at full thrust.  That's a strong card to play in any discussion of the merits of different systems.  By implication, it points to a particular vulnerability in launch vehicle designs that depend on dual SRBs....
Title: Re: AJAX Launcher
Post by: Downix on 01/02/2011 04:07 am
Incidentally, with the reduced core #'s, T/W with full payloads:

420 - 1.18
440 - 1.19
460 - 1.20
480 - 1.20

Optimized the core around 1.2 and with the payload and optimized burn design, every configuration is resulting in ~1.2.

These values are really encouraging.  No critic will be able to assert these vehicles wouldn't be able to get off the pad with good speed.  On a related aspect of the system, does the plan call for full thrust hold-down before release?  What's the implication of that for the 480 configuration, i.e. just how much thrust is 0.2 times the mass of the beast?

Obviously the Falcon 9 and Falcon 1 launch systems have gotten huge benefit from their ability to hold the vehicle down at full thrust.  That's a strong card to play in any discussion of the merits of different systems.  By implication, it points to a particular vulnerability in launch vehicle designs that depend on dual SRBs....
I do have a hold-down period.  Of course the hold-down is 4 seconds for the SSME and 2 for the CCB's, so the fuel burn-off is slight, but it is plenty of time based on what I've discovered for both the shuttle and Atlas to determine if all systems are go.
Title: Re: AJAX Launcher
Post by: Xplor on 01/10/2011 06:50 pm
Can someone please provide a brief description of AJAX.  I looked at the beginning of this thread and didn't find one.
Thank You
Title: Re: AJAX Launcher
Post by: sdsds on 01/10/2011 07:04 pm
Can someone please provide a brief description of AJAX.

In brief, the AJAX design is much like the Jupiter design proposed by DIRECT.  Like Jupiter, AJAX places SSMEs under a core derived from the Shuttle external tank.  But where Jupiter uses solid-propellant boosters, AJAX uses liquid-propellant boosters.  Specifically, AJAX uses as its boosters the liquid-propellant core of Atlas V.

The numbering convention for AJAX variants is fairly straight forward:  the first digit is the number of SSMEs on the core, the second digit is the number of Atlas V boosters, and the third digit is the number of engines on the upper stage.
Title: Re: AJAX Launcher
Post by: Downix on 01/10/2011 07:06 pm
Can someone please provide a brief description of AJAX.  I looked at the beginning of this thread and didn't find one.
Thank You
Making a vehicle to fit the SLS requirements for the Shuttle follow-on utilizing replacements for the Solid Rocket Boosters in the guise of Atlas V Common Core Boosters.  By being able to strap on between 2 and 8 of these CCB's, AJAX can scale from a 50mT launcher to over 130mT with evolution.  By sharing components with the EELV's, the support cost for AJAX is lower than for other shuttle-derived vehicles while it also adds R&D money to advance the EELV's lineup to be more competitive in the world launch market.  My belief is, this represents the most cost-effective way to heavy lift under the SLS programs guidelines.
Title: Re: AJAX Launcher
Post by: Xplor on 01/10/2011 08:01 pm
Can someone please provide a brief description of AJAX.  I looked at the beginning of this thread and didn't find one.
Thank You
Making a vehicle to fit the SLS requirements for the Shuttle follow-on utilizing replacements for the Solid Rocket Boosters in the guise of Atlas V Common Core Boosters.  By being able to strap on between 2 and 8 of these CCB's, AJAX can scale from a 50mT launcher to over 130mT with evolution.  By sharing components with the EELV's, the support cost for AJAX is lower than for other shuttle-derived vehicles while it also adds R&D money to advance the EELV's lineup to be more competitive in the world launch market.  My belief is, this represents the most cost-effective way to heavy lift under the SLS programs guidelines.

Thanks.  Let me repeat what I think you said to ensure that I understand:
- Retirement of ATK Shuttle SRM?
- ET derived core.  Manufactured at Michoud?
- Brand new engine module under 8m tank with SSME or RS68?  How many?
- 2 to 8 existing, single RD180 Atlas cores as strap ons. Is there a no strap on version?
- ACES upper stage? Powered by RL10's or J2X's? How many?
- New payload fairing, 8m or 10m or larger?
Title: Re: AJAX Launcher
Post by: Downix on 01/10/2011 08:49 pm
Can someone please provide a brief description of AJAX.  I looked at the beginning of this thread and didn't find one.
Thank You
Making a vehicle to fit the SLS requirements for the Shuttle follow-on utilizing replacements for the Solid Rocket Boosters in the guise of Atlas V Common Core Boosters.  By being able to strap on between 2 and 8 of these CCB's, AJAX can scale from a 50mT launcher to over 130mT with evolution.  By sharing components with the EELV's, the support cost for AJAX is lower than for other shuttle-derived vehicles while it also adds R&D money to advance the EELV's lineup to be more competitive in the world launch market.  My belief is, this represents the most cost-effective way to heavy lift under the SLS programs guidelines.

Thanks.  Let me repeat what I think you said to ensure that I understand:
- Retirement of ATK Shuttle SRM?
That has happened already.  ATK is developing Ares SRB's now, not the Shuttles.  They may share components, but they are not the same.  This would simply not carry-forward the incomplete SRB system, saving several billion in R&D cost.  Restarting the shuttles SRB's at this point is also looking to be at least a half billion
Quote
- ET derived core.  Manufactured at Michoud?
Correct on both.  The core is smaller than other Shuttle-derived vehicles such as DIRECT, same 8.4m with but shorter so as to better mate up with the Ares CCB
Quote
- Brand new engine module under 8m tank with SSME or RS68?  How many?
Using RS-25's, RS-25d's initially, RS-25e's being a longer term solution.  Not having to support the SRB's enables the R&D cost for the reduced-cost RS-25e.  Baseline is listed as 4 RS-25's.

The RS-68 is not safe for human flight, we considered it but the R&D necessary to make it safe, and the changes needed, would cost more than the RS-25e.  It's thrust was higher, allowing one less core engine, but it's isp was worse, resulting in the requiring of a high-thrust US engine, like the J-2X, which would cost more than either the RS-25 or RS-68.  To reduce cost, the RS-25 is by and far the best choice for this particular application.
Quote
- 2 to 8 existing, single RD180 Atlas cores as strap ons. Is there a no strap on version?
There are no plans for it.
Quote
- ACES upper stage? Powered by RL10's or J2X's? How many?
We would be using ACES as proposed by ULA, not a modified version.  The ACES papers list, 2-4 RL-10's with a tank size of either 41 or 71mT.
Quote
- New payload fairing, 8m or 10m or larger?
The Ares 10m fairing was to fit the Lunar lander, which under ACES development would be redundant due to the ACES capacity to be utilized as a horizontal lander.  8m would be the base fairing, but a 10 or 12m option would be there should the need arose.
Title: Re: AJAX Launcher
Post by: Xplor on 01/10/2011 11:59 pm
Interesting idea.  In an effort to further streamline the recurring cost you may want to consider:
- Have the 8m tank built at Decatur allowing Michoud to also be closed
- Perform finally assembly at KSC in the O&C building
- Maximize component commonality with Atlas, Delta, Falcon and Taurus
- Perform all integration in the VAB, minimizing the massive LC-39 pad infrastructure (clean pad)
Title: Re: AJAX Launcher
Post by: Downix on 01/11/2011 12:14 am
Interesting idea.  In an effort to further streamline the recurring cost you may want to consider:
- Have the 8m tank built at Decatur allowing Michoud to also be closed
- Perform finally assembly at KSC in the O&C building
- Maximize component commonality with Atlas, Delta, Falcon and Taurus
- Perform all integration in the VAB, minimizing the massive LC-39 pad infrastructure (clean pad)

(editing to make things less muddled)
We considered building at Decatur, but there is no mechanism to transport the tank.  The waterway is too shallow at points for Pegasus to navigate.  And as this is a system meant help politicaly, as a shutdown of Michaud's ET system in addition to the loss of the SRB system would make this a show killer.  In addition, having to build a new barge transport for the core would be an incredibly tough sell.

*however* Michaud itself is not a cost-inefficient structure, nor is it limited to just the tank manufacture.  It is also the manufacturing point for the Orion capsule as well as handling functions for other agencies, such as the Dept of Agriculture and the Coast Guard.  By having it's costs shared, the overhead for it is remarkably low. The ET assembly itself is not the most efficient thing in the world, admittedly, and in long-term it may be moved to Decatur along with replacing Pegasus with a shallower-draft barge, but that is not within the scope of planning at this time.

Final Assembly was planned for KSC, with a flat pad at LC39.  Thanks to Ajax not requiring heavy solids, you can have the MLP more like Saturn or Atlas, with the gantry on the platform rather than the pad. 

The idea is to minimize unique support systems.  The fewer parts which need to be directly supported, or rather the more commonality with other systems, the better.  Hence why ACES rather than AIUS, why RL-10 rather than J-2X.  By reducing the amount of custom equipment, and custom facilities, you reduce the systems overhead and make it affordable to operate.  It surprised me how many system redundancies could be minimized by crossing with other vendors. 
Title: Re: AJAX Launcher
Post by: 2552 on 01/17/2011 12:51 am
Downix, when do you think the AJAX presentation paper will be finished?
Title: Re: AJAX Launcher
Post by: Downix on 01/17/2011 07:18 am
Downix, when do you think the AJAX presentation paper will be finished?
When it's ready.  Only just got the full data together this weekend (and then spilled tea on my laptop, letting it dry out right now).
Title: Re: AJAX Launcher
Post by: Downix on 01/19/2011 06:55 am
I finished crunching the numbers.  Having folk go over things now.  I never realized how much I actually knew about space ops, it's quite terrifying to realize.
Title: Re: AJAX Launcher
Post by: Downix on 01/29/2011 11:08 pm
In my moves, I misplaced the SLWT document with the details on full structure. I need to reference it in the doc,  so I am hoping someone out there has a link to it. My Google-fu has failed me.
Title: Re: AJAX Launcher
Post by: jml on 02/03/2011 12:05 am
Bump.

http://forum.nasaspaceflight.com/index.php?topic=23003.msg687608#msg687608

(Sayonara SRBs and hello LRBs?)
Title: Re: AJAX Launcher
Post by: Downix on 02/03/2011 02:27 am
Ok, got the document back, friends in Lockheed are handy things. 

Upon review, I realized a few errors I'd made, but nothing too drastic.  It is looking good.

I had a thought, however.  We need to make a case that this fits into the SLS requirements.  I've got a small document on my thoughts, but how about yours?  What angle can we utilize?
Title: Re: AJAX Launcher
Post by: 2552 on 02/03/2011 03:36 am
The AJAX-440 obviously fits the 70 to 100 short ton requirement, but what about the 130 short ton requirement? Will the 71mt ACES meet that, or will an 8.4m JUS with RL-10s or J-2X be needed?

Also, will the SRBs require doubling the size of Orion's LAS, and how much will that cost? Would this render Orion "not practicable" to complete by December 31, 2016? The CCBs, being liquid fueled, would avoid this, right?

Title: Re: AJAX Launcher
Post by: Downix on 02/03/2011 03:44 am
The AJAX-440 obviously fits the 70 to 100 short ton requirement, but what about the 130 short ton requirement? Will the 71mt ACES meet that, or will an 8.4m JUS with RL-10s or J-2X be needed?
An AJAX 484 will do this, with the 71mT ACES.  One advantage AJAX has over the Ares V Classic, we can bolt on more boosters.  No other design changes needed.
Quote
Also, will the SRBs require doubling the size of Orion's LAS, and how much will that cost? Would this render Orion "not practicable" to complete by December 31, 2016? The CCBs, being liquid fueled, would avoid this, right?
The Orion LAS is already designed for SRB's, while yes, there are more SRB's in a DIRECT or AVC, the capsule is further away as well, so the existing LAS should suffice.

Orion is almost complete now, it launches in two years, remember?
Title: Re: AJAX Launcher
Post by: A_M_Swallow on 02/03/2011 01:33 pm
The AJAX-440 obviously fits the 70 to 100 short ton requirement, but what about the 130 short ton requirement? Will the 71mt ACES meet that, or will an 8.4m JUS with RL-10s or J-2X be needed?

Any valid compatibility between landers and upper stages?  The same engines for instance.
Title: Re: AJAX Launcher
Post by: Downix on 02/03/2011 02:53 pm
The AJAX-440 obviously fits the 70 to 100 short ton requirement, but what about the 130 short ton requirement? Will the 71mt ACES meet that, or will an 8.4m JUS with RL-10s or J-2X be needed?

Any valid compatibility between landers and upper stages?  The same engines for instance.
The idea was to use the ACES horizontal lander. So, they would be about 90% identical.
Title: Re: AJAX Launcher
Post by: Lobo on 02/03/2011 06:13 pm
The AJAX-440 obviously fits the 70 to 100 short ton requirement, but what about the 130 short ton requirement? Will the 71mt ACES meet that, or will an 8.4m JUS with RL-10s or J-2X be needed?

Any valid compatibility between landers and upper stages?  The same engines for instance.
The idea was to use the ACES horizontal lander. So, they would be about 90% identical.

I've read ULA's proposal for using ACES for common EELV upperstages, depots, Orion Service Module, and horizontal lunar lander.  It was very interesting.
But that's all based around a 5m ACES stage optimized for EELV's.  The Direct guys seem to think that for an 8.4m core, you'd want a dedicated 8.4m upper stage (JUS in their case), which is derived from ACES tech, but wider, rather than putting a 5m upperstage on the 8.4m core in a PLF.
So, how would that workout for AJAX?
I don't know if you want an 8.4m horizontal lander, which you'd have to have if you were using commonality with an AJAX upper stage.  Might need LOT more RL-10 engines to land something that size.  ULA's proposal was an all-5m diameter architecture.
Or maybe you could use the 5m diameter ACES core, assuming it'd be devleped for Atlas and Delta along with the larger one for AJAX?  Use that for the Orion SM and for the Lander.
An 8.4m ACES stage would make for a much larger depot.
Title: Re: AJAX Launcher
Post by: Downix on 02/03/2011 06:49 pm
The AJAX-440 obviously fits the 70 to 100 short ton requirement, but what about the 130 short ton requirement? Will the 71mt ACES meet that, or will an 8.4m JUS with RL-10s or J-2X be needed?

Any valid compatibility between landers and upper stages?  The same engines for instance.
The idea was to use the ACES horizontal lander. So, they would be about 90% identical.

I've read ULA's proposal for using ACES for common EELV upperstages, depots, Orion Service Module, and horizontal lunar lander.  It was very interesting.
But that's all based around a 5m ACES stage optimized for EELV's.  The Direct guys seem to think that for an 8.4m core, you'd want a dedicated 8.4m upper stage (JUS in their case), which is derived from ACES tech, but wider, rather than putting a 5m upperstage on the 8.4m core in a PLF.
So, how would that workout for AJAX?
I don't know if you want an 8.4m horizontal lander, which you'd have to have if you were using commonality with an AJAX upper stage.  Might need LOT more RL-10 engines to land something that size.  ULA's proposal was an all-5m diameter architecture.
Or maybe you could use the 5m diameter ACES core, assuming it'd be devleped for Atlas and Delta along with the larger one for AJAX?  Use that for the Orion SM and for the Lander.
An 8.4m ACES stage would make for a much larger depot.

Our plan is for the 5m ACES, same one EELV's use.  A smaller US is not an issue, as Atlas 5m demonstrates.  They put the Centaur inside of the US fairing. 

Here's a picture of Atlas with such an arrangement:
http://www.skyrocket.de/space/img_lau/atlas-5-501__nrol-41__1.jpg

The Centaur fits within the shroud.

Here's a drawing of the inside to show how it works:
http://www.nap.edu/books/12554/xhtml/images/p20016d11g112001.jpg

Something I realized, the width of the US is not important once you've left the atmosphere, where there is no atmospheric drag.  So, why waste time developing a form-factor US?
Title: Re: AJAX Launcher
Post by: Downix on 02/09/2011 05:44 pm
Slightly interesting note, the Russians are developing a solution similar to AJAX as an upgrade path for their Atlas V clone, the Rus-M.  Multiple Rus-M cores strapped around a large middle core with RD-0120 engines:

Title: Re: AJAX Launcher
Post by: Lars_J on 02/09/2011 07:04 pm
*developing* is a strong word for this. It is just another powerpoint study, just like ULA's Atlas V phase III or Delta IV growth studies.
Title: Re: AJAX Launcher
Post by: Downix on 02/09/2011 07:18 pm
*developing* is a strong word for this. It is just another powerpoint study, just like ULA's Atlas V phase III or Delta IV growth studies.
Semi, the Rus-M is in the late-design stage, and the core tooling already exists.
Title: Re: AJAX Launcher
Post by: spacenut on 02/09/2011 10:56 pm
What is the diameter of the Rus-M core?  Is this their Mars rocket? How does it compare to the Ajax booster configurations?
Title: Re: AJAX Launcher
Post by: Downix on 02/09/2011 11:19 pm
What is the diameter of the Rus-M core?  Is this their Mars rocket? How does it compare to the Ajax booster configurations?
The Rus-M is 3.8m wide, 32m tall, almost identical to Atlas's 3.81m wide, 32.4m tall, so close it could be a rounding error.  Their core appears to be a stubby Energia 7m core, which based on the length will make it's weight match up to our stubby core very closely.  Frankly, it's AJAX, or Vulkan, depending on how you look at it, with the advantage of Russia studying our Atlas for optimization tricks.

Original Energia was 59m tall, this core is 53m tall.  Taking that out of the fuel tank, it's approximately a 13% tank shrink, which dovetails with the posted core weight of 788.8 mT, over Energia's original 905mt, fully loaded.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 02/09/2011 11:21 pm
What is the diameter of the Rus-M core?  Is this their Mars rocket? How does it compare to the Ajax booster configurations?
The Rus-M is 3.8m wide, 32m tall, almost identical to Atlas's 3.81m wide, 32.4m tall, so close it could be a rounding error.  Their core appears to be the Energia 7m core, which based on the length will make it's weight match up to our stubby core very closely.  Frankly, it's AJAX, or Vulkan, depending on how you look at it, with the advantage of Russia studying our Atlas for optimization tricks.
guess that means the ruskies stole our idea ;) (joking ofc)

Interesting though I think this further validates the AJAX concept.
Title: Re: AJAX Launcher
Post by: Lampyridae on 02/10/2011 08:54 am
So, on a topic of Ares I on Huffington, had someone call me Mr Ajax.  It actually made me smile, even as he was trying to use it in a mocking way.

I'm getting into the swing of things.  This is going to be a very good thing.  Almost have my Blender model of AJAX together.  Then, presentations.  What do we want in it?

A very clear diagram showing synergies. Compare this to existing costs for Ares V and ET/SSME ops. Long list of what it doesn't need compared to HEFT 5/5. Some Phil Metschan-type designer flair.
Title: Re: AJAX Launcher
Post by: spacenut on 02/11/2011 03:59 pm
Downix,
Have you considered adding a few monolithic solids to the 440 for additional lift?  Or would it work?  Would it be less expensive to go with the 460 or 480 AJAX for the extra lift?  Is it safer? 

I like the AJAX.  Hope it flys if the Jupiter doesn't.  I just don't like the big solids because of cost and safety in the VAB. 

Another question, have you thought of reusable strap ons by parachute like the old Soviet space shuttle design boosters?  Are thy worth it?
Title: Re: AJAX Launcher
Post by: Downix on 02/11/2011 06:22 pm
Downix,
Have you considered adding a few monolithic solids to the 440 for additional lift?  Or would it work?  Would it be less expensive to go with the 460 or 480 AJAX for the extra lift?  Is it safer? 

I like the AJAX.  Hope it flys if the Jupiter doesn't.  I just don't like the big solids because of cost and safety in the VAB. 

Another question, have you thought of reusable strap ons by parachute like the old Soviet space shuttle design boosters?  Are thy worth it?

The goal is to lower the cost. To do this we minimized the unique pieces. Would monolithic solids work? Yes, the AJAX utilizes the Atlas SRB mount as is to connect the Atlas booster, so it would not be major work to use them. We are not, however, due to time and money. The SRB's will not give enough of a performance benefit to be worth the cost, with 8 giving similar performance to two CCB's. Reusable boosters may come in time, but the time and money crunch means it cannot be a baseline. Lockheed is developing a reusable booster, so if we ever gain one, would come out of such a partnership.
Title: Re: AJAX Launcher
Post by: Ronsmytheiii on 02/11/2011 08:34 pm
Original Energia was 59m tall, this core is 53m tall.  Taking that out of the fuel tank, it's approximately a 13% tank shrink, which dovetails with the posted core weight of 788.8 mT, over Energia's original 905mt, fully loaded.

Not necessarily, Energia carried its payload sidemount like shuttle-C, so the tank was in the shape of a cone.  For this proposal the tank could be changed to a cylindrical shape that has the same volume, but it shorter.
Title: Re: AJAX Launcher
Post by: Ronsmytheiii on 02/11/2011 08:53 pm
1.  In terms of weight, why not go for a common bulkhead between the LOx/LH2 tank. without SRBs there no longer need to be a trust beam that gets in the way so is now possible, and NASA already has the experience via work on the ares I upper stage.  IT shouldn't be the long pole, as the tank will need to be redesigned for inline thrust and from forces from the attach point on the bottom.

2.  The name should be Daedalus.
Title: Re: AJAX Launcher
Post by: Downix on 02/11/2011 09:00 pm
1.  In terms of weight, why not go for a common bulkhead between the LOx/LH2 tank. without SRBs there no longer need to be a trust beam that gets in the way so is now possible, and NASA already has the experience via work on the ares I upper stage.  IT shouldn't be the long pole, as the tank will need to be redesigned for inline thrust and from forces from the attach point on the bottom.

2.  The name should be Daedalus.
1) AIUS is Boeing, ET is Lockheed. Experience on one does not necessarily carry over. Also, the ET uses the intertank for reinforcement. To go for a common bulkhead means more work, longer development time.

2) Thank you for the suggestion. Sticking with AJAX for now, but who knows.
Title: Re: AJAX Launcher
Post by: Downix on 02/11/2011 09:02 pm
Original Energia was 59m tall, this core is 53m tall.  Taking that out of the fuel tank, it's approximately a 13% tank shrink, which dovetails with the posted core weight of 788.8 mT, over Energia's original 905mt, fully loaded.

Not necessarily, Energia carried its payload sidemount like shuttle-C, so the tank was in the shape of a cone.  For this proposal the tank could be changed to a cylindrical shape that has the same volume, but it shorter.
If you checked mass, this is 13% lighter as well, with less fuel.
Title: Re: AJAX Launcher
Post by: clongton on 02/12/2011 12:40 am
Slightly interesting note, the Russians are developing a solution similar to AJAX as an upgrade path for their Atlas V clone, the Rus-M.  Multiple Rus-M cores strapped around a large middle core with RD-0120 engines:



It absolutely *is* a Russian AJAX, right down to the lift capacities and ability to use the LRB as a standalone CLV.

http://en.wikipedia.org/wiki/Rus-M
Title: Re: AJAX Launcher
Post by: Downix on 02/12/2011 09:23 pm
Slightly interesting note, the Russians are developing a solution similar to AJAX as an upgrade path for their Atlas V clone, the Rus-M.  Multiple Rus-M cores strapped around a large middle core with RD-0120 engines:



It absolutely *is* a Russian AJAX, right down to the lift capacities and ability to use the LRB as a standalone CLV.

http://en.wikipedia.org/wiki/Rus-M
If you've followed the Rus-M, you'd realize it was little more than a Russian Atlas V.  The sizes are almost identical, the engines are identical, the upper stage for the Russians is almost identical to the ACES, in short, it looks like the Russians have the Atlas V Phase I here, and they intend to use it for just such a design.  I've heard from a few friends of mine in Russia that there is activity in the old Energia plant, and that the transport M-4 has been taken out again.  The new launch pad at Vostochny will be the real test, how they will build it.
Title: Re: AJAX Launcher
Post by: sdsds on 02/12/2011 09:37 pm
I've heard from a few friends of mine in Russia that there is activity in the old Energia plant, and that the transport M-4 has been taken out again.

I love this photo:

http://www.buran.ru/images/jpg/atlant2.jpg

"Barge?  What barge?  We don't need no stinkin' barge!"
Title: Re: AJAX Launcher
Post by: Patchouli on 02/12/2011 11:00 pm
I've heard from a few friends of mine in Russia that there is activity in the old Energia plant, and that the transport M-4 has been taken out again.

I love this photo:

http://www.buran.ru/images/jpg/atlant2.jpg

"Barge?  What barge?  We don't need no stinkin' barge!"

I'm surprised NASA has not contracted for one of these yet.

http://en.wikipedia.org/wiki/Boeing_747_Large_Cargo_Freighter
Title: Re: AJAX Launcher
Post by: Downix on 02/12/2011 11:15 pm
I've heard from a few friends of mine in Russia that there is activity in the old Energia plant, and that the transport M-4 has been taken out again.

I love this photo:

http://www.buran.ru/images/jpg/atlant2.jpg

"Barge?  What barge?  We don't need no stinkin' barge!"

I'm surprised NASA has not contracted for one of these yet.

http://en.wikipedia.org/wiki/Boeing_747_Large_Cargo_Freighter
I live up the street from where these are stored between ferrying operations.

But their size limit of 6.2m eliminates them from our particular applications.  The barge will suffice for us.

Title: Re: AJAX Launcher
Post by: Dmitry_V_home on 02/13/2011 02:43 pm
Slightly interesting note, the Russians are developing a solution similar to AJAX as an upgrade path for their Atlas V clone, the Rus-M.  Multiple Rus-M cores strapped around a large middle core with RD-0120 engines:

Also Amur-5 and Enisey-5 from Khrunichev. May 2008.
Title: Re: AJAX Launcher
Post by: Downix on 02/13/2011 04:52 pm
Slightly interesting note, the Russians are developing a solution similar to AJAX as an upgrade path for their Atlas V clone, the Rus-M.  Multiple Rus-M cores strapped around a large middle core with RD-0120 engines:

Also Amur-5 and Enisey-5 from Khrunichev. May 2008.
I have seen those before, but their use of the RD-170 made them less of an example.  But very good point Dmitry.  The Russians have the right idea.  And we need to get this together.
Title: Re: AJAX Launcher
Post by: fotoguzzi on 02/13/2011 10:26 pm
I've heard from a few friends of mine in Russia that there is activity in the old Energia plant, and that the transport M-4 has been taken out again.

I love this photo:

http://www.buran.ru/images/jpg/atlant2.jpg

"Barge?  What barge?  We don't need no stinkin' barge!"
http://www.youtube.com/watch?v=quILBGryShU

It looks to me as if the are trying to avoid inflight refueling.

Modify: Please remove or alter if this violates any link policies.
Title: Re: AJAX Launcher
Post by: PahTo on 02/13/2011 11:22 pm

What is the diameter of the core stage for the Amur-Enisey or the "RUS-M-as LRB"?  And is that the same diameter as the Buran ET?  Gotta' love that Bison!
Thanks...
Title: Re: AJAX Launcher
Post by: Downix on 02/13/2011 11:33 pm

What is the diameter of the core stage for the Amur-Enisey or the "RUS-M-as LRB"?  And is that the same diameter as the Buran ET?  Gotta' love that Bison!
Thanks...
Rus-M as LRB is the same as Atlas, 3.8m.  And that particular design is the Energia, or Buran ET as you call it.  It's not an ET, however, it's a 7.75m wide rocket stage, with 4 RD-0120 engines on the bottom. 

Comparing AJAX to this, AJAX has a better payload capacity due in part to the SSME's better thrust capacity, about 20% higher. 
Title: Re: AJAX Launcher
Post by: PahTo on 02/13/2011 11:46 pm

Thanks Downix, I hadn't realized the core stage of the next gen "Russian AJAX" is literally the Energia (duh).  It's all making sense now...
Gotta' love strap on boosters that exceed 300s Isp!
Title: Re: AJAX Launcher
Post by: tnphysics on 02/14/2011 12:11 am
If only they were flybacks!
Title: Re: AJAX Launcher
Post by: Downix on 02/14/2011 01:25 am

Thanks Downix, I hadn't realized the core stage of the next gen "Russian AJAX" is literally the Energia (duh).  It's all making sense now...
Gotta' love strap on boosters that exceed 300s Isp!
Almost, but not quite.  They did the same with their core that we are doing with ours, shrinking it to fit the thrust of the LRB's.  In their case, a 13% size reduction vs our 18%.
Title: Re: AJAX Launcher
Post by: Downix on 02/14/2011 01:27 am
If only they were flybacks!
One thing at a time.
Title: Re: AJAX Launcher
Post by: Lars_J on 02/14/2011 01:49 am
Slightly interesting note, the Russians are developing a solution similar to AJAX as an upgrade path for their Atlas V clone, the Rus-M.  Multiple Rus-M cores strapped around a large middle core with RD-0120 engines:

Also Amur-5 and Enisey-5 from Khrunichev. May 2008.

Oh, the concept is a lot older than that. The early proposed Vulcan derivative of Energia is one example: http://www.k26.com/buran/Info/Hercules/vulkan.html
Title: Re: AJAX Launcher
Post by: Downix on 02/14/2011 04:22 am
While it is nice to look at the Zenit based lifters, the Zenit first stage is a lot beefier than the Atlas CCB's.  However, this only is a minor piece of the puzzle.  Using the CCB's we can deliver a better performing design in all but the highest configurations, due to optimization of the core around the design needs.
Title: Re: AJAX Launcher
Post by: spacenut on 02/14/2011 12:53 pm
Maybe you should incorporate what the Russians plan to to with their program in your presentation.  We already have the Atlas V, and we can set up to make the RD-180. 

My idea is to develop a reusable strap on booster like the Atlas V or Atlas V phase II.  Then develop a plug nozzle core to retrieve the core from space for reuse, using the plug nozzle as a heat shield.  This would be long term planning.  Also build resuable ferries from Earth to L1 or L2, and a reusable lander for the moon from L1 or L2.  Then build an assembly station at L1 or L2 for a reusable Mars transfer vehicle. 
Title: Re: AJAX Launcher
Post by: Halidon on 02/15/2011 01:25 am
My idea is to develop a reusable strap on booster like the Atlas V or Atlas V phase II.  Then develop a plug nozzle core to retrieve the core from space for reuse, using the plug nozzle as a heat shield.  This would be long term planning.  Also build resuable ferries from Earth to L1 or L2, and a reusable lander for the moon from L1 or L2.  Then build an assembly station at L1 or L2 for a reusable Mars transfer vehicle. 
Neither the Atlas nor Delta cores were designed for reusability. Using either as a starting point instead of a clean-sheet or Falcon, which was designed for reusability, wouldn't get you much.
Title: Re: AJAX Launcher
Post by: 2552 on 02/15/2011 01:37 am
My idea is to develop a reusable strap on booster like the Atlas V or Atlas V phase II.  Then develop a plug nozzle core to retrieve the core from space for reuse, using the plug nozzle as a heat shield.  This would be long term planning.  Also build resuable ferries from Earth to L1 or L2, and a reusable lander for the moon from L1 or L2.  Then build an assembly station at L1 or L2 for a reusable Mars transfer vehicle. 
Neither the Atlas nor Delta cores were designed for reusability. Using either as a starting point instead of a clean-sheet or Falcon, which was designed for reusability, wouldn't get you much.

There is a proposal to reuse the Atlas V's RD-180 using mid-air recovery though: http://ulalaunch.com/site/docs/publications/PartialRocketReuseUsingMidAirRecovery20087874.pdf
Title: Re: AJAX Launcher
Post by: Downix on 02/15/2011 01:48 am
Reuse is, at best, a decade off. Focus.
Title: Re: AJAX Launcher
Post by: Downix on 02/16/2011 03:08 pm
On one of the SpaceX threads yesterday was a video discussing successful programs, and why they worked. It has made me think a bit. We have done a good job on the technical bits, but we need to say why this idea is better.
Title: Re: AJAX Launcher
Post by: spacenut on 02/16/2011 06:47 pm
I like the concept of dialing up what you need, 2, 4, 6, or 8 Atlas V's for various loads.  Add a second stage for heaver loads or for high orbits.  I like the modular approach.  Then, if enough Atlas V's manufacturing threshold is reached, then the Atlas V Phase II can be made. 
Title: Re: AJAX Launcher
Post by: Downix on 02/16/2011 07:33 pm
I like the concept of dialing up what you need, 2, 4, 6, or 8 Atlas V's for various loads.  Add a second stage for heaver loads or for high orbits.  I like the modular approach.  Then, if enough Atlas V's manufacturing threshold is reached, then the Atlas V Phase II can be made. 
That's still the What.  We need the Why.

Think like Apple here.  We need a why, why does the US need AJAX? 
Title: Re: AJAX Launcher
Post by: A_M_Swallow on 02/16/2011 08:38 pm
Think like Apple here.  We need a why, why does the US need AJAX? 

The USA needs AJAX because NASA wants to put large objects into space and the US is a high wage country.

People play the lowest price they can when buying commodity items.  This is why consumer goods like radios are manufactured in low wage countries like China.  The factories that used to manufacture home radios and tv in the USA have closed down (or like the farmers charge you twice {subsidies are a second payment}).

Consequently to pay high wages American companies have to do things that Chinese, Japanese and Korea companies cannot do.  One of those things is launching large rockets.

Large items that NASA wishes to launch (if it can get the money) include Moon bases and Mars Transfer Vehicles (spaceships).

Big things can be constructed out of small things but it takes a long time.  For instance the International Space Station currently weights over 375 metric tons and was constructed out of parts massing no more than 20 mT.  It has taken (2011 - 1998 + 1) = 14 years and (x?) launches so far, which have cost a large fortune.  The AJAX could have lifted it in about 4 launches.
Title: Re: AJAX Launcher
Post by: spacenut on 02/16/2011 08:41 pm
It can solve multiple loads plus being manrated.  It can deliver Orion to the space station and to the moon.  It can deliver cargo to both.  It can be used for an L1 station or a Mars program as well as a moon base.  It is more flexable than solids.  It has a safe background history.  It can be used for the next 50 years.   
Title: Re: AJAX Launcher
Post by: Cherokee43v6 on 02/16/2011 08:51 pm
I think Downix has hit on a vital question... perhaps one that needs its own thread.

Why space?  What will motivate us to get off this rock?  A lot of people talk grandly about extinction threats and the survival of humanity, but how is that going to affect me today, tomorrow or next week?

I think where we need to look is economics.  We need to find a compelling good or service that can be made available more cheaply than from terrestrial options via human-robust space resources.

We need to find the 'space goldrush material'.  Once we have that, then all our pipe-dreams have the potential to come true.  Until we have that, however, we remain at the mercy of public policy.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 02/17/2011 12:14 am
I think Downix has hit on a vital question... perhaps one that needs its own thread.

Why space?  What will motivate us to get off this rock?  A lot of people talk grandly about extinction threats and the survival of humanity, but how is that going to affect me today, tomorrow or next week?

I think where we need to look is economics.  We need to find a compelling good or service that can be made available more cheaply than from terrestrial options via human-robust space resources.

We need to find the 'space goldrush material'.  Once we have that, then all our pipe-dreams have the potential to come true.  Until we have that, however, we remain at the mercy of public policy.

Vital question yes topic of this thread no.

Answer: there is nothing. Period. Exploration of space is probably only ever going to be for the sake of exploration or colonization of other heavenly bodies (which would be very useful for a variety of reasons). Beyond that, no reason.
Which means in times of economic discord space takes a back seat. In any event this pertains little to our topic

I am interested to know where we stand on the following:
Core length and number of engines
Number and length of boosters (still standard atlas CCBs?)
T/W issue solved by shortened boosters/ core ?
Technical analysis

Also would like to start getting the baseline better defined until we have something similar to the J 130 (need graphics please). Baseball cards would be nice too.

The more clear our proposal is the better. I have a feeling that solids are going to go south in the next few years.
Title: Re: AJAX Launcher
Post by: Downix on 02/17/2011 12:26 am
Think like Apple here.  We need a why, why does the US need AJAX? 

The USA needs AJAX because NASA wants to put large objects into space and the US is a high wage country.

People play the lowest price they can when buying commodity items.  This is why consumer goods like radios are manufactured in low wage countries like China.  The factories that used to manufacture home radios and tv in the USA have closed down (or like the farmers charge you twice {subsidies are a second payment}).

Consequently to pay high wages American companies have to do things that Chinese, Japanese and Korea companies cannot do.  One of those things is launching large rockets.

Large items that NASA wishes to launch (if it can get the money) include Moon bases and Mars Transfer Vehicles (spaceships).

Big things can be constructed out of small things but it takes a long time.  For instance the International Space Station currently weights over 375 metric tons and was constructed out of parts massing no more than 20 mT.  It has taken (2011 - 1998 + 1) = 14 years and (x?) launches so far, which have cost a large fortune.  The AJAX could have lifted it in about 4 launches.
That is still the what. We do need that, but we need something first. We went to the moon because we were sold the why: Not because it is easy, but because it is hard.

We need a why statement.

Economically, we work. AJAX can do more, with less. But where every space program since the Shuttle has failed is this fundamental point: Why?
Title: Re: AJAX Launcher
Post by: Downix on 02/17/2011 12:32 am
I think Downix has hit on a vital question... perhaps one that needs its own thread.

Why space?  What will motivate us to get off this rock?  A lot of people talk grandly about extinction threats and the survival of humanity, but how is that going to affect me today, tomorrow or next week?

I think where we need to look is economics.  We need to find a compelling good or service that can be made available more cheaply than from terrestrial options via human-robust space resources.

We need to find the 'space goldrush material'.  Once we have that, then all our pipe-dreams have the potential to come true.  Until we have that, however, we remain at the mercy of public policy.

Vital question yes topic of this thread no.

Answer: there is nothing. Period. Exploration of space is probably only ever going to be for the sake of exploration or colonization of other heavenly bodies (which would be very useful for a variety of reasons). Beyond that, no reason.
Which means in times of economic discord space takes a back seat. In any event this pertains little to our topic

I am interested to know where we stand on the following:
Core length and number of engines
Number and length of boosters (still standard atlas CCBs?)
T/W issue solved by shortened boosters/ core ?
Technical analysis

Also would like to start getting the baseline better defined until we have something similar to the J 130 (need graphics please). Baseball cards would be nice too.

The more clear our proposal is the better. I have a feeling that solids are going to go south in the next few years.
That is coming.
Title: Re: AJAX Launcher
Post by: A_M_Swallow on 02/17/2011 03:27 am
That is still the what. We do need that, but we need something first. We went to the moon because we were sold the why: Not because it is easy, but because it is hard.

We need a why statement.

Economically, we work. AJAX can do more, with less. But where every space program since the Shuttle has failed is this fundamental point: Why?

Your reply show that you are asking the wrong question.  Not, "Why AJAX?" but, "Why Moon mission?".
Title: Re: AJAX Launcher
Post by: luke strawwalker on 02/17/2011 03:37 am
Something I realized, the width of the US is not important once you've left the atmosphere, where there is no atmospheric drag.  So, why waste time developing a form-factor US?

The main reason for a wider upperstage is the propellant capacity versus height.  A wider upperstage tankage can hold more propellant in less vehicle height than narrower tankage, which must be taller to contain the same propellant load.  That makes for a shorter vehicle, lighter fairing, and of course gives more room for a larger fairing or more room inside the fairing if a larger or outsize payload comes up.
There was a graphic showing a Jupiter 24X with either a 12 or 15 meter fairing on it sized to fit within the VAB doors somewhere (I saved it somewhere as well) and the fairing was bigger than the J-24X, almost big enough to hide an orbiter inside it on top of the stack...

That said, if the presumably then-existing ACES tankage holds sufficient propellant to do the job, then it would be rather pointless building a larger wide-body stage just to match the diameter of the core... (which I'm assuming the upper stage would be SOMEWHAT smaller diameter anyway to fit within the fairing anyway, for boiloff reasons...

Just sayin'... OL JR :)
Title: Re: AJAX Launcher
Post by: Downix on 02/17/2011 04:05 am
Something I realized, the width of the US is not important once you've left the atmosphere, where there is no atmospheric drag.  So, why waste time developing a form-factor US?

The main reason for a wider upperstage is the propellant capacity versus height.  A wider upperstage tankage can hold more propellant in less vehicle height than narrower tankage, which must be taller to contain the same propellant load.  That makes for a shorter vehicle, lighter fairing, and of course gives more room for a larger fairing or more room inside the fairing if a larger or outsize payload comes up.
There was a graphic showing a Jupiter 24X with either a 12 or 15 meter fairing on it sized to fit within the VAB doors somewhere (I saved it somewhere as well) and the fairing was bigger than the J-24X, almost big enough to hide an orbiter inside it on top of the stack...

That said, if the presumably then-existing ACES tankage holds sufficient propellant to do the job, then it would be rather pointless building a larger wide-body stage just to match the diameter of the core... (which I'm assuming the upper stage would be SOMEWHAT smaller diameter anyway to fit within the fairing anyway, for boiloff reasons...

Just sayin'... OL JR :)
The launch model in mind does not use an upper stage for lift, but for EDS and orbital maneuvering. The core effectively is the upper stage in most launch scenarios. For EDS an ACES 71 surpasses the Ares V US for our need.

If you're confused how, some math for a bit:

The Ares V EDS uses approximately 132mt of it's 223mt of fuel in getting to orbit.  This means only 91mT of fuel for actual EDS operations.  Now, the Ares V EDS utilizes the J-2X engine, high thrust but not so good an ISP over the ACES RL-10 engines.  For EDS, that ISP is critical, comparing a 443isp engine against four 462 isp engines with 1/4 of the thrust, you're making up for the lack of 20mT of fuel right there and then some.

And there are some plans for larger/wider ACES in the future, 100+ mT models.  But those are future plans, and not anything beyond napkin level drawings.

For our application, being able to bring a fully loaded ACES into orbit with it's payload, and then pushing that through EDS, AJAX could rival, or even beat Ares for mass to lunar orbit, or even Mars.
Title: Re: AJAX Launcher
Post by: Downix on 02/17/2011 04:14 am
That is still the what. We do need that, but we need something first. We went to the moon because we were sold the why: Not because it is easy, but because it is hard.

We need a why statement.

Economically, we work. AJAX can do more, with less. But where every space program since the Shuttle has failed is this fundamental point: Why?

Your reply show that you are asking the wrong question.  Not, "Why AJAX?" but, "Why Moon mission?".
Actually, no. It shows why we are not giving the right answers. We think of a rocket. I am trying to get us to think of a goal. An Artemis program.

Apollo was a poor name for a lunar program, the symbol of the sun. Artemis, the moons shadow, is more fitting.
Title: Re: AJAX Launcher
Post by: Dmitry_V_home on 02/17/2011 03:59 pm

Oh, the concept is a lot older than that. The early proposed Vulcan derivative of Energia is one example: http://www.k26.com/buran/Info/Hercules/vulkan.html


Original "Vulcan":
Title: Re: AJAX Launcher
Post by: Downix on 02/17/2011 04:03 pm

Oh, the concept is a lot older than that. The early proposed Vulcan derivative of Energia is one example: http://www.k26.com/buran/Info/Hercules/vulkan.html


Original "Vulcan":

Damned sexy rocket.
Title: Re: AJAX Launcher
Post by: Downix on 02/18/2011 12:10 am
That is still the what. We do need that, but we need something first. We went to the moon because we were sold the why: Not because it is easy, but because it is hard.

We need a why statement.

Economically, we work. AJAX can do more, with less. But where every space program since the Shuttle has failed is this fundamental point: Why?

Your reply show that you are asking the wrong question.  Not, "Why AJAX?" but, "Why Moon mission?".
Actually, no. It shows why we are not giving the right answers. We think of a rocket. I am trying to get us to think of a goal.
Sitting here, looking at what we have. This is more than a rocket, it is a re-imagining of NASA. It can be done as the same contract method as CCDev and COTS. It can untie NASAs hands. I see NASA as Gulliver with its old model holding it down.

Damnit, we went to the moon, the solar system should be our Oyster. Why AJAX? Because the human race deserves better. It is not easy, the challenge is greater than any single one of us. But we will do it, because we must. We are the first step, the next stage in humanity. Will our children look upon us with admiration for our willingness to move forward, or pity as we were too afraid?
Title: Re: AJAX Launcher
Post by: baldusi on 02/18/2011 06:51 pm
Sitting here, looking at what we have. This is more than a rocket, it is a re-imagining of NASA. It can be done as the same contract method as CCDev and COTS. It can untie NASAs hands. I see NASA as Gulliver with its old model holding it down.
Do you have a paper? I don't know if I have missed it (since you already have some renders).
Title: Re: AJAX Launcher
Post by: Downix on 02/19/2011 07:22 am
Sitting here, looking at what we have. This is more than a rocket, it is a re-imagining of NASA. It can be done as the same contract method as CCDev and COTS. It can untie NASAs hands. I see NASA as Gulliver with its old model holding it down.
Do you have a paper? I don't know if I have missed it (since you already have some renders).
Not yet, we're working on it right now.  A lot of the renders are very old "sketches" don't forget.

Putting everything together is a challenge.
Title: Re: AJAX Launcher
Post by: baldusi on 02/20/2011 03:12 pm
Sitting here, looking at what we have. This is more than a rocket, it is a re-imagining of NASA. It can be done as the same contract method as CCDev and COTS. It can untie NASAs hands. I see NASA as Gulliver with its old model holding it down.
Do you have a paper? I don't know if I have missed it (since you already have some renders).
Not yet, we're working on it right now.  A lot of the renders are very old "sketches" don't forget.

Putting everything together is a challenge.
I'm an economist. If you want me to look over some economics stuff, pm.
Title: Re: AJAX Launcher
Post by: spacetraveler on 02/22/2011 03:34 am
I'd be interested to see some projected launch costs for the various configurations.
Title: Re: AJAX Launcher
Post by: fotoguzzi on 02/22/2011 03:51 am
I'd be interested to see some projected launch costs for the various configurations.
I wonder if someone could edit the first post in the thread to include a brief definition of Ajax and its advantages.
Title: Re: AJAX Launcher
Post by: Downix on 02/22/2011 04:29 am
I'd be interested to see some projected launch costs for the various configurations.
I wonder if someone could edit the first post in the thread to include a brief definition of Ajax and its advantages.
Not a bad idea.
Title: Re: AJAX Launcher
Post by: 2552 on 02/22/2011 04:36 am
I'd be interested to see some projected launch costs for the various configurations.
I wonder if someone could edit the first post in the thread to include a brief definition of Ajax and its advantages.
Not a bad idea.

Aside from the description, it should probably also mention the AJAX paper that's in work, then link to it when it's released.
Title: Re: AJAX Launcher
Post by: Downix on 02/22/2011 05:01 am
I'd be interested to see some projected launch costs for the various configurations.
I wonder if someone could edit the first post in the thread to include a brief definition of Ajax and its advantages.
Not a bad idea.

Aside from the description, it should probably also mention the AJAX paper that's in work, then link to it when it's released.
Done.  Any suggestions on what needs to be added?
Title: Re: AJAX Launcher
Post by: 2552 on 02/22/2011 06:08 am
I'd be interested to see some projected launch costs for the various configurations.
I wonder if someone could edit the first post in the thread to include a brief definition of Ajax and its advantages.
Not a bad idea.

Aside from the description, it should probably also mention the AJAX paper that's in work, then link to it when it's released.
Done.  Any suggestions on what needs to be added?

The end of the 1st paragraph should probably say "existing ULA Atlas V Common Core Booster" so there's no CCB/CBC confusion. Other than that, great intro  :).
Title: Re: AJAX Launcher
Post by: spacetraveler on 02/22/2011 09:46 am
I think there's a typo in this sentence:

"Because the CCB's have less sea level thrust than the SRB's, the ET's fuel load, as it, was too heavy."
Title: Re: AJAX Launcher
Post by: Dmitry_V_home on 02/22/2011 03:36 pm
Damned sexy rocket.

Oh,yeah... Very, very sexy rocket...
Title: Re: AJAX Launcher
Post by: Downix on 02/22/2011 04:30 pm
I think there's a typo in this sentence:

"Because the CCB's have less sea level thrust than the SRB's, the ET's fuel load, as it, was too heavy."
fixed
Title: Re: AJAX Launcher
Post by: gladiator1332 on 02/22/2011 04:58 pm
Nitpicking here, but first sentence of paragraph two needs an apostrophe s.

"The AJAX configuration is centered around a reduced size core module, based on the Space Shuttle's External Tank. "

And paragraph 4 you spelled Michoud as michaud:

Should read: "Michoud would be shared with the Orion space capsule, LC-39 with manned Atlas V Launches, and the boosters would come from Decatur."
Title: Re: AJAX Launcher
Post by: 93143 on 02/23/2011 08:59 pm
All regarding paragraph 2:

Plurals do not get apostrophes, and it doesn't matter if what you're pluralizing is an acronym/abbreviation or not.  SRBs and CCBs, not SRB's and CCB's.

Of course, it still works for possessives, so ET's (as in "the ET's fuel load") is still correct...  though you might want to replace "fuel" with "propellant"...

Oh, and I think you meant that shrinking the ET by ~20% results in an increase in the T/W, not a decrease...
Title: Re: AJAX Launcher
Post by: truth is life on 02/23/2011 11:59 pm
Damned sexy rocket.

Oh,yeah... Very, very sexy rocket...

Indeed.

In the spirit of nitpicking, I noticed that the second sentence in the fourth paragraph said "as many of those.," when I think you mean "as many of those as possible."
Title: Re: AJAX Launcher
Post by: fotoguzzi on 02/24/2011 02:51 am
Damned sexy rocket.
Indeed.
Still a couple of stray apostrophes, but it's now a much better introduction to AJAX.

Possible additions:

1) One thing that is not clear from the newly written introduction. Does it use SSMEs? How many?

2) I presume the AJAX boosters use kerosene propellant? It might be useful to remind new readers what's in the ET, and mention the same for the boosters.

Thanks for updating it!

http://theoatmeal.com/comics/apostrophe

Modify: change text as front article continues to improve.




Title: Re: AJAX Launcher
Post by: Downix on 02/24/2011 03:42 am
Ok, updated.  Keep em coming.
Title: Re: AJAX Launcher
Post by: 2552 on 02/24/2011 04:48 am
Ok, updated.  Keep em coming.

OK.

Quote
By studying the various shuttle components, it was determined the best configuration, for political, engineering, and cost purposes was to replace the existing pair of segmented solid rocket boosters with paired liquid rocket boosters..  For cost, political and performance purposes, AJAX chose the ULA Atlas Common Core Booster.

These 2 sentences seem partially redundant, both listing cost, political and performance purposes. The first could be shortened, like this:

"By studying the various Shuttle components, it was determined the best configuration would replace the existing pair of segmented solid rocket boosters with paired liquid rocket boosters.  For cost, political and performance purposes, AJAX chose the ULA Atlas Common Core Booster."

Title: Re: AJAX Launcher
Post by: clongton on 02/24/2011 03:12 pm
Quote
By studying the various shuttle components, it was determined the best configuration, for political, engineering, and cost purposes was to replace the existing pair of segmented solid rocket boosters with paired liquid rocket boosters..  For cost, political and performance purposes, AJAX chose the ULA Atlas Common Core Booster.

These 2 sentences seem partially redundant, both listing cost, political and performance purposes. The first could be shortened, like this:

"By studying the various Shuttle components, it was determined the best configuration would be to replace the existing pair of segmented solid rocket boosters with 2 pairs of paired liquid rocket boosters.  For cost, political and performance purposes, AJAX chose the ULA Atlas Common Core Booster (CCB)."

Made a couple of suggested changes in-line to your excellent suggestion.


Title: Re: AJAX Launcher
Post by: Downix on 02/24/2011 05:02 pm
ok, fixed
Title: Re: AJAX Launcher
Post by: Proponent on 02/25/2011 01:54 am
"for a lot" -> "much"
Title: Re: AJAX Launcher
Post by: Downix on 02/25/2011 03:43 am
Ok, looking better. 

Title: Re: AJAX Launcher
Post by: gladiator1332 on 02/26/2011 04:11 pm
Worked on paragraph 3:

In addition to the CCBs, AJAX would share other components with the EELVs, such as existing ULA developed upper stages. This would further reduce overhead costs and eliminate the need to develop a new upper stage. AJAX proposes to fund the development of ULA's ACES upper stage, creating a common upper stage across three vehicles. With the utilization of the CCB, AJAX would enable the development of the Atlas V HLV for crew launch from LC-39.
Title: Re: AJAX Launcher
Post by: 93143 on 02/26/2011 07:12 pm
Quote
EELV's

Heh...  looks like I missed one too...

Also, shouldn't "ULA developed" be hyphenated?  On the other hand, I like the old phrasing of that section more...
Title: Re: AJAX Launcher
Post by: Lobo on 02/28/2011 07:15 pm
I like the concept of dialing up what you need, 2, 4, 6, or 8 Atlas V's for various loads.  Add a second stage for heaver loads or for high orbits.  I like the modular approach.  Then, if enough Atlas V's manufacturing threshold is reached, then the Atlas V Phase II can be made. 
That's still the What.  We need the Why.

Think like Apple here.  We need a why, why does the US need AJAX? 

Well, we don't, really.  Any more than we -need- any HLV or any Space program at all.  At some level, any type of government space program is optional.

So, let's assume that all the arguments for a SDHLV over a zillion EELV's or larger phase private EELV have been hashed out, and a SDHLV wins as something we must have.  SO the question is, why is AJAX better than something like Direct?  Well, here's some pro's and con's.

AJAX Pro's over Direct SDHLV:
1)  Safer #1:  Nothing if fueled before being on the pad.  (You could also say nothing is being transported by rail fueled like SRB segs, but in fact, the RP-1 and LOX are transported themselves, so that's really not a great argument)

2)  Safer #2:  LRB's can be shut down if there's a problem at ignition.

3)  Safer #3:  Don't need your LAS to get crew away from burning solids.

4)  More flexible:  Because you aren't transporting the heavy boosters to the pad, you can strap on more boosters with existing MLP's and crawlers. 

5)  Clean PAd Option:  BEcause you are rolling it out unfueled, you can go back to a Saturn-V style clean pad, with towers on the MLP's.  I assume that's advantageous over the way the shuttle does it because that was what they wanted to do first, but had to go back to a fixed tower with Shuttle.

Direct SDHLV pros over AJAX:
1)  Time:  Would likely be ready to go much sooner as the stack is more or less flying right now with an orbitor slung onto the side.  (I'm speaking generally not literally, so don't jump on me.  BUt the Direct config is much closer to what's currently flying than AJAX is).

2)  Better understood hardware and operation:  Direct would move the SSME's to the bottom of the tank, but there's a lot of experience with SRB burning attached to the ET, base heating loads, etc.  AJAX's interaction between the CCB's and the ET and SSME's would all be brand new.  Not that it's a big problem, just that Direct probably has a faster path because of past experience.

3)  Cost:  AJAX is probably cheaper down the road, but it'd likely be more expensive up front, as you are breaking more new ground integrating the CCB's with the core (even though both currently exist) and integrating that.  There'll be more pad, MLP, and LC-39 mods for AJAX (adding RP-1 system, etc).  Again, not like these things are HUGE, just every step along the way will take a little longer, and cost a little more, because it's a little farther away from the Shuttle than Direct is.

4)  Politics:  ATK certainly wouldn't want AJAX.  Probably other forces too like Utah Senators and Congressmen.  Now, that can be balanced by those who would benefit from AJAX.  Those tied into the Atlas CCB production.  But they don't have a foot in the door already with NASA's HSF program the way the existing ones do.

So those will be what others come back at you with as far as why we need something more shuttle derived than AJAX.  HOWEVER, if NASA starts to creep too far away from something Direct-like (5-seg boosters, a 5th SSME, any core diameter change, etc.)  Than those arguments really start going away and AJAX really shines because then it becomes more closely shuttled derived than something more like Ares in terms of new hardware.  AJAX also has the flexibility to go up to 8 CCB's, which gives it a capacity similar to whatever balooning new HLV NASA might start to creep to.  So you get that high potential with the same 8.4m core and same 4 SSME's. 

So, if you are a big supporter of AJAX, you'd almost WANT NASA to start to creep away from something Direct like, because then really AJAX wins everywhere.  IF you were to just go with something very close to what Ross & Co. propose, it'l be harder to argue for (although it would still have a lot of merrit).  In fact, Direct supporters could argue AJAX is "creep" away from the fastest and cheapest replacement.
Title: Re: AJAX Launcher
Post by: Downix on 02/28/2011 07:26 pm
@Lobo:
You're quite on target.  The longer SLS drags on, the better AJAX looks, because we *can* get the target dates on-time. 
Title: Re: AJAX Launcher
Post by: Proponent on 03/01/2011 07:28 am
An extraneous apostrophe remains in the first sentence of the third paragraph: "EELV's".
Title: Re: AJAX Launcher
Post by: sdsds on 03/01/2011 07:31 am
I have a suggested edit to the first sentence, which currently reads:
Quote
AJAX is a method to accomplish the goals of the Congressionally mandated Space Launch System while reducing the overhead costs through shared resources.

AJAX is a method to accomplish the goals of the Congressionally mandated Space Launch System while reducing overhead costs by sharing resources with other United States launch systems.
Title: Re: AJAX Launcher
Post by: Proponent on 03/01/2011 07:40 am
AJAX is a method to accomplish the goals of the Congressionally mandated Space Launch System while reducing overhead costs by sharing resources with other United States launch systems.

I like that.  If I may, I suggest replacing "is a method to achieve" with the slightly more streamlined "is a means of achieving".  I'd also hyphenate "Congressionally mandated".
Title: Re: AJAX Launcher
Post by: Downix on 03/01/2011 02:37 pm
How about now?
Title: Re: AJAX Launcher
Post by: Lobo on 03/01/2011 05:59 pm
I have a suggested edit to the first sentence, which currently reads:
Quote
AJAX is a method to accomplish the goals of the Congressionally mandated Space Launch System while reducing the overhead costs through shared resources.

AJAX is a method to accomplish the goals of the Congressionally mandated Space Launch System while reducing overhead costs by sharing resources with other United States launch systems.

Certainly more pithy than my long post.  ;-)

Does anyone have a reasonable SWAG guess as to how much more AJAX might be than let's say Direct initial development costs?

And also, once developed, would it be more, less, or about the same as Direct would be in per launch cost, and annual sustaining costs?

Also, how long would it take for AJAX to fly compared to like Direct?  Similar?  Longer?

I'm pretty sure it'd have to be more to develop, but just wondering if that's likely to be significant (several billion) or relatively minior (1 or 2 billion), in which case if the per launch and annual costs are on parity with Direct, then the added growth and flexibility (and safety) of AJAX becomes more apparent. 

If NASA goes creeps a SDHLV away from something like Direct, and more towards an Ares Lite or Classic (5-seg boosters, 5 SSME, requirement of a 2nd stage to get to LEO then I think because the core would burn out too quickly to do it?, possibly stretched tank)  Then AJAX just gets better, because now you are talking about boosters that have never been flown with a core for both AJAX and Ares-X, and I think the ET then needs mods to the supports for the longer SRB's, right?  So both require tank mods in their booster support.  And if hte Ares-X is looking at a diameter change or stretch, and AJAX doesn't (right?)  then AJAX looks a little easier to do.
Title: Re: AJAX Launcher
Post by: Downix on 03/01/2011 07:23 pm
I have a suggested edit to the first sentence, which currently reads:
Quote
AJAX is a method to accomplish the goals of the Congressionally mandated Space Launch System while reducing the overhead costs through shared resources.

AJAX is a method to accomplish the goals of the Congressionally mandated Space Launch System while reducing overhead costs by sharing resources with other United States launch systems.

Certainly more pithy than my long post.  ;-)

Does anyone have a reasonable SWAG guess as to how much more AJAX might be than let's say Direct initial development costs?
By my estimates for operational flight, they're about the same, at $9 billion.  But while DIRECT had more cost for things like SRB testing, recertification, and support costs for Utah, AJAX has those costs put into LC39, outfitting for EELV operation, Kerolox, and refurbishment.  But evolution is where AJAX costs a bit more, because it's evolutions include Phase I and II EELV (total cost $6 billion, after initial operation) while DIRECT has only the EDS to develop (at $4 billion).  But those can be stretched out over longer periods as well.
Quote
And also, once developed, would it be more, less, or about the same as Direct would be in per launch cost, and annual sustaining costs?
Per launch is equal, but sustaining cost is over $1 bil/year less.  Also, as LC-39 would, under the AJAX plan, be used for manned EELV launches as well, the sustaining cost would be supporting a larger operation than just AJAX.
Quote
Also, how long would it take for AJAX to fly compared to like Direct?  Similar?  Longer?
Initial flight, longer.  Fully operational, the same.  The reason for the longer initial flight is due to the changes to the ET.  However, once done, it can be made operational sooner as the other systems for it would be able to be tested on EELV launches beforehand.
Quote
I'm pretty sure it'd have to be more to develop, but just wondering if that's likely to be significant (several billion) or relatively minior (1 or 2 billion), in which case if the per launch and annual costs are on parity with Direct, then the added growth and flexibility (and safety) of AJAX becomes more apparent. 

If NASA goes creeps a SDHLV away from something like Direct, and more towards an Ares Lite or Classic (5-seg boosters, 5 SSME, requirement of a 2nd stage to get to LEO then I think because the core would burn out too quickly to do it?, possibly stretched tank)  Then AJAX just gets better, because now you are talking about boosters that have never been flown with a core for both AJAX and Ares-X, and I think the ET then needs mods to the supports for the longer SRB's, right?  So both require tank mods in their booster support.  And if hte Ares-X is looking at a diameter change or stretch, and AJAX doesn't (right?)  then AJAX looks a little easier to do.

No diameter core change nor stretch.  Actually, AJAX shrinks the core.  As the LRB's burn for several minutes longer than the SRB's, AJAX does not need as much fuel in the core, as the SSME's can be run throttled down for almost two minutes longer before throttling up for orbital acceleration.  This is done by removing a ring from the LH2 tank, and not using as large a ring for LOX (actually, recycles the existing LOX ring, mounting two of them with a copy of the LH2 top done, instead of the one + new longer ring as DIRECT does).  There have been ET's built already with similar ring-swaps, so the techniques for it are already there, and the equipment can more than handle it.
Title: Re: AJAX Launcher
Post by: baldusi on 03/01/2011 07:30 pm
I've only seen other, more informed people do comments. But I seem to recall that even a Direct would require significant restructuring. Is true that the same tooling of the ET might be used, but you've to do every check, test and simulation again. Plus you now have to reinforce the base for the push structure. The Orbiter pushed from one side, and the SRB from top sides. In Ajax you'd get only on the bottom. But you'd still have to bear the 2nd stage and payload on the top.
The whole ECU, flight computers and guidance system has to be redone. Most electronics (as I understand it) where on the Orbiter. So you either use the 30 years old system and try to retrofit it to a different layout and system, or use a more modern system. In the case of AJAX the ECU would be the Atlas, so it's hardly less reliable than the RS-25. At least is made to be disposable.
In fact, the gantry would be easier since the dry weight would be a lot less. But you'd have to re pipe the RP1 plumbing and pumping system. Plus, I don't know about the service tower compatibility.
Overall, from my ignorant point of view, it should be on the same ball park.
Title: Re: AJAX Launcher
Post by: sdsds on 03/01/2011 07:34 pm
There have been ET's built already with similar ring-swaps

This bit is news to me.  To what tanks does this refer?
Title: Re: AJAX Launcher
Post by: Downix on 03/01/2011 08:16 pm
There have been ET's built already with similar ring-swaps

This bit is news to me.  To what tanks does this refer?
ET-128, if you check the documentation you'll notice the Rings of the LH2 tank are out of order, having been switched in assembly.  I can't recall off hand why it was done, but I suspect it had to do with the foam loss issue being addressed.
Title: Re: AJAX Launcher
Post by: Downix on 03/01/2011 08:28 pm
I've only seen other, more informed people do comments. But I seem to recall that even a Direct would require significant restructuring. Is true that the same tooling of the ET might be used, but you've to do every check, test and simulation again. Plus you now have to reinforce the base for the push structure. The Orbiter pushed from one side, and the SRB from top sides. In Ajax you'd get only on the bottom. But you'd still have to bear the 2nd stage and payload on the top.
As I've described a few times, the CCB's and SSME's would be pushing "from the side", the support ring currently used for the Orbiter would be located below the fuel tank itself, and reinforced for this with a structure derived from the SRB mount, no longer needed.  The top portion would be derived from the bipod section of the tank.  As for the 2nd stage and payload, we have addressed that, in the document we're working on.  It's a simple and elegant solution to the issue, designed to minimize tooling changes.
Quote
The whole ECU, flight computers and guidance system has to be redone. Most electronics (as I understand it) where on the Orbiter. So you either use the 30 years old system and try to retrofit it to a different layout and system, or use a more modern system. In the case of AJAX the ECU would be the Atlas, so it's hardly less reliable than the RS-25. At least is made to be disposable.
Would we need a new ECU?  Of course, but that can be derived from existing systems, Delta's being a prime candidate, and would be found in the upper stage.  Remember, Ares IX utilized an off the shelf ECU, Atlas V's.  There is no reason why we could not consider a similar approach.  By re-using and adapting existing systems as much as possible, we can keep the costs down.  By augmenting proven liquid boosters, we make this possible.
Quote
In fact, the gantry would be easier since the dry weight would be a lot less. But you'd have to re pipe the RP1 plumbing and pumping system. Plus, I don't know about the service tower compatibility.
Overall, from my ignorant point of view, it should be on the same ball park.
There is none, AJAX is a flat-pad, service tower demolished completely.  The towers would be on the MLP's, two new ones designed for AJAX. (The Ares I MLP would be used for manned EELV launches in this program)  We know the cost of the MLP's already, thanks to Ares I's MLP recently being constructed.  The cost to restore Kerolox to LC-39 is also fairly well understood.  Overall, the costs are comparable.  Remember, LC-39 used to have RP1, the ground structures are still there, you just need to put new systems in their place, new tanks, pipes, etc.  But those are not a major cost.  Not trying to salvage the now almost 50 year old Saturn MLP that the shuttle is using is also a money saving measure.  The modifications to them, and the pad, would be too costly in comparison to just replacing them with a pair of new MLP's.  Total pad work would be $1.7 billion, including the MLP construction.  By putting the majority of the work into the MLP, you speed up the work for the pad as well, and by utilizing the Ares I MLP, modified for the Atlas V Heavy, you can test out and verify the systems ahead of system rollout.
Title: Re: AJAX Launcher
Post by: baldusi on 03/01/2011 08:43 pm
May be my English is lacking. But I wanted to say what you answered to me. In other words, DIRECT does need a LOT of new stuff. The fact that they propose to use off the shelf parts, doesn't mean that other proposal can't.
I hate it when they propose to use "existing" SS technologies, but competing proposals must have "new" parts. They have to certify and qualify everything anyways. And EELV has a lot of very reliable parts.
Title: Re: AJAX Launcher
Post by: martin hegedus on 03/02/2011 01:19 am

Quote
Also, how long would it take for AJAX to fly compared to like Direct?  Similar?  Longer?
Initial flight, longer.  Fully operational, the same.  The reason for the longer initial flight is due to the changes to the ET.  However, once done, it can be made operational sooner as the other systems for it would be able to be tested on EELV launches beforehand.

What systems were you planning to test on EELV launches beforehand?  Computer syms, lab testing, and ground testing should be enough.  Then do a test flight of the complete AJAX.  I don't see the need for an AJAX 1-X.  Unless you plan on turning this into a research project.

And why would DIRECT's initial flight take less time than AJAX's due to ET?  The ET would go through the redesign process for both Jupiter and AJAX.  So the time allocated for the ET to get to CDR would more or less be the same.  Why would it be different?  Or are you saying that AJAX's ET takes more time than Jupiter's after CDR?  Does that mean manufacturing the first ET would take more time, or does that mean testing and certification would take more time?  Or both?
Title: Re: AJAX Launcher
Post by: Downix on 03/02/2011 01:37 am

Quote
Also, how long would it take for AJAX to fly compared to like Direct?  Similar?  Longer?
Initial flight, longer.  Fully operational, the same.  The reason for the longer initial flight is due to the changes to the ET.  However, once done, it can be made operational sooner as the other systems for it would be able to be tested on EELV launches beforehand.

What systems were you planning to test on EELV launches beforehand?  Computer syms, lab testing, and ground testing should be enough.  Then do a test flight of the complete AJAX.  I don't see the need for an AJAX 1-X.  Unless you plan on turning this into a research project.
It's not an AJAX 1-X, however, it's manned Atlas V HLV from LC-39.  That would allow ground control to get familiar with the new workflow before a full-up launch.  In addition, would also be able to test the CCB's as boosters that way, as the Atlas V HLV would use them as well.  It would also enable manned Orion utilization, to get those systems in-order.  An "Apollo 7" as it were.
Quote
And why would DIRECT's initial flight take less time than AJAX's due to ET?  The ET would go through the redesign process for both Jupiter and AJAX.  So the time allocated for the ET to get to CDR would more or less be the same.  Why would it be different?  Or are you saying that AJAX's ET takes more time than Jupiter's after CDR?  Does that mean manufacturing the first ET would take more time, or does that mean testing and certification would take more time?  Or both?

DIRECT already has incomplete shuttle ET's which can be converted into DIRECT cores as/is.  In addition, DIRECT can fly the LWT as/is as a demo flight, with a dummy US cap added to the existing tank, and an SSME pod mounted to the base.

AJAX could, by comparison, only make use of two of them, the two with the least amount of work.  Less existing material to work from == slower time to initial flight.

But, both would be ready for operational status about the same time.  DIRECT operation would be delayed due to being unable to test the orbital elements until at least two or three full-up tests.  AJAX can test those on Atlas V, due to the commonality of the systems, which means only one full-up test will be needed.
Title: Re: AJAX Launcher
Post by: martin hegedus on 03/02/2011 02:11 am

It's not an AJAX 1-X, however, it's manned Atlas V HLV from LC-39.  That would allow ground control to get familiar with the new workflow before a full-up launch.  In addition, would also be able to test the CCB's as boosters that way, as the Atlas V HLV would use them as well.  It would also enable manned Orion utilization, to get those systems in-order.  An "Apollo 7" as it were.

Your call, but I do hope your engineers and operations people are of a caliber to handle this without doing an EELV launch for practice or data verification.

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DIRECT already has incomplete shuttle ET's which can be converted into DIRECT cores as/is.  In addition, DIRECT can fly the LWT as/is as a demo flight, with a dummy US cap added to the existing tank, and an SSME pod mounted to the base.

AJAX could, by comparison, only make use of two of them, the two with the least amount of work.  Less existing material to work from == slower time to initial flight.

But, both would be ready for operational status about the same time.  DIRECT operation would be delayed due to being unable to test the orbital elements until at least two or three full-up tests.  AJAX can test those on Atlas V, due to the commonality of the systems, which means only one full-up test will be needed.

Do you mean the SLWT or the LWT?  The SLWT is optimized for the Shuttle.  The talk I've seen on this site that the factor of safety for the ET is 1.4 is false if they are referring to the SLWT.  I wouldn't believe that the SLWT can handle the Jupiter configuration unless someone showed me a detailed structural analysis.  And I don't believe the DIRECT team has a structural analysis since they do not have aero loads (i.e. pressures).
Title: Re: AJAX Launcher
Post by: Downix on 03/02/2011 03:26 am

It's not an AJAX 1-X, however, it's manned Atlas V HLV from LC-39.  That would allow ground control to get familiar with the new workflow before a full-up launch.  In addition, would also be able to test the CCB's as boosters that way, as the Atlas V HLV would use them as well.  It would also enable manned Orion utilization, to get those systems in-order.  An "Apollo 7" as it were.

Your call, but I do hope your engineers and operations people are of a caliber to handle this without doing an EELV launch for practice or data verification.
It's more a case of being prepared in case commercial crew is unable to deliver in-time, in the guise of test flights.  I never like anything unless I am doing 3 things at once.
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DIRECT already has incomplete shuttle ET's which can be converted into DIRECT cores as/is.  In addition, DIRECT can fly the LWT as/is as a demo flight, with a dummy US cap added to the existing tank, and an SSME pod mounted to the base.

AJAX could, by comparison, only make use of two of them, the two with the least amount of work.  Less existing material to work from == slower time to initial flight.

But, both would be ready for operational status about the same time.  DIRECT operation would be delayed due to being unable to test the orbital elements until at least two or three full-up tests.  AJAX can test those on Atlas V, due to the commonality of the systems, which means only one full-up test will be needed.

Do you mean the SLWT or the LWT?  The SLWT is optimized for the Shuttle.  The talk I've seen on this site that the factor of safety for the ET is 1.4 is false if they are referring to the SLWT.  I wouldn't believe that the SLWT can handle the Jupiter configuration unless someone showed me a detailed structural analysis.  And I don't believe the DIRECT team has a structural analysis since they do not have aero loads (i.e. pressures).

The LWT, ET-94, is unused, and would be able to be used for a test flight for DIRECT.  The existing partially completed SLWT would be modified into dummy test flights, for both DIRECT and AJAX in order to get the tooling back into operation and the staff back into the swing.

An Example picture of using ET-94 as a test vehicle.
http://www.nasaspaceflight.com/wp-content/uploads/2010/06/A171.jpg
Title: Re: AJAX Launcher
Post by: martin hegedus on 03/02/2011 04:44 am

It's not an AJAX 1-X, however, it's manned Atlas V HLV from LC-39.  That would allow ground control to get familiar with the new workflow before a full-up launch.  In addition, would also be able to test the CCB's as boosters that way, as the Atlas V HLV would use them as well.  It would also enable manned Orion utilization, to get those systems in-order.  An "Apollo 7" as it were.

Your call, but I do hope your engineers and operations people are of a caliber to handle this without doing an EELV launch for practice or data verification.
It's more a case of being prepared in case commercial crew is unable to deliver in-time, in the guise of test flights.  I never like anything unless I am doing 3 things at once.
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DIRECT already has incomplete shuttle ET's which can be converted into DIRECT cores as/is.  In addition, DIRECT can fly the LWT as/is as a demo flight, with a dummy US cap added to the existing tank, and an SSME pod mounted to the base.

AJAX could, by comparison, only make use of two of them, the two with the least amount of work.  Less existing material to work from == slower time to initial flight.

But, both would be ready for operational status about the same time.  DIRECT operation would be delayed due to being unable to test the orbital elements until at least two or three full-up tests.  AJAX can test those on Atlas V, due to the commonality of the systems, which means only one full-up test will be needed.

Do you mean the SLWT or the LWT?  The SLWT is optimized for the Shuttle.  The talk I've seen on this site that the factor of safety for the ET is 1.4 is false if they are referring to the SLWT.  I wouldn't believe that the SLWT can handle the Jupiter configuration unless someone showed me a detailed structural analysis.  And I don't believe the DIRECT team has a structural analysis since they do not have aero loads (i.e. pressures).

The LWT, ET-94, is unused, and would be able to be used for a test flight for DIRECT.  The existing partially completed SLWT would be modified into dummy test flights, for both DIRECT and AJAX in order to get the tooling back into operation and the staff back into the swing.

An Example picture of using ET-94 as a test vehicle.
http://www.nasaspaceflight.com/wp-content/uploads/2010/06/A171.jpg

If a test is not required for the CDR, don't do it.  If a test is required for the CDR, that means other things are waiting for the results.  All required research should more or less end at the CDR.  After the CDR, focus on your vehicle.  If your vehicle does not use an LWT, don't mess with it.  If the partially completed SLWT doesn't match your configuration for your intended test, certification, or training, don't mess with it.
Title: Re: AJAX Launcher
Post by: Downix on 03/02/2011 05:33 am

It's not an AJAX 1-X, however, it's manned Atlas V HLV from LC-39.  That would allow ground control to get familiar with the new workflow before a full-up launch.  In addition, would also be able to test the CCB's as boosters that way, as the Atlas V HLV would use them as well.  It would also enable manned Orion utilization, to get those systems in-order.  An "Apollo 7" as it were.

Your call, but I do hope your engineers and operations people are of a caliber to handle this without doing an EELV launch for practice or data verification.
It's more a case of being prepared in case commercial crew is unable to deliver in-time, in the guise of test flights.  I never like anything unless I am doing 3 things at once.
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DIRECT already has incomplete shuttle ET's which can be converted into DIRECT cores as/is.  In addition, DIRECT can fly the LWT as/is as a demo flight, with a dummy US cap added to the existing tank, and an SSME pod mounted to the base.

AJAX could, by comparison, only make use of two of them, the two with the least amount of work.  Less existing material to work from == slower time to initial flight.

But, both would be ready for operational status about the same time.  DIRECT operation would be delayed due to being unable to test the orbital elements until at least two or three full-up tests.  AJAX can test those on Atlas V, due to the commonality of the systems, which means only one full-up test will be needed.

Do you mean the SLWT or the LWT?  The SLWT is optimized for the Shuttle.  The talk I've seen on this site that the factor of safety for the ET is 1.4 is false if they are referring to the SLWT.  I wouldn't believe that the SLWT can handle the Jupiter configuration unless someone showed me a detailed structural analysis.  And I don't believe the DIRECT team has a structural analysis since they do not have aero loads (i.e. pressures).

The LWT, ET-94, is unused, and would be able to be used for a test flight for DIRECT.  The existing partially completed SLWT would be modified into dummy test flights, for both DIRECT and AJAX in order to get the tooling back into operation and the staff back into the swing.

An Example picture of using ET-94 as a test vehicle.
http://www.nasaspaceflight.com/wp-content/uploads/2010/06/A171.jpg

If a test is not required for the CDR, don't do it.  If a test is required for the CDR, that means other things are waiting for the results.  All required research should more or less end at the CDR.  After the CDR, focus on your vehicle.  If your vehicle does not use an LWT, don't mess with it.  If the partially completed SLWT doesn't match your configuration for your intended test, certification, or training, don't mess with it.

That is rather my point.  The incomplete SWLT's are in such a shape that, for DIRECT, they all can be modified to suit.  For AJAX, only the two which are nothing but the domes can be utilized due to some of the modifications which need to be done.
Title: Re: AJAX Launcher
Post by: 2552 on 03/02/2011 07:50 am
Per launch is equal, but sustaining cost is over $1 bil/year less.  Also, as LC-39 would, under the AJAX plan, be used for manned EELV launches as well, the sustaining cost would be supporting a larger operation than just AJAX.

Over 1 billion less in fixed costs is impressive. What are the exact figures of the fixed costs of AJAX vs DIRECT, for comparison?
Title: Re: AJAX Launcher
Post by: 93143 on 03/02/2011 08:54 am
And I don't believe the DIRECT team has a structural analysis since they do not have aero loads (i.e. pressures).

Are you sure about that?  I thought they had done substantial CFD.  Not full-resolution with WT to compare, but enough to determine that a 12 m fairing was feasible and that a 15 m fairing might be.
Title: Re: AJAX Launcher
Post by: martin hegedus on 03/02/2011 10:10 am
And I don't believe the DIRECT team has a structural analysis since they do not have aero loads (i.e. pressures).

Are you sure about that?  I thought they had done substantial CFD.  Not full-resolution with WT to compare, but enough to determine that a 12 m fairing was feasible and that a 15 m fairing might be.

They have done CFD to assist in their design of the payload fairing.  How much, specifically for the PLF, I have no idea.  However, from Ross's reply to a question of mine a while back regarding the amount of CFD on the vehicles, they have not done it on the entire vehicle.  Ross specified the PLF only.  Therefore, it sounds like they are a long way from having a substantial amount of CFD.  And, I'm not clear on what type of CFD they did perform on the PLF.  Was it Euler or RANS?  Did it include angle of attack?  What Mach numbers?  Nor do I know what code they used.  I really wish the DIRECT team would have been more transparent on what technical work they did perform.  Oh well.

Edit:  DIRECT's comments in regards to NASA's questions about Analysis Methodology can be found in DIRECT's rebuttal to NASA's findings on DIRECT's vehicles, pg 61-63.

In regards to aero, here is a quote from the rebuttal.

"Aerodynamic assessments are being performed utilizing Pro-E’s FEM capabilities plus other tools being utilized by MSFC for analyzing the Ares-I. A modified version of NASA’s 1993 NLS aero-database is being used, suitably altered to fit the different configurations of the various Jupiter vehicles. We are investigating a recent offer to utilize a high-speed wind-tunnel, but at this time have not done so."

Pro-E's FEM capabilities?  That is not an industry accept analysis tool for compressible aerodynamics.  I don't even think it is compressible.  Is this what DIRECT means by CFD?  And, DIRECT does not mention the other NASA tools they used.  What were they?  APAS (which, at best, is only a panel code)? PANAIR (again, panel only)? CART3D? OVERFLOW? CFL3D? TetrUSS/USM3D?  There is no secret about the codes NASA uses.  NASA has been very clear about the aero codes they use on their vehicles.  So why the vagueness from DIRECT?

Title: Re: AJAX Launcher
Post by: Downix on 03/02/2011 03:24 pm
Per launch is equal, but sustaining cost is over $1 bil/year less.  Also, as LC-39 would, under the AJAX plan, be used for manned EELV launches as well, the sustaining cost would be supporting a larger operation than just AJAX.

Over 1 billion less in fixed costs is impressive. What are the exact figures of the fixed costs of AJAX vs DIRECT, for comparison?
The estimates I have for DIRECT's fixed costs is $2.1 billion.  AJAX's estimate is hovering at $1 billion, but it's preliminary estimation. 
Title: Re: AJAX Launcher
Post by: 2552 on 03/02/2011 04:26 pm
Per launch is equal, but sustaining cost is over $1 bil/year less.  Also, as LC-39 would, under the AJAX plan, be used for manned EELV launches as well, the sustaining cost would be supporting a larger operation than just AJAX.

Over 1 billion less in fixed costs is impressive. What are the exact figures of the fixed costs of AJAX vs DIRECT, for comparison?
The estimates I have for DIRECT's fixed costs is $2.1 billion.  AJAX's estimate is hovering at $1 billion, but it's preliminary estimation. 

If the fixed cost is only about 1 billion, that figure should probably be in the intro, such as: "In short, it would share overhead, spreading out the cost over multiple agencies, making an AJAX based SLS affordable to operate, with annual operating costs around $1 billion/year.  "
Title: Re: AJAX Launcher
Post by: Downix on 03/02/2011 06:01 pm
Per launch is equal, but sustaining cost is over $1 bil/year less.  Also, as LC-39 would, under the AJAX plan, be used for manned EELV launches as well, the sustaining cost would be supporting a larger operation than just AJAX.

Over 1 billion less in fixed costs is impressive. What are the exact figures of the fixed costs of AJAX vs DIRECT, for comparison?
The estimates I have for DIRECT's fixed costs is $2.1 billion.  AJAX's estimate is hovering at $1 billion, but it's preliminary estimation. 

If the fixed cost is only about 1 billion, that figure should probably be in the intro, such as: "In short, it would share overhead, spreading out the cost over multiple agencies, making an AJAX based SLS affordable to operate, with annual operating costs around $1 billion/year.  "
Until we finish the full paper and verify the numbers, I'd rather wait.  As it is right now, we have too many support cost estimates, which is the concern.  I'd rather have it nailed down before putting it into an official document.  While I know I'm in the ballpark, I don't have enough verified to nail it down.  And after seeing how NASA dissected DIRECT, I am taking no chances.
Title: Re: AJAX Launcher
Post by: 2552 on 03/02/2011 06:13 pm
Per launch is equal, but sustaining cost is over $1 bil/year less.  Also, as LC-39 would, under the AJAX plan, be used for manned EELV launches as well, the sustaining cost would be supporting a larger operation than just AJAX.

Over 1 billion less in fixed costs is impressive. What are the exact figures of the fixed costs of AJAX vs DIRECT, for comparison?
The estimates I have for DIRECT's fixed costs is $2.1 billion.  AJAX's estimate is hovering at $1 billion, but it's preliminary estimation. 

If the fixed cost is only about 1 billion, that figure should probably be in the intro, such as: "In short, it would share overhead, spreading out the cost over multiple agencies, making an AJAX based SLS affordable to operate, with annual operating costs around $1 billion/year.  "
Until we finish the full paper and verify the numbers, I'd rather wait.  As it is right now, we have too many support cost estimates, which is the concern.  I'd rather have it nailed down before putting it into an official document.  While I know I'm in the ballpark, I don't have enough verified to nail it down.  And after seeing how NASA dissected DIRECT, I am taking no chances.

Yeah, that makes sense.
Title: Re: AJAX Launcher
Post by: Downix on 03/02/2011 06:27 pm
Per launch is equal, but sustaining cost is over $1 bil/year less.  Also, as LC-39 would, under the AJAX plan, be used for manned EELV launches as well, the sustaining cost would be supporting a larger operation than just AJAX.

Over 1 billion less in fixed costs is impressive. What are the exact figures of the fixed costs of AJAX vs DIRECT, for comparison?
The estimates I have for DIRECT's fixed costs is $2.1 billion.  AJAX's estimate is hovering at $1 billion, but it's preliminary estimation. 

If the fixed cost is only about 1 billion, that figure should probably be in the intro, such as: "In short, it would share overhead, spreading out the cost over multiple agencies, making an AJAX based SLS affordable to operate, with annual operating costs around $1 billion/year.  "
Until we finish the full paper and verify the numbers, I'd rather wait.  As it is right now, we have too many support cost estimates, which is the concern.  I'd rather have it nailed down before putting it into an official document.  While I know I'm in the ballpark, I don't have enough verified to nail it down.  And after seeing how NASA dissected DIRECT, I am taking no chances.

Yeah, that makes sense.
I can, however, give the basics:

LC-39 costs about $800 mil a year to support.
Michoud costs about $600 mil a year to support

*however* Michoud's support costs are offset due to other agencies, and companies, utilizing the space.  They pay for about half of Michouds support costs, $300 mil per year.

LC-39 is also less efficient than it could be due to several elements, most notably being the support towers, orbiter processing, and VAB operational limits caused by the SRB's.  The process for turning LC-39A and B into flat-pads would include cost reduction measures, converting the OPB's, and eliminating the SRB's limits bringing the support cost down by about $200 mil a year, by estimates.

So, using those rough numbers, extracted over budgets for the past decade adjusted for inflation, I came up with just under $1 billion.  But I need to verify numbers.
Title: Re: AJAX Launcher
Post by: Lobo on 03/02/2011 08:05 pm

No diameter core change nor stretch.  Actually, AJAX shrinks the core.  As the LRB's burn for several minutes longer than the SRB's, AJAX does not need as much fuel in the core, as the SSME's can be run throttled down for almost two minutes longer before throttling up for orbital acceleration.  This is done by removing a ring from the LH2 tank, and not using as large a ring for LOX (actually, recycles the existing LOX ring, mounting two of them with a copy of the LH2 top done, instead of the one + new longer ring as DIRECT does).  There have been ET's built already with similar ring-swaps, so the techniques for it are already there, and the equipment can more than handle it.

Great info Downix, thanks. I followed AJAX a bit right at it's conception, but hadn't read through all of the pages of this thread.  So sorry if all of this had already been talked about.

So, the LRB's would basically be jettisoned in orbit, for burnup on reentry like the ET?  So no reuse possibility there?
Not that I think it's a big deal to try to reuse them.  Just wondering if the pro-SRB folks would argue the SRB's "reusability" vs. the disposable LRB's?
So then that begs the question, although you already said that AJAX would be a little cheaper overal to operate in reoccuring costs, and about the same per launch as Direct?  So 4 new LRB's every mission, vs. 2 refubished and refueled SRB's every mission (to compare apples to apples) is about the same?  Even though the SRB's are "reusable", are they not actually any cheaper in terms of real-world dollars?  It wouldn't surprise me if not, but pondering a question that would certainly come up in a Debate between SDHLV and AJAX.

Also, new question (hope I'm not pestering here), How does AJAX then compare to some SDHLV that NASA creeped from Direct-like, to something ARes like?  Meaning, 5-Seg SRB's, 5-SSME core, possible tank stetch.  LIke I said above, I assume once you are to this monster, AJAX then become more affordable in both development and recurring costs?
What sort of SWAG numbers are we looking at comparing AJAX to something like that (as it sounds like there's some in NASA thinking about creeping SDHLV from Direct like to Ares-X like, or at least I've heard some things to that effect, rather than them just going with the most obvious SDHLV in Direct).

Lastly, what about AJAX upper stage?  AJAX doesn't need an US to get payloads to LEO, right?  Were US costs in that $6 billion number you cited earlier?  Or was that just for the booster development?
Title: Re: AJAX Launcher
Post by: Lobo on 03/02/2011 08:10 pm
Per launch is equal, but sustaining cost is over $1 bil/year less.  Also, as LC-39 would, under the AJAX plan, be used for manned EELV launches as well, the sustaining cost would be supporting a larger operation than just AJAX.


Hmmm....can you expand on this some?  So what, would like pad 39B be configured to launch the CCB's solo with smaller payloads and LEO manned capsules?
And like 39A would be cofigured to launch manned and unmanned AJAX's?

If so, that's very interesting.  Interesting commonality.  So how would that interact with like SpaceX launching crews on F9, or ULA launching Atlas CCB's?  What would NASA be launching on the boosters only?  A booster can't lift Orion even to like the ISS can it?
CAn you elaborate on this?
Title: Re: AJAX Launcher
Post by: Downix on 03/02/2011 08:33 pm

No diameter core change nor stretch.  Actually, AJAX shrinks the core.  As the LRB's burn for several minutes longer than the SRB's, AJAX does not need as much fuel in the core, as the SSME's can be run throttled down for almost two minutes longer before throttling up for orbital acceleration.  This is done by removing a ring from the LH2 tank, and not using as large a ring for LOX (actually, recycles the existing LOX ring, mounting two of them with a copy of the LH2 top done, instead of the one + new longer ring as DIRECT does).  There have been ET's built already with similar ring-swaps, so the techniques for it are already there, and the equipment can more than handle it.

Great info Downix, thanks. I followed AJAX a bit right at it's conception, but hadn't read through all of the pages of this thread.  So sorry if all of this had already been talked about.

So, the LRB's would basically be jettisoned in orbit, for burnup on reentry like the ET?  So no reuse possibility there?
The existing LRB's, no.  However, the USAF has contracted studies with Lockheed and Andrews to develop what are effectively reusable EELV's, so who knows what direction that will go in
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Not that I think it's a big deal to try to reuse them.  Just wondering if the pro-SRB folks would argue the SRB's "reusability" vs. the disposable LRB's?
That is one of the arguments, but also one of the cases against the SRB's is the huge overhead cost caused by the inefficient reusable system, having to fetch them, then move them back to Utah for refurbishment.  Politically good, cost wise, horrid.
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So then that begs the question, although you already said that AJAX would be a little cheaper overal to operate in reoccuring costs, and about the same per launch as Direct?  So 4 new LRB's every mission, vs. 2 refubished and refueled SRB's every mission (to compare apples to apples) is about the same? 
The per-launch cost comes out about the same. (about $100 mil per launch)  The advantage for LRB's is the lack of overhead costs mentioned above.
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Even though the SRB's are "reusable", are they not actually any cheaper in terms of real-world dollars?  It wouldn't surprise me if not, but pondering a question that would certainly come up in a Debate between SDHLV and AJAX.

Also, new question (hope I'm not pestering here), How does AJAX then compare to some SDHLV that NASA creeped from Direct-like, to something ARes like?  Meaning, 5-Seg SRB's, 5-SSME core, possible tank stetch.
AJAX, due to it's LRB base, scales further.  8 CCB's vs 4, with a higher energy upper stage like ACES, rivals the 5-seg, 5 SSME, stretched tank Ares V Classic for capabilty, but does it without costing you addition R&D, and retains the older configuration for when missions demand it.  The big issue of the big-gun approach is, once you've done the work, you've dismantled the older system, locking you into the larger 5/5/stretch.
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LIke I said above, I assume once you are to this monster, AJAX then become more affordable in both development and recurring costs?
What sort of SWAG numbers are we looking at comparing AJAX to something like that (as it sounds like there's some in NASA thinking about creeping SDHLV from Direct like to Ares-X like, or at least I've heard some things to that effect, rather than them just going with the most obvious SDHLV in Direct).
AJAX becomes even more affordable then.  By the math, for the cost of Ares V Classic, AJAX could get Atlas V Phase I and II completed, which would make AJAX perform closer to Ares V, the big 180mT model.  It would also make Atlas V more affordable and capable as well.
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Lastly, what about AJAX upper stage?  AJAX doesn't need an US to get payloads to LEO, right?  Were US costs in that $6 billion number you cited earlier?  Or was that just for the booster development?
AJAX uses the EELV's US.  It does not require a US, but one is handy for final orbital burn, but even using a Delta-K would suffice.  The development cost was for the full system, including certifying the EELV US's for use. (primarily focused on Delta IV's 5m upper stage, with Centaur as a backup option)
Title: Re: AJAX Launcher
Post by: Downix on 03/02/2011 08:40 pm
Per launch is equal, but sustaining cost is over $1 bil/year less.  Also, as LC-39 would, under the AJAX plan, be used for manned EELV launches as well, the sustaining cost would be supporting a larger operation than just AJAX.


Hmmm....can you expand on this some?  So what, would like pad 39B be configured to launch the CCB's solo with smaller payloads and LEO manned capsules?
And like 39A would be cofigured to launch manned and unmanned AJAX's?

If so, that's very interesting.  Interesting commonality.  So how would that interact with like SpaceX launching crews on F9, or ULA launching Atlas CCB's?  What would NASA be launching on the boosters only?  A booster can't lift Orion even to like the ISS can it?
CAn you elaborate on this?
Both pads would be flat pads, identical to each other and capable of launching both AJAX and EELV's.  The reason this works is because the key interfacing technology is in the MLP's, not the pads.  Roll Atlas V's MLP out to Pad 39B, AJAX's MLP out to 39A, you're set, or roll back and switch them, not a problem.  This is how LC-39 was originally developed, this is why it used the MLP's to begin with, to enable the same launch site to handle multiple rocket options.  Originally, the idea was Saturn and Nova, but in our case, AJAX, Atlas and even possibly Delta, Falcon or Taurus in the future.  It would be part of the "21st Century Launch Complex" concept, enabling private firms to utilize the existing pads, reducing their cost to operate manned launches as a result through a shared resource.  The only cost would be the MLP's for the launchers, and as I checked, LC-39 can support up to 7 right now, and adding support for more is not difficult nor expensive, and could be added into the up-front costs of any new launcher which wishes to make use of the system.

Remember, AJAX is also partly about better utilizing the systems we have, which includes enabling the use of currently Shuttle only systems by other parties.  Utilizing LC-39 more efficiently is part of that.
Title: Re: AJAX Launcher
Post by: Lobo on 03/03/2011 05:03 pm
AJAX uses the EELV's US.  It does not require a US, but one is handy for final orbital burn, but even using a Delta-K would suffice.  The development cost was for the full system, including certifying the EELV US's for use. (primarily focused on Delta IV's 5m upper stage, with Centaur as a backup option)

So the 8.4m core uses a 5m upper stage?  Does that have enough power to put a heavy paylaod into BLEO?  Can it take paylaod to the Moon?  I wouldn't think such a small US would be adequate for what AJAX can loft.

Direct's US would not only get into LEO, but be the EDS as well.  What does AJAX do for EDS?
Title: Re: AJAX Launcher
Post by: Downix on 03/03/2011 05:13 pm
AJAX uses the EELV's US.  It does not require a US, but one is handy for final orbital burn, but even using a Delta-K would suffice.  The development cost was for the full system, including certifying the EELV US's for use. (primarily focused on Delta IV's 5m upper stage, with Centaur as a backup option)

So the 8.4m core uses a 5m upper stage?  Does that have enough power to put a heavy paylaod into BLEO?  Can it take paylaod to the Moon?  I wouldn't think such a small US would be adequate for what AJAX can loft.

Direct's US would not only get into LEO, but be the EDS as well.  What does AJAX do for EDS?
The 5m Atlas uses a 3m wide Centaur, no reason an 8m wide cannot ride on a 5m wide upper stage. And as I said, AJAX doesn't need an US, but when one is needed, would use an off the shelf one.  I'd note, DIRECT was planning on missions using the same stage for lunar missions, notably the Orion redeux of Apollo 8.  The two engine Delta Upper Stage would be more than sufficient for most roles.

And yes, the two engine, or when ACES comes online, it would work as EDS.  The key there is to not use the US for orbital insertion at all, or any of the lift, but to lift it into orbit directly, so unlike Ares V or DIRECT, which have only a partially filled EDS due to the need for the orbit burn, we'd have a fully fueled EDS.  Once ACES is ready, the AJAX EDS would have as much fuel load as Ares V would have, but with a far more efficient engine setup, enabling heavier lunar missions.
Title: Re: AJAX Launcher
Post by: Lobo on 03/03/2011 05:24 pm
Both pads would be flat pads, identical to each other and capable of launching both AJAX and EELV's.  The reason this works is because the key interfacing technology is in the MLP's, not the pads.  Roll Atlas V's MLP out to Pad 39B, AJAX's MLP out to 39A, you're set, or roll back and switch them, not a problem.  This is how LC-39 was originally developed, this is why it used the MLP's to begin with, to enable the same launch site to handle multiple rocket options.  Originally, the idea was Saturn and Nova, but in our case, AJAX, Atlas and even possibly Delta, Falcon or Taurus in the future.  It would be part of the "21st Century Launch Complex" concept, enabling private firms to utilize the existing pads, reducing their cost to operate manned launches as a result through a shared resource.  The only cost would be the MLP's for the launchers, and as I checked, LC-39 can support up to 7 right now, and adding support for more is not difficult nor expensive, and could be added into the up-front costs of any new launcher which wishes to make use of the system.

Remember, AJAX is also partly about better utilizing the systems we have, which includes enabling the use of currently Shuttle only systems by other parties.  Utilizing LC-39 more efficiently is part of that.

Now this intrigues me. So, you are saying LC39 would basically move from launching Shuttle only (or Shuttle successor only) to being a full space port?  Launching like F9H? (LC40 can't currently launch a Falcon 9 heavy), Atlas-5H (can LC41 launch an Atlas 5H?), or even Delta-4's?  (even thought LC37 can launch both regular and heavy Delta 4's).
Or later Phases of those EELV's?  (which would require new pads anyway)

Would all EELV launch operations then move to LC39?  And then they'd share costs with NASA for operating it then?
What would happen to LC40, 41, and 37?  Decommissioned?

So how would all of that work?

YEa, I know LC39 was originally designed for multiple rockets at once, of multiple designs (it handled Saturn V and Saturn 1B as clean pad).  And the VAB originally could be stacking 4 rockets at once.  I think it's down to 3 active bays now, but the 4th could probably be reopened.  It never actually handled the kind of volume it was designed for though.  I don't think it probably ever had more than two rockets (or shuttles) in there at once, did it?  Seems like a huge waste of capacity.
With clean pads, as I understand it, you don't need the rocket out there for nearly as long as the shuttle is, because it's really not processed much there.  Just rolled out, checked out, fueled and launched, right?

So is that what you had in mind?
Title: Re: AJAX Launcher
Post by: Downix on 03/03/2011 05:31 pm
Both pads would be flat pads, identical to each other and capable of launching both AJAX and EELV's.  The reason this works is because the key interfacing technology is in the MLP's, not the pads.  Roll Atlas V's MLP out to Pad 39B, AJAX's MLP out to 39A, you're set, or roll back and switch them, not a problem.  This is how LC-39 was originally developed, this is why it used the MLP's to begin with, to enable the same launch site to handle multiple rocket options.  Originally, the idea was Saturn and Nova, but in our case, AJAX, Atlas and even possibly Delta, Falcon or Taurus in the future.  It would be part of the "21st Century Launch Complex" concept, enabling private firms to utilize the existing pads, reducing their cost to operate manned launches as a result through a shared resource.  The only cost would be the MLP's for the launchers, and as I checked, LC-39 can support up to 7 right now, and adding support for more is not difficult nor expensive, and could be added into the up-front costs of any new launcher which wishes to make use of the system.

Remember, AJAX is also partly about better utilizing the systems we have, which includes enabling the use of currently Shuttle only systems by other parties.  Utilizing LC-39 more efficiently is part of that.

Now this intrigues me. So, you are saying LC39 would basically move from launching Shuttle only (or Shuttle successor only) to being a full space port?  Launching like F9H? (LC40 can't currently launch a Falcon 9 heavy), Atlas-5H (can LC41 launch an Atlas 5H?), or even Delta-4's?  (even thought LC37 can launch both regular and heavy Delta 4's).
Or later Phases of those EELV's?  (which would require new pads anyway)

Would all EELV launch operations then move to LC39?  And then they'd share costs with NASA for operating it then?
What would happen to LC40, 41, and 37?  Decommissioned?

So how would all of that work?
I'd imagine it being limited to manned flight, with the other pads remaining for their unmanned purposes.  LC-39 is designed for manned operations already, those capabilities would need to be added to any other pads desiring to do manned launches, so this becomes a compromise with the ELV operators, they get an extra pad to launch from for low cost for their manned flights, meaning that adding those capabilities to the existing pads won't threaten to disrupt operations there. (one of the big concerns I was reading about was that adding manned capability to either of the EELV pads could disrupt their manifest of flights)
Quote

YEa, I know LC39 was originally designed for multiple rockets at once, of multiple designs (it handled Saturn V and Saturn 1B as clean pad).  And the VAB originally could be stacking 4 rockets at once.  I think it's down to 3 active bays now, but the 4th could probably be reopened.  It never actually handled the kind of volume it was designed for though.  I don't think it probably ever had more than two rockets (or shuttles) in there at once, did it?  Seems like a huge waste of capacity.
Agreed, which is why I want to expand it and make it more utilized than it is now.
Quote
With clean pads, as I understand it, you don't need the rocket out there for nearly as long as the shuttle is, because it's really not processed much there.  Just rolled out, checked out, fueled and launched, right?

So is that what you had in mind?
You got it.  Rollout would be the day before launch I would imagine, to give time to fuel it up.
Title: Re: AJAX Launcher
Post by: Lobo on 03/03/2011 06:02 pm
You got it.  Rollout would be the day before launch I would imagine, to give time to fuel it up.

How long where the Saturn's on the pad before they were launched?
Title: Re: AJAX Launcher
Post by: Lobo on 03/03/2011 06:10 pm
I suppose if Direct or something Direct like were chosen, you could still do something similar with LC39.  They could do a fixed pad on 39A and a clean pad on 39B, and put an RP-1 system back on 39B.

Then you could do MLP's for launched manned EELV's (and perhaps even EELV's that want to use that rather than upgrading their own pads, like F9H or A5H, or Phase 2 of any EELV that might need a bigger pad)

Then you could still use it as a Space Port.  It just wouldn't be as flexible as with 2 clean pads.  And there's really no need to have two pads that can launch SDHLV anymore, is there?  One pad can support the likely launch rate of a SDHLV, just as 39A's done with the Shuttles.  The only thing they've needed 39B for in the past several years was for the Hubble backup Shuttle.  Altough, I suppose if you are doing a 2XJ246 launch architecture for lunar missions, you'd want a pad that can launch the second rocket ready in case the first launch damages the pad and repairs are needed?
Title: Re: AJAX Launcher
Post by: Downix on 03/03/2011 07:46 pm
You got it.  Rollout would be the day before launch I would imagine, to give time to fuel it up.

How long where the Saturn's on the pad before they were launched?
A month or more. One thing to remember is they rolled up a mobile service system in order to maintain Saturn on the pad, to do the same job that the service tower does for Shuttle.  I've often times pondered what options could be done to better refine this process.

In all probability we'd still be looking at a week on-pad, but I'd like to figure out ways to get it down to a far more efficient operation.  I know the LCROSS mission was rolled out less than 48 hours before launch. 

Title: Re: AJAX Launcher
Post by: Lobo on 03/03/2011 11:30 pm
A month or more. One thing to remember is they rolled up a mobile service system in order to maintain Saturn on the pad, to do the same job that the service tower does for Shuttle.  I've often times pondered what options could be done to better refine this process.

In all probability we'd still be looking at a week on-pad, but I'd like to figure out ways to get it down to a far more efficient operation.  I know the LCROSS mission was rolled out less than 48 hours before launch. 


Hmmm...I guess I thought that the MSS was only used if there was a problem with the LEM or CSM.  That everything was really done in the VAB, and the MSS was more used in case there's some issue at checkout or fueling.  Then they can bring a clean room to the pad without needing to rollback.  But maybe I was in error?
Everything was stacked and stowed in the VAB right?  (unlike the Shuttle which often has the payload added at the pad in the RSS).  So what were they doing with the MSS other than checking systems out and making minor fixes if there's problems?

I don't know how long the Saturn's were at the pad, but if everything was stacked at the VAB, not sure why they needed more than a week or two.  Unless they were doing extensive system double checks to be safe?

A month or more seems like a long time if they aren't doing something like adding the payload at the PAd.  Although I guess Discovery was rolled out like 3-4 weeks before launch this last time, and the payload was already installed.  *shrug*  Dunno...

AS far as LCROSS goes, it might be that unmanned missions don't need quite so much redundant system checking, and so if it's already stacked, it wouldn't take too long to check systems (since there's no cockpit, human controls, life support systems, etc).
Title: Re: AJAX Launcher
Post by: Downix on 03/03/2011 11:57 pm
A month or more. One thing to remember is they rolled up a mobile service system in order to maintain Saturn on the pad, to do the same job that the service tower does for Shuttle.  I've often times pondered what options could be done to better refine this process.

In all probability we'd still be looking at a week on-pad, but I'd like to figure out ways to get it down to a far more efficient operation.  I know the LCROSS mission was rolled out less than 48 hours before launch. 


Hmmm...I guess I thought that the MSS was only used if there was a problem with the LEM or CSM.  That everything was really done in the VAB, and the MSS was more used in case there's some issue at checkout or fueling.  Then they can bring a clean room to the pad without needing to rollback.  But maybe I was in error?
Everything was stacked and stowed in the VAB right?  (unlike the Shuttle which often has the payload added at the pad in the RSS).  So what were they doing with the MSS other than checking systems out and making minor fixes if there's problems?

I don't know how long the Saturn's were at the pad, but if everything was stacked at the VAB, not sure why they needed more than a week or two.  Unless they were doing extensive system double checks to be safe?

A month or more seems like a long time if they aren't doing something like adding the payload at the PAd.  Although I guess Discovery was rolled out like 3-4 weeks before launch this last time, and the payload was already installed.  *shrug*  Dunno...

AS far as LCROSS goes, it might be that unmanned missions don't need quite so much redundant system checking, and so if it's already stacked, it wouldn't take too long to check systems (since there's no cockpit, human controls, life support systems, etc).
Saturn was the first manned rocket not assembled on-pad, so they were taking no chances.  My guess is, they were taking no chances.  With modern systems, I am confident that we can do it without the long delays.
Title: Re: AJAX Launcher
Post by: douglas100 on 03/04/2011 01:20 pm
The first manned rocket not assembled on the pad was the first manned rocket--Vostok. This allowed Vostok 3 and Vostok 4 to be launched 24 hours apart in 1962.
Title: Re: AJAX Launcher
Post by: Downix on 03/04/2011 02:52 pm
The first manned rocket not assembled on the pad was the first manned rocket--Vostok. This allowed Vostok 3 and Vostok 4 to be launched 24 hours apart in 1962.
I know this, hence the mention specifically of Mercury and Gemini.
Title: Re: AJAX Launcher
Post by: douglas100 on 03/04/2011 03:13 pm
Sorry, I didn't notice a mention of Mercury or Gemini. If you had said "US rocket" of course I would have made no comment.
Title: Re: AJAX Launcher
Post by: spacenut on 03/04/2011 04:09 pm
Do you guys have any sketches of AJAX compaired to Jupiter Direct, Shuttle or Saturn V? 
Title: Re: AJAX Launcher
Post by: Downix on 03/04/2011 05:04 pm
Do you guys have any sketches of AJAX compaired to Jupiter Direct, Shuttle or Saturn V? 
It's still quite preliminary, we're adjusting the virtual metal to give us maximum capacity with minimal development.  So anything posted would likely be wrong by the time we're finished.
Title: Re: AJAX Launcher
Post by: Lobo on 03/04/2011 07:28 pm
Saturn was the first manned rocket not assembled on-pad, so they were taking no chances.  My guess is, they were taking no chances.  With modern systems, I am confident that we can do it without the long delays.

Yea, that'd be my guess too.  Back then, we took chances and did bold things.  Today we can barely get out of our own way it seems sometimes.  They were dealing with cutting edge tech, unproven rockets and hardware, and a lot of firsts.  I wonder if we could be that bold again today?  I sort of doubt it.

Anyway, could just a service device be built into the ubilical tower in a new clean-pad LC39?  It wouldn't make much sense to have another MSS if you were planning on launching more than one manned LV from there.  What works for AJAX wouldn't probably work for an Atlas or F9.  Or would it probably be too serverely damaged during a launch to be cost effective?  I would assume that's why they might not to have done that with the Saturn MLP's.  Maybe if it swung away 180 degrees so the clean room was on the opposite side of the tower from the rocket.  Maybe it could be protected enough from the blast then?

So what would they likely do in your LC39 Spaceport concept to service multiple rocket designs on the pad?
Title: Re: AJAX Launcher
Post by: Downix on 03/04/2011 07:42 pm
Saturn was the first manned rocket not assembled on-pad, so they were taking no chances.  My guess is, they were taking no chances.  With modern systems, I am confident that we can do it without the long delays.

Yea, that'd be my guess too.  Back then, we took chances and did bold things.  Today we can barely get out of our own way it seems sometimes.  They were dealing with cutting edge tech, unproven rockets and hardware, and a lot of firsts.  I wonder if we could be that bold again today?  I sort of doubt it.

Anyway, could just a service device be built into the ubilical tower in a new clean-pad LC39?  It wouldn't make much sense to have another MSS if you were planning on launching more than one manned LV from there.  What works for AJAX wouldn't probably work for an Atlas or F9.  Or would it probably be too serverely damaged during a launch to be cost effective?  I would assume that's why they might not to have done that with the Saturn MLP's.  Maybe if it swung away 180 degrees so the clean room was on the opposite side of the tower from the rocket.  Maybe it could be protected enough from the blast then?

So what would they likely do in your LC39 Spaceport concept to service multiple rocket designs on the pad?
I'd put that work onto the MLP. *if* something was needed that could not be done on-site, rather than a scaffolding service pad, roll it back to the VAB.  By limiting time on pad, the bay it came from won't be occupied.  This would require all four bays to be open, of course, so other work can be done in the other bays.
Title: Re: AJAX Launcher
Post by: spacenut on 03/08/2011 12:40 pm
Downix, are you going to have a paper ready for Nasa to consider as one of the heavy lift vehicles?  I like it better than Direct.  Direct 130 was offered several years ago, and if Nasa would have gone to it, we would already have the heavy lift by now. 

Since ATK has quit making the 4 seg solids and are making the more expensive 5 segs, it doesn't make sense to go that route now.  With Ajax you can dial up vairous lift capacities. 

I still think if we go Ajax, with the money saved, we should begin manufacturing our own RD-180's and go to the 5m 2 engine Atlas V phase II.  This twin engine 5 meter rocket would replace the Delta IV heavy with 3 cores and 3 engines in a single rocket.  From what I read this rocket also can be launched from the same facilities and can launch Orion. 

I also think we should develop RL-60 for a second stage engine. It has thrust in an engine about the same size as the RL-10.  Also more efficient than J2X.   
Title: Re: AJAX Launcher
Post by: Downix on 03/08/2011 03:27 pm
Downix, are you going to have a paper ready for Nasa to consider as one of the heavy lift vehicles?  I like it better than Direct.  Direct 130 was offered several years ago, and if Nasa would have gone to it, we would already have the heavy lift by now. 

Since ATK has quit making the 4 seg solids and are making the more expensive 5 segs, it doesn't make sense to go that route now.  With Ajax you can dial up vairous lift capacities. 

I still think if we go Ajax, with the money saved, we should begin manufacturing our own RD-180's and go to the 5m 2 engine Atlas V phase II.  This twin engine 5 meter rocket would replace the Delta IV heavy with 3 cores and 3 engines in a single rocket.  From what I read this rocket also can be launched from the same facilities and can launch Orion. 

I also think we should develop RL-60 for a second stage engine. It has thrust in an engine about the same size as the RL-10.  Also more efficient than J2X.   
Working on a paper.  As for the rest, R&D is included only as a long term goal, not an initial.  We need to focus on an immediate solution right now, and having more than the barest of development is too much.  We lack the time and money.  Could I see a future with AVP2?  Sure.  Would I like the RL-60?  Sure.  But those are long-term goals.  Right now the focus is on the near term, to get the foot in the door.
Title: Re: AJAX Launcher
Post by: Lobo on 03/21/2011 11:14 pm
Downix,

I thought I'd take this back over here, since this is more specifically about AJAX than a general Kerosene super lifter.

I've been intrigued with the AVP2.  Looks like about 29mt to LEO, but with 2 engines instead of 3 like the AVH.

http://www.astronautix.com/lvs/atlhase2.htm

So, if 4 RD-180's on 4 Atlas V CCB's can lift AJAX, what would two AVP2 boosters do?  You still have the same amount of engines, but I'm assuming you'd be lighter?  (I assume that's how you get AVH performance out of the AVP2, but with one less engine). 
Seems like the AVP2 would be a better rocket to man-rate and partner with AJAX as the booster as it seems like it'd be a better launcher for Orion LEO missions.  (ISS contingency missions, Orion check out, LEO satellite servicing with a 5mt mission module, etc).  Or an AVP2-Heavy could be launched for a manned mission requiring medium-heavy lift.  Although I suppose that'd compete directly with AJAX (less US)?
But it'd be an option.  A single stick AV doesn't realy do much for Orion as it can't lift it.  AVH can, but it seems like the AVP2 is more efficient and ultimately cheaper.

If something like AJAX were chosen for SLS, and that development money went into ULA, they should have the money to develop AVP2 and ACES, right?  As well as perhaps a US-made RD-180. 

Also, what do you think about using Falcon 9's with Merlin 2's for AJAX's LRB's?  Or a pair of Falcon X's? 
SpaceX LRB's would be interesting because they will already be launching crewed Dragons on Falcon 9's.  So 4 Falcon 9 LRB, or go to the Falcon X as it could carry Orion.  Keep it "all in the family" so to speak.
Even if SpaceX is low on their cost estimates, unless they are off by a factor of 3, Their rockets should be cheaper than ULA. 
Title: Re: AJAX Launcher
Post by: Downix on 03/21/2011 11:25 pm
Downix,

I thought I'd take this back over here, since this is more specifically about AJAX than a general Kerosene super lifter.

I've been intrigued with the AVP2.  Looks like about 29mt to LEO, but with 2 engines instead of 3 like the AVH.

http://www.astronautix.com/lvs/atlhase2.htm

So, if 4 RD-180's on 4 Atlas V CCB's can lift AJAX, what would two AVP2 boosters do?  You still have the same amount of engines, but I'm assuming you'd be lighter?  (I assume that's how you get AVH performance out of the AVP2, but with one less engine). 
Seems like the AVP2 would be a better rocket to man-rate and partner with AJAX as the booster as it seems like it'd be a better launcher for Orion LEO missions.  (ISS contingency missions, Orion check out, LEO satellite servicing with a 5mt mission module, etc).  Or an AVP2-Heavy could be launched for a manned mission requiring medium-heavy lift.  Although I suppose that'd compete directly with AJAX (less US)?
But it'd be an option.  A single stick AV doesn't realy do much for Orion as it can't lift it.  AVH can, but it seems like the AVP2 is more efficient and ultimately cheaper.

If something like AJAX were chosen for SLS, and that development money went into ULA, they should have the money to develop AVP2 and ACES, right?  As well as perhaps a US-made RD-180. 
That is the long term goal.  Instead of reducing the boosters, however, in my viewpoint the main advantage would be to reduce the number of RS-25's.  Each booster would have more spare thrust, so we could drop two RS-25's and still gain T/W as well as payload. 

For manned operations, AVP2 would reduce the cost of launching Orion it looks like.
Quote
Also, what do you think about using Falcon 9's with Merlin 2's for AJAX's LRB's?  Or a pair of Falcon X's? 
SpaceX LRB's would be interesting because they will already be launching crewed Dragons on Falcon 9's.  So 4 Falcon 9 LRB, or go to the Falcon X as it could carry Orion.  Keep it "all in the family" so to speak.
Even if SpaceX is low on their cost estimates, unless they are off by a factor of 3, Their rockets should be cheaper than ULA. 

We looked at them.  Frankly, they fell short in several areas, the biggest one being time to delivery.  New engine development means you now have a long pole.  Add to it new core, and forget it, you've lost any cost advantage. While I am confident of SpaceX's ability to deliver Merlin 2, it does mean that no test launches can be done *until* the Merlin 2 ships.  This is unacceptable on multiple levels.  We do not have the time to waste for developing a whole new rocket engine.  We limited ourselves to just systems which are already shipping, which means Merlin 2 is out for this program. Making a US built RD-180, on the other hand, or even a replacement kerolox arrangement on the CCB's, means that test flights can occur utilizing the existing warehouse inventory.  The only remote possibility for something similar for Merlin 2 would be if we brought several of the F-1's out, refurbished them, and fit them up to Falcon 9's as their performance is similar to the Merlin 2.  But this adds more to the cost, as you need to re-quality and re-test the engines due to how long they've been sitting around.  More potential delays.
Title: Re: AJAX Launcher
Post by: clongton on 03/22/2011 12:16 am
Lobo
The advantage AJAX has over everything else is not developing *anything* new.
We go with what we already have. Think about improving it in 10 years or so.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 12:31 am
"Perfect is the enemy of good enough".

Always keep this in mind.  Any R&D not absolutely required is not part of the baseline.  Do I have ACES as an evolution path?  Yes.  Is it necessary for AJAX? No.  The key to hitting the Congressional limits is to not develop anything beyond the absolute minimum to get the job done.

Here's a story of mine.  In High School, there was a class, applied architecture. Great class, you designed a house, then you built a scale model of it.  Not the outside, a shell, but the whole thing, using miniature 2x6's, shingles, even plumbing and electrical wiring.  There was extra credit if you could finish your house.  The requirements were, a bedroom, living room, kitchen, bathroom, and it had to have stairs.  Well, of course most people designed this multi-story house with multiple bedrooms, huge plans.  I stripped it to the minimum, and designed an octagonal house, with one living room, one kitchen, one bathroom, and an upstairs loft bedroom.  Guess who was the only person in his class to complete his house?

That is exactly the attitude I've taken with AJAX.  Get it done, with the minimum absolute requirement.  Anything not critical to meet the requirement is thrown out.
Title: Re: AJAX Launcher
Post by: CitabriaFlyer on 03/22/2011 12:56 am
Downix,
What is your political plan?  What strategy(ies) would get this idea in front of the important political leaders?  I have to think Shelby would love this.  A core managed by MSFC stimulating the production of a booster manufactured just a few miles down the road.  Can you meet with any of his people?  What about Nelson and other space politicians?
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 01:26 am
Downix,
What is your political plan?  What strategy(ies) would get this idea in front of the important political leaders?  I have to think Shelby would love this.  A core managed by MSFC stimulating the production of a booster manufactured just a few miles down the road.  Can you meet with any of his people?  What about Nelson and other space politicians?
The prime focus is the senators from Colorado, Alabama, Louisiana, Mississippi, Florida, California and Washington.  Utah would be diminished while Alabama and Colorado would gain.  This is a dream come true for Shelby.  Utah lost Bennett, as a result it has only half of the strength it once did as it's new Senator has minimal space ties and little influence.  The added influence of Washington will help as well, due to its senators positions on the Budget, Energy, Transport, Finance and Appropriations.

But the key is not to go after the Senators directly, it is to get it in front of NASA.  By building on the political structure, but to present it to the scientists, it becomes a tool.  Can we fall back to the political?  Of course.  But if we can convince those inside of NASA Management to even look at it, the advantages will start to sell themselves. 

From a Political standpoint, it is well positioned, taking advantage of the current dynamic in the Senate and House.  I'm not concerned there.  My concern is with Bolton and Garver.  Based on their proposal for NASA, I am reading them to prefer EELV's.  This gives them a tool to give what they wish for, while giving Congress what they wish for.  That is my focus, a compromise which fits the needs of Congress, and delivers to NASA what it needs as well.  In addition, the "Ares V sized launchers" crowd leftover from Griffin would also be satisfied.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 02:38 pm

We looked at them.  Frankly, they fell short in several areas, the biggest one being time to delivery.  New engine development means you now have a long pole.  Add to it new core, and forget it, you've lost any cost advantage. While I am confident of SpaceX's ability to deliver Merlin 2, it does mean that no test launches can be done *until* the Merlin 2 ships.  This is unacceptable on multiple levels.  We do not have the time to waste for developing a whole new rocket engine.  We limited ourselves to just systems which are already shipping, which means Merlin 2 is out for this program. Making a US built RD-180, on the other hand, or even a replacement kerolox arrangement on the CCB's, means that test flights can occur utilizing the existing warehouse inventory.  The only remote possibility for something similar for Merlin 2 would be if we brought several of the F-1's out, refurbished them, and fit them up to Falcon 9's as their performance is similar to the Merlin 2.  But this adds more to the cost, as you need to re-quality and re-test the engines due to how long they've been sitting around.  More potential delays.

But couldn't you test with the existing Falcon 9?  I mean, AJAX plans on using the 3.8m Atlas cores with Ruskie engines, couldn't you use the Merlin 1's?
Now, I know the next question is you are lighting off 36 booser engines.  And frankly, I don't know if that's hard or not because I don't know much about the ignition systems, and if it's much more of a task or not to light off banks of engines rather than just a few?  But I imagine whatever setup SpaceX is currently using to ignite their bank of 9 Merlins over at LC-40 could be quadrupled on a MLP at LC-39.  And if you detect 1 or more of the engines didn't light, you can shut everything down right?  I mean, that's the advertised advantage of an all-liquid rocket, right? 
After a couple of pad static firing test to make sure 40 engines will all light when you want them too, and an unmanned test flight or two (which you'd have with Atlas CCB's anyway), then you can commit a crew.  Then once the Merlin 2's are built and checked out, you add F9's with them on your next launch, with slight pad mods to ignite the fewer number of engines.

Again, I'm not sure how SpaceX ignites their engines (or how SSME's are ignited, or how RD-180's or RS-68's are ignited, so if I'm missing the boat here, please fill me in) but if they can light a bank of 9 successfully, then it doesn't seem like rocket science (pardon the pun) to light 4 banks of 9. Seems like it'd still be much safer than lighting 2 huge SRB's knowing you'll have a catestrophic failure if one doesn't light one time....which is what you had with STS, and will have with 5/5 or Direct.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 02:52 pm
Lobo
The advantage AJAX has over everything else is not developing *anything* new.
We go with what we already have. Think about improving it in 10 years or so.

Chuck,

See my previous post.  Unless igniting 4 banks of 9 engines is some insurmountable engineer task?  (which it seems more like a college senior design project level task to my uninformed mind anyway).  SpaceX already plans to be able to light 3 banks of 9 engines with the F9H.
So you really wouldn't have anything new...

And I don't bring up SpaceX because I have a dog in the fight, just that they would have a -different- set of advantages over ULA.  Cost obviously.  Unless their costs estimates are -wildly- off when they start mass producing the F9 (as Jim seems to think they will be), then you are probably going to be around 1/2 the cost per booster.
Also, the F9 is being designed to be man-rated for the eventual launch of crewed Dragons as I understand.  And it will be launching crews to the ISS, so your manned LV will have commonality.  The Falcon X would be able to lift Orion just as AVP2 can, when that gets there.  Both are new vehicles, so that part is similar.  But in both cases, AVH and F9H aren't flying yet, but will be a slight modification of flying hardware.  Both the AVH and F9H can lift Orion. 

So, they are pretty similar in many respects.  Atlas's are more mature obviously, but two F9's have launched successfully.  Falcons should be a good deal cheaper, and will be launching crews on Dragons.  F9H's can launch Orions, and Falcon booster AJAX's can launch Orion + payloads.  Merlin 2's or Falcon X's aren't critical path items.  And you are pumping money into a young and dynamic company, rather than a quasi-government company ladened with beuracracy and overhead.  (as -all- primary government contractor companies are.  I know, I've worked with a few.  They aren't quite as bad as the government itself...but they are close...)

If there's show stoppers with SpaceX, I obviously have no qualms with ULA.  Go with the best option I say.  Just asking the questions, that's all.  :-)
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 03:02 pm

We looked at them.  Frankly, they fell short in several areas, the biggest one being time to delivery.  New engine development means you now have a long pole.  Add to it new core, and forget it, you've lost any cost advantage. While I am confident of SpaceX's ability to deliver Merlin 2, it does mean that no test launches can be done *until* the Merlin 2 ships.  This is unacceptable on multiple levels.  We do not have the time to waste for developing a whole new rocket engine.  We limited ourselves to just systems which are already shipping, which means Merlin 2 is out for this program. Making a US built RD-180, on the other hand, or even a replacement kerolox arrangement on the CCB's, means that test flights can occur utilizing the existing warehouse inventory.  The only remote possibility for something similar for Merlin 2 would be if we brought several of the F-1's out, refurbished them, and fit them up to Falcon 9's as their performance is similar to the Merlin 2.  But this adds more to the cost, as you need to re-quality and re-test the engines due to how long they've been sitting around.  More potential delays.

But couldn't you test with the existing Falcon 9?  I mean, AJAX plans on using the 3.8m Atlas cores with Ruskie engines, couldn't you use the Merlin 1's?
Now, I know the next question is you are lighting off 36 booser engines.  And frankly, I don't know if that's hard or not because I don't know much about the ignition systems, and if it's much more of a task or not to light off banks of engines rather than just a few?  But I imagine whatever setup SpaceX is currently using to ignite their bank of 9 Merlins over at LC-40 could be quadrupled on a MLP at LC-39.  And if you detect 1 or more of the engines didn't light, you can shut everything down right?  I mean, that's the advertised advantage of an all-liquid rocket, right? 
After a couple of pad static firing test to make sure 40 engines will all light when you want them too, and an unmanned test flight or two (which you'd have with Atlas CCB's anyway), then you can commit a crew.  Then once the Merlin 2's are built and checked out, you add F9's with them on your next launch, with slight pad mods to ignite the fewer number of engines.

Again, I'm not sure how SpaceX ignites their engines (or how SSME's are ignited, or how RD-180's or RS-68's are ignited, so if I'm missing the boat here, please fill me in) but if they can light a bank of 9 successfully, then it doesn't seem like rocket science (pardon the pun) to light 4 banks of 9. Seems like it'd still be much safer than lighting 2 huge SRB's knowing you'll have a catestrophic failure if one doesn't light one time....which is what you had with STS, and will have with 5/5 or Direct.
The Falcon 9 with the Merlin-1's could technically do the job, but the total thrust is 35% lower than the Merlin 2.  So, you have an issue for T/W.  If you develop the core optimized for Merlin 2, then it will not be able to take off on the F9.  If you optimize the core for Merlin 1, when Merlin 2 comes out it will be too light and you will need to re-design it again or else risk high G-loads.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 03:06 pm
"Perfect is the enemy of good enough".

Always keep this in mind.  Any R&D not absolutely required is not part of the baseline.  Do I have ACES as an evolution path?  Yes.  Is it necessary for AJAX? No.  The key to hitting the Congressional limits is to not develop anything beyond the absolute minimum to get the job done.

Here's a story of mine.  In High School, there was a class, applied architecture. Great class, you designed a house, then you built a scale model of it.  Not the outside, a shell, but the whole thing, using miniature 2x6's, shingles, even plumbing and electrical wiring.  There was extra credit if you could finish your house.  The requirements were, a bedroom, living room, kitchen, bathroom, and it had to have stairs.  Well, of course most people designed this multi-story house with multiple bedrooms, huge plans.  I stripped it to the minimum, and designed an octagonal house, with one living room, one kitchen, one bathroom, and an upstairs loft bedroom.  Guess who was the only person in his class to complete his house?

That is exactly the attitude I've taken with AJAX.  Get it done, with the minimum absolute requirement.  Anything not critical to meet the requirement is thrown out.

Yup, we all probably have stories like that.  And I've always been a "shortest path between two points is a straight line" kind of guy.
When I was in highschool, I went to a very small school, and we participated in a day long "Physics Olympics" one time with teams from much larger schools in in the city.  One of our competitions was building a bridge out of paper and masking tape between two desks, and seem how many pennies in a little bucket it could support.  It was a timed event.  The only requirements were the bridge must span the gap between the two desks, and we could hank the bucket anywhere on it we wanted.  So we built a supperficial bridge that wouldn't hold much over the span, but we beefed up one side where it attached to the desk, and that's where we hung the bucket to get smallest possible moment arm.  Not only did we win (against these schools that were 10 times the size of my school) that competition, but we like quadrupled the number of pennies of the next closest design.
So I hear ya man.  :-)

That's why I think, if you are considering an SRB SDHLV, Direct is the clear and obviously "straight line".  That it's not the option that's head and shoulders about the rest is mind boggling.  2nd most straight line is AJAX.  Better in the long run, but not quite as "politically" attractive as Direct, in some people's eyes.  That they are looking still at the J2X, 5-seg SRB's, a core stretch, 5 SSME's, etc is not taking the straight line path. 

So my mistake was proposing the Falcon 9 with the merlin 2.  I should have proposed the existing Falcon 9 with an upgrade later to the Merlin 2 when it's available.  So I see your point there.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 03:09 pm
Downix,
What is your political plan?  What strategy(ies) would get this idea in front of the important political leaders?  I have to think Shelby would love this.  A core managed by MSFC stimulating the production of a booster manufactured just a few miles down the road.  Can you meet with any of his people?  What about Nelson and other space politicians?
The prime focus is the senators from Colorado, Alabama, Louisiana, Mississippi, Florida, California and Washington.  Utah would be diminished while Alabama and Colorado would gain.  This is a dream come true for Shelby.  Utah lost Bennett, as a result it has only half of the strength it once did as it's new Senator has minimal space ties and little influence.  The added influence of Washington will help as well, due to its senators positions on the Budget, Energy, Transport, Finance and Appropriations.

But the key is not to go after the Senators directly, it is to get it in front of NASA.  By building on the political structure, but to present it to the scientists, it becomes a tool.  Can we fall back to the political?  Of course.  But if we can convince those inside of NASA Management to even look at it, the advantages will start to sell themselves. 

From a Political standpoint, it is well positioned, taking advantage of the current dynamic in the Senate and House.  I'm not concerned there.  My concern is with Bolton and Garver.  Based on their proposal for NASA, I am reading them to prefer EELV's.  This gives them a tool to give what they wish for, while giving Congress what they wish for.  That is my focus, a compromise which fits the needs of Congress, and delivers to NASA what it needs as well.  In addition, the "Ares V sized launchers" crowd leftover from Griffin would also be satisfied.

So, in the real world, what is being done to get AJAX actually in front of people who make the decisions?  To actually get it ont he radar of the people that count?  (rather than just a bunch of cheerleaders like us on the forum  :-)   )
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 03:12 pm

If there's show stoppers with SpaceX, I obviously have no qualms with ULA.  Go with the best option I say.  Just asking the questions, that's all.  :-)

ULA has more political clout at the moment as well.  I have to think in terms of politics as well.  SpaceX does not play this game anywhere near as well as ULA does.  Fighting against ATK, as this would inevitably be, you need as many 800 lbs gorillas on your side as possible.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 03:14 pm
Downix,
What is your political plan?  What strategy(ies) would get this idea in front of the important political leaders?  I have to think Shelby would love this.  A core managed by MSFC stimulating the production of a booster manufactured just a few miles down the road.  Can you meet with any of his people?  What about Nelson and other space politicians?
The prime focus is the senators from Colorado, Alabama, Louisiana, Mississippi, Florida, California and Washington.  Utah would be diminished while Alabama and Colorado would gain.  This is a dream come true for Shelby.  Utah lost Bennett, as a result it has only half of the strength it once did as it's new Senator has minimal space ties and little influence.  The added influence of Washington will help as well, due to its senators positions on the Budget, Energy, Transport, Finance and Appropriations.

But the key is not to go after the Senators directly, it is to get it in front of NASA.  By building on the political structure, but to present it to the scientists, it becomes a tool.  Can we fall back to the political?  Of course.  But if we can convince those inside of NASA Management to even look at it, the advantages will start to sell themselves. 

From a Political standpoint, it is well positioned, taking advantage of the current dynamic in the Senate and House.  I'm not concerned there.  My concern is with Bolton and Garver.  Based on their proposal for NASA, I am reading them to prefer EELV's.  This gives them a tool to give what they wish for, while giving Congress what they wish for.  That is my focus, a compromise which fits the needs of Congress, and delivers to NASA what it needs as well.  In addition, the "Ares V sized launchers" crowd leftover from Griffin would also be satisfied.

So, in the real world, what is being done to get AJAX actually in front of people who make the decisions?  To actually get it ont he radar of the people that count?  (rather than just a bunch of cheerleaders like us on the forum  :-)   )
That, my friend, is a secret.  Shh! (it is who you know, not what you know)
Title: Re: AJAX Launcher
Post by: FinalFrontier on 03/22/2011 03:17 pm
Downix,
What is your political plan?  What strategy(ies) would get this idea in front of the important political leaders?  I have to think Shelby would love this.  A core managed by MSFC stimulating the production of a booster manufactured just a few miles down the road.  Can you meet with any of his people?  What about Nelson and other space politicians?
The prime focus is the senators from Colorado, Alabama, Louisiana, Mississippi, Florida, California and Washington.  Utah would be diminished while Alabama and Colorado would gain.  This is a dream come true for Shelby.  Utah lost Bennett, as a result it has only half of the strength it once did as it's new Senator has minimal space ties and little influence.  The added influence of Washington will help as well, due to its senators positions on the Budget, Energy, Transport, Finance and Appropriations.

But the key is not to go after the Senators directly, it is to get it in front of NASA.  By building on the political structure, but to present it to the scientists, it becomes a tool.  Can we fall back to the political?  Of course.  But if we can convince those inside of NASA Management to even look at it, the advantages will start to sell themselves. 

From a Political standpoint, it is well positioned, taking advantage of the current dynamic in the Senate and House.  I'm not concerned there.  My concern is with Bolton and Garver.  Based on their proposal for NASA, I am reading them to prefer EELV's.  This gives them a tool to give what they wish for, while giving Congress what they wish for.  That is my focus, a compromise which fits the needs of Congress, and delivers to NASA what it needs as well.  In addition, the "Ares V sized launchers" crowd leftover from Griffin would also be satisfied.

So, in the real world, what is being done to get AJAX actually in front of people who make the decisions?  To actually get it ont he radar of the people that count?  (rather than just a bunch of cheerleaders like us on the forum  :-)   )
That, my friend, is a secret.  Shh! (it is who you know, not what you know)

Glad to see that thing have progressed and the concept is moving forward :D Please let me know via message how I can help, as I have not been involved beyond keeping up to date with this thread with the concept since the initial discussion. Also will talk to some of my contacts if needed.
Title: Re: AJAX Launcher
Post by: baldusi on 03/22/2011 03:18 pm
Do you have a bigger logo of the AJAX? Seems nice.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 03:21 pm
The Falcon 9 with the Merlin-1's could technically do the job, but the total thrust is 35% lower than the Merlin 2.  So, you have an issue for T/W.  If you develop the core optimized for Merlin 2, then it will not be able to take off on the F9.  If you optimize the core for Merlin 1, when Merlin 2 comes out it will be too light and you will need to re-design it again or else risk high G-loads.

Couldn't you -design- for the Merlin 2, but just fly with a reduced max payload with the merlin 1's until such a time that the merline 2 is ready?
It's not like there's going to be any hardware ready for a lunar mission before the Merlin 2 would likely be ready.  But you'd still have HLV capability in the interim.

Also, don't the 9XMerlin 1C's produce more thrust than the 1XRD-180?  So wouldn't you have a slightly better performance using the F9's with Merlin 1C's over the Atlas CCB's anyway?

Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 03:22 pm

If there's show stoppers with SpaceX, I obviously have no qualms with ULA.  Go with the best option I say.  Just asking the questions, that's all.  :-)

ULA has more political clout at the moment as well.  I have to think in terms of politics as well.  SpaceX does not play this game anywhere near as well as ULA does.  Fighting against ATK, as this would inevitably be, you need as many 800 lbs gorillas on your side as possible.

Good point!
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 03:24 pm
That, my friend, is a secret.  Shh! (it is who you know, not what you know)

Ahhhh....
(queue 'Mission Impossible' theme music now)


Is it safe to say at least that some people in position to consider AJAX have/will see the concept and it'll get a look?
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 03:30 pm
The Falcon 9 with the Merlin-1's could technically do the job, but the total thrust is 35% lower than the Merlin 2.  So, you have an issue for T/W.  If you develop the core optimized for Merlin 2, then it will not be able to take off on the F9.  If you optimize the core for Merlin 1, when Merlin 2 comes out it will be too light and you will need to re-design it again or else risk high G-loads.

Couldn't you -design- for the Merlin 2, but just fly with a reduced max payload with the merlin 1's until such a time that the merline 2 is ready?
It's not like there's going to be any hardware ready for a lunar mission before the Merlin 2 would likely be ready.  But you'd still have HLV capability in the interim.

Also, don't the 9XMerlin 1C's produce more thrust than the 1XRD-180?  So wouldn't you have a slightly better performance using the F9's with Merlin 1C's over the Atlas CCB's anyway?


The payload isn't the issue, it's the 280 metric ton difference in the core fuel load that is.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 03:32 pm
Do you have a bigger logo of the AJAX? Seems nice.
It's just something I threw together quick using a picture of the statue of Atlas in Rockefeller Plaza in NY I took some years back.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 03:32 pm
Downix,
What is your political plan?  What strategy(ies) would get this idea in front of the important political leaders?  I have to think Shelby would love this.  A core managed by MSFC stimulating the production of a booster manufactured just a few miles down the road.  Can you meet with any of his people?  What about Nelson and other space politicians?
The prime focus is the senators from Colorado, Alabama, Louisiana, Mississippi, Florida, California and Washington.  Utah would be diminished while Alabama and Colorado would gain.  This is a dream come true for Shelby.  Utah lost Bennett, as a result it has only half of the strength it once did as it's new Senator has minimal space ties and little influence.  The added influence of Washington will help as well, due to its senators positions on the Budget, Energy, Transport, Finance and Appropriations.

But the key is not to go after the Senators directly, it is to get it in front of NASA.  By building on the political structure, but to present it to the scientists, it becomes a tool.  Can we fall back to the political?  Of course.  But if we can convince those inside of NASA Management to even look at it, the advantages will start to sell themselves. 

From a Political standpoint, it is well positioned, taking advantage of the current dynamic in the Senate and House.  I'm not concerned there.  My concern is with Bolton and Garver.  Based on their proposal for NASA, I am reading them to prefer EELV's.  This gives them a tool to give what they wish for, while giving Congress what they wish for.  That is my focus, a compromise which fits the needs of Congress, and delivers to NASA what it needs as well.  In addition, the "Ares V sized launchers" crowd leftover from Griffin would also be satisfied.

So, in the real world, what is being done to get AJAX actually in front of people who make the decisions?  To actually get it ont he radar of the people that count?  (rather than just a bunch of cheerleaders like us on the forum  :-)   )
That, my friend, is a secret.  Shh! (it is who you know, not what you know)

Glad to see that thing have progressed and the concept is moving forward :D Please let me know via message how I can help, as I have not been involved beyond keeping up to date with this thread with the concept since the initial discussion. Also will talk to some of my contacts if needed.
Soon, very soon.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 03:43 pm
That, my friend, is a secret.  Shh! (it is who you know, not what you know)

Ahhhh....
(queue 'Mission Impossible' theme music now)


Is it safe to say at least that some people in position to consider AJAX have/will see the concept and it'll get a look?
Not quite that good at the moment.  Right now the focus is on making sure the engineering is right, although we've just about gotten that wrapped up.  Then it is presentation, the pinache!
Title: Re: AJAX Launcher
Post by: clongton on 03/22/2011 03:49 pm
AJAX's ET-based Core is designed to support the loads of 8xCCB LRB's plus an upper stage and payload, in the same way that the DIRECT team worked Jupiter's ET-based core and for the same reason; build the core just one time and it will support all flight configurations.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 04:31 pm
AJAX's ET-based Core is designed to support the loads of 8xCCB LRB's plus an upper stage and payload, in the same way that the DIRECT team worked Jupiter's ET-based core and for the same reason; build the core just one time and it will support all flight configurations.
Right, but unlike DIRECT, AJAX does not need to develop an upper stage to make use of the extra capability built into the core.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 05:00 pm
I was reading over on the L2 HEFT thread, and someone said something to the effect that American desiners keep grabbing ahold of the strap on booster design, which they shouldn't because it's more expensive and more complex [than a serial inline].

I've been ripping on the serial inline because it's kind of a one trick pony with no real commonality with anything else (except maybe the engines).  Where a strap on design has core and engine commonality with other programs, plus the ability to launch your crew without the entire Heavy lifter if the mission calls for that.

So is a serial inline like a Saturn V redux really cheaper/simpler than a strap on modular design?  I'd thought the Saturn V was so expensive that once the exitedment for landing on the moon ebbed, it was just too expensive to maintain.  So I'm not sure on the validity of it.
What say you?
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 05:39 pm
I was reading over on the L2 HEFT thread, and someone said something to the effect that American desiners keep grabbing ahold of the strap on booster design, which they shouldn't because it's more expensive and more complex [than a serial inline].

I've been ripping on the serial inline because it's kind of a one trick pony with no real commonality with anything else (except maybe the engines).  Where a strap on design has core and engine commonality with other programs, plus the ability to launch your crew without the entire Heavy lifter if the mission calls for that.

So is a serial inline like a Saturn V redux really cheaper/simpler than a strap on modular design?  I'd thought the Saturn V was so expensive that once the exitedment for landing on the moon ebbed, it was just too expensive to maintain.  So I'm not sure on the validity of it.
What say you?
You need a lot of missions to support a Saturn V, which is why it became so expensive once the missions began petering out.  As it is a monolithic system, and can share less costs with other systems, you would wind up with fewer opportunities due to it's larger payload capacity.

This is the real failure of Saturn, too many unique systems.  The only component similar between Saturn I and Saturn V being the uppermost stage.  If Saturn II had been built, it would have brought the costs down to the point that it may have been affordable.  But, having to support not one, but 4 complete assembly lines all by itself, with few missions, that was the death-stroke.
Title: Re: AJAX Launcher
Post by: clongton on 03/22/2011 06:31 pm
Huge launchers, like the Saturn-V and Ares-V are far too expensive to design, build, operate and maintain. They suck all the air out of the room leaving the mission planners to starve to death. While there is no question in the minds of the professionals that a HLV capability is required before we can do anything really sustainable BEO, that does not mean that the capability can only be fulfilled by a huge rocket that has a low flight rate. The BEO capability that is required is far better fulfilled by a MLV, not a HLV, that has the design capability to be configured for HLV missions by *adding capability* to the launcher. The consensus among most space experts is that there are going to be 100 ton payloads necessary before manned missions to Mars and beyond for example can become reasonably economical. But to build a 100 ton HLV to lift that payload is just not smart because there are not and will not be that many of those payloads. The HLV system will spend the majority of its life just sitting around gathering dust, doing nothing and sucking up precious funds, while the rest of the space program starves.

Most folks really don't realize how big a spacecraft that masses 60-80 tons really is, physical size-wise. It's huge, the size of a small 3-bedroom house! The vast majority of launches that support large BEO missions can be economically handled by a LV that can put 60-80 tons in orbit. NOTE: That's 60-80 tons of "hardware", not propellant. A 60-80 ton "spacecraft" is a very large spacecraft indeed; much larger than anything we have done before. Most hardware/spacecraft launches in support of almost any BEO mission you can envision for the foreseeable future will be in this mass range. So the proper LV for such payload masses should be sized for that, with the design capacity to add performance capability by adding more strap-on LRBs to accommodate the odd 100-120 ton payload; and there *will* be some of those, just not too many.

Building a Saturn-V redux or an Ares-V behemoth is just not the right thing to do. It wastes far too much of the nation's treasure by starving the rest of the space science program, leaving us without the funding to actually do anything with our shiney new rocket. HSF BEO is going to be expensive, very expensive. We cannot afford to waste a major percentage of the available funding on a rocket that will not be useful for the *entire* space effort, not just the occasional odd heavy lift need. No, the mainstay workhourse launcher needs to be a MLV, not a dedicated, 1-trick pony HLV. At least that size rocket can and will find itself occupied with a far larger percentage of the mission launches as well as being useful for other parts of the whole space program.

AJAX is the best of both worlds. In its basic configuration, the MLV A-440, it can put 70 tons in orbit - plus. That is right in the middle of the expected majority of the BEO mission launch needs. In its HLV A-480 configuration, that capability begins to creep toward the 150 ton mark. And that is still without an upper stage. And that's the MLV/HLV. Let's talk about the LRB for a second.

We're talking about the Atlas-V. It would be capable of doing triple duty. It can continue as the outstanding EELV that it is, flying government, DoD and commercial payloads. It can also be the Crew Launch Vehicle for the MPCV (Orion) into LEO. Or, its first stage, the CCB, can be strapped on to the side of the AJAX core in 2, 3 or 4 opposing pairs, to give AJAX more total lift capacity than we are likely to need for the next 50 years. The benefits of this synergy are too numerous to mention. they'll be better detailed in the upcoming paper.

Going serial does have its benefits, and DIRECT's Jupiter took that path. Jupiter's limitation was keeping the SRB's because solids quickly reach a point where no matter how powerful they are, they just weigh too much to be practical. That's where AJAX came in. Take a Jupiter-130, delete the 2xSRB's, add the 4th SSME and 2 pairs of Atlas-V CCB's, and you have the AJAX-440. To give the Jupiter its due, the design mandate was not to come up with the best launch vehicle, but to come up with the best Shuttle-derived launch vehicle that stayed within the law as defined by the NASA Authorization Act of 2005. DIRECT's Jupiter accomplished that. But getting rid of the SRB's was not an option then, as it presently is with the current Authorization Act.

AJAX gives us what we need with a LV that is correctly sized; not too big, and not too small. It does not compete with the EELV fleet, but compliments it. It does not give in to the pipedream of the world's biggest rocket. That was the Saturn-V, and always will be. We do not need to build anything that big – ever again.

AJAX – the right launch vehicle today for tomorrow's BEO missions. Sharing today's existing flight-proven hardware to build tomorrow's Space Program in an economic, efficient and timely manner.
Title: Re: AJAX Launcher
Post by: martin hegedus on 03/22/2011 07:08 pm
That, my friend, is a secret.  Shh! (it is who you know, not what you know)

Ahhhh....
(queue 'Mission Impossible' theme music now)


Is it safe to say at least that some people in position to consider AJAX have/will see the concept and it'll get a look?
Not quite that good at the moment.  Right now the focus is on making sure the engineering is right, although we've just about gotten that wrapped up.  Then it is presentation, the pinache!

And the question by others will be "do you have the engineering right?"  I know, people like to think the schedule and costs are all about politics.  Especially from those who don't have in depth knowledge about the engineering process.

The reality is that engineers have a way of scaring those less knowledgeable.  Not that engineers do it intentionally, in my opinion, it is just how they think.  They think about risk in an effort to mitigate it.  Of course when those with less understanding of the risks take those risks and run with them, rest assured cost and schedule will increase.

Recently there have been a number of papers released on NTRS about the Ares aero.  Wow, a lot of aero work.  If one does all this aero, I don't think a two year schedule for CDR is enough.

So the question then is, how much of this aero is required for CDR?  That is your question to answer.  It is up to the AJAX team to show what is required and that their schedule up to CDR allows for those things to be done.  Please, no arm waving about schedules.  You might be disappointed.

And, you'll need to convince people such as Dr. Robert Hall, at least in regards to aero.  I found the section titled "Pitfalls in Characterizing Aerodynamics" in his paper "Aerodynamic Characterization of a Modern Launch Vehicle" interesting.  You can find the paper at NTRS.

I found it interesting because of his use of Pegasus XL and HXLV as pitfall examples.  But he did not say that the root issue with those vehicles was because of high angle of attack.  Something Ares will not experience.  Also this quote "First, during development of that vehicle, the complexity of its aerodynamics was underestimated.  The vehicle was assumed to be a typical missile while, in fact, it had a significant lifting wing." got my attention.  LOL, rest assured that the people at Nielsen Engineering and Research understood the aerodynamics.  It is f*ing tricky.  And their extensive knowledge of highly maneuverable missiles contributed to their knowledge.  And Dr. Hall is an old timer.  He personally knows the people at Nielsen.  I know that for a fact.  And Dr. Hall understands high angle of attack issues.  I know that for a fact.  Obviously his purpose is to justify the aerodynamics analysis.  And there are very few people who could say that the difficulties with the Pegasus XL and HXLV aerodynamics don't carry over to Ares.  Some of this knowledge is arcane.  Granted, Ares will have other difficulties, such as transonic buffet.  But, I'm skeptical of how well WT or CFD can adequately predict this.  It is something aerodynamicists do not like to admit too.  It doesn't help sell WT or CFD results if something can not be predicted.  I'm not trying to simplifying the issues.  There are issues.  But if the issues are not know, you'll find yourself spending time and money hunting daemons that do not exist.  You must understand what physical features your vehicle will encounter and what it takes to analyze them.  If you don't, the experts will shoot you down, making it hard to get to the politician's ears.

And rest assured that if people such as Dr. Hall say your aero is inadequate, you could find yourself fighting an up hill battle.  Please, no arm waving about it.  You will be disappointed.  That is the part I find interesting about this SLS/Congress/NASA admin/President discussion.  I'm not sure that is reality.  I believe reality, in regards to aero determination for CDR, is represented by people such as Dr. Hall.

This leads me to the next point.  I found the lack of clarity of DIRECT's engineering approach disappointing.  For example, they were never explicitly clear on how they determined their aero.  The most I heard was CFD on PLF and their comments in their rebuttal.  Oh well.
Title: Re: AJAX Launcher
Post by: Jim on 03/22/2011 07:25 pm
Aero is a secondary consideration in LV.  Once you get pass controllability it only has second order effects.
Title: Re: AJAX Launcher
Post by: sdsds on 03/22/2011 07:45 pm
Even without a full aerodynamic analysis it might be possible to use aerodynamics to argue in favor of AJAX.  AJAX is principally "competing" with designs using RSRM, so it might be sufficient to simply show that e.g. max-q would be lower with AJAX.

The other aerodynamic argument is essentially that ULA must have already solved this to have the confidence they express in Atlas V Heavy.  Admittedly the core diameters are different, but ... how difficult can it be to resolve that?  At worst, isn't the solution "just" to add more structure?
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 07:49 pm
Even without a full aerodynamic analysis it might be possible to use aerodynamics to argue in favor of AJAX.  AJAX is principally "competing" with designs using RSRM, so it might be sufficient to simply show that e.g. max-q would be lower with AJAX.

The other aerodynamic argument is essentially that ULA must have already solved this to have the confidence they express in Atlas V Heavy.  Admittedly the core diameters are different, but ... how difficult can it be to resolve that?  At worst, isn't the solution "just" to add more structure?
If you study, the aerodynamics are similar to Energia, and in several ways superior in regards to Max-Q handling.  AJAX is not a new concept, just a new implementation of an existing concept.  We have existing material from the NLS studies and Energia to pull from, along with the existing Ares studies and ULA launchers.  We've gone over a lot of the aero needs earlier, even running computer simulations of various configurations to reach a good-enough design for our needs.

As you say, you don't need perfection, you just need to be better than the competition.
Title: Re: AJAX Launcher
Post by: martin hegedus on 03/22/2011 07:50 pm
Aero is a secondary consideration in LV.  Once you get pass controllability it only has second order effects.

??

What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow.  Why did NASA spend all that effort on aero?  Why do other companies do the same?  Why do launch vehicles go into the wind tunnel?

Sigh.  I don't mind.  No need to bother with the questions.  I hear this a lot.  That attitude is a contributing factor for a lot of aero failures.  I do what I do and I know what my past and present clients are interested in.  And, of course, aerodynamic failure analysis does pay well.

Title: Re: AJAX Launcher
Post by: martin hegedus on 03/22/2011 08:04 pm
Even without a full aerodynamic analysis it might be possible to use aerodynamics to argue in favor of AJAX.  AJAX is principally "competing" with designs using RSRM, so it might be sufficient to simply show that e.g. max-q would be lower with AJAX.

The other aerodynamic argument is essentially that ULA must have already solved this to have the confidence they express in Atlas V Heavy.  Admittedly the core diameters are different, but ... how difficult can it be to resolve that?  At worst, isn't the solution "just" to add more structure?

It is more than just diameter changes.  That is just F=CD*Area.  There is a wealth of information on ntrs that can assist you.  With non-linear aero, small changes can have much different affects.  So, in regards to Atlas V, one needs to know if there are any iffy aero areas.

Anyway, if someone as experienced as Jim says aero is second order, I'm going to leave it at that.  I guess he likes to put me in my place.  I'm just an aero guy.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 08:08 pm
Even without a full aerodynamic analysis it might be possible to use aerodynamics to argue in favor of AJAX.  AJAX is principally "competing" with designs using RSRM, so it might be sufficient to simply show that e.g. max-q would be lower with AJAX.

The other aerodynamic argument is essentially that ULA must have already solved this to have the confidence they express in Atlas V Heavy.  Admittedly the core diameters are different, but ... how difficult can it be to resolve that?  At worst, isn't the solution "just" to add more structure?

It is more than just diameter changes.  That is just F=CD*Area.  There is a wealth of information on ntrs that can assist you.  With non-linear aero, small changes can have much different affects.  So, in regards to Atlas V, one needs to know if there are any iffy aero areas.

Anyway, if someone as experienced as Jim says aero is second order, I'm going to leave it at that.  I guess he likes to put me in my place.  I'm just an aero guy.

And a good aero guy to boot.  I always appreciate the feedback.  We have been taking aerodynamics into regards, which is why we have Energia/Ariane style nosecaps over the Delta IV style.
Title: Re: AJAX Launcher
Post by: Jim on 03/22/2011 08:23 pm
What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow. 

All secondary effects.  Items that are worked on after the basic vehicle has been laid out.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 08:49 pm
Aero is a secondary consideration in LV.  Once you get pass controllability it only has second order effects.

??

What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow.  Why did NASA spend all that effort on aero?  Why do other companies do the same?  Why do launch vehicles go into the wind tunnel?

Sigh.  I don't mind.  No need to bother with the questions.  I hear this a lot.  That attitude is a contributing factor for a lot of aero failures.  I do what I do and I know what my past and present clients are interested in.  And, of course, aerodynamic failure analysis does pay well.



In the end I'm pretty sure it's not a major problem.  They got the Shuttle to fly with an 8.4m core and two big strapon SRB's, and a big, ungangly, unaerodynamic shuttle hanging off the side (unaerodynamic when compared to a bullet like shape like a rocket or booster) and got it to fly without shaking itself apart or nosediving into the ocean.  An 8.4m bullet shaped core with 4, 6, or 8 bullet shaped boosters with a geometric cross section and perfectly inline thrust loads, won't be a difficult shape to work with.  :-)
Base heating shouldn't be a problem because the RS-25's are regen cooled, and the RD-180's basically flew successfully on Energia (in their 4-chamber version of the RD-170).   In fact, Energia with it's 4XRD-0120 hydrolox engines (each about the equivalent of the SSME) and it's 4XRD-170 was the equivalent of the AJAX-480, as each RD-170 is basically two RD-180's.  So Energia was launching successfully basically in the same configuration as AJAX-480.  So if that flies ok, then AJAX-440 or 460 should fly just fine. 

Some wind tunnel testing to tweak the design is a given.  Maybe it would be better to have Energia type sloped nosecones on the Atlas V's, or maybe a standard bullet nosecone like the SRB's will be fine.

Title: Re: AJAX Launcher
Post by: robertross on 03/22/2011 09:03 pm
My 'small' point of view:

I have no problem with AJAX as a design. It has a lot going for it.

My question would be: is NASA even looking at it? I've been reading this thread, and the Kerolox one, and the fundamental questions that come to mind are

1) Does it meet the intent of Congress
2) Are NASA's current studies even looking at this design?

We seem to think there's 'maneuvering room' in the 'letter of the law'. So without any firm determination, we'll have to wait on that one (and we've beaten it up quite well).

So what about #2? If NASA isn't looking at an AJAX 'style' launcher, then do we really expect, when NASA presents its report to congress, that they will say "Nope, go back and do this all over again". Or will they say "this one".

The result from congress is pretty important. I'm certainly seeing why having congress involved in rocket selection is such a bad idea. But it's especially troubling now, since they can't even make up their minds on most things, how will they come to any concensus on this?

Now this play by NASA, on the various concepts as being 'leaked', and them putting together ANY launcher other than a SD-HLV, makes me think it's their way of playing chicken with congress giving them, essentially, TWO options:

1) Un-affordable inline SD-HLV (as mentioned by Gen. Bolden)
or
2) An affordable alternative, kerolox-based.

"Which will it be congress?": should make for an INTERESTING moment.

So again, is the AJAX design even being considered by NASA? Because if it isn't, I don't see it surviving to a third round.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 09:15 pm

AJAX gives us what we need with a LV that is correctly sized; not too big, and not too small. It does not compete with the EELV fleet, but compliments it. It does not give in to the pipedream of the world's biggest rocket. That was the Saturn-V, and always will be. We do not need to build anything that big – ever again.

AJAX – the right launch vehicle today for tomorrow's BEO missions. Sharing today's existing flight-proven hardware to build tomorrow's Space Program in an economic, efficient and timely manner.


Well, let's pull on this thread a little bit.  (maybe this needs a new thread).
What's the -most- modular design with the -most- commonality with existing LV's?
While the 8.4m ET and SSME's currently exist, nothing else uses them.  No commonality.  (maybe some of the reason CxP originally wanted to use RS-68's?)
It's obviously not as one-trick pony as Direct, 5/5, STS, CxP, or Saturn V redux, but still, 1/2 of your LV is sole-purpose. 
To just brainstorm some, and tossing aside the NASA Authorization act, what's the best "clean-sheet" design that utilizes the largest amount of existing systems, or systems that would be developed but then used on other LV's (like an ACES US). 
Take this idea to it's limit, and what are some of the options we have?

Downix, you mentioned a study that looked at wraping a D4 core modified with an RS-25 engine with 6 AV CCB's, and an upper stage would get in the range of 130mt into LEO?  Could something like that be used for a medium heavy lifter to LEO without the US like AJAX or J130 could?  Or is the US required for any launch?  Would the 5.1m ACES upper stage be a good match for that design, and then could be used on other Atlas V or Delta 4 cargo or Orion launches?

What other possibilities are there?  That still leaves us with the RS-25 being used with no commonality with other systems. 
Is there something that could use RD-180's or maybe Merlin 1C's upgrading to Merlin 2's soley for the first stage, and could get payloads to LEO without needing an US.  And then an ACES or common Centaur US could be added for more payload to LEO, or BLEO?

I guess Atlas Phase 3 gets you there too, right?  As would a SpaceX Falcon X heavy and super heavy (4 strapon's rather than 2, like Atlas Phas 3).  Can AVP2-Heavy, AVP3, F9XH, or F9XSH get useful payloads to LEO without an US like AJAX or Direct?

Any other options?

What's the best, and what are it's pro's and con's vs. AJAX?

(I'm not trying to downplay AJAX, just taking one of the big advantages of it, and maybe taking it to the next level). 
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 09:34 pm

AJAX gives us what we need with a LV that is correctly sized; not too big, and not too small. It does not compete with the EELV fleet, but compliments it. It does not give in to the pipedream of the world's biggest rocket. That was the Saturn-V, and always will be. We do not need to build anything that big – ever again.

AJAX – the right launch vehicle today for tomorrow's BEO missions. Sharing today's existing flight-proven hardware to build tomorrow's Space Program in an economic, efficient and timely manner.


Well, let's pull on this thread a little bit.  (maybe this needs a new thread).
What's the -most- modular design with the -most- commonality with existing LV's?
While the 8.4m ET and SSME's currently exist, nothing else uses them.  No commonality.  (maybe some of the reason CxP originally wanted to use RS-68's?)
It's obviously not as one-trick pony as Direct, 5/5, STS, CxP, or Saturn V redux, but still, 1/2 of your LV is sole-purpose. 
To just brainstorm some, and tossing aside the NASA Authorization act, what's the best "clean-sheet" design that utilizes the largest amount of existing systems, or systems that would be developed but then used on other LV's (like an ACES US). 
Take this idea to it's limit, and what are some of the options we have?

Downix, you mentioned a study that looked at wraping a D4 core modified with an RS-25 engine with 6 AV CCB's, and an upper stage would get in the range of 130mt into LEO?  Could something like that be used for a medium heavy lifter to LEO without the US like AJAX or J130 could?  Or is the US required for any launch?  Would the 5.1m ACES upper stage be a good match for that design, and then could be used on other Atlas V or Delta 4 cargo or Orion launches?

What other possibilities are there?  That still leaves us with the RS-25 being used with no commonality with other systems. 
Is there something that could use RD-180's or maybe Merlin 1C's upgrading to Merlin 2's soley for the first stage, and could get payloads to LEO without needing an US.  And then an ACES or common Centaur US could be added for more payload to LEO, or BLEO?

I guess Atlas Phase 3 gets you there too, right?  As would a SpaceX Falcon X heavy and super heavy (4 strapon's rather than 2, like Atlas Phas 3).  Can AVP2-Heavy, AVP3, F9XH, or F9XSH get useful payloads to LEO without an US like AJAX or Direct?

Any other options?

What's the best, and what are it's pro's and con's vs. AJAX?

(I'm not trying to downplay AJAX, just taking one of the big advantages of it, and maybe taking it to the next level). 
Ah, but there is commonality.  The RS-25, while itself unique, utilizes much of the same work as the RL-10, so the overhead for it is shared.  The 8.4m tank itself may be unique, but the factory which makes it is not, and builds other products as well (windmills being a big one, the Orion being another). 

As for the AIUS and D4 core idea, the staging issues are much more severe, to the point that there is a good chance on every launch for an incident.  Too many boosters around a core.  In addition, it does push the congressional requirements too far.

As for Atlas Phase III, you do realize it uses an 8.4m core... the ET derived AJAX core in fact.  While it would require redesign (expanded LOX tank, shrunk fueltank, and swapping where they are) it would be possible to share a factory and tooling for both.  If the ET line is shutdown, Phase III will require a redesign.

With the other options, we crunched the numbers, multiple times.  Only the Atlas V and D4 gave the immediacy needed, could meet the schedule and budget demands, and had the flight record.  And of those, AV had key advantages in the R&D timetable and cost due to it's being closer to man-rating.
Title: Re: AJAX Launcher
Post by: martin hegedus on 03/22/2011 09:36 pm
What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow. 

All secondary effects.  Items that are worked on after the basic vehicle has been laid out.

Oh, you mean something like ...  Never mind, no names.  That works for me too.  Oh, very much so!  I'm drooling.  Wow, that pays better than failure analysis.  Nothing like chewing up the clock trying to make a design match something that was marketed earlier that doesn't work well.  Investors hate seeing change and managers don't like accepting they were wrong to a bigger crowd.

And I like it when things turn into a research project.  Of course, Boeing and Lockheed have experts in various fields who know the ins and outs and can speak up if a preliminary design is pushing the research bounds.  Others, such as DIRECT and AJAX, may not be so lucky.

I'm not sure why you are saying some of these issues are secondary if they impact cost and schedule up to CDR and further, but I guess that is what you are saying.

Not to be misunderstood, I do feel that if several different historically traditional preliminary designs are done right, and by the same group, then the design cost and schedule (up to CDR) for each will be similarish to each other.  But, that is only true if the preliminary designs are not technically sloppy.  Again, my opinion.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 09:41 pm
What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow. 

All secondary effects.  Items that are worked on after the basic vehicle has been laid out.

Oh, you mean something like ...  Never mind, no names.  That works for me too.  Oh, very much so!  I'm drooling.  Wow, that pays better than failure analysis.  Nothing like chewing up the clock trying to make a design match something that was marketed earlier that doesn't work well.  Investors hate seeing change and managers don't like accepting they were wrong to a bigger crowd.

And I like it when things turn into a research project.  Of course, Boeing and Lockheed have experts in various fields who know the ins and outs and can speak up if a preliminary design is pushing the research bounds.  Others, such as DIRECT and AJAX, may not be so lucky.

I'm not sure why you are saying some of these issues are secondary if they impact cost and schedule up to CDR and further, but I guess that is what you are saying.

Not to be misunderstood, I do feel that if several different historically traditional preliminary designs are done right, and by the same group, then the design cost and schedule (up to CDR) for each will be similarish to each other.  But, that is only true if the preliminary designs are not technically sloppy.  Again, my opinion.

You are quite right too say so.  And are very right, which is why we studied the aerodynamics, the pressure points at Max-Q, etc.  While we lack the computing capacity of the big boys, we are patient.  Several pieces of the design came about due to this, such as the ariane-like nose caps, and that the core is not as stubby as the reduced tank would allow.  Any shorter, and the pressure built up too much at Max-Q.  Too long, you get vibration issues. 
Title: Re: AJAX Launcher
Post by: Jim on 03/22/2011 09:44 pm
What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow. 

All secondary effects.  Items that are worked on after the basic vehicle has been laid out.

Oh, you mean something like ...  Never mind, no names.  That works for me too.  Oh, very much so!  I'm drooling.  Wow, that pays better than failure analysis.  Nothing like chewing up the clock trying to make a design match something that was marketed earlier that doesn't work well.  Investors hate seeing change and managers don't like accepting they were wrong to a bigger crowd.

And I like it when things turn into a research project.  Of course, Boeing and Lockheed have experts in various fields who know the ins and outs and can speak up if a preliminary design is pushing the research bounds.  Others, such as DIRECT and AJAX, may not be so lucky.

I'm not sure why you are saying some of these issues are secondary if they impact cost and schedule up to CDR and further, but I guess that is what you are saying.

Not to be misunderstood, I do feel that if several different historically traditional preliminary designs are done right, and by the same group, then the design cost and schedule (up to CDR) for each will be similarish to each other.  But, that is only true if the preliminary designs are not technically sloppy.  Again, my opinion.


Just need adequate margins in the beginning to account for design tweaking once getting down to real design.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 09:50 pm
What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow. 

All secondary effects.  Items that are worked on after the basic vehicle has been laid out.

Oh, you mean something like ...  Never mind, no names.  That works for me too.  Oh, very much so!  I'm drooling.  Wow, that pays better than failure analysis.  Nothing like chewing up the clock trying to make a design match something that was marketed earlier that doesn't work well.  Investors hate seeing change and managers don't like accepting they were wrong to a bigger crowd.

And I like it when things turn into a research project.  Of course, Boeing and Lockheed have experts in various fields who know the ins and outs and can speak up if a preliminary design is pushing the research bounds.  Others, such as DIRECT and AJAX, may not be so lucky.

I'm not sure why you are saying some of these issues are secondary if they impact cost and schedule up to CDR and further, but I guess that is what you are saying.

Not to be misunderstood, I do feel that if several different historically traditional preliminary designs are done right, and by the same group, then the design cost and schedule (up to CDR) for each will be similarish to each other.  But, that is only true if the preliminary designs are not technically sloppy.  Again, my opinion.


Just need adequate margins in the beginning to account for design tweaking once getting down to real design.
I know all about margins.  We estimate we only need 55mt for the core, so we list 63mt.  Better to overestimate just in case.
Title: Re: AJAX Launcher
Post by: martin hegedus on 03/22/2011 10:04 pm
What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow. 

All secondary effects.  Items that are worked on after the basic vehicle has been laid out.

Oh, you mean something like ...  Never mind, no names.  That works for me too.  Oh, very much so!  I'm drooling.  Wow, that pays better than failure analysis.  Nothing like chewing up the clock trying to make a design match something that was marketed earlier that doesn't work well.  Investors hate seeing change and managers don't like accepting they were wrong to a bigger crowd.

And I like it when things turn into a research project.  Of course, Boeing and Lockheed have experts in various fields who know the ins and outs and can speak up if a preliminary design is pushing the research bounds.  Others, such as DIRECT and AJAX, may not be so lucky.

I'm not sure why you are saying some of these issues are secondary if they impact cost and schedule up to CDR and further, but I guess that is what you are saying.

Not to be misunderstood, I do feel that if several different historically traditional preliminary designs are done right, and by the same group, then the design cost and schedule (up to CDR) for each will be similarish to each other.  But, that is only true if the preliminary designs are not technically sloppy.  Again, my opinion.

You are quite right too say so.  And are very right, which is why we studied the aerodynamics, the pressure points at Max-Q, etc.  While we lack the computing capacity of the big boys, we are patient.  Several pieces of the design came about due to this, such as the ariane-like nose caps, and that the core is not as stubby as the reduced tank would allow.  Any shorter, and the pressure built up too much at Max-Q.  Too long, you get vibration issues. 

There is also another preliminary point, Max-Temp.  A back of the envelope calc would be the point at which the vehicle reaches max 0.5*rho*V*V*V, i.e. V^3.  There are better methods such as heating of a sphere, but not sure how much better.  And, better is relative.  An engineering code such as MINIVAR really should be used at this stage.
Title: Re: AJAX Launcher
Post by: martin hegedus on 03/22/2011 10:07 pm
What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow. 

All secondary effects.  Items that are worked on after the basic vehicle has been laid out.

Oh, you mean something like ...  Never mind, no names.  That works for me too.  Oh, very much so!  I'm drooling.  Wow, that pays better than failure analysis.  Nothing like chewing up the clock trying to make a design match something that was marketed earlier that doesn't work well.  Investors hate seeing change and managers don't like accepting they were wrong to a bigger crowd.

And I like it when things turn into a research project.  Of course, Boeing and Lockheed have experts in various fields who know the ins and outs and can speak up if a preliminary design is pushing the research bounds.  Others, such as DIRECT and AJAX, may not be so lucky.

I'm not sure why you are saying some of these issues are secondary if they impact cost and schedule up to CDR and further, but I guess that is what you are saying.

Not to be misunderstood, I do feel that if several different historically traditional preliminary designs are done right, and by the same group, then the design cost and schedule (up to CDR) for each will be similarish to each other.  But, that is only true if the preliminary designs are not technically sloppy.  Again, my opinion.


Just need adequate margins in the beginning to account for design tweaking once getting down to real design.

Oh, I hear that a lot too.  But that only holds true if your preliminary design is in the zone.  Margins do not help a bad design.

Edit:  I don't mean to imply that AJAX is a bad design.  It was a general comment.  I have not seen the AJAX design yet.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 10:07 pm

As for Atlas Phase III, you do realize it uses an 8.4m core... the ET derived AJAX core in fact.  While it would require redesign (expanded LOX tank, shrunk fueltank, and swapping where they are) it would be possible to share a factory and tooling for both.  If the ET line is shutdown, Phase III will require a redesign.


Well, I should have specified "AVP3A".  Going with the 3B sort of then kills my own point about a single purpose item like the 8.4 ET core.  3A gets you 107mt to LEO (not enough for NASA authorization Act, but like I said, pretend that's not a constraint for this exercise.)  You use 5 CCB cores that would be used for other AVP2 LV's (and D4's, but with different tankage).  That LV has 10 RD-180's, so we're not talking a crazy number of engines.  And you get rid of the expensive RS-25's.  Too bad D4's weren't using a pair of them instead of the RS-68 so there was commonality there. 



With the other options, we crunched the numbers, multiple times.  Only the Atlas V and D4 gave the immediacy needed, could meet the schedule and budget demands, and had the flight record.  And of those, AV had key advantages in the R&D timetable and cost due to it's being closer to man-rating.

Ok, cool.  I haven't crunched any numbers (don't know enough about it to get the numbers to crunch!  heheheh) myself, so I was just curious.

Is it your opinion that AJAX is about as good as we are going to get for an HLV with commonality with other programs?
Obviously, politically, it has an advantage of using "legacy" hardware in the ET-derived core and SSME's.  But legacy hardware doesn't always mean the "best" way.  So you feel this is indeed the most streamline, common, and flexible option, politics aside?
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 10:18 pm
Downix,

A few more AJAX related questions (which probably have already been adressed many pages ago, I just don't know where).

1)  Does AJAX work fine with an ACES-41 US?  Or does it need an optimized 8.4m US like a J246?

2)  Can AJAX us an ACES-71 too?

3)  Looks like Atlas Phase 2/3 has a groth option of a stretched Centaur with 6 RL10's, but still 5m dia.   I'm assuming that's something like an ACES-71, but with 6 RL10's?  Is this something AJAX could use too?
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 10:26 pm

As for Atlas Phase III, you do realize it uses an 8.4m core... the ET derived AJAX core in fact.  While it would require redesign (expanded LOX tank, shrunk fueltank, and swapping where they are) it would be possible to share a factory and tooling for both.  If the ET line is shutdown, Phase III will require a redesign.


Well, I should have specified "AVP3A".  Going with the 3B sort of then kills my own point about a single purpose item like the 8.4 ET core.  3A gets you 107mt to LEO (not enough for NASA authorization Act, but like I said, pretend that's not a constraint for this exercise.)  You use 5 CCB cores that would be used for other AVP2 LV's (and D4's, but with different tankage).  That LV has 10 RD-180's, so we're not talking a crazy number of engines.  And you get rid of the expensive RS-25's.  Too bad D4's weren't using a pair of them instead of the RS-68 so there was commonality there. 
The RS-25e should not be much more expensive than the RS-68, and would bring more commonality with other systems as well.  And that it brings ground-to-orbit capacity only makes it even better.  Alternatively, one could follow up on Boeing's proposal to continue reusing the RS-25d's as/is, through a recovery module of some sort.
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With the other options, we crunched the numbers, multiple times.  Only the Atlas V and D4 gave the immediacy needed, could meet the schedule and budget demands, and had the flight record.  And of those, AV had key advantages in the R&D timetable and cost due to it's being closer to man-rating.

Ok, cool.  I haven't crunched any numbers (don't know enough about it to get the numbers to crunch!  heheheh) myself, so I was just curious.

Is it your opinion that AJAX is about as good as we are going to get for an HLV with commonality with other programs?
Obviously, politically, it has an advantage of using "legacy" hardware in the ET-derived core and SSME's.  But legacy hardware doesn't always mean the "best" way.  So you feel this is indeed the most streamline, common, and flexible option, politics aside?
From an engineering standpoint, it is about as good as we can get in the time table we have.  All other solutions would either have higher overhead, longer R&D, higher operating costs, or multiples of them.  If we did not have the timetable or budget limits, then we could easily design a better system.  If it were me designing, for instance, I'd have something which looks like Son-of-Saturn I, Atlas LOX tanks wrapped around a DIV LH2 tank, running four RS-68's and two RS-25's.  Drop the RS-68's a la Atlas part way up.  Or I would take the RS-25 and TAN it, have drop Kerosene tanks, with four on the bottom of a winged tank, which then does a once-around orbit to land at KSC or one of the other shuttle landing centers.  If ferrying is needed, for instance if it lands in California, rather than strap it to the back of something, instead it flys itself using add-on engines.  Focus on reuse of the core stage initially.  Without these limits, there are tons of ideas to follow.  But, there are these limits, so we stick to working within then.
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 10:27 pm
Downix,

A few more AJAX related questions (which probably have already been adressed many pages ago, I just don't know where).

1)  Does AJAX work fine with an ACES-41 US?  Or does it need an optimized 8.4m US like a J246?
Off the shelf ACES-41 is the idea
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2)  Can AJAX us an ACES-71 too?
That too.  The ACES-71 it turns out gives almost as much in-orbit fuel as Ares V does, but with much more efficient engines.
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3)  Looks like Atlas Phase 2/3 has a groth option of a stretched Centaur with 6 RL10's, but still 5m dia.   I'm assuming that's something like an ACES-71, but with 6 RL10's?  Is this something AJAX could use too?
If it is developed, of course.  I suspect it would not happen, but who knows.
Title: Re: AJAX Launcher
Post by: Lobo on 03/22/2011 10:55 pm
Hmmmm...
A few more questions, if you don't mind:

1)  Is the growth 5m, 6 engine Centaur basically an ACES-71 with 6 engines?  Or is that a different US entirely?  I sometimes get confused with the various existing and proposed US's.

2)  What do you think then of ULA's ACES-based lunar architecture?  If ACES is developed for AJAX as well as Atlas and Delta, would that be the way to go?  The commonality is obivous.  Or is there a better way to do it? 
The idea of an ACES-service module for Orion is intriguing in their proposal too.

3)  What's the plan to get around the Russian made engine issue?  Have PWR start developing a US made version, and use Russian inventory for testing phases?  Or would it be ok to use the Russian engines intially as long as NASA did transition to a US built one down the road?
Is the fact the engines are Russian built really much of a show stopper as some people say it will be?

4)  I know you said earlier you can't say much, but from what I've been reading, it seems like 5/5 or a new monolithic serial Kerolox booster are the two HEFT front runners.  Is AJAX going to be able to crack into that for consideration?
Title: Re: AJAX Launcher
Post by: Downix on 03/22/2011 11:17 pm
Hmmmm...
A few more questions, if you don't mind:

1)  Is the growth 5m, 6 engine Centaur basically an ACES-71 with 6 engines?  Or is that a different US entirely?  I sometimes get confused with the various existing and proposed US's.
It's an alternate option, but I suspect it will be carried over to ACES if needed. 
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2)  What do you think then of ULA's ACES-based lunar architecture?  If ACES is developed for AJAX as well as Atlas and Delta, would that be the way to go?  The commonality is obivous.  Or is there a better way to do it? 
The idea of an ACES-service module for Orion is intriguing in their proposal too.
AJAX would enhance their architecture, enabling exploration before fuel depots are in-service, as it can lift the full ACES-71 into orbit by itself.  If I were to suggest any particular lunar architecture, it would be a merging of ULA's and the Spudis concept.
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3)  What's the plan to get around the Russian made engine issue?  Have PWR start developing a US made version, and use Russian inventory for testing phases?  Or would it be ok to use the Russian engines intially as long as NASA did transition to a US built one down the road?
Is the fact the engines are Russian built really much of a show stopper as some people say it will be?
You pretty much hit the nail on the head.  It falls under the same agreement for the Atlas V in the first place, that PWR will produce it domestically when a demand for it is there.  This would generate that demand.  Alternatively, both Northrup and Aerojet have alternate engines which could meet the demand.  In the meantime, using the warehoused engines in order to enable flight testing.  This meets the requirements listed under SLS, for the specification is for final configuration.  If the final form utilizes domestic engines, it qualifies.
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4)  I know you said earlier you can't say much, but from what I've been reading, it seems like 5/5 or a new monolithic serial Kerolox booster are the two HEFT front runners.  Is AJAX going to be able to crack into that for consideration?
I have a feeling we can do it.  I may have to compromise a bit to do so, but it can be done.  And that is the limit to what I can say.
Title: Re: AJAX Launcher
Post by: sdsds on 03/22/2011 11:45 pm
[...] makes me think it's their way of playing chicken with congress giving them, essentially, TWO options [...]
So again, is the AJAX design even being considered by NASA? Because if it isn't, I don't see it surviving to a third round.

and

it seems like 5/5 or a new monolithic serial Kerolox booster are the two HEFT front runners.  Is AJAX going to be able to crack into that for consideration?

I frankly doubt that reports published by NASA HQ or hearings held in Congress will drive the overall process.  I also don't think we're going to see new authorization legislation from Congress, and I don't think the appropriations legislation is going to provide much direction on SLS design choices.

The real indicators of design progress are likely to come with contract milestones.  So for example, ATK has said they will conduct the DM-3 test firing sometime in calendar year 2011.  If at that time they even mention the possibility of a four segment motor it will mean something like the HEFT 4/3 configuration, at least as a "Block 0" SLS, is under consideration.  It's going to be difficult for AJAX to get much consideration if ATK shows a willingness to accept that kind of compromise.
Title: Re: AJAX Launcher
Post by: CitabriaFlyer on 03/23/2011 12:51 am
Downix,
What is your political plan?  What strategy(ies) would get this idea in front of the important political leaders?  I have to think Shelby would love this.  A core managed by MSFC stimulating the production of a booster manufactured just a few miles down the road.  Can you meet with any of his people?  What about Nelson and other space politicians?
The prime focus is the senators from Colorado, Alabama, Louisiana, Mississippi, Florida, California and Washington.  Utah would be diminished while Alabama and Colorado would gain.  This is a dream come true for Shelby.  Utah lost Bennett, as a result it has only half of the strength it once did as it's new Senator has minimal space ties and little influence.  The added influence of Washington will help as well, due to its senators positions on the Budget, Energy, Transport, Finance and Appropriations.

But the key is not to go after the Senators directly, it is to get it in front of NASA.  By building on the political structure, but to present it to the scientists, it becomes a tool.  Can we fall back to the political?  Of course.  But if we can convince those inside of NASA Management to even look at it, the advantages will start to sell themselves. 

From a Political standpoint, it is well positioned, taking advantage of the current dynamic in the Senate and House.  I'm not concerned there.  My concern is with Bolton and Garver.  Based on their proposal for NASA, I am reading them to prefer EELV's.  This gives them a tool to give what they wish for, while giving Congress what they wish for.  That is my focus, a compromise which fits the needs of Congress, and delivers to NASA what it needs as well.  In addition, the "Ares V sized launchers" crowd leftover from Griffin would also be satisfied.

So, in the real world, what is being done to get AJAX actually in front of people who make the decisions?  To actually get it ont he radar of the people that count?  (rather than just a bunch of cheerleaders like us on the forum  :-)   )
That, my friend, is a secret.  Shh! (it is who you know, not what you know)

Glad to see that thing have progressed and the concept is moving forward :D Please let me know via message how I can help, as I have not been involved beyond keeping up to date with this thread with the concept since the initial discussion. Also will talk to some of my contacts if needed.
Soon, very soon.
I am a native Floridian, resident of Alabama, working in Florida now.  I would be willing to write or otherwise engage the appropriate political leaders.  Perhaps Sen Nelson would have some pull with the current NASA administration.
Title: Re: AJAX Launcher
Post by: 2552 on 03/23/2011 01:34 am
I know ACES is the baseline upper stage for AJAX, but are you studying options for an 8.4 meter J-2X stage? What would be the payload to LEO of an AJAX-441 and of an AJAX-481? Even if an AJAX core is chosen, a J-2X upper stage seems likely to be chosen anyway.
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 01:54 am
I know ACES is the baseline upper stage for AJAX, but are you studying options for an 8.4 meter J-2X stage? What would be the payload to LEO of an AJAX-441 and of an AJAX-481? Even if an AJAX core is chosen, a J-2X upper stage seems likely to be chosen anyway.

No, we're not.  We did the basic evaluation and realized that there was only a marginal improvement in performance.  You would up with 88mT of fuel for EDS, and an engine with lower ISP.  The end result was a total 800kg improvement in TLI payload, which is what is important here.

If we're keeping the RS-25, the J-2X is no longer needed.
Title: Re: AJAX Launcher
Post by: sdsds on 03/23/2011 03:01 am
If we're keeping the RS-25, the J-2X is no longer needed.

I think the right way to phrase this is:  "If we're keeping the RS-25, the J-2X is not needed as soon."

When would it ever be needed?  Maybe in clusters of 3 or 4, to blast some giant Mars-destined mega-mission out of LEO, where a cluster of several dozen RL-10 engines would look ungainly?

Getting J-2X canceled is not the point of the AJAX exercise.
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 03:27 am
If we're keeping the RS-25, the J-2X is no longer needed.

I think the right way to phrase this is:  "If we're keeping the RS-25, the J-2X is not needed as soon."

When would it ever be needed?  Maybe in clusters of 3 or 4, to blast some giant Mars-destined mega-mission out of LEO, where a cluster of several dozen RL-10 engines would look ungainly?

Getting J-2X canceled is not the point of the AJAX exercise.
J-2X will not get you to Mars, NASA is putting it's money into VASIMR for that.  If we have the RS-25, the J-2X simply isn't needed. 

http://www.theregister.co.uk/2011/03/10/ad_astra_nasa_vf200_announcement/

Why would we want to invest several more billion into an engine without a role?
Title: Re: AJAX Launcher
Post by: sdsds on 03/23/2011 04:19 am
Why would we want to invest several more billion into an engine without a role?

The United States might want to support full employment for its liquid-propellant rocket engine designers.  Or it might want a "backup" to VASIMR.  Who knows why these things have the support they do!

You're certainly right that AJAX shouldn't advocate investing in an engine it doesn't plan to use.  But does AJAX really benefit much from advocating the cancellation of J-2X?  Sure, there would be slightly less conflict getting access to the test stands at Stennis.  The RS-25 acceptance test effort might need a different home.  The legislators from California probably know of someplace other than Mississippi for that.  Or have you stopped looking for political support for the AJAX effort?
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 04:33 am
Why would we want to invest several more billion into an engine without a role?

The United States might want to support full employment for its liquid-propellant rocket engine designers.  Or it might want a "backup" to VASIMR.  Who knows why these things have the support they do!

You're certainly right that AJAX shouldn't advocate investing in an engine it doesn't plan to use.  But does AJAX really benefit much from advocating the cancellation of J-2X?  Sure, there would be slightly less conflict getting access to the test stands at Stennis.  The RS-25 acceptance test effort might need a different home.  The legislators from California probably know of someplace other than Mississippi for that.  Or have you stopped looking for political support for the AJAX effort?
Yes, it is the difference between a program which fits Congress' budget limits, and one which doesn't.  That goes without care of which launcher you speak of.  As for political support, there would be no loss from it, for the J-2X contract would be modified, as allowed by the Congressional order, for the RS-25e program.  In fact, it would have more political clout, due to the higher production quantity of runs of the RS-25e vs J-2X. (4 per launch vs 2)

Remember, we have only $12 billion to spend.  As it is we're looking at $3.5-$5 billion to develop the J-2X, and as it is already under development, any halt to development now would result in a loss of the money invested already ($2.8 billion) as that would need to be partially, if not completely recaptured.  Which means that money would have to come out of somewhere.  The most likely source would be by gutting the R&D money for both the Americanized RD-180 and the RS-25e effort, two components which Congress wants.  But even that would require an additional $2 billion, which means pick what you want to kill, the core, the launch pad renovations, what?

DIRECT has the same issue, not enough money in the program to support the J-2X.

The point of AJAX is to develop as little as possible.  Developing a whole new, not needed upper stage engine with limited beyond-orbit applications is not it.  It is not for the Mars mission, it's lack of throttling, poor isp, and limited restart and burn capability is a deal breaker.  For every Mars scenario I've seen it is either RL-10 or VASIMR.
Title: Re: AJAX Launcher
Post by: Lobo on 03/23/2011 03:35 pm
You pretty much hit the nail on the head.  It falls under the same agreement for the Atlas V in the first place, that PWR will produce it domestically when a demand for it is there.  This would generate that demand.  Alternatively, both Northrup and Aerojet have alternate engines which could meet the demand.  In the meantime, using the warehoused engines in order to enable flight testing.  This meets the requirements listed under SLS, for the specification is for final configuration.  If the final form utilizes domestic engines, it qualifies.

What are the Northrup and Aeroject engine's?  (just give me model numbers and I'll look them up myself.  Thanks).
Would there be much issue with fitting either of them to the Atlas V?  I mean, would suddenly be all these requalification and enormous expenses everyone talks about any time there's a minor change?
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 03:42 pm
You pretty much hit the nail on the head.  It falls under the same agreement for the Atlas V in the first place, that PWR will produce it domestically when a demand for it is there.  This would generate that demand.  Alternatively, both Northrup and Aerojet have alternate engines which could meet the demand.  In the meantime, using the warehoused engines in order to enable flight testing.  This meets the requirements listed under SLS, for the specification is for final configuration.  If the final form utilizes domestic engines, it qualifies.

What are the Northrup and Aeroject engine's?  (just give me model numbers and I'll look them up myself.  Thanks).
Would there be much issue with fitting either of them to the Atlas V?  I mean, would suddenly be all these requalification and enormous expenses everyone talks about any time there's a minor change?
TR-107 for Northrup and two AJ-26's for Aerojet.  Both were considered for Atlas, and contingency plans should the RD-180 be unavailable would be to either produce it domestically or should that prove impossible, switch. The TR-107 would require more R&D, but the AJ-26 is available now.
Title: Re: AJAX Launcher
Post by: spacenut on 03/23/2011 03:57 pm
I read somewhere that someone had a plan to use one Delta IV heavy core with two RS-25s instead of the one RS-68.  It would have two Atlas V's strapped to this core with no upper stage.  Does anyone have anything about this launcher?  Sounds like a good launcher for Orion to LEO, and use AJAX for heavy lift. 
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 04:05 pm
I read somewhere that someone had a plan to use one Delta IV heavy core with two RS-25s instead of the one RS-68.  It would have two Atlas V's strapped to this core with no upper stage.  Does anyone have anything about this launcher?  Sounds like a good launcher for Orion to LEO, and use AJAX for heavy lift. 
I tinkered with that, but the two RS-25's were overkill, only one was needed.  Two did not help performance.  But it would require more R&D, and not meet requirements in any other way.  Plus the Delta IV's reason for not being man-rated is not only due to the engine, there are 12 other points on the CBC which require re-design.
Title: Re: AJAX Launcher
Post by: baldusi on 03/23/2011 04:07 pm
TR-107 for Northrup and two AJ-26's for Aerojet.  Both were considered for Atlas, and contingency plans should the RD-180 be unavailable would be to either produce it domestically or should that prove impossible, switch. The TR-107 would require more R&D, but the AJ-26 is available now.
Wasn't the TR-107 the one SpaceX licensed to make the Merlin?
Two NK-33 would give 3.01MN vs 3.83MN, and 14s less of isp. Unless the AJ-26 works at 127% and they can improve the isp, I don't see it as a replacement. It is lighter, though 2,470kg (both) vs 5,480kg fot the RD-180. But I don't think that 3,000kg in the first stage change enough the performance to actually compensate.
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 04:22 pm
TR-107 for Northrup and two AJ-26's for Aerojet.  Both were considered for Atlas, and contingency plans should the RD-180 be unavailable would be to either produce it domestically or should that prove impossible, switch. The TR-107 would require more R&D, but the AJ-26 is available now.
Wasn't the TR-107 the one SpaceX licensed to make the Merlin?
Two NK-33 would give 3.01MN vs 3.83MN, and 14s less of isp. Unless the AJ-26 works at 127% and they can improve the isp, I don't see it as a replacement. It is lighter, though 2,470kg (both) vs 5,480kg fot the RD-180. But I don't think that 3,000kg in the first stage change enough the performance to actually compensate.
The AJ-26 on the Taurus II is running at 108% with improved isp.  They have run it higher as well so I've heard.  This brings the AJ-26 to a total of 3.62MN vac, or 3.46MN sl.  This means that the total thrust loss for liftoff is 44,631 lbs/20,448kg.  And that is with only a 108%, which is the AJ-26 running optimized for the Taurus II.  If we push that up to 115%, it should be within spitting distance of even-steven.  The isp at 108% is also several points better as well.

And I SpaceX licensed the RS-84 if I recall correctly.
Title: Re: AJAX Launcher
Post by: mike robel on 03/23/2011 04:35 pm
Ahem.  Its Northrop-Grumman.  Speaking as a former NG employee.  :)
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 04:47 pm
Ahem.  Its Northrop-Grumman.  Speaking as a former NG employee.  :)
Ah, my sincere apology.
Title: Re: AJAX Launcher
Post by: baldusi on 03/23/2011 05:04 pm
Why do you consider the TR107 an option and not the RS-84. Neither was ready. And the dual A26 is still short on thrust. Unless Aerojet integrates TAN, which would mean to wholly license the engine and start almost again. In any case PWR can start the RD-180 production lines now and start pumping new engines in three years.
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 05:09 pm
Why do you consider the TR107 an option and not the RS-84. Neither was ready. And the dual A26 is still short on thrust. Unless Aerojet integrates TAN, which would mean to wholly license the engine and start almost again. In any case PWR can start the RD-180 production lines now and start pumping new engines in three years.
The RS-84 is not in the same thrust category.  It is also made by PWR, and if using a PWR engine why go for that over just starting domestic RD-180 production?  As for the AJ-26, as mentioned, it can throttle up more than just the 108% they're running it on the Taurus II.  It's not that much short of thrust, and as it is lighter as well you only need to add 6-7% more thrust to the engine to get it to perform the same as the RD-180.  But this is for AJAX, which has enough margin that the AJ-26 as it is would do without loss of performance.  Shoot, for the flight profile we've identified, we weren't even using the RD-180 at 100% for anything but takeoff. Using the AJ-26 we would have to run the RS-25's at 109%, rather than the 104% we were planning, for liftoff. It would mean that ULA would be producing CCB's and not installing the engines in the factory, which so I understand is not an issue for them.  We would then have to install the engines at KSC.
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 08:33 pm
And all of these are fallback positions, not the recommended.  Like Delta IV CBC instead of CCB, a fallback.  (Delta IV just enables less RS-25's on the core, but would take more time to develop due to the lack of a man-rated CBC) 
Title: Re: AJAX Launcher
Post by: baldusi on 03/23/2011 08:53 pm
Atlas V flies what? four to six missions per year? Let's say five RD-180 per year. A single AJAX 440 would almost double the demand. Dual missions per year of 440 would almost triple current demand of CBC. At twelve to fifteen engines per year, wouldn't it be reasonable to setup local manufacturing? PWC would also make the RS-25E, so they would have to make 8 RS-25E and 8 RD-180 per year. I don't know how much overhead can they share, but at least on the administrative and client interface (i.e. NASA) they should be able to save a lot. If you do a couple of 480 per year then you better plan a very big factory because you'd be breaking big engines manufacturing records.
The real question is, how does Congress, DOD and NROL see the local production of the RD-180? It's been implied that the D4 is used by NROL because the origin of the RD-180. Would this change that view? Would it be American enough, even though it's a completely foreign design? Wouldn't it be good to do a cheap (a few millions) investment to have purely American electronics and such and give it a new name, RS-something? That way the people at congress won't feel that to be so foreign.
Title: Re: AJAX Launcher
Post by: Downix on 03/23/2011 10:58 pm
Atlas V flies what? four to six missions per year? Let's say five RD-180 per year. A single AJAX 440 would almost double the demand. Dual missions per year of 440 would almost triple current demand of CBC. At twelve to fifteen engines per year, wouldn't it be reasonable to setup local manufacturing? PWC would also make the RS-25E, so they would have to make 8 RS-25E and 8 RD-180 per year. I don't know how much overhead can they share, but at least on the administrative and client interface (i.e. NASA) they should be able to save a lot. If you do a couple of 480 per year then you better plan a very big factory because you'd be breaking big engines manufacturing records.
The real question is, how does Congress, DOD and NROL see the local production of the RD-180? It's been implied that the D4 is used by NROL because the origin of the RD-180. Would this change that view? Would it be American enough, even though it's a completely foreign design? Wouldn't it be good to do a cheap (a few millions) investment to have purely American electronics and such and give it a new name, RS-something? That way the people at congress won't feel that to be so foreign.
They rate "Domestic vs Foreign" based on the money for each bit of origin.  It does not matter who designs it, it matters on where the money for it goes.  Which is why the Taurus II, despite it's Ukranian first stage and Russian origin engines qualifies as a US made vehicle, of the $5 mil per engine cost, $1 mil is Russian, $4 mil is US.

And by my calcs, if we get AJAX to two flights a year, it would be more economically advantageous for domestic production.  At 4-5, it's not.  The break-even point seems to be 8-10, which is why the focus has been to develop a program which can be flown at a rate of 2 a year, affordably.  If NASA is funding the toolup, then it's a win-win for PWR, ULA and NASA. 
Title: Re: AJAX Launcher
Post by: baldusi on 03/24/2011 12:26 am
Which is sort of my point, you might add a bullet point of "Eliminates reliance on Russian engines for National security payloads" or something along those lines.
And I guess you do take into account the improved economies of scale at PWR (RL10+RS25E+RD-180) for DOD, NROL and NASA. I guess you should talk to ULA, because they have stated that the end of the shuttle program will increase significantly the cost of the RL10. And tripling the production rate of the CBC should have a real impact on cost. In fact, having an American RD-180 might even put all the NROL payloads into Atlas V (save for those that actually need D4H).
As you stated, if you added a couple of human rated A5H it would mean some 20 CBC per year. At those rates it should even be competitive in the commercial market.
Title: Re: AJAX Launcher
Post by: Downix on 03/24/2011 01:34 am
Which is sort of my point, you might add a bullet point of "Eliminates reliance on Russian engines for National security payloads" or something along those lines.
And I guess you do take into account the improved economies of scale at PWR (RL10+RS25E+RD-180) for DOD, NROL and NASA. I guess you should talk to ULA, because they have stated that the end of the shuttle program will increase significantly the cost of the RL10. And tripling the production rate of the CBC should have a real impact on cost. In fact, having an American RD-180 might even put all the NROL payloads into Atlas V (save for those that actually need D4H).
As you stated, if you added a couple of human rated A5H it would mean some 20 CBC per year. At those rates it should even be competitive in the commercial market.
In addition, many of the techniques pioneered for the J-2X can be carried forward to the RS-25e, like channel wall construction, which means even the sunk-costs for J-2X will not be lost.  It is truly a win-win-win.

The main concern then would be, would Delta become redundant?  I don't think so, the Delta has some logistics advantages.  I suspect the current role, Atlas for NASA and Commercial and Delta for government will continue for a long time.
Title: Re: AJAX Launcher
Post by: baldusi on 03/24/2011 10:11 pm
Downmix, I had this idea, that might be ridiculous, but couldn't you put an LH2 tank over the CBC to top of the ET? It would be dry mass shred at staging and you'd end up with either a smaller ET, or a bigger amount if fuel. Of course the mass fraction wouldn't be as good as a bigger tank, but you'd shred more dry weight at staging. Seeing how the Atlas CBC already has the attachments for a second stage, and the ET has the LH2 on the lower part, it might be a relatively low risk development. You know, a dumb LH2 tank with some pipes running to the ET fill manifold and some valves (one way, control, etc.). Just an idea.
Title: Re: AJAX Launcher
Post by: Downix on 03/24/2011 11:41 pm
Downmix, I had this idea, that might be ridiculous, but couldn't you put an LH2 tank over the CBC to top of the ET? It would be dry mass shred at staging and you'd end up with either a smaller ET, or a bigger amount if fuel. Of course the mass fraction wouldn't be as good as a bigger tank, but you'd shred more dry weight at staging. Seeing how the Atlas CBC already has the attachments for a second stage, and the ET has the LH2 on the lower part, it might be a relatively low risk development. You know, a dumb LH2 tank with some pipes running to the ET fill manifold and some valves (one way, control, etc.). Just an idea.
The problem is not dry weight,however, it's fuel-weight.
Title: Re: AJAX Launcher
Post by: 93143 on 03/25/2011 12:26 am
To elaborate:  AJAX is pretty low on T/W at liftoff already.  That's why they shortened the core.  It's not that four SSMEs couldn't push it at separation; it's that the stack was too slow heaving itself off the pad.
Title: Re: AJAX Launcher
Post by: baldusi on 03/25/2011 02:17 am
To elaborate:  AJAX is pretty low on T/W at liftoff already.  That's why they shortened the core.  It's not that four SSMEs couldn't push it at separation; it's that the stack was too slow heaving itself off the pad.
Then, why not 5 RS-25E?
Title: Re: AJAX Launcher
Post by: Downix on 03/25/2011 03:34 am
To elaborate:  AJAX is pretty low on T/W at liftoff already.  That's why they shortened the core.  It's not that four SSMEs couldn't push it at separation; it's that the stack was too slow heaving itself off the pad.
Then, why not 5 RS-25E?
Hurt performance.  With the CCB's burning for so long, we actually found that we did not need the full thrust capability of the SSME's.  We could even shut off two of them after 30 seconds of flight without any loss in performance. 
Title: Re: AJAX Launcher
Post by: baldusi on 03/25/2011 03:02 pm
Hurt performance.  With the CCB's burning for so long, we actually found that we did not need the full thrust capability of the SSME's.  We could even shut off two of them after 30 seconds of flight without any loss in performance. 
So, with a theoretical RS-25T (with TAM) you'd only need two?
Why is NASA so focused on having a HLV by 2016 without budget for any payload? Why don't they finish the investment on new engines  (like the RS-83, RS-84 or the RL-60), instead of leaving unfinished engines that could make a much saner HLV architecture?
Title: Re: AJAX Launcher
Post by: Downix on 03/25/2011 03:35 pm
Hurt performance.  With the CCB's burning for so long, we actually found that we did not need the full thrust capability of the SSME's.  We could even shut off two of them after 30 seconds of flight without any loss in performance. 
So, with a theoretical RS-25T (with TAM) you'd only need two?
Why is NASA so focused on having a HLV by 2016 without budget for any payload? Why don't they finish the investment on new engines  (like the RS-83, RS-84 or the RL-60), instead of leaving unfinished engines that could make a much saner HLV architecture?
With a TAN'd RS-25, we could drop it to two most likely.  In addition, with Atlas P2 we could drop two SSME's as well.  If we went Delta we could drop one.  But for the budget and timetable, not in the cards.

As for engines, it is bird-in-the-hand vs bird-in-the-bush.  Yes, those engines would be great.  But they suck the air out of the room with R&D costs.  Only engines which exist can be delivered on the schedule required.  If you develop a new engine, new variables enter into the picture.  Look at the issues which developed with Ares I, and how it's engine development resulted in delays which put it's launch from 5 years out to 10+.  It was originally to launch this year for full operation, don't forget. 

(ironic how the RS-83 keeps coming up in conversations, just got done talking to my friend in Boeing about it)
Title: Re: AJAX Launcher
Post by: baldusi on 03/25/2011 03:52 pm
Also the RS-84 keeps coming up. The issue is that all current HLV start with: "If we had a regen RS-68", "If we had a modern F1 class kerolox", "If we had a 600kN 450s of isp hydrolox engine", etc. I mean, the last new engine that NASA has produced is what, 30 years old?
Title: Re: AJAX Launcher
Post by: Downix on 03/25/2011 04:45 pm
Also the RS-84 keeps coming up. The issue is that all current HLV start with: "If we had a regen RS-68", "If we had a modern F1 class kerolox", "If we had a 600kN 450s of isp hydrolox engine", etc. I mean, the last new engine that NASA has produced is what, 30 years old?
Not at all.  RS-68 is under a decade old. 
Title: Re: AJAX Launcher
Post by: Halidon on 03/25/2011 05:32 pm
Why is NASA so focused on having a HLV by 2016 without budget for any payload? Why don't they finish the investment on new engines
FY2011 proposed to do precisely that. Congress ridiculed the need to develop new engine technology and shape a comprehensive exploration architecture over time. They said fly a 70t ("evolvable" to 130t) HLLV by 2016, call it SLS, use existing CXP and STS contracts, oh and fit it into a reduced budget. So NASA's trying to do that.
Title: Re: AJAX Launcher
Post by: baldusi on 03/25/2011 05:36 pm
Isn't RS-68 more of a DOD engine? Nasa's would have been the B version.
It would seem that I sidetracked from the AJAX thread. But I was trying to form an idea. Intel uses something called the Tick-Tock strategy. They are constantly developing new architectures (which are faster at equal speed) and new fabrication technologies (that allow an existing architecture to run faster). But they do two very intelligent things:
1) They have a constant investment flow.
2) The research run 180deg out of phase.
Let's say both development usually take three years. So they have a new architecture in the old fab. 18 months later they apply the same architecture at a better fab. 18 months later they launch a new architecture in that fab. Etc.
In the LV case, I would say that you should develop new engines first, adapt to existing LV. Then design new LV around the new engines. Then develop new engines. Etc.
AJAX would allow to decouple the engine from the LV development. Have an RS-84? swap for the RD-180 and get better performance. Develop a new AVP2? apply to the thrusters. Develop the RS-86? Swap the RS-25. Develop a TANed RS-25? Apply.
You've got the improved AJAX? Develop a new LV with the new engines.
The important thing is that you have single programs that improve an existing architecture. If the program fails, you keep launching the old technology. But the cost of launch won't prevent the development of new technology.
If you had AJAX, an ideal development would be something akin to a TANed RS-86. So you could evolve the EELV into using an RP-1 agumented H2/LOX. Then you could replace both the RS-25 and RD-180 (and may be the J-2X if you had an air started version).
But all depends on having new engines that are a know quantity and fully air qualified and human rated. Else the engines are always the long pole.
Title: Re: AJAX Launcher
Post by: Downix on 03/25/2011 05:42 pm
Isn't RS-68 more of a DOD engine? Nasa's would have been the B version.
It would seem that I sidetracked from the AJAX thread. But I was trying to form an idea. Intel uses something called the Tick-Tock strategy. They are constantly developing new architectures (which are faster at equal speed) and new fabrication technologies (that allow an existing architecture to run faster). But they do two very intelligent things:
1) They have a constant investment flow.
2) The research run 180deg out of phase.
Let's say both development usually take three years. So they have a new architecture in the old fab. 18 months later they apply the same architecture at a better fab. 18 months later they launch a new architecture in that fab. Etc.
In the LV case, I would say that you should develop new engines first, adapt to existing LV. Then design new LV around the new engines. Then develop new engines. Etc.
AJAX would allow to decouple the engine from the LV development. Have an RS-84? swap for the RD-180 and get better performance. Develop a new AVP2? apply to the thrusters. Develop the RS-86? Swap the RS-25. Develop a TANed RS-25? Apply.
You've got the improved AJAX? Develop a new LV with the new engines.
The important thing is that you have single programs that improve an existing architecture. If the program fails, you keep launching the old technology. But the cost of launch won't prevent the development of new technology.
If you had AJAX, an ideal development would be something akin to a TANed RS-86. So you could evolve the EELV into using an RP-1 agumented H2/LOX. Then you could replace both the RS-25 and RD-180 (and may be the J-2X if you had an air started version).
But all depends on having new engines that are a know quantity and fully air qualified and human rated. Else the engines are always the long pole.
You're not far off from the actual AJAX plan.  Remember, part of the plan is to get a system working with the parts we have now, off the shelf, *then* develop improvements.  RS-25e, Domestically produced kerolox engine, ACES upper stage, Phase II CCB's, etc.  We have no J-2X program, however, for our "upper stage" motor *is* the RS-25.  Ground launched to orbit.  Why develop another engine to do the same job?  For EDS, RL-10 or the follow-on engine already being bantered about.
Title: Re: AJAX Launcher
Post by: Robotbeat on 03/25/2011 05:48 pm
What is the AJAX escape performance (if any)?
Title: Re: AJAX Launcher
Post by: Downix on 03/25/2011 06:16 pm
What is the AJAX escape performance (if any)?
It depends on which EDS you use.  Using the 5m DCSS, on a 440, I am getting about 19mT.

*edit* To clarify this vs the other EDS using the same US, this is for a straight release without any other burn, no maneuvering, just a single burn.  The other is for using gravitational tricks and low-energy transfer strategies. 
Title: Re: AJAX Launcher
Post by: baldusi on 03/25/2011 06:45 pm
I've just made the connection that AeroJet made the M-1. And they have the TAM patent. There is an interesting engine development for an HLV. If they are studying a new F1A, I think a TAMed M-1 would be the ultimate HLV engine. A single M-1T should be able to launch an ET.
Which makes a very interesting economic question for AJAX. We've sort of established that AJAX would mean about 15 RD-180 per year (EELV plus NASA), plus some eight RS-25E, plus whatever the US or EDS requires for PWR.
A TAM M-1 would mean two engines per year, from a different manufacturer, plus whatever the US or EDS would require. So the RD-180 should go back to the Russians (or make enough for a long manifest) and PWR would have to support their rocket engines structure with the RL-10.
What price should such an ideal engine have to cost to actually be worth it? In other words, what's the sweet spot between fixed costs and commonality on one hand, and the amount of engines on the other?
Title: Re: AJAX Launcher
Post by: Proponent on 03/25/2011 06:48 pm
TAN (thrust-augmented nozzle), please, not "TAM."
Title: Re: AJAX Launcher
Post by: Lobo on 03/25/2011 09:08 pm
Isn't RS-68 more of a DOD engine? Nasa's would have been the B version.
It would seem that I sidetracked from the AJAX thread. But I was trying to form an idea. Intel uses something called the Tick-Tock strategy. They are constantly developing new architectures (which are faster at equal speed) and new fabrication technologies (that allow an existing architecture to run faster). But they do two very intelligent things:
1) They have a constant investment flow.
2) The research run 180deg out of phase.
Let's say both development usually take three years. So they have a new architecture in the old fab. 18 months later they apply the same architecture at a better fab. 18 months later they launch a new architecture in that fab. Etc.
In the LV case, I would say that you should develop new engines first, adapt to existing LV. Then design new LV around the new engines. Then develop new engines. Etc.
AJAX would allow to decouple the engine from the LV development. Have an RS-84? swap for the RD-180 and get better performance. Develop a new AVP2? apply to the thrusters. Develop the RS-86? Swap the RS-25. Develop a TANed RS-25? Apply.
You've got the improved AJAX? Develop a new LV with the new engines.
The important thing is that you have single programs that improve an existing architecture. If the program fails, you keep launching the old technology. But the cost of launch won't prevent the development of new technology.
If you had AJAX, an ideal development would be something akin to a TANed RS-86. So you could evolve the EELV into using an RP-1 agumented H2/LOX. Then you could replace both the RS-25 and RD-180 (and may be the J-2X if you had an air started version).
But all depends on having new engines that are a know quantity and fully air qualified and human rated. Else the engines are always the long pole.
You're not far off from the actual AJAX plan.  Remember, part of the plan is to get a system working with the parts we have now, off the shelf, *then* develop improvements.  RS-25e, Domestically produced kerolox engine, ACES upper stage, Phase II CCB's, etc.  We have no J-2X program, however, for our "upper stage" motor *is* the RS-25.  Ground launched to orbit.  Why develop another engine to do the same job?  For EDS, RL-10 or the follow-on engine already being bantered about.

Out of curiosity, what do the RS-25 engines run compared to the Atlas CCB's with RD-180 engines.  Could you run 6 or 8 CCB's and drop two RS-25's for medium heavy lift, and save any money?  Or would that cost more?
(Add more RS-25's rather than more CCB's to increase max lift.)

It would probably be more expensive to do that, but I was just curious.
Title: Re: AJAX Launcher
Post by: Lobo on 03/25/2011 09:18 pm
Another question.

And RD-180 is basically the Russian RD-170, but with two combustion chambers instead of 4?  So if ULA were to develop the AVP2, and they put two RD-180 engines on it, would that really be an RD-170?
Obivously I'm no rocket scientist, so I was wondering about the difference between two RD-180's on a single core, vs. a single RD-170.

Can PWR make the RD-170/171 too?  Or are they only licensed to make the RD-180?

The reason for the question is if AVP2 were actually built, and considered an upgrade option for AJAX, would AJAX then be powered by RD-170's?  Which is an F-1 class engine I believe. 
Title: Re: AJAX Launcher
Post by: Downix on 03/25/2011 10:04 pm
Out of curiosity, what do the RS-25 engines run compared to the Atlas CCB's with RD-180 engines.  Could you run 6 or 8 CCB's and drop two RS-25's for medium heavy lift, and save any money?  Or would that cost more?
(Add more RS-25's rather than more CCB's to increase max lift.)

It would probably be more expensive to do that, but I was just curious.
The RS-25's we estimate are going to be less than $50 mil each.  Each CCB is $40 mil each.  So you'd be right, would cost more.
Title: Re: AJAX Launcher
Post by: Downix on 03/25/2011 10:07 pm
Another question.

And RD-180 is basically the Russian RD-170, but with two combustion chambers instead of 4?  So if ULA were to develop the AVP2, and they put two RD-180 engines on it, would that really be an RD-170?
Obivously I'm no rocket scientist, so I was wondering about the difference between two RD-180's on a single core, vs. a single RD-170.

Can PWR make the RD-170/171 too?  Or are they only licensed to make the RD-180?

The reason for the question is if AVP2 were actually built, and considered an upgrade option for AJAX, would AJAX then be powered by RD-170's?  Which is an F-1 class engine I believe. 
So I understand, there are turbopump differences between the two along with control systems and exhaust systems.  I have been told that 60% of the parts on the RD-180 are the same as from the RD-170. 

I do understand that the agreement to enable PWR to make the RD-180 gave license to all RD-170 derivatives, including the RD-171 which is what would be used in this case.  And yes, it is possible that is what would happen.

And the RD-171 is better than the F-1 in almost every category.
Title: Re: AJAX Launcher
Post by: sdsds on 03/25/2011 10:11 pm
Out of curiosity, what do the RS-25 engines run compared to the Atlas CCB's with RD-180 engines.

For RS-25, and probably for any engine, the price you pay depends on the rate at which you are buying them.  Over time, it also depends on the rate at which you are willing to invest in upgraded tooling, etc.

For RS-25D switching to RS-25E, the chart below might show a scenario somewhat close to what's practicable.
Title: Re: AJAX Launcher
Post by: Downix on 03/25/2011 10:13 pm
Out of curiosity, what do the RS-25 engines run compared to the Atlas CCB's with RD-180 engines.

For RS-25, and probably for any engine, the price you pay depends on the rate at which you are buying them.  Over time, it also depends on the rate at which you are willing to invest in upgraded tooling, etc.

For RS-25D switching to RS-25E, the chart below might show a scenario somewhat close to what's practicable.
That's a good chart, mind if I use it? (it's not far off actually)
Title: Re: AJAX Launcher
Post by: sdsds on 03/25/2011 10:22 pm
For RS-25D switching to RS-25E, the chart below might show a scenario somewhat close to what's practicable.
That's a good chart, mind if I use it? (it's not far off actually)

Feel free to use it in any way you see fit.  It is based on information from DIRECT, provided openly in this forum, so I assume it is in no way proprietary.
Title: Re: AJAX Launcher
Post by: Lobo on 03/25/2011 11:29 pm
Chris's new article:

http://www.nasaspaceflight.com/2011/03/sls-studies-focusing-sd-hlv-versus-rp-1-f-1-engines/

Mentions that the RAC-1 team, "The teams is allowed to trade SSME's with RS-68's, while also trading SRB's with LRB's in order to ensure they have the best configuration to battle with the other HLV candidates".

It goes on to mention that J130 and/or 5/5 are the leading favorites from RAC-1.  Did they really look at the LRB option yet?  Are people on that team where AJAX needs to get their proposal in front of? 
What are people's thoughts on that?
Title: Re: AJAX Launcher
Post by: Downix on 03/26/2011 04:25 am
I should make clear, with the discussions about payloads and such, that the numbers being worked with are still in flux as we refine the design, so they will change, for both positive and negative, as we work on it.  I posted the results on a configuration which has already changed since the posting, so don't take them as gospel, just as a guide, alright?  We're trying to optimize this, not for performance, but for political expediency and margin.  Best to err on the side of caution.
Title: Re: AJAX Launcher
Post by: Downix on 03/27/2011 06:01 am
A little something to give an idea for scale, it puts things in perspective.  Saturn, Shuttle, Atlas V Heavy, and AJAX.
Title: Re: AJAX Launcher
Post by: clongton on 03/27/2011 11:35 am
A little something to give an idea for scale, it puts things in perspective.  Saturn, Shuttle, Atlas V Heavy, and AJAX.

Nice!
Title: Re: AJAX Launcher
Post by: FinalFrontier on 03/28/2011 01:41 am
I should make clear, with the discussions about payloads and such, that the numbers being worked with are still in flux as we refine the design, so they will change, for both positive and negative, as we work on it.  I posted the results on a configuration which has already changed since the posting, so don't take them as gospel, just as a guide, alright?  We're trying to optimize this, not for performance, but for political expediency and margin.  Best to err on the side of caution.

Was curious as to the number of main engines and whether we are still using shortened/partial fill ET+full size CCBS. Would like to discuss this and other details via personal messages Downix.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 03/28/2011 01:51 am
Liking the size. The smaller and closer we keep this to block 0 SLS (j130 sized) the happier I will be. Also I am planning to start looking at upper stage options. Currently my favorite is a DIVUS acting as a kick stage and/or a take on this acting as an obrital bus for station missions. Also going to be looking at options like having a stage made by another contractor (example just having Spacex build raptor stage for us, or having them build a custom stage specifically for this vehicle if needed). I am not really looking at large EDS style upper stage options mainly due to expense. Want to keep it small and simple at the moment and only look at options that would have immediate applications. There is a possibility of far more flexibility on these regarding AJAX vs SLS and it would sweeten the deal to have lower cost, more flexible upper stage options.
Title: Re: AJAX Launcher
Post by: clongton on 03/28/2011 01:58 am
I should make clear, with the discussions about payloads and such, that the numbers being worked with are still in flux as we refine the design, so they will change, for both positive and negative, as we work on it.  I posted the results on a configuration which has already changed since the posting, so don't take them as gospel, just as a guide, alright?  We're trying to optimize this, not for performance, but for political expediency and margin.  Best to err on the side of caution.

Was curious as to the number of main engines and whether we are still using shortened/partial fill ET+full size CCBS. Would like to discuss this and other details via personal messages Downix.

The baseline is 4xSSME and 4xCCBs. The ET is shortened by 1 barrel section. CCBs are delivered to KSC "off the shelf" to prevent any problems with the USAF. The minor mods needed for AJAX are performed at the Cape.
Title: Re: AJAX Launcher
Post by: clongton on 03/28/2011 01:59 am
Liking the size. The smaller and closer we keep this to block 0 SLS (j130 sized) the happier I will be. Also I am planning to start looking at upper stage options. Currently my favorite is a DIVUS acting as a kick stage and/or a take on this acting as an obrital bus for station missions. Also going to be looking at options like having a stage made by another contractor (example just having Spacex build raptor stage for us, or having them build a custom stage specifically for this vehicle if needed). I am not really looking at large EDS style upper stage options mainly due to expense. Want to keep it small and simple at the moment and only look at options that would have immediate applications. There is a possibility of far more flexibility on these regarding AJAX vs SLS and it would sweeten the deal to have lower cost, more flexible upper stage options.

Think ACES. The more commonality we can have with the EELV side of the house the better it is for everyone.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 03/28/2011 02:03 am
Understood. And yes ACES was my first thought, the issue is ULA may not go forward with the plan to use ACES on their rockets, that remains to be seen. I guess we could have it made exclusively for AJAX but if we go that route we must consider other options as well (such as the Spacex idea). I need to get in touch with Spacex at some point regarding that but not until the initial AJAX proposal is completed.

Thats probably all from me tonight, need to get to work early tomorrow.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 03/28/2011 02:04 am
I should make clear, with the discussions about payloads and such, that the numbers being worked with are still in flux as we refine the design, so they will change, for both positive and negative, as we work on it.  I posted the results on a configuration which has already changed since the posting, so don't take them as gospel, just as a guide, alright?  We're trying to optimize this, not for performance, but for political expediency and margin.  Best to err on the side of caution.

Was curious as to the number of main engines and whether we are still using shortened/partial fill ET+full size CCBS. Would like to discuss this and other details via personal messages Downix.

The baseline is 4xSSME and 4xCCBs. The ET is shortened by 1 barrel section. CCBs are delivered to KSC "off the shelf" to prevent any problems with the USAF. The minor mods needed for AJAX are performed at the Cape.

That would be the 440-S (for shortened). Or just 440.
Title: Re: AJAX Launcher
Post by: clongton on 03/28/2011 02:05 am
I should make clear, with the discussions about payloads and such, that the numbers being worked with are still in flux as we refine the design, so they will change, for both positive and negative, as we work on it.  I posted the results on a configuration which has already changed since the posting, so don't take them as gospel, just as a guide, alright?  We're trying to optimize this, not for performance, but for political expediency and margin.  Best to err on the side of caution.

Was curious as to the number of main engines and whether we are still using shortened/partial fill ET+full size CCBS. Would like to discuss this and other details via personal messages Downix.

The baseline is 4xSSME and 4xCCBs. The ET is shortened by 1 barrel section. CCBs are delivered to KSC "off the shelf" to prevent any problems with the USAF. The minor mods needed for AJAX are performed at the Cape.

That would be the 440-S (for shortened). Or just 440.

Just 440
Title: Re: AJAX Launcher
Post by: 2552 on 03/28/2011 02:07 am
What about the ULA Common Centaur stage (http://www.ulalaunch.com/site/docs/product_cards/guides/AtlasVUsersGuide2010.pdf) (Ch.8, Future Enhancements)? It should have replaced the current Centaur and DCUS by 2016, and would probably have more in common with a future ACES than DCUS would (pad mods, etc).
Title: Re: AJAX Launcher
Post by: FinalFrontier on 03/28/2011 02:09 am
What about the ULA Common Centaur stage (http://www.ulalaunch.com/site/docs/product_cards/guides/AtlasVUsersGuide2010.pdf) (Ch.8, Future Enhancements)? It should have replaced the current Centaur and DCUS by 2016, and would probably have more in common with a future ACES than DCUS would (pad mods, etc).

That would be my preference, if ULA intends to go forward with it. I really am not sure that ACES will happen at this point, thats the main issue with ACES, IMO. I will look into the CCS.
Title: Re: AJAX Launcher
Post by: Downix on 03/28/2011 03:36 am
The idea is not to have ACES so much as a capable upper stage which is shared with the EELV's.  If the Common Centaur is the final decision, then it is what we will use. 

The key is commonality first and foremost.

If, however, the EDS proposal from NASA is to be persued, I would make certain that it was also available to ULA for their own launchers.  A 7m on top of a 5m core would work by my estimation.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 03/28/2011 04:19 am
The idea is not to have ACES so much as a capable upper stage which is shared with the EELV's.  If the Common Centaur is the final decision, then it is what we will use. 

The key is commonality first and foremost.

If, however, the EDS proposal from NASA is to be persued, I would make certain that it was also available to ULA for their own launchers.  A 7m on top of a 5m core would work by my estimation.

Same, I don't see any outstanding issue with that.
Title: Re: AJAX Launcher
Post by: alexw on 03/28/2011 04:47 am
The idea is not to have ACES so much as a capable upper stage which is shared with the EELV's.  If the Common Centaur is the final decision, then it is what we will use. 
The key is commonality first and foremost.
If, however, the EDS proposal from NASA is to be persued, I would make certain that it was also available to ULA for their own launchers.  A 7m on top of a 5m core would work by my estimation.
Same, I don't see any outstanding issue with that.

    Sure there is. Now you have to throw away the 5m fairing infrastructure and rebuild everything to handle 7m everywhere. You may need a new logistics train, and possibly new transportation methods. (Remember that 3.8m is not quite a random number, nor is ~6m).
 
    You also have to produce the upper stage at a cost comparable to Common Centaur. That seems unlikely, since ULA is designing Common Centaur free of political considerations but to reduce common costs specifically for Atlas and Delta. A $6 billion NASA-led CPS with fancy features irrelevant to ULA's core business is pretty much diametrically opposite.

   -Alex
Title: Re: AJAX Launcher
Post by: Downix on 03/28/2011 05:27 am
Ok, I keep getting requests for a larger version of the simple logo I whipped together.  So spent a few hours cleaning it up, adding a bit, and here we go.  It's just for fun, mind you.  Any criticisms for improving it, let me know.
Title: Re: AJAX Launcher
Post by: baldusi on 03/28/2011 03:57 pm
A little something to give an idea for scale, it puts things in perspective.  Saturn, Shuttle, Atlas V Heavy, and AJAX.
Why did I thought Saturn V, Shuttle, Atlas Phase 2 and Energia?  :D
Title: Re: AJAX Launcher
Post by: Downix on 03/28/2011 04:59 pm
A little something to give an idea for scale, it puts things in perspective.  Saturn, Shuttle, Atlas V Heavy, and AJAX.
Why did I thought Saturn V, Shuttle, Atlas Phase 2 and Energia?  :D
Heh, not quite.  We're taller than Energia, shorter than Energia-II, and AVP2 is actually slightly taller. 

Now I should clarify, that is with the smallest fairing for AJAX.  Under that you can fit a DCSS and Orion, or a Centaur with a payload the same length as the shuttles payload bay.

I'm working on getting my hand drawings of some of the structural ideas into a CAD form, easier to share on here.
Title: Re: AJAX Launcher
Post by: Downix on 03/28/2011 05:15 pm
The idea is not to have ACES so much as a capable upper stage which is shared with the EELV's.  If the Common Centaur is the final decision, then it is what we will use. 
The key is commonality first and foremost.
If, however, the EDS proposal from NASA is to be persued, I would make certain that it was also available to ULA for their own launchers.  A 7m on top of a 5m core would work by my estimation.
Same, I don't see any outstanding issue with that.

    Sure there is. Now you have to throw away the 5m fairing infrastructure and rebuild everything to handle 7m everywhere. You may need a new logistics train, and possibly new transportation methods. (Remember that 3.8m is not quite a random number, nor is ~6m).
 
    You also have to produce the upper stage at a cost comparable to Common Centaur. That seems unlikely, since ULA is designing Common Centaur free of political considerations but to reduce common costs specifically for Atlas and Delta. A $6 billion NASA-led CPS with fancy features irrelevant to ULA's core business is pretty much diametrically opposite.

   -Alex

Assuming of course it is done instead of CC.  I never even suggested that, only that it be made available.  As for the remainder of the issues, you're quite right, and would need to be addressed in that event, which is not my desire in any case.  I'd sooner have ACES or CC on AJAX than anything.
Title: Re: AJAX Launcher
Post by: Lobo on 03/28/2011 05:56 pm
Chris's new article:

http://www.nasaspaceflight.com/2011/03/sls-studies-focusing-sd-hlv-versus-rp-1-f-1-engines/

Mentions that the RAC-1 team, "The teams is allowed to trade SSME's with RS-68's, while also trading SRB's with LRB's in order to ensure they have the best configuration to battle with the other HLV candidates".

It goes on to mention that J130 and/or 5/5 are the leading favorites from RAC-1.  Did they really look at the LRB option yet?  Are people on that team where AJAX needs to get their proposal in front of? 
What are people's thoughts on that?

Again, any idea what this might mean for AJAX?  HAs AJAX just not gotten a good look yet?  Or are the powers that be likely to go one of these other direction, regardless of how many benefits AJAX has?
Title: Re: AJAX Launcher
Post by: 2552 on 03/28/2011 06:11 pm
How would AJAX handle the 5-seg SRB contract? With Block 0 SLS/J-130, it could just be novated it into a 4-seg SRB sustaining contract, right?

Also, how much in terms of pad mods could Common Centaur have with a future large hydrolox EDS, especially if JUS-like (Centaur-derived)?
Title: Re: AJAX Launcher
Post by: Downix on 03/28/2011 06:58 pm
How would AJAX handle the 5-seg SRB contract? With Block 0 SLS/J-130, it could just be novated it into a 4-seg SRB sustaining contract, right?

Also, how much in terms of pad mods could Common Centaur have with a future large hydrolox EDS, especially if JUS-like (Centaur-derived)?
The whole contract is now under attack due to it not being bid on.  From what I understand, it was done in a no-bid manner under the claim that only ATK had the technology able to produce the SRB, which is false as Aerojet also has the capability.  This will tie up the contract with litigation for months, if not years, with the result that neither the 5-seg nor 4-seg may be an option if judicial blocks are put on it.  Under AJAX, the alternate completion of the contract would be enacted, namely closedown with the penalty paid, which would by-pass the whole issue and turn it into a purely monetary issue rather than a potential point of failure for the program.  It also would be cheaper than to actually finish and support the SRB in the interim.  In it's place, a new contract would be bid, with the winner handling the integration of the CCB to the specifications AJAX would require.  ULA may win the contract, but so could Aerojet, Boeing, Lockheed, Andrews etc.  It becomes a core preparation contract, as we'd be COTS'ing the booster.

As for the US, there would be no pad differences, as the manner in which I've been preparing would be to have US maintenance, fueling, etc handled through the core, not directly from the pad.  So, the same pad structure would be used, and the differences would be the mechanism inside of AJAX itself.  This is one of the reasons why a full-sized US is not planned, we will need the room under the Shroud to handle the fueling and control lines.  So, from a pad perspective, there would be no difference, Centaur, ACES, DCSS.  The core is built on a per-launch system anyways, so the US for it is known beforehand, so the appropriate interface can be added during manufacture.
Title: Re: AJAX Launcher
Post by: 2552 on 03/28/2011 07:40 pm
How would AJAX handle the 5-seg SRB contract? With Block 0 SLS/J-130, it could just be novated it into a 4-seg SRB sustaining contract, right?

Also, how much in terms of pad mods could Common Centaur have with a future large hydrolox EDS, especially if JUS-like (Centaur-derived)?
The whole contract is now under attack due to it not being bid on.  From what I understand, it was done in a no-bid manner under the claim that only ATK had the technology able to produce the SRB, which is false as Aerojet also has the capability.  This will tie up the contract with litigation for months, if not years, with the result that neither the 5-seg nor 4-seg may be an option if judicial blocks are put on it.  Under AJAX, the alternate completion of the contract would be enacted, namely closedown with the penalty paid, which would by-pass the whole issue and turn it into a purely monetary issue rather than a potential point of failure for the program.  It also would be cheaper than to actually finish and support the SRB in the interim.  In it's place, a new contract would be bid, with the winner handling the integration of the CCB to the specifications AJAX would require.  ULA may win the contract, but so could Aerojet, Boeing, Lockheed, Andrews etc.  It becomes a core preparation contract, as we'd be COTS'ing the booster.

The technology claim may be false, but the NASA Authorization Act of 2010 sets December 31, 2016 as the goal for availability of the SLS core stage. RAC-1 (http://www.nasaspaceflight.com/2011/03/sls-studies-focusing-sd-hlv-versus-rp-1-f-1-engines/) is now proposing to start with a Block 0 SD-HLV, with 4-seg SRBs, so it can be online by then. Could a claim be made that neither ATK's 5-seg SRB nor Aerojet's ASRM on the core stage could meet the 2016 date? Is it possible NASA could use the ATK 4-seg SRB for Block 0 but be ordered to recompete the booster contract for Block 1?

IANAL, of course.
Title: Re: AJAX Launcher
Post by: yg1968 on 03/28/2011 08:15 pm
How would AJAX handle the 5-seg SRB contract? With Block 0 SLS/J-130, it could just be novated it into a 4-seg SRB sustaining contract, right?

Also, how much in terms of pad mods could Common Centaur have with a future large hydrolox EDS, especially if JUS-like (Centaur-derived)?
The whole contract is now under attack due to it not being bid on.  From what I understand, it was done in a no-bid manner under the claim that only ATK had the technology able to produce the SRB, which is false as Aerojet also has the capability.  This will tie up the contract with litigation for months, if not years, with the result that neither the 5-seg nor 4-seg may be an option if judicial blocks are put on it.  Under AJAX, the alternate completion of the contract would be enacted, namely closedown with the penalty paid, which would by-pass the whole issue and turn it into a purely monetary issue rather than a potential point of failure for the program.  It also would be cheaper than to actually finish and support the SRB in the interim.  In it's place, a new contract would be bid, with the winner handling the integration of the CCB to the specifications AJAX would require.  ULA may win the contract, but so could Aerojet, Boeing, Lockheed, Andrews etc.  It becomes a core preparation contract, as we'd be COTS'ing the booster.

As for the US, there would be no pad differences, as the manner in which I've been preparing would be to have US maintenance, fueling, etc handled through the core, not directly from the pad.  So, the same pad structure would be used, and the differences would be the mechanism inside of AJAX itself.  This is one of the reasons why a full-sized US is not planned, we will need the room under the Shroud to handle the fueling and control lines.  So, from a pad perspective, there would be no difference, Centaur, ACES, DCSS.  The core is built on a per-launch system anyways, so the US for it is known beforehand, so the appropriate interface can be added during manufacture.

It seems a little late to make a protest for a contract that was awarded in 2007. I am guessing that Aerojet's argument is that a novated contract is a new contract and a new bidding should be issued for it. If there is no novation of the contract, I doubt Aerojet has any case to ask for a new bidding process. Although, except for termination liability, there is nothing preventing NASA from rebidding the contract if they believe it to be in their interest to do so.
Title: Re: AJAX Launcher
Post by: Downix on 03/28/2011 08:19 pm
How would AJAX handle the 5-seg SRB contract? With Block 0 SLS/J-130, it could just be novated it into a 4-seg SRB sustaining contract, right?

Also, how much in terms of pad mods could Common Centaur have with a future large hydrolox EDS, especially if JUS-like (Centaur-derived)?
The whole contract is now under attack due to it not being bid on.  From what I understand, it was done in a no-bid manner under the claim that only ATK had the technology able to produce the SRB, which is false as Aerojet also has the capability.  This will tie up the contract with litigation for months, if not years, with the result that neither the 5-seg nor 4-seg may be an option if judicial blocks are put on it.  Under AJAX, the alternate completion of the contract would be enacted, namely closedown with the penalty paid, which would by-pass the whole issue and turn it into a purely monetary issue rather than a potential point of failure for the program.  It also would be cheaper than to actually finish and support the SRB in the interim.  In it's place, a new contract would be bid, with the winner handling the integration of the CCB to the specifications AJAX would require.  ULA may win the contract, but so could Aerojet, Boeing, Lockheed, Andrews etc.  It becomes a core preparation contract, as we'd be COTS'ing the booster.

As for the US, there would be no pad differences, as the manner in which I've been preparing would be to have US maintenance, fueling, etc handled through the core, not directly from the pad.  So, the same pad structure would be used, and the differences would be the mechanism inside of AJAX itself.  This is one of the reasons why a full-sized US is not planned, we will need the room under the Shroud to handle the fueling and control lines.  So, from a pad perspective, there would be no difference, Centaur, ACES, DCSS.  The core is built on a per-launch system anyways, so the US for it is known beforehand, so the appropriate interface can be added during manufacture.

It seems a little late to make a protest for a contract that was awarded in 2007. I am guessing that Aerojet's argument is that a novated contract is a new contract and a new bidding should be issued for it. If there is no novation of the contract, I doubt Aerojet has any case to ask for a new bidding process. Although, except for termination liability, there is nothing preventing NASA from rebidding the contract if they believe it to be in their interest to do so.
The original contract was for a first stage, but now it is for a booster.  That is the angle, so I understand.  In any case, regardless of the merits, it does give an angle for a contract buy-out.  I already calculated out the total required, thanks to ATK's own filings in regards to this, and realized it would be less to buy it out, than to support the cost of it until operation.  And unlike a cancellation, the contract includes the buy-out feature so no grounds for complaint.  It meets the requirements of the Act, as it does fulfill the contract, just not in the way intended.
Title: Re: AJAX Launcher
Post by: yg1968 on 03/28/2011 08:21 pm
Interesting.
Title: Re: AJAX Launcher
Post by: 2552 on 03/28/2011 08:28 pm
The original contract was for a first stage, but now it is for a booster.  That is the angle, so I understand.  In any case, regardless of the merits, it does give an angle for a contract buy-out.  I already calculated out the total required, thanks to ATK's own filings in regards to this, and realized it would be less to buy it out, than to support the cost of it until operation.  And unlike a cancellation, the contract includes the buy-out feature so no grounds for complaint.  It meets the requirements of the Act, as it does fulfill the contract, just not in the way intended.

Wasn't it originally meant to be a booster for Ares V?
Title: Re: AJAX Launcher
Post by: Downix on 03/28/2011 08:32 pm
The original contract was for a first stage, but now it is for a booster.  That is the angle, so I understand.  In any case, regardless of the merits, it does give an angle for a contract buy-out.  I already calculated out the total required, thanks to ATK's own filings in regards to this, and realized it would be less to buy it out, than to support the cost of it until operation.  And unlike a cancellation, the contract includes the buy-out feature so no grounds for complaint.  It meets the requirements of the Act, as it does fulfill the contract, just not in the way intended.

Wasn't it originally meant to be a booster for Ares V?

Nope, the Ares V Booster contract was never actually written nor submitted.  The current ATK contract is based on the Ares I first stage contract.
Title: Re: AJAX Launcher
Post by: yg1968 on 03/28/2011 08:38 pm
The original contract was for a first stage, but now it is for a booster.  That is the angle, so I understand.  In any case, regardless of the merits, it does give an angle for a contract buy-out.  I already calculated out the total required, thanks to ATK's own filings in regards to this, and realized it would be less to buy it out, than to support the cost of it until operation.  And unlike a cancellation, the contract includes the buy-out feature so no grounds for complaint.  It meets the requirements of the Act, as it does fulfill the contract, just not in the way intended.

Wasn't it originally meant to be a booster for Ares V?

Nope, the Ares V Booster contract was never actually written nor submitted.  The current ATK contract is based on the Ares I first stage contract.

I wonder how it would work if the contract was rebidded. Wouldn't ATK have an advantage over Aerojet since the development of their 5 segment booster is already half completed. So their bid for the development of the 5 segment boosters contract would likely be lower than Aerojet, wouldn't it? 
Title: Re: AJAX Launcher
Post by: Downix on 03/28/2011 08:40 pm
The original contract was for a first stage, but now it is for a booster.  That is the angle, so I understand.  In any case, regardless of the merits, it does give an angle for a contract buy-out.  I already calculated out the total required, thanks to ATK's own filings in regards to this, and realized it would be less to buy it out, than to support the cost of it until operation.  And unlike a cancellation, the contract includes the buy-out feature so no grounds for complaint.  It meets the requirements of the Act, as it does fulfill the contract, just not in the way intended.

Wasn't it originally meant to be a booster for Ares V?

Nope, the Ares V Booster contract was never actually written nor submitted.  The current ATK contract is based on the Ares I first stage contract.

I wonder how it would work if it was rebidded. Wouldn't ATK have an advantage over Aerojet since the development of their 5 segment booster is already half completed. So their bid for the development of the 5 segment boosters contract would likely be lower than Aerojet, wouldn't it? 
Beats me.  I just know that it can force a kind of compromise, or loss of access, etc.  I don't even know how much merit Aerojet has for it.  IANAL after all.  Which is why in my proposal it would be to bypass the whole thing entirely through an orderly shutdown of the contract and to then focus on a new contract.
Title: Re: AJAX Launcher
Post by: sdsds on 03/28/2011 11:46 pm
As for the US, there would be no pad differences, as the manner in which I've been preparing would be to have US maintenance, fueling, etc handled through the core, not directly from the pad.  So, the same pad structure would be used, and the differences would be the mechanism inside of AJAX itself.

Wow, that seems super-clever!  Has that approach been taken before for other vehicle designs?  And more importantly, "What would Jim say?"
Title: Re: AJAX Launcher
Post by: Downix on 03/29/2011 12:19 am
As for the US, there would be no pad differences, as the manner in which I've been preparing would be to have US maintenance, fueling, etc handled through the core, not directly from the pad.  So, the same pad structure would be used, and the differences would be the mechanism inside of AJAX itself.

Wow, that seems super-clever!  Has that approach been taken before for other vehicle designs?  And more importantly, "What would Jim say?"
Actually, he inspired it way back when.  His suggestions was to focus all changes on the core, and to utilize any other pieces as/is without modifications.  This was just extrapolating from that.
Title: Re: AJAX Launcher
Post by: Lobo on 03/29/2011 04:28 pm
As for the US, there would be no pad differences, as the manner in which I've been preparing would be to have US maintenance, fueling, etc handled through the core, not directly from the pad.  So, the same pad structure would be used, and the differences would be the mechanism inside of AJAX itself.

Wow, that seems super-clever!  Has that approach been taken before for other vehicle designs?  And more importantly, "What would Jim say?"
Actually, he inspired it way back when.  His suggestions was to focus all changes on the core, and to utilize any other pieces as/is without modifications.  This was just extrapolating from that.

Interesting.  So do you put the fuel hose up to a port on the thrust structure, and then it pumps out into the CCB's?  Same with the LOX?
How much more complex is the plumbing in the core by doing that?
Title: Re: AJAX Launcher
Post by: Downix on 03/29/2011 05:00 pm
As for the US, there would be no pad differences, as the manner in which I've been preparing would be to have US maintenance, fueling, etc handled through the core, not directly from the pad.  So, the same pad structure would be used, and the differences would be the mechanism inside of AJAX itself.

Wow, that seems super-clever!  Has that approach been taken before for other vehicle designs?  And more importantly, "What would Jim say?"
Actually, he inspired it way back when.  His suggestions was to focus all changes on the core, and to utilize any other pieces as/is without modifications.  This was just extrapolating from that.

Interesting.  So do you put the fuel hose up to a port on the thrust structure, and then it pumps out into the CCB's?  Same with the LOX?
How much more complex is the plumbing in the core by doing that?
Only for the upper stage.  The CCB's are fueled from the base, which if you look at the exact fueling point, is facing away from the core.
Title: Re: AJAX Launcher
Post by: spacenut on 03/29/2011 06:39 pm
Downix,
I read somewhere on here about the Delta IV core with 2-RS-25's instead of the RS-68.  This was surrounded by 6 or 8 Atlas V's.  They said this would get 80 tons to LEO and with a proper upper stage would get 130 tons.  Is this being presented by ULA?  Would it conflict with AJAX?  What do you know of the cost difference? 
Title: Re: AJAX Launcher
Post by: Downix on 03/29/2011 07:19 pm
Downix,
I read somewhere on here about the Delta IV core with 2-RS-25's instead of the RS-68.  This was surrounded by 6 or 8 Atlas V's.  They said this would get 80 tons to LEO and with a proper upper stage would get 130 tons.  Is this being presented by ULA?  Would it conflict with AJAX?  What do you know of the cost difference? 
That was something I mentioned on another thread, but it was just an off-handed comment about having run some numbers through Schillings.  (only 1 RS-25 mind you, not 2)  It hit just over 70mt, and with an AIUS upper stage got close to 115mt, just shy of 130 imperial tons.  No idea if anyone would do it, just was me crunching numbers
Title: Re: AJAX Launcher
Post by: spacenut on 03/29/2011 07:46 pm
Just out of curosity, would it do better with an ACES upper stage?  Also, I believe you said AJAX does 130 tons with an ACES?
Title: Re: AJAX Launcher
Post by: Downix on 03/29/2011 07:52 pm
Just out of curosity, would it do better with an ACES upper stage?  Also, I believe you said AJAX does 130 tons with an ACES?
Not really.  For LEO work, the AIUS is better than ACES, but it's less capable once you go beyond just LEO insertion.  AJAX would get more payload with an AIUS for LEO work, but would loose capability for BEO.  I would rather have the BEO capacity, personally.  The way it broke down on the AJAX 48x was:

LEO:
~132mT with AIUS
~130mT with ACES

BEO:
~50mT with AIUS
~80mT with ACES

Not much gain on LEO with AIUS, but a bigger loss on BEO.  Add to that the fact that AIUS would be a unique US, with the overhead issues and higher costs accordingly, ACES is the better fit.
Title: Re: AJAX Launcher
Post by: neilh on 03/30/2011 03:36 am
I'm not sure if anybody's noticed this before, but I was digging through this presentation from Lockheed Martin's 2005 VSE final report:

http://exploration.nasa.gov/documents/reports/cer_final/Lockheed_Martin.pdf

On page 56 of the presentation there's a figure of a "hybrid, Opt 6" 130+ mt vehicle which seems to be an awful lot like AJAX: a shuttle ET core with two Atlas V Phase 2 boosters.

The same figure is on page 39 of the midterm report:

http://exploration.nasa.gov/documents/reports/cer_midterm/Lockheed_Martin.pdf
Title: Re: AJAX Launcher
Post by: Downix on 03/30/2011 04:36 am
I'm not sure if anybody's noticed this before, but I was digging through this presentation from Lockheed Martin's 2005 VSE final report:

http://exploration.nasa.gov/documents/reports/cer_final/Lockheed_Martin.pdf

On page 56 of the presentation there's a figure of a "hybrid, Opt 6" 130+ mt vehicle which seems to be an awful lot like AJAX: a shuttle ET core with two Atlas V Phase 2 boosters.

The same figure is on page 39 of the midterm report:

http://exploration.nasa.gov/documents/reports/cer_midterm/Lockheed_Martin.pdf
Option 7, yes, I am familiar with it.  Found it interesting how it gets mentioned, then vanishes from the details.
Title: Re: AJAX Launcher
Post by: Lobo on 03/30/2011 08:09 pm
I'm not sure if anybody's noticed this before, but I was digging through this presentation from Lockheed Martin's 2005 VSE final report:

http://exploration.nasa.gov/documents/reports/cer_final/Lockheed_Martin.pdf

On page 56 of the presentation there's a figure of a "hybrid, Opt 6" 130+ mt vehicle which seems to be an awful lot like AJAX: a shuttle ET core with two Atlas V Phase 2 boosters.

The same figure is on page 39 of the midterm report:

http://exploration.nasa.gov/documents/reports/cer_midterm/Lockheed_Martin.pdf
Option 7, yes, I am familiar with it.  Found it interesting how it gets mentioned, then vanishes from the details.

Is that Option 7 a Shuttle Core with 4 SSME's and two A5P2 boosters and an upper stage?
That can do 130mt to LEO?
That's about the same thrust as an AJAX 440 with an upper stage? I thought that performance was more like 100mt?
Where do they get the extra 30mt?
Title: Re: AJAX Launcher
Post by: Downix on 03/30/2011 08:38 pm
I'm not sure if anybody's noticed this before, but I was digging through this presentation from Lockheed Martin's 2005 VSE final report:

http://exploration.nasa.gov/documents/reports/cer_final/Lockheed_Martin.pdf

On page 56 of the presentation there's a figure of a "hybrid, Opt 6" 130+ mt vehicle which seems to be an awful lot like AJAX: a shuttle ET core with two Atlas V Phase 2 boosters.

The same figure is on page 39 of the midterm report:

http://exploration.nasa.gov/documents/reports/cer_midterm/Lockheed_Martin.pdf
Option 7, yes, I am familiar with it.  Found it interesting how it gets mentioned, then vanishes from the details.

Is that Option 7 a Shuttle Core with 4 SSME's and two A5P2 boosters and an upper stage?
That can do 130mt to LEO?
That's about the same thrust as an AJAX 440 with an upper stage? I thought that performance was more like 100mt?
Where do they get the extra 30mt?
If you have ESAS LV27 (5/5) upper stage (2x J-2S) on top of it, you'd hit about that by my estimates.
Title: Re: AJAX Launcher
Post by: spacenut on 03/30/2011 09:02 pm
Also, does not the single AV Phase II have less tankage metal than two standard Atlas V's?  The Phase II would therefore have more LEO throw weight? 
Title: Re: AJAX Launcher
Post by: Downix on 03/30/2011 09:12 pm
Also, does not the single AV Phase II have less tankage metal than two standard Atlas V's?  The Phase II would therefore have more LEO throw weight? 
Precisely.  It's tankage metal is actually a bit less than the Zenit booster in my study of the proposal, despite having more actual fuel.  In addition, the SSME core is more deeply throttlable than the RD-0120, enabling more fuel to be available later in flight by throttling down during the boost stage.  Add to that the J-2S upper stage engines are quite good for boosting to LEO, and you get a very good LEO capable rocket.  Of course, going BEO, it falls short.

If AVP2 does arrive, AJAX becomes more capable, for lower total cost.  With 8 P2CCB's, AJAX surpasses Ares V, with one less stage, for far better cost.  But this is long term thinking.  Need to get over the first hurdle, we need a working model.  I think we have most of the work down.  Should be ready to show soon.
Title: Re: AJAX Launcher
Post by: Lobo on 03/30/2011 10:09 pm
Also, does not the single AV Phase II have less tankage metal than two standard Atlas V's?  The Phase II would therefore have more LEO throw weight? 
Precisely.  It's tankage metal is actually a bit less than the Zenit booster in my study of the proposal, despite having more actual fuel.  In addition, the SSME core is more deeply throttlable than the RD-0120, enabling more fuel to be available later in flight by throttling down during the boost stage.  Add to that the J-2S upper stage engines are quite good for boosting to LEO, and you get a very good LEO capable rocket.  Of course, going BEO, it falls short.

If AVP2 does arrive, AJAX becomes more capable, for lower total cost.  With 8 P2CCB's, AJAX surpasses Ares V, with one less stage, for far better cost.  But this is long term thinking.  Need to get over the first hurdle, we need a working model.  I think we have most of the work down.  Should be ready to show soon.

That was going to be my 2nd question.  CAn you attach more than 2 AVP2 CCB's to the AJAX core.  I'd think 4 would be ok, but 6 or eight?  is ther enough room?
And would that require a complete redesign of the core's attachment point, or would they more or less the same as with the 3.8m CCB's?
Title: Re: AJAX Launcher
Post by: Downix on 03/30/2011 10:21 pm
Also, does not the single AV Phase II have less tankage metal than two standard Atlas V's?  The Phase II would therefore have more LEO throw weight? 
Precisely.  It's tankage metal is actually a bit less than the Zenit booster in my study of the proposal, despite having more actual fuel.  In addition, the SSME core is more deeply throttlable than the RD-0120, enabling more fuel to be available later in flight by throttling down during the boost stage.  Add to that the J-2S upper stage engines are quite good for boosting to LEO, and you get a very good LEO capable rocket.  Of course, going BEO, it falls short.

If AVP2 does arrive, AJAX becomes more capable, for lower total cost.  With 8 P2CCB's, AJAX surpasses Ares V, with one less stage, for far better cost.  But this is long term thinking.  Need to get over the first hurdle, we need a working model.  I think we have most of the work down.  Should be ready to show soon.

That was going to be my 2nd question.  CAn you attach more than 2 AVP2 CCB's to the AJAX core.  I'd think 4 would be ok, but 6 or eight?  is ther enough room?
And would that require a complete redesign of the core's attachment point, or would they more or less the same as with the 3.8m CCB's?
The diameter is the same as the Delta's CBC, and we did calculate that you can fit 8 of those around the core, so that should not be an issue.  It would require a slight change in the attachments, but nothing drastic.  They are similar, but studying the P2, they did intend a few changes.
Title: Re: AJAX Launcher
Post by: simonbp on 03/30/2011 10:31 pm
Downix,

I forget, did you run any for CBC-diameter tankage with a single F-1A each? The Isp is lower and the thrust higher than 2x RD-180, so I'm curious how it would compare.
Title: Re: AJAX Launcher
Post by: Downix on 03/31/2011 12:11 am
Downix,

I forget, did you run any for CBC-diameter tankage with a single F-1A each? The Isp is lower and the thrust higher than 2x RD-180, so I'm curious how it would compare.
F-1A:
vac thrust - 9,189.60 kN / isp - 310
SL thrust -  8,003.80 kN / isp - 270

RD-180 x 2:
vac thrust: 8,300.0 kN / isp - 338
SL thrust - 7,660.0 kN / isp - 311

Ok, so, we'd be gaining between 600-350 kN of thrust, but the trade off is loosing 39-28 seconds of isp.  So, a 6% thrust improvement, with a loss of 10% isp, roughly.  This would mean that the CBC would run out of fuel before the benefit of it's added thrust would be effective.

And every engine I've seen in the F-1A's range winds up with the same trade-off.  I honestly feel that the RD-180/RS-84/TR-107 level of kerolox is the sweet spot for performance.
Title: Re: AJAX Launcher
Post by: Lobo on 03/31/2011 04:23 pm
Downix,

I forget, did you run any for CBC-diameter tankage with a single F-1A each? The Isp is lower and the thrust higher than 2x RD-180, so I'm curious how it would compare.
F-1A:
vac thrust - 9,189.60 kN / isp - 310
SL thrust -  8,003.80 kN / isp - 270

RD-180 x 2:
vac thrust: 8,300.0 kN / isp - 338
SL thrust - 7,660.0 kN / isp - 311

Ok, so, we'd be gaining between 600-350 kN of thrust, but the trade off is loosing 39-28 seconds of isp.  So, a 6% thrust improvement, with a loss of 10% isp, roughly.  This would mean that the CBC would run out of fuel before the benefit of it's added thrust would be effective.

And every engine I've seen in the F-1A's range winds up with the same trade-off.  I honestly feel that the RD-180/RS-84/TR-107 level of kerolox is the sweet spot for performance.

Well, if they are looking for a new "F-1", PWR could start building RD-171's.  I'm no expert but from what I've read it's basically just a 4 chamber RD-180, which PWR can build domestically.  Most of the components of the RD-180 and RD-171 are common, so the assembly line could probably make both with mostly the same tooling (correct me if that's in error), so you could have your F-1 class engine, but that would actually have better performance than the F-1 and slightly better (it looks like) than an F-1A, and you can still make the RD-180's for the 3.8m Atlas V's.  Since most of the components are common, if you man-rate one, you basically have man-rated both. 
So rather than remaking the F-1, maybe go that route instead?
Then you can use the RD-171's on the A5P2 cores, which like you said is basically a D4 core.  I could see ULA's desire to start making the A5P2 because then your two main LV's are both common cores, with different fuel tanks and engines.  Then you could maybe shut down the 3.8m tooling, and fly those 10-15mt payloads on single-stick D4, and above that go to the A5P2.  You can basically retire the D4H (as the A5P2 will do about the same) and 3.8m Atlas V.   Add in ACES 5m dia common upperstage on that, and now the two LV systems are more streamlined with more commonality. 

PS:  As an aside, now that ULA is one consortium, is there really any reason to fly both the D4 and the A5?  I mean, they both have about the same performance.  I know originally the military wanted redundancy, right?  But now that Boeing and LM are together, is there really any reason for two?
Title: Re: AJAX Launcher
Post by: sdsds on 03/31/2011 04:53 pm
I honestly feel that the RD-180/RS-84/TR-107 level of kerolox is the sweet spot for performance.

Well, if they are looking for a new "F-1", PWR could start building RD-171's.

The connection to the current AJAX launcher is tenuous, but it is definitely worth exploring this as a domestic engine that enabled an AJAX-2 (with half as many boosters) would be an upgrade path responsive to several criticisms AJAX may face.

NASA has already spent $100M on RS-84 and $20M on TR-107 back when SLI and NGLT were popular acronyms.  IF NASA does want "a new F-1", they will need to solicit bids for the work....
Title: Re: AJAX Launcher
Post by: Lobo on 03/31/2011 05:49 pm
Ok Downix,  I'm going to pick your ginormous brain for awhile.

The thread about the Depot proposal got me thinking, but I think this is the more appropriate thread for this.

Consider the merging of AJAX with ULA's all-EELV lunar exploration proposal.

http://www.ulalaunch.com/site/docs/publications/AffordableExplorationArchitecture2009.pdf

So my thought is with AJAX plus EELV's, you can do away with the LEO depot, and just have the lunar orbit (or an L1 or L2 depot).
Once the reusable lander ascent stage is at the depot, then you'd just need fuel, another descent stage, and Orion with the ACES service module sent up. 
1)  CAn an AJAX-440 put Orion + SM + DS into LEO with enough fuel to get to the lunar depot?  Orion CM is about 8mt (inlcuding crew and cargo), and the empty SM with EECLS is about 7mt, and the DS is about 7mt.  So that's about 22mt dry.  CAn AJAX carry enough additional fuel to get that stack to a depot?

2)  Conversely, you could launch Orion + SM + fuel directly to the Depot on AJAX (SM acting as the EDS).  In which case, how much extra propellant can be delivered to the depot on that launch?
Then you can launch the descent stage (full packed with cargo) on an EELV with enough fuel to get to the depot, with the DS acting as it's own EDS.  Then once it delivers any residual fuel to the depot, it can dock with the ascent stage and await the crew on Orion. 

3)  how much additional propellant would need to be delivered to get the lander to the surface and back, and then Orion home?  How many more EELV tanker launches would be needed above those two launches?

AJAX seems like a good fit for that, since it doesn't need it's own 2nd stage to get to LEO.  SO it can deliver the ACES stages (in the form of a CM or DM) and they can do their own TLI burns.  You get some dual purpose hardware, and aren't thowing away a 2nd stage like you would with like a monolithic RP-1 booster or something. 
Title: Re: AJAX Launcher
Post by: Downix on 03/31/2011 06:17 pm
I honestly feel that the RD-180/RS-84/TR-107 level of kerolox is the sweet spot for performance.

Well, if they are looking for a new "F-1", PWR could start building RD-171's.

The connection to the current AJAX launcher is tenuous, but it is definitely worth exploring this as a domestic engine that enabled an AJAX-2 (with half as many boosters) would be an upgrade path responsive to several criticisms AJAX may face.

NASA has already spent $100M on RS-84 and $20M on TR-107 back when SLI and NGLT were popular acronyms.  IF NASA does want "a new F-1", they will need to solicit bids for the work....
Quite right.  I can easily see PWR pushing RD-170 or some "US branded" form of it.  I can see Aerojet pushing a TAN'd AJ-26-59 (their rebuilt NK-43 with the larger bell), SpaceX with Merlin 2, Northrup with an up-scaled TR-107, lot of options here.  And i, for one, do not care which one would win the bid. 

And that is on the table, the upgrade path.
Title: Re: AJAX Launcher
Post by: clongton on 03/31/2011 06:36 pm
So my thought is with AJAX plus EELV's, you can do away with the LEO depot ...

For the foreseeable future, the United States will be the only country with a HLV capability, in the SLS. Without the LEO depot the rest of the nations are effectively cut out of meaningful BEO exploration. I agree with having depots at EML-1/2, but I disagree with not having them in LEO. Earth - as a whole - will need access to LEO propellant.
Title: Re: AJAX Launcher
Post by: Downix on 03/31/2011 06:42 pm
Ok Downix,  I'm going to pick your ginormous brain for awhile.

The thread about the Depot proposal got me thinking, but I think this is the more appropriate thread for this.

Consider the merging of AJAX with ULA's all-EELV lunar exploration proposal.

http://www.ulalaunch.com/site/docs/publications/AffordableExplorationArchitecture2009.pdf

So my thought is with AJAX plus EELV's, you can do away with the LEO depot, and just have the lunar orbit (or an L1 or L2 depot).
I wouldn't get rid of it in any case.  The LEO depot makes the EML depot far less expensive to implement, and also, if we abandon such an idea we could not partner with international or commercial interests as easily.
Quote
Once the reusable lander ascent stage is at the depot, then you'd just need fuel, another descent stage, and Orion with the ACES service module sent up. 
1)  CAn an AJAX-440 put Orion + SM + DS into LEO with enough fuel to get to the lunar depot?  Orion CM is about 8mt (inlcuding crew and cargo), and the empty SM with EECLS is about 7mt, and the DS is about 7mt.  So that's about 22mt dry.  CAn AJAX carry enough additional fuel to get that stack to a depot?
It should be able to by my calcs, assuming that the SM is ACES derived.
Quote
2)  Conversely, you could launch Orion + SM + fuel directly to the Depot on AJAX (SM acting as the EDS).  In which case, how much extra propellant can be delivered to the depot on that launch?
Then you can launch the descent stage (full packed with cargo) on an EELV with enough fuel to get to the depot, with the DS acting as it's own EDS.  Then once it delivers any residual fuel to the depot, it can dock with the ascent stage and await the crew on Orion. 
A few tons, not that much.  It would burn most of it's own fuel as EDS.  In every scenario I've plotted out, I had it launched with another ACES which serves as EDS, in order to have enough fuel to help with the depot function.
Quote
3)  how much additional propellant would need to be delivered to get the lander to the surface and back, and then Orion home?  How many more EELV tanker launches would be needed above those two launches?
Quite a few.  Moving out of LEO adds a new level of issues and uses more fuel.
Quote
AJAX seems like a good fit for that, since it doesn't need it's own 2nd stage to get to LEO.  SO it can deliver the ACES stages (in the form of a CM or DM) and they can do their own TLI burns.  You get some dual purpose hardware, and aren't thowing away a 2nd stage like you would with like a monolithic RP-1 booster or something. 
Indeed there.
Title: Re: AJAX Launcher
Post by: Lobo on 03/31/2011 07:22 pm
Ok, let me rephrase this.

You wouldn't -need- a LEO depot for lunar missions.   But if you have ACES, and a lunar ACES depot, there's not reason to not have a LEO depot as well for other missions and other LV.  You just wouldn't -need- it for a lunar mission.  you could start doing them before the LEO was up if that was the case.

And you could also do the lunar Mission with 2 AJAX-440 launches.

Launch 1:  Orion + ACES/SM + fuel
Launch 2:  Lander DM + fuel (assume that the AM is reusable and is already there).

If Orion + ACES/SM is about 15mt dry.  And the DM is about 7mt dry (5mt ACES-41 + 2mt of DM mods and cargo per ULA proposal).
So, between those two AJAX-440 launches, you should have enough extra propellent after your TLI burns to get to the surface and back, and get Orion home, right?  I'd assume so, or else something's out of whack.

Or you could do a single AJAX-440 launch, plus supporting EELV prop launches if that's cheaper. 

The lunar depot does more than just act as a fuel station though, that's why it's such a clever idea.  You can pump residual propellant out of the Orion ACES/SM into the depot for low boil-off storage while the crew is on the surface.  The depot provides the station keeping for Orion during the mission.  The depot also gives you a place to park the reusable lander ascent module between missions, where it has station keeping and could also potentially tap off the depot's electrical power to keep standby power between missions.  Then it refuels Orion ACES/SM with just enough prop to get it back to Earth (which really isn't that much as I understand from a high lunar orbit or L point)  So it provides a solution to a few different concerns. 
Title: Re: AJAX Launcher
Post by: Patchouli on 03/31/2011 07:26 pm
I honestly feel that the RD-180/RS-84/TR-107 level of kerolox is the sweet spot for performance.

Well, if they are looking for a new "F-1", PWR could start building RD-171's.

The connection to the current AJAX launcher is tenuous, but it is definitely worth exploring this as a domestic engine that enabled an AJAX-2 (with half as many boosters) would be an upgrade path responsive to several criticisms AJAX may face.

NASA has already spent $100M on RS-84 and $20M on TR-107 back when SLI and NGLT were popular acronyms.  IF NASA does want "a new F-1", they will need to solicit bids for the work....
Quite right.  I can easily see PWR pushing RD-170 or some "US branded" form of it.  I can see Aerojet pushing a TAN'd AJ-26-59 (their rebuilt NK-43 with the larger bell), SpaceX with Merlin 2, Northrup with an up-scaled TR-107, lot of options here.  And i, for one, do not care which one would win the bid. 

And that is on the table, the upgrade path.

Since NASA seems keen on making a modern F1 could the Atlas CCB make use of it?
Though the F1A seems very over powered for the standard Atlas CCB,
But Zenit on the other hand does makes use of a similar sized engine the RD-171.

The higher thrust of the F1 might make an Ajax 240 or 230 configuration possible for LEO missions.
Title: Re: AJAX Launcher
Post by: Downix on 03/31/2011 08:10 pm
I honestly feel that the RD-180/RS-84/TR-107 level of kerolox is the sweet spot for performance.

Well, if they are looking for a new "F-1", PWR could start building RD-171's.

The connection to the current AJAX launcher is tenuous, but it is definitely worth exploring this as a domestic engine that enabled an AJAX-2 (with half as many boosters) would be an upgrade path responsive to several criticisms AJAX may face.

NASA has already spent $100M on RS-84 and $20M on TR-107 back when SLI and NGLT were popular acronyms.  IF NASA does want "a new F-1", they will need to solicit bids for the work....
Quite right.  I can easily see PWR pushing RD-170 or some "US branded" form of it.  I can see Aerojet pushing a TAN'd AJ-26-59 (their rebuilt NK-43 with the larger bell), SpaceX with Merlin 2, Northrup with an up-scaled TR-107, lot of options here.  And i, for one, do not care which one would win the bid. 

And that is on the table, the upgrade path.

Since NASA seems keen on making a modern F1 could the Atlas CCB make use of it?
Though the F1A seems very over powered for the standard Atlas CCB,
But Zenit on the other hand does makes use of a similar sized engine the RD-171.

The higher thrust of the F1 might make an Ajax 240 or 230 configuration possible for LEO missions.
Studying things a bit, I actually found the RD-171 is not the ideal size for Zenit as a standalone rocket.  It's great for Zenit's use as a booster, but if you look at the follow-ons, Taurus II basically uses a Zenit first stage, but with half of the thrust.  Rus-M is also basically a Zenit with an RD-180 instead of the RD-171, with comparable performance. 

Now, if an F-1 or F-1A were put on the CCB for AJAX, yes, it would improve things in some manners, but worsten them in others due to the weak isp.  I would sooner have two RD-180's, an RD-170 or 4 AJ-26, personally, due to the better overall performance.
Title: Re: AJAX Launcher
Post by: baldusi on 03/31/2011 10:44 pm
Now, if an F-1 or F-1A were put on the CCB for AJAX, yes, it would improve things in some manners, but worsten them in others due to the weak isp.  I would sooner have two RD-180's, an RD-170 or 4 AJ-26, personally, due to the better overall performance.
The F-1A had 270 isp (not soooo bad). Merlin 1C is about 275. Do you think no GG RP-1 can get even close to the staged combustion? SpaceX said that the better isp of a staged engine was offset by a worse T/W. But the the AJ-26 kill everybody in T/W and has a nice isp to boot. And a few extra hundred of kilograms on a 500tn first stage can't be that bad.
Title: Re: AJAX Launcher
Post by: Downix on 03/31/2011 11:23 pm
Now, if an F-1 or F-1A were put on the CCB for AJAX, yes, it would improve things in some manners, but worsten them in others due to the weak isp.  I would sooner have two RD-180's, an RD-170 or 4 AJ-26, personally, due to the better overall performance.
The F-1A had 270 isp (not soooo bad). Merlin 1C is about 275. Do you think no GG RP-1 can get even close to the staged combustion? SpaceX said that the better isp of a staged engine was offset by a worse T/W. But the the AJ-26 kill everybody in T/W and has a nice isp to boot. And a few extra hundred of kilograms on a 500tn first stage can't be that bad.
AJ-26 is a staged engine, it was one of the first in fact.  The first production staged combustion engine was either the NK-9 or 11D33, depending on which reports you read.  The AJ-26 is an evolved form from the NK-9.   

Plus, the weight of the engine is not the killer, it is the weight of the fuel, and that is why higher isp is so critical.  The engine weight will typically consist of less than 1/20th of the weight of the rocket, so a gain of 5-10% there is not critical.  But with Fuel being 90% of the total weight, a gain of 5-10% to compensate for lower isp, that could break the design.

If you recall, on historical we discussed ways in which the N-1 could have been made to work.  I pushed that if the 3rd stage had been dropped, and an expanded, hydrolox 2nd stage was used, it would have improved the design far more.  The reasons why were simple, weight saved.  The Hydrolox based design saved hundreds of metric tons in fuel, with the result being that one could remove a full third of the first stage engines without harming liftoff capacity.  It is the fuel weight to focus on.
Title: Re: AJAX Launcher
Post by: KEdward5 on 04/01/2011 12:57 am
Downix, do you have a hi res image of your AJAX logo?
Title: Re: AJAX Launcher
Post by: kirghizstan on 04/01/2011 01:00 am
Downix, do you have a hi res image of your AJAX logo?

is this high res enough for you?

http://forum.nasaspaceflight.com/index.php?topic=22266.msg714664#msg714664
Title: Re: AJAX Launcher
Post by: KEdward5 on 04/01/2011 01:17 am
Thanks, missed that.
Title: Re: AJAX Launcher
Post by: Downix on 04/01/2011 01:19 am
Thanks, missed that.
No worries.  I was going to hope you didn't mean larger than that, as I don't have one at this moment.  (getting an embroidery friend of mine to make me a patch though)
Title: Re: AJAX Launcher
Post by: baldusi on 04/01/2011 11:50 am
Now, if an F-1 or F-1A were put on the CCB for AJAX, yes, it would improve things in some manners, but worsten them in others due to the weak isp.  I would sooner have two RD-180's, an RD-170 or 4 AJ-26, personally, due to the better overall performance.
The F-1A had 270 isp (not soooo bad). Merlin 1C is about 275. Do you think no GG RP-1 can get even close to the staged combustion? SpaceX said that the better isp of a staged engine was offset by a worse T/W. But the the AJ-26 kill everybody in T/W and has a nice isp to boot. And a few extra hundred of kilograms on a 500tn first stage can't be that bad.
AJ-26 is a staged engine, it was one of the first in fact.  The first production staged combustion engine was either the NK-9 or 11D33, depending on which reports you read.  The AJ-26 is an evolved form from the NK-9.   

Plus, the weight of the engine is not the killer, it is the weight of the fuel, and that is why higher isp is so critical.  The engine weight will typically consist of less than 1/20th of the weight of the rocket, so a gain of 5-10% there is not critical.  But with Fuel being 90% of the total weight, a gain of 5-10% to compensate for lower isp, that could break the design.

If you recall, on historical we discussed ways in which the N-1 could have been made to work.  I pushed that if the 3rd stage had been dropped, and an expanded, hydrolox 2nd stage was used, it would have improved the design far more.  The reasons why were simple, weight saved.  The Hydrolox based design saved hundreds of metric tons in fuel, with the result being that one could remove a full third of the first stage engines without harming liftoff capacity.  It is the fuel weight to focus on.
Well, my whole point was that SpaceX's assertion that the T/W issues of a staged combustion engine would offset its isp advantage was bollocks, for the RP-1 case. It's true that Hydrolox usually has far greater isp. But the T/W of the engines is usually lower and the mass fraction higher due to the huge volumetric requirement. My ideal rocket would use only TAN'd (with RP-1) hydrolox, though, so I concur. In any case the discussion was that a full staged RP-1 is very difficult to top for a first stage. So I still think NASA should work on both TR-107 and RS-84.
But I've read a presentation from a Russian from Energomash (I think) where they explore on an RD171 by swapping to methane, and experimenting on different stages (staging either fuel or oxidized). The end result was that you could go full staged since you don't have cocking problems, the density is similar to LOX so you can use a single shaft for the turbopump and they got their best isp outside of H2. If I where Nasa, I would seriously work on a methane full staged engine. Not only has it grat potential, it could solve the Mars return problem with ISRU. Of course it would have to invest in ISRU research, too. Have you seen that presentation?
May be the problem is that the Congress wants to go to Mars without investing on all the technologies necessary to actually make it reasonable. The just want the Huge Shiny Rocket.
Title: Re: AJAX Launcher
Post by: Patchouli on 04/02/2011 06:10 pm
Now, if an F-1 or F-1A were put on the CCB for AJAX, yes, it would improve things in some manners, but worsten them in others due to the weak isp.  I would sooner have two RD-180's, an RD-170 or 4 AJ-26, personally, due to the better overall performance.
The F-1A had 270 isp (not soooo bad). Merlin 1C is about 275. Do you think no GG RP-1 can get even close to the staged combustion? SpaceX said that the better isp of a staged engine was offset by a worse T/W. But the the AJ-26 kill everybody in T/W and has a nice isp to boot. And a few extra hundred of kilograms on a 500tn first stage can't be that bad.
AJ-26 is a staged engine, it was one of the first in fact.  The first production staged combustion engine was either the NK-9 or 11D33, depending on which reports you read.  The AJ-26 is an evolved form from the NK-9.   

Plus, the weight of the engine is not the killer, it is the weight of the fuel, and that is why higher isp is so critical.  The engine weight will typically consist of less than 1/20th of the weight of the rocket, so a gain of 5-10% there is not critical.  But with Fuel being 90% of the total weight, a gain of 5-10% to compensate for lower isp, that could break the design.

If you recall, on historical we discussed ways in which the N-1 could have been made to work.  I pushed that if the 3rd stage had been dropped, and an expanded, hydrolox 2nd stage was used, it would have improved the design far more.  The reasons why were simple, weight saved.  The Hydrolox based design saved hundreds of metric tons in fuel, with the result being that one could remove a full third of the first stage engines without harming liftoff capacity.  It is the fuel weight to focus on.

The 270 ISP  of the F-1A on the booster would not hurt things as the RSRM only has an ISP of 269 vacuum.
 AJAX with F9 cores in place of the Atlas V CCB and supposedly has better performance because F9 has a higher thrust to weight.

F-1A CCBs may have an even higher performance but you would have the cost of an engine production line to deal with.
The LV would have close 9 million lbs of thrust assuming 4 F-1As and 4 SSMEs.

You'd be producing 3 unique engines for AJAX the SSME,F-1A, and the J-2X.
Title: Re: AJAX Launcher
Post by: Downix on 04/02/2011 06:26 pm
Now, if an F-1 or F-1A were put on the CCB for AJAX, yes, it would improve things in some manners, but worsten them in others due to the weak isp.  I would sooner have two RD-180's, an RD-170 or 4 AJ-26, personally, due to the better overall performance.
The F-1A had 270 isp (not soooo bad). Merlin 1C is about 275. Do you think no GG RP-1 can get even close to the staged combustion? SpaceX said that the better isp of a staged engine was offset by a worse T/W. But the the AJ-26 kill everybody in T/W and has a nice isp to boot. And a few extra hundred of kilograms on a 500tn first stage can't be that bad.
AJ-26 is a staged engine, it was one of the first in fact.  The first production staged combustion engine was either the NK-9 or 11D33, depending on which reports you read.  The AJ-26 is an evolved form from the NK-9.   

Plus, the weight of the engine is not the killer, it is the weight of the fuel, and that is why higher isp is so critical.  The engine weight will typically consist of less than 1/20th of the weight of the rocket, so a gain of 5-10% there is not critical.  But with Fuel being 90% of the total weight, a gain of 5-10% to compensate for lower isp, that could break the design.

If you recall, on historical we discussed ways in which the N-1 could have been made to work.  I pushed that if the 3rd stage had been dropped, and an expanded, hydrolox 2nd stage was used, it would have improved the design far more.  The reasons why were simple, weight saved.  The Hydrolox based design saved hundreds of metric tons in fuel, with the result being that one could remove a full third of the first stage engines without harming liftoff capacity.  It is the fuel weight to focus on.

The 270 ISP  of the F-1A on the booster would not hurt things as the RSRM only has an ISP of 269 vacuum.

I seen some numbers of AJAX with F9 cores in place of the Atlas V CCB and supposedly the numbers are even better because F9 has a higher thrust to weight.

F-1A CCBs may have an even higher performance but you would have the cost of an engine production line to deal with.
You'd be producing 3 unique engines for AJAX the SSME,F-1A, and J-2X.

The F-1A may have slightly better isp than the RSRB, but the RSRB has far better thrust.  If we were to develop a new 7m core with two F-1A's on the bottom, then it would surpass the RSRB, but so long as you have the weight of two boosters per one RSRB being replaced, you won't match it's performance. (utilizing Atlas CCB's for weight ratios here)

The F9 information is not public, so can't comment on it's performance with AJAX.  I know that out of the three we did assess (Atlas CCB, Delta CBC, and Taurus II first stage) the Delta had the best T/W performance.  But the program cost made the Atlas V the right booster for the job.  If you have a good source of the F9's information, more than willing to crunch those numbers for comparison.

As for unique engines, where are you getting the J-2X from?  In no scenario do I have the J-2X, it is not the right engine for the job.  The RL-10, however, is.  I found that for TLI, J-2X with a JUS or AIUS/AVUS would actually deliver only a marginal improvement over an RL-10 based ACES, but with almost 4x the cost.  If we could get the RL-60 developed, or when the USAF NGE is introduced, they would outperform the J-2X based designs and have the advantage of commonality, as well.
Title: Re: AJAX Launcher
Post by: baldusi on 04/03/2011 12:25 am
Downix,
  I know the AJ-26 is a pet peeve of you, so I have a question. Couldn't Aerojet use 4 NK-33 chambers and make a bigger turbopump and make a sort of RD-171 but with AJ-26 T/W and ISP?
Title: Re: AJAX Launcher
Post by: Downix on 04/03/2011 12:30 am
Downix,
  I know the AJ-26 is a pet peeve of you, so I have a question. Couldn't Aerojet use 4 NK-33 chambers and make a bigger turbopump and make a sort of RD-171 but with AJ-26 T/W and ISP?
peeve?  Hardly, I like the AJ-26. 

In theory they could, the development would be more difficult than to just cluster 4 engines with separate turbopumps.
Title: Re: AJAX Launcher
Post by: sdsds on 04/03/2011 12:45 am
Couldn't Aerojet use 4 NK-33 chambers and make a bigger turbopump and make a sort of RD-171 but with AJ-26 T/W and ISP?
In theory they could, the development would be more difficult than to just cluster 4 engines with separate turbopumps.

I think that's an understatement, and a bit of discussion is within scope of the AJAX thread.  (N.B.:  Everything below has the caveat, "As I understand it.")

PWR, through RDAMROSS, has a license for the metallurgy needed to domestically produce the combustion chambers and turbopump parts (blades, ducts, etc.) that would let it make RD-171 family engines.  Aerojet has a domestic inventory of NK-33, but no license to the metallurgy techniques used to produce NK-33 parts.

AJAX works because RD-180 could legally be produced domestically.  The NK-33 derived engine you suggest could not be, even if you scavenged combustion chambers from the domestic NK-33 inventory, because the robust ducts and other turbo-machine parts would not be available.

Personally I wish Northrop Grumman would propose something like what you describe based on the TR107 engine component technologies they developed for SLI/NGLT.  It too used an oxygen-rich preburner.
http://www.nasa.gov/centers/marshall/pdf/172380main_tr107.pdf
Title: Re: AJAX Launcher
Post by: Downix on 04/03/2011 01:37 am
Couldn't Aerojet use 4 NK-33 chambers and make a bigger turbopump and make a sort of RD-171 but with AJ-26 T/W and ISP?
In theory they could, the development would be more difficult than to just cluster 4 engines with separate turbopumps.

I think that's an understatement, and a bit of discussion is within scope of the AJAX thread.  (N.B.:  Everything below has the caveat, "As I understand it.")

PWR, through RDAMROSS, has a license for the metallurgy needed to domestically produce the combustion chambers and turbopump parts (blades, ducts, etc.) that would let it make RD-171 family engines.  Aerojet has a domestic inventory of NK-33, but no license to the metallurgy techniques used to produce NK-33 parts.

AJAX works because RD-180 could legally be produced domestically.  The NK-33 derived engine you suggest could not be, even if you scavenged combustion chambers from the domestic NK-33 inventory, because the robust ducts and other turbo-machine parts would not be available.

Personally I wish Northrop Grumman would propose something like what you describe based on the TR107 engine component technologies they developed for SLI/NGLT.  It too used an oxygen-rich preburner.
http://www.nasa.gov/centers/marshall/pdf/172380main_tr107.pdf
Actually, Aerojet does have license to produce NK-33's.    As for the TR-107, I too feel that Northrup has a good design in the TR-107 and I wish SLI had progressed further.
Title: Re: AJAX Launcher
Post by: Zed_Noir on 04/03/2011 02:51 am
Could SpaceX in theory be capable of producing the parts and turbo-pump needed for the sort of RD-171? Since they are making their own turbo-pump for the Merlin-1D.
Title: Re: AJAX Launcher
Post by: Downix on 04/03/2011 02:54 am
Could SpaceX in theory be capable of producing the parts and turbo-pump needed for the sort of RD-171? Since they are making their own turbo-pump for the Merlin-1D.

In theory, a high school metalworking shop class could if they were given the knowledge, tools and materials to do so.
Title: Re: AJAX Launcher
Post by: baldusi on 04/03/2011 03:47 pm
Downix,
  I know the AJ-26 is a pet peeve of you, so I have a question. Couldn't Aerojet use 4 NK-33 chambers and make a bigger turbopump and make a sort of RD-171 but with AJ-26 T/W and ISP?
peeve?  Hardly, I like the AJ-26. 

In theory they could, the development would be more difficult than to just cluster 4 engines with separate turbopumps.
From what I remember from the RD-180 development, they stated that the only significant development was the turbopump. And I thought that the turbopump liked to be big. Besides, a 6.6MN with a SL isp of 297 and a T/W of 150 would be amazing. And people here usually hates to put more than 5 engines on a rocket.
Title: Re: AJAX Launcher
Post by: baldusi on 04/05/2011 06:56 pm
Another question Downix. Does the ECB stage of the Ariane 5 offers any advantage wrt the Common Centaur? It could be a great way to share the cost of missions with another partner.
Title: Re: AJAX Launcher
Post by: Downix on 04/05/2011 07:01 pm
Another question Downix. Does the ECB stage of the Ariane 5 offers any advantage wrt the Common Centaur? It could be a great way to share the cost of missions with another partner.
No advantage, less fuel, less thrust.  It would work, of course, for if AJAX were to be used for an ESA mission or a partner mission.  No real advantage to it other than political, courting the ESA for a mission.  But it would work, just need to make a new adaption system for the core.  I'd not baseline it for the design, but not be against if the ESA were to fund making the necessary components to have it work either.
Title: Re: AJAX Launcher
Post by: baldusi on 04/05/2011 07:23 pm
Actually, I got inspired by Liberty. If there's some piece of equipment around that could already work as an US or EDS. But the only other really powerful hydrolox and restartable engine I've found was the YF-77. I don't see much chance of cooperation there  :-[
Title: Re: AJAX Launcher
Post by: Downix on 04/05/2011 07:57 pm
Actually, I got inspired by Liberty. If there's some piece of equipment around that could already work as an US or EDS. But the only other really powerful hydrolox and restartable engine I've found was the YF-77. I don't see much chance of cooperation there  :-[
The idea is to be able to handle any upper stage practical for the design.  For instance, I could see a Russian mission using a Blok-D.  If the ESA does want a mission, and to use their own US for it, not an issue I can see with the proposal.  A win-win for both sides, really.
Title: Re: AJAX Launcher
Post by: Lobo on 04/06/2011 05:11 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 
Title: Re: AJAX Launcher
Post by: Downix on 04/06/2011 06:26 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 
Now you're thinking like I have for almost a year now.
Title: Re: AJAX Launcher
Post by: clongton on 04/06/2011 07:40 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 
Now you're thinking like I have for almost a year now.

That's 3 of us :)
Title: Re: AJAX Launcher
Post by: FinalFrontier on 04/06/2011 11:13 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 
Now you're thinking like I have for almost a year now.

That's 3 of us :)

4

Also there appears to be some interest. But current issues loom (budget issue, spacex now has hlv plan that could supercede sls or at least will bar consideration, sls study not yet complete)


I can see an easy way in as far as foot in the door. The main issue is who wants to go against atk and who doesn't. Also: who wants the trouble of brining this up again with so many other problems at the moment.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 04/06/2011 11:22 pm
Also any chance someone can get the performance numbers for an AJAX 440+Common Centaur Stage? Of many of the upper stage options I have been looking at, currently CCS or Raptor are the attractive ones. Aces on the table ofc.
Title: Re: AJAX Launcher
Post by: Patchouli on 04/07/2011 01:08 am
Actually, I got inspired by Liberty. If there's some piece of equipment around that could already work as an US or EDS. But the only other really powerful hydrolox and restartable engine I've found was the YF-77. I don't see much chance of cooperation there  :-[

The J-2X pretty much outspecs the YF-77 with a higher ISP and nearly twice the thrust.
 If Spacex builds Raptor it likely would be a more capable engine as well.
Title: Re: AJAX Launcher
Post by: Downix on 04/07/2011 01:23 am
Actually, I got inspired by Liberty. If there's some piece of equipment around that could already work as an US or EDS. But the only other really powerful hydrolox and restartable engine I've found was the YF-77. I don't see much chance of cooperation there  :-[

The J-2X pretty much outspecs the YF-77 with a higher ISP and nearly twice the thrust.
 If Spacex builds Raptor it likely would be a more capable engine as well.
Which is why my focus is on RL-10.  Far better engine for our application.
Title: Re: AJAX Launcher
Post by: Downix on 04/07/2011 01:25 am
Also any chance someone can get the performance numbers for an AJAX 440+Common Centaur Stage? Of many of the upper stage options I have been looking at, currently CCS or Raptor are the attractive ones. Aces on the table ofc.
The plan for using a CC or ACES are only for EDS.  If you use them as an US instead, you'd gain between 10-15mT roughly.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 04/07/2011 07:18 am
Also any chance someone can get the performance numbers for an AJAX 440+Common Centaur Stage? Of many of the upper stage options I have been looking at, currently CCS or Raptor are the attractive ones. Aces on the table ofc.
The plan for using a CC or ACES are only for EDS.  If you use them as an US instead, you'd gain between 10-15mT roughly.

Ty for the info. Any numbers run on  l 1 injection burn using ACES?+460 or something similar? 
Title: Re: AJAX Launcher
Post by: Lobo on 04/07/2011 03:30 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 
Now you're thinking like I have for almost a year now.

That's 3 of us :)

I've seen the light...
Title: Re: AJAX Launcher
Post by: grr on 04/07/2011 04:29 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 

Long before this is ready, SpaceX will be building their Falcon XX (possibly completed). The interesting issue about SpaceX is that they build most everything themselves (and increasingly more of it). As such, they control their costs.

OTH, ULA does not own the engines,  the solid booster, the avionics, etc. They have little control over their costs.

It strikes me that ULA would be better off pushing for a COTS-SHLV for two vehicles. Certainly SpaceX would be a clear winner. But I think that it is a fair bet that the second winner would be ULA. Ideally, ULA would decide to limit the outside companies that they partner with. My guess is just PWR. As such, they could again get control of such a launch system and compete.
Title: Re: AJAX Launcher
Post by: Downix on 04/07/2011 04:38 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 

Long before this is ready, SpaceX will be building their Falcon XX (possibly completed). The interesting issue about SpaceX is that they build most everything themselves (and increasingly more of it). As such, they control their costs.

OTH, ULA does not own the engines,  the solid booster, the avionics, etc. They have little control over their costs.

It strikes me that ULA would be better off pushing for a COTS-SHLV for two vehicles. Certainly SpaceX would be a clear winner. But I think that it is a fair bet that the second winner would be ULA. Ideally, ULA would decide to limit the outside companies that they partner with. My guess is just PWR. As such, they could again get control of such a launch system and compete.
Falcon XX can't be made ready before this is, it requires all new development.  New engines, both main and upper stage, new manufacturing tools, new tank technologies, new launch facility to operate from, everything.  It's a 6-7 year program, compared to a 4-5 year program for AJAX. 

In addition, what you list as an advantage (owning their own engines) I classify as a drawback to SpaceX.  They have production delays, or R&D issues, they get the whole thing delayed.  ULA, however, can pick from any engine vendor they wish.  If the RD-180 is no longer available from Energomash, Northrup, PWR, and Aerojet all are ready and willing to step up.  ULA does have control over it's costs as a result.  The only real issue is US engines, PWR have a virtual lock-in for US made hydrolox upper stage engines, for now.  Aerojet has been discussing an alternative, and TsSKB Progress offers one as well. 

When you have sole source, even if that source is yourself, you find yourself a victim of that sources own issues.  And issues always come up.  I worked for a computer manufacturer for years, and our sole-sourcing bit us in the butt more times than I care to remember.  And some of that was from self-made components.
Title: Re: AJAX Launcher
Post by: Lobo on 04/07/2011 04:45 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 

Long before this is ready, SpaceX will be building their Falcon XX (possibly completed). The interesting issue about SpaceX is that they build most everything themselves (and increasingly more of it). As such, they control their costs.

OTH, ULA does not own the engines,  the solid booster, the avionics, etc. They have little control over their costs.

It strikes me that ULA would be better off pushing for a COTS-SHLV for two vehicles. Certainly SpaceX would be a clear winner. But I think that it is a fair bet that the second winner would be ULA. Ideally, ULA would decide to limit the outside companies that they partner with. My guess is just PWR. As such, they could again get control of such a launch system and compete.

Long before what is ready, FXX will be flying?  Long before AJAX could be ready?

I'm no expert, but I don't think there's a snowball's chance in hell of that.  SpaceX is -barely- flying the F9.  F9H won't fly for another couple years, and it's basically 90% build of existing hardware in the Falcon cores and Merlin 1 engines.  FXX is a -completely- new rocket with -completely- new engines.
AJAX is about 80% existing hardware.  Engines and CCB's are all unchanged.  The Core needs some mods, and a new aft thrust structure needs built.  But that's it.  AJAX could be flying in 4-5 years.  (probably less if it wasn't for the NASA beuracracy). 

I think you'd be lucky to be bending metal or test firing engines for the FXX in 4-5 years....if you started right now.

Now, that -could- be different if NASA simply chose FXX as it's SLS and threw their full weight and money behind it.  And then maybe SpaceX uses MAF to build those big cores as I doubt their facilities could be converted to do that any time soon.  But otherwise, I don't think there's a chance that FXX could fly anytime near AJAX, much less before.
Title: Re: AJAX Launcher
Post by: Downix on 04/07/2011 04:50 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 

Long before this is ready, SpaceX will be building their Falcon XX (possibly completed). The interesting issue about SpaceX is that they build most everything themselves (and increasingly more of it). As such, they control their costs.

OTH, ULA does not own the engines,  the solid booster, the avionics, etc. They have little control over their costs.

It strikes me that ULA would be better off pushing for a COTS-SHLV for two vehicles. Certainly SpaceX would be a clear winner. But I think that it is a fair bet that the second winner would be ULA. Ideally, ULA would decide to limit the outside companies that they partner with. My guess is just PWR. As such, they could again get control of such a launch system and compete.

Long before what is ready, FXX will be flying?  Long before AJAX could be ready?

I'm no expert, but I don't think there's a snowball's chance in hell of that.  SpaceX is -barely- flying the F9.  F9H won't fly for another couple years, and it's basically 90% build of existing hardware in the Falcon cores and Merlin 1 engines.  FXX is a -completely- new rocket with -completely- new engines.
AJAX is about 80% existing hardware.  Engines and CCB's are all unchanged.  The Core needs some mods, and a new aft thrust structure needs built.  But that's it.  AJAX could be flying in 4-5 years.  (probably less if it wasn't for the NASA beuracracy). 

I think you'd be lucky to be bending metal or test firing engines for the FXX in 4-5 years....if you started right now.

Now, that -could- be different if NASA simply chose FXX as it's SLS and threw their full weight and money behind it.  And then maybe SpaceX uses MAF to build those big cores as I doubt their facilities could be converted to do that any time soon.  But otherwise, I don't think there's a chance that FXX could fly anytime near AJAX, much less before.
Personally, I don't like FXX as much as Falcon-X.  Not as scalable.  Sure, if you have a lot of big missions, FXX is great.  But that's not the real world, where you have more smaller missions.  Falcon-X is a good fit for that, and can be clustered to fit the needs of heavy lift.

And even then, it does not scale as well as AJAX does.  Something fits with AJAX.  It changes the dynamic of the launcher, or rather, it changes the way it works just enough to make BEO more affordable.  Yes, it will require work on the long duration upper stages from ULA, but that work is already underway, with several test flights already accomplished and several more planned for various system components.  And once done, we have a far more capable system than SpaceX offers, or is planning to offer.  Even the FXX cannot match AJAX with an ACES for earth departure, and in this program, being able to leave earth orbit means more. 
Title: Re: AJAX Launcher
Post by: grr on 04/07/2011 05:01 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 

Long before this is ready, SpaceX will be building their Falcon XX (possibly completed). The interesting issue about SpaceX is that they build most everything themselves (and increasingly more of it). As such, they control their costs.

OTH, ULA does not own the engines,  the solid booster, the avionics, etc. They have little control over their costs.

It strikes me that ULA would be better off pushing for a COTS-SHLV for two vehicles. Certainly SpaceX would be a clear winner. But I think that it is a fair bet that the second winner would be ULA. Ideally, ULA would decide to limit the outside companies that they partner with. My guess is just PWR. As such, they could again get control of such a launch system and compete.
Falcon XX can't be made ready before this is, it requires all new development.  New engines, both main and upper stage, new manufacturing tools, new tank technologies, new launch facility to operate from, everything.  It's a 6-7 year program, compared to a 4-5 year program for AJAX. 

In addition, what you list as an advantage (owning their own engines) I classify as a drawback to SpaceX.  They have production delays, or R&D issues, they get the whole thing delayed.  ULA, however, can pick from any engine vendor they wish.  If the RD-180 is no longer available from Energomash, Northrup, PWR, and Aerojet all are ready and willing to step up.  ULA does have control over it's costs as a result.  The only real issue is US engines, PWR have a virtual lock-in for US made hydrolox upper stage engines, for now.  Aerojet has been discussing an alternative, and TsSKB Progress offers one as well. 

While there are advantages to picking up parts from around, you lose a number of advantages. The first is that with more and more companies in there, all of them have increasing profits. That makes it hard to lower costs.


When you have sole source, even if that source is yourself, you find yourself a victim of that sources own issues.  And issues always come up.  I worked for a computer manufacturer for years, and our sole-sourcing bit us in the butt more times than I care to remember.  And some of that was from self-made components.

Well, as somebody who was worked at HP, IBM ( and even NASA as well as TLAs), I know exactly what you are referring to. However, what bit HP, IBM and others in the hardware was not the production of hardware, but the money games that were AND CONTINUE to be played by nations with their money. The biggest bites were/are nations that manipulate their money against the dollar, of which the worst today is China. However, many nations are doing that. Sadly, it continues to this day.
About the only other one is patent issues.


BTW, I agree with your later post about FX vs. FXX. I actually meant to put FX, but ....
Title: Re: AJAX Launcher
Post by: Downix on 04/07/2011 05:10 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 

Long before this is ready, SpaceX will be building their Falcon XX (possibly completed). The interesting issue about SpaceX is that they build most everything themselves (and increasingly more of it). As such, they control their costs.

OTH, ULA does not own the engines,  the solid booster, the avionics, etc. They have little control over their costs.

It strikes me that ULA would be better off pushing for a COTS-SHLV for two vehicles. Certainly SpaceX would be a clear winner. But I think that it is a fair bet that the second winner would be ULA. Ideally, ULA would decide to limit the outside companies that they partner with. My guess is just PWR. As such, they could again get control of such a launch system and compete.
Falcon XX can't be made ready before this is, it requires all new development.  New engines, both main and upper stage, new manufacturing tools, new tank technologies, new launch facility to operate from, everything.  It's a 6-7 year program, compared to a 4-5 year program for AJAX. 

In addition, what you list as an advantage (owning their own engines) I classify as a drawback to SpaceX.  They have production delays, or R&D issues, they get the whole thing delayed.  ULA, however, can pick from any engine vendor they wish.  If the RD-180 is no longer available from Energomash, Northrup, PWR, and Aerojet all are ready and willing to step up.  ULA does have control over it's costs as a result.  The only real issue is US engines, PWR have a virtual lock-in for US made hydrolox upper stage engines, for now.  Aerojet has been discussing an alternative, and TsSKB Progress offers one as well. 

While there are advantages to picking up parts from around, you lose a number of advantages. The first is that with more and more companies in there, all of them have increasing profits. That makes it hard to lower costs.
Quite true, but lots of companies is not an issue in aerospace.  I only hope one day that is an issue.  We have six rocket engine manufacturers in the US.  Of those, three offer engines in the thrust range needed for AJAX's boosters, four offer the capacity to build the engines needed for AJAX's core. Remember, the SSME is technically US property, even if PWR builds them under contract.  The US can assign another company to manufacture it, and Aerojet, Northrup and Boeing all have the capacity to do so.  This means it is easier to lower cost through a COTS style contract.
Quote


When you have sole source, even if that source is yourself, you find yourself a victim of that sources own issues.  And issues always come up.  I worked for a computer manufacturer for years, and our sole-sourcing bit us in the butt more times than I care to remember.  And some of that was from self-made components.

Well, as somebody who was worked at HP, IBM ( and even NASA as well as TLAs), I know exactly what you are referring to. However, what bit HP, IBM and others in the hardware was not the production of hardware, but the money games that were AND CONTINUE to be played by nations with their money. The biggest bites were/are nations that manipulate their money against the dollar, of which the worst today is China. However, many nations are doing that. Sadly, it continues to this day.
About the only other one is patent issues.


BTW, I agree with your later post about FX vs. FXX. I actually meant to put FX, but ....
It happens.  And hey, former competitor! (I worked for Dell)
Title: Re: AJAX Launcher
Post by: grr on 04/07/2011 05:39 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 

Long before this is ready, SpaceX will be building their Falcon XX (possibly completed). The interesting issue about SpaceX is that they build most everything themselves (and increasingly more of it). As such, they control their costs.

OTH, ULA does not own the engines,  the solid booster, the avionics, etc. They have little control over their costs.

It strikes me that ULA would be better off pushing for a COTS-SHLV for two vehicles. Certainly SpaceX would be a clear winner. But I think that it is a fair bet that the second winner would be ULA. Ideally, ULA would decide to limit the outside companies that they partner with. My guess is just PWR. As such, they could again get control of such a launch system and compete.
Falcon XX can't be made ready before this is, it requires all new development.  New engines, both main and upper stage, new manufacturing tools, new tank technologies, new launch facility to operate from, everything.  It's a 6-7 year program, compared to a 4-5 year program for AJAX. 

In addition, what you list as an advantage (owning their own engines) I classify as a drawback to SpaceX.  They have production delays, or R&D issues, they get the whole thing delayed.  ULA, however, can pick from any engine vendor they wish.  If the RD-180 is no longer available from Energomash, Northrup, PWR, and Aerojet all are ready and willing to step up.  ULA does have control over it's costs as a result.  The only real issue is US engines, PWR have a virtual lock-in for US made hydrolox upper stage engines, for now.  Aerojet has been discussing an alternative, and TsSKB Progress offers one as well. 
...

One last thought about the short time frame that you list on this:
Constellation and Direct (Otherwise known as SLS).

Both are shuttle derived and require building new frame, pad, and slightly modified engines. Yet, the frame existed already in the ET. The pad needed some changes. And the engines were being enhanced.  How long did it take ? Even with things in about the same shape as atlas/srbs today, after 6 years, they still had 2-4 years to go.
I do no believe that starting with different systems and trying to merge them into a new system  is that easy. As as software engineer, I saw that over and over the difficulty involved. Now, we are talking about one of the largest most complex systems on this planet (today's rockets, along with nuke power plants, are the most complex systems built by man), merging in different companies with different philosophies, and each trying to get a bigger piece of the pie, well, it is bound to go a lot slower than most will think.
What SpaceX has is the advantage of having a group of ppl that have worked together and know each other. In addition, they are driven by competing against other companies.

ULA needs that. Heck, if a COTS-SHLV was started, then ULA COULD submit AJAX as their idea. I seriously doubt that they would do that. I think that they would partner with PWR and do a brand new rocket and it would like far more like Falcon than it would the shuttle.
If nothing else, super computers in the CS world should show you that. We used to do single large CPUs. Parallelism took hold and now, all of the top computers are pretty much parallel CPUs working together under Linux.
Title: Re: AJAX Launcher
Post by: Downix on 04/07/2011 05:51 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 

Long before this is ready, SpaceX will be building their Falcon XX (possibly completed). The interesting issue about SpaceX is that they build most everything themselves (and increasingly more of it). As such, they control their costs.

OTH, ULA does not own the engines,  the solid booster, the avionics, etc. They have little control over their costs.

It strikes me that ULA would be better off pushing for a COTS-SHLV for two vehicles. Certainly SpaceX would be a clear winner. But I think that it is a fair bet that the second winner would be ULA. Ideally, ULA would decide to limit the outside companies that they partner with. My guess is just PWR. As such, they could again get control of such a launch system and compete.
Falcon XX can't be made ready before this is, it requires all new development.  New engines, both main and upper stage, new manufacturing tools, new tank technologies, new launch facility to operate from, everything.  It's a 6-7 year program, compared to a 4-5 year program for AJAX. 

In addition, what you list as an advantage (owning their own engines) I classify as a drawback to SpaceX.  They have production delays, or R&D issues, they get the whole thing delayed.  ULA, however, can pick from any engine vendor they wish.  If the RD-180 is no longer available from Energomash, Northrup, PWR, and Aerojet all are ready and willing to step up.  ULA does have control over it's costs as a result.  The only real issue is US engines, PWR have a virtual lock-in for US made hydrolox upper stage engines, for now.  Aerojet has been discussing an alternative, and TsSKB Progress offers one as well. 
...

One last thought about the short time frame that you list on this:
Constellation and Direct (Otherwise known as SLS).

Both are shuttle derived and require building new frame, pad, and slightly modified engines. Yet, the frame existed already in the ET. The pad needed some changes. And the engines were being enhanced.  How long did it take ? Even with things in about the same shape as atlas/srbs today, after 6 years, they still had 2-4 years to go.
I do no believe that starting with different systems and trying to merge them into a new system  is that easy. As as software engineer, I saw that over and over the difficulty involved. Now, we are talking about one of the largest most complex systems on this planet (today's rockets, along with nuke power plants, are the most complex systems built by man), merging in different companies with different philosophies, and each trying to get a bigger piece of the pie, well, it is bound to go a lot slower than most will think.
What SpaceX has is the advantage of having a group of ppl that have worked together and know each other. In addition, they are driven by competing against other companies.
Try 15 years to go.  There was nothing Shuttle Derived left in Ares.  The new SRB shared casings with the Shuttle for test firings, but that was about it with them needing new, lighter weight casings for the final version.  Two new upper stage engines, not a modification of a currently existing design. (Ares I and V needed different versions of the J-2X)  They scrapped plans to use the ET and were designing a new core framework, 10m wide.  The ground engines for Ares V were virtually to be all-new, sharing only a few systems with the existing RD-68.  Ares I was at least 6-8 years from liftoff, and even then it failed to meet it's performance goals of 30mT.  It was looking to hit 16-18mT.  And then, what?  Ares I was worthless without Ares V, married at the hip.  There was nothing Shuttle left in Ares beyond the orange foam.
Quote

ULA needs that. Heck, if a COTS-SHLV was started, then ULA COULD submit AJAX as their idea. I seriously doubt that they would do that. I think that they would partner with PWR and do a brand new rocket and it would like far more like Falcon than it would the shuttle.
If nothing else, super computers in the CS world should show you that. We used to do single large CPUs. Parallelism took hold and now, all of the top computers are pretty much parallel CPUs working together under Linux.
AJAX is parallel, however, unlike the monolithic Falcon-XX or Ares concepts.  Look at it for a moment.  AJAX is, at it's heart, a parallel staged high-energy core, utilizing ULA's CCB's as first stage.  It scales, to enable differing options.  What it does it enable our existing assets to be better utilized.  It's an option, not a solution, a tool in the chest, not the only tool in the store.  The issue I see with many Shuttle Derived ideas is that their focus is on the rocket, not in what the rocket is there to do.  AJAX focuses on what it is to do, and worked from a minimal approach to get to that.  Falcon, as nice as it is, cannot do that.  Their Heavy design locked them into a profile for years to come which eliminates the potential to take advantage of AJAX's capability.
Title: Re: AJAX Launcher
Post by: Lobo on 04/07/2011 06:00 pm
Personally, I don't like FXX as much as Falcon-X.  Not as scalable.  Sure, if you have a lot of big missions, FXX is great.  But that's not the real world, where you have more smaller missions.  Falcon-X is a good fit for that, and can be clustered to fit the needs of heavy lift.

And even then, it does not scale as well as AJAX does.  Something fits with AJAX.  It changes the dynamic of the launcher, or rather, it changes the way it works just enough to make BEO more affordable.  Yes, it will require work on the long duration upper stages from ULA, but that work is already underway, with several test flights already accomplished and several more planned for various system components.  And once done, we have a far more capable system than SpaceX offers, or is planning to offer.  Even the FXX cannot match AJAX with an ACES for earth departure, and in this program, being able to leave earth orbit means more. 

Me too.  (and apparently so does grr, as he later clarified).

I think the FXX is a little more for a concept of, "Hey, if you really want a monolithic big rocket, we can do that too...here it is and here's about what it could lift".

But I think SpaceX growing to FX is where the real action is/would be.  Between the F9 and FX cores, you are only bilding two core sizes.  (currently they are building 2 core sizes, F1 and F9.  F1 would probably be retired).  FX would really make F9H redundant, although it still might have a role as a heavy crew launcher with all of it's redundancy and engine out capability.  But F9's can still launch the lighter payloads, and LEO Dragons, and FX gives you scalability of medium-heavy, to heavy, to super heavy if you do a 5-core FX Super Heavy like ULA proposed with Atlas V PH3a.  Ed Kyle's paper, "Space LAunch Report" puts FX at 32t to LEO, and FXH at 125t to LEO.  This same report has the F9H at 34t to LEO, so perhaps the FXH could do more than 125t (although, since 125t is about 4X FX, it might already assume crossfeed, so 125t would be it's limit).
So, roughly, a 5-core FXSH should do around 200mt to LEO!  Couple that with a high performanc hydrolox US and you are really cooking with gas!
That's significantly more than FXX, and the really nice thing, is all of the times you don't need something that heavy, you are still flying the one and 3 core configurations. 
In fact, upon looking at Ed Kyle's numbers, the main difference between the FXH and FXX in lifting capacity, is that the FXH shoes the Merlin 2's at 1.2Mlb thrust, and the FXX shows the Merlin 2's at 1.7Mlb thrust.  So if the FXH has 1.7Mlb Merlin 2's and crossfeed, be intereting to know how much that could loft.  Might be as much as FXX.  (although maybe it'd burn the fuel out a little too quick that way.)

So, with FX, you can almost get where the FXX gets you with just the FXH 3-core variant.  If you do a 5-core variant, you could do far more.   PRobably far more than we'd ever have a payload for prior to a manned mars mission.  And it's all using the same cores and engines. 

So yea, lots of flexibility and "growth" ability there.

To be honest, I'm starting to lean towards that as a better option than either Jupiter or AJAX (sorry Downix).  Now, if it's a political possibility is another matter entirely, as you'd basically be slashing a very large number of existing NASA personnel with the end of anything Shuttle or Shuttle Derived, and cancelling that ATK contract without even the weight of ULA supporting you.  Not sure how much ULA would fight NASA though, because they don't seem to be lobbying very hard for something akin to AJAX...which surprises me.

Going with SpaceX and an all-commerccial build rocket gives the ability to "grow" into the payloads.  Sounds like either Jupiter or AJAX might not have that many payloads for awhile.  FX is still a new rocket with a new engine, and likely wouldn't be flying until after Jupiter or AJAX would.  However, in the mean time you'd have F9H that could launch Orion.  First for unmanned tests.  Then crewed tests (as Musk said it should basically be man-rated out of the box), then crewed missions to the ISS with Orion and 25mt of cargo.  Possibly a lunar flyby.  There'd probably be a desire to do that early on to give Orion something to do until there's some hardware build to go back to the Moon, or a NEO.   

By the time you have payloads that need more than 53mt, you would have FX and FXH. 
Title: Re: AJAX Launcher
Post by: Downix on 04/07/2011 06:34 pm
Personally, I don't like FXX as much as Falcon-X.  Not as scalable.  Sure, if you have a lot of big missions, FXX is great.  But that's not the real world, where you have more smaller missions.  Falcon-X is a good fit for that, and can be clustered to fit the needs of heavy lift.

And even then, it does not scale as well as AJAX does.  Something fits with AJAX.  It changes the dynamic of the launcher, or rather, it changes the way it works just enough to make BEO more affordable.  Yes, it will require work on the long duration upper stages from ULA, but that work is already underway, with several test flights already accomplished and several more planned for various system components.  And once done, we have a far more capable system than SpaceX offers, or is planning to offer.  Even the FXX cannot match AJAX with an ACES for earth departure, and in this program, being able to leave earth orbit means more. 

Me too.  (and apparently so does grr, as he later clarified).

I think the FXX is a little more for a concept of, "Hey, if you really want a monolithic big rocket, we can do that too...here it is and here's about what it could lift".

But I think SpaceX growing to FX is where the real action is/would be.  Between the F9 and FX cores, you are only bilding two core sizes.  (currently they are building 2 core sizes, F1 and F9.  F1 would probably be retired).  FX would really make F9H redundant, although it still might have a role as a heavy crew launcher with all of it's redundancy and engine out capability.  But F9's can still launch the lighter payloads, and LEO Dragons, and FX gives you scalability of medium-heavy, to heavy, to super heavy if you do a 5-core FX Super Heavy like ULA proposed with Atlas V PH3a.  Ed Kyle's paper, "Space LAunch Report" puts FX at 32t to LEO, and FXH at 125t to LEO.  This same report has the F9H at 34t to LEO, so perhaps the FXH could do more than 125t (although, since 125t is about 4X FX, it might already assume crossfeed, so 125t would be it's limit).
So, roughly, a 5-core FXSH should do around 200mt to LEO!  Couple that with a high performanc hydrolox US and you are really cooking with gas!
That's significantly more than FXX, and the really nice thing, is all of the times you don't need something that heavy, you are still flying the one and 3 core configurations. 
In fact, upon looking at Ed Kyle's numbers, the main difference between the FXH and FXX in lifting capacity, is that the FXH shoes the Merlin 2's at 1.2Mlb thrust, and the FXX shows the Merlin 2's at 1.7Mlb thrust.  So if the FXH has 1.7Mlb Merlin 2's and crossfeed, be intereting to know how much that could loft.  Might be as much as FXX.  (although maybe it'd burn the fuel out a little too quick that way.)

So, with FX, you can almost get where the FXX gets you with just the FXH 3-core variant.  If you do a 5-core variant, you could do far more.   PRobably far more than we'd ever have a payload for prior to a manned mars mission.  And it's all using the same cores and engines. 

So yea, lots of flexibility and "growth" ability there.

To be honest, I'm starting to lean towards that as a better option than either Jupiter or AJAX (sorry Downix).  Now, if it's a political possibility is another matter entirely, as you'd basically be slashing a very large number of existing NASA personnel with the end of anything Shuttle or Shuttle Derived, and cancelling that ATK contract without even the weight of ULA supporting you.  Not sure how much ULA would fight NASA though, because they don't seem to be lobbying very hard for something akin to AJAX...which surprises me.

Going with SpaceX and an all-commerccial build rocket gives the ability to "grow" into the payloads.  Sounds like either Jupiter or AJAX might not have that many payloads for awhile.  FX is still a new rocket with a new engine, and likely wouldn't be flying until after Jupiter or AJAX would.  However, in the mean time you'd have F9H that could launch Orion.  First for unmanned tests.  Then crewed tests (as Musk said it should basically be man-rated out of the box), then crewed missions to the ISS with Orion and 25mt of cargo.  Possibly a lunar flyby.  There'd probably be a desire to do that early on to give Orion something to do until there's some hardware build to go back to the Moon, or a NEO.   

By the time you have payloads that need more than 53mt, you would have FX and FXH. 
*if* we had time, I may agree with you.  However, then we hit the same issue of single-sourcing.  I always kept in mind, SpaceX was developing something along these lines (although they went further than I thought they would).  As a result, it becomes an ideal fallback should things happen.  Whenever the Shuttle had an issue, it grounded the fleet.  No redundancy, delaying operations.  I would never want to be in that boat again.  So, to me, SpaceX becomes that redundancy.
Title: Re: AJAX Launcher
Post by: Lobo on 04/07/2011 06:52 pm
*if* we had time, I may agree with you.  However, then we hit the same issue of single-sourcing.  I always kept in mind, SpaceX was developing something along these lines (although they went further than I thought they would).  As a result, it becomes an ideal fallback should things happen.  Whenever the Shuttle had an issue, it grounded the fleet.  No redundancy, delaying operations.  I would never want to be in that boat again.  So, to me, SpaceX becomes that redundancy.

Fair enough.  Although you could go with SpaceX as your primary, and then seed ULA to develop Atlas PH2 as you backup.  Once they have Atlas PH2, that's the equivalent of a FX.  1, 3, and 5 core versions as necessary.  In fact, part of the "seed" money could be investment for them to develop ACES and get it flying, and use ACES for Orion SM, Lunar lander DM, depots, and EDS's. 
You'd be then using both SpaceX and ULA.  I'm sure ULA would like to build an Atlas PH2 as it then makes no need to every build an A5H, and probably means they can retire the D4H. 
SpaceX gets the contract for the LV's, ULA gets the contract for the upperstages which would fly on the F9H and FX's, and with a little kicker to build A5PH2 as backup. 
Then you are supporting two separate companies, each would be able to take over fully if required.
Title: Re: AJAX Launcher
Post by: Downix on 04/07/2011 07:04 pm
*if* we had time, I may agree with you.  However, then we hit the same issue of single-sourcing.  I always kept in mind, SpaceX was developing something along these lines (although they went further than I thought they would).  As a result, it becomes an ideal fallback should things happen.  Whenever the Shuttle had an issue, it grounded the fleet.  No redundancy, delaying operations.  I would never want to be in that boat again.  So, to me, SpaceX becomes that redundancy.

Fair enough.  Although you could go with SpaceX as your primary, and then seed ULA to develop Atlas PH2 as you backup.  Once they have Atlas PH2, that's the equivalent of a FX.  1, 3, and 5 core versions as necessary.  In fact, part of the "seed" money could be investment for them to develop ACES and get it flying, and use ACES for Orion SM, Lunar lander DM, depots, and EDS's. 
You'd be then using both SpaceX and ULA.  I'm sure ULA would like to build an Atlas PH2 as it then makes no need to every build an A5H, and probably means they can retire the D4H. 
SpaceX gets the contract for the LV's, ULA gets the contract for the upperstages which would fly on the F9H and FX's, and with a little kicker to build A5PH2 as backup. 
Then you are supporting two separate companies, each would be able to take over fully if required.
But more time to develop, more money to do so.  You'd need to develop both a first and second stage, rather than repurposing an existing first stage into a core, and using existing components.  The refurbishment costs to LC-39 would remain, the support costs remain, but you'd now have long-poles in development, many more than otherwise.

Think on it, the alternative being suggested is to design a new first stage, new second stage, new engines. 

That is too many potential shortfalls, too many potential traps.  That is what doomed Constellation, too many long poles.  AJAX eliminates that, with just 1 new element, a modified ET.  Even SpaceX is not offering that, Falcon 9 Heavy is a new center stage, new booster stages, and noone knows about the upper stage as of yet.  Also involves new engines as well don't forget. 
Title: Re: AJAX Launcher
Post by: grr on 04/07/2011 07:11 pm
....
*if* we had time, I may agree with you.  However, then we hit the same issue of single-sourcing.  I always kept in mind, SpaceX was developing something along these lines (although they went further than I thought they would).  As a result, it becomes an ideal fallback should things happen.  Whenever the Shuttle had an issue, it grounded the fleet.  No redundancy, delaying operations.  I would never want to be in that boat again.  So, to me, SpaceX becomes that redundancy.

Actually, that is why I like the idea of a COTS-SHLV with 2 SHLVs.
It would be interesting to see if ULA elects to submit something like this, or build new.

It is better to have 2 systems of similar size, BUT, with private space orders. The truth is, that had Bill Gates done what he promised, then EELVs would be dirt cheap. Boeing/L-Mart counted on that. Sadly, he did not materialize his word. Likewise, the issue with having 1 SHLV, let alone 2, absolutely requires that they have plenty of none gov. contracts. Now, I realize that many on this site (such as jim) do not believe that businesses should be helped along. And yet, oddly, NASA is responsible for building silicon valley. Likewise, NASA and DOD are responsible for the one time large aerospace companies that we had. And of course, COTS is a clear winner. There is little doubt in my mind that we are back on the edge of that same precipice if we help out Bigelow and IDC.  Again, we need BOTH of these businesses and not just one. Once you have multiple stations, with multiple businesses, well, they will want to go to the moon for new businesses.

Regardless, this is all off-topic again, and I am sorry. Please go back to Ajax. It is useful to see different approaches and ideas. More importantly, I am sure that others find AJAX useful as well.
Title: Re: AJAX Launcher
Post by: clongton on 04/07/2011 07:27 pm
WRT FX and FXX everyone seems to be forgetting that neither one exists, and likely won't for a good decade or longer. Hell, FH was just announced and even that doesn't exist yet. Granted it's a lot closer to reality but believe me when I say that SpaceX is going to be flying F9/FH for a very long time. If F9/FH will do the bulk of the stuff that needs doing SpaceX isn't going to spend the money when the HLV market isn't even matured yet. Truth be told the HLV market that Elon is banking on doesn't even exist yet. It will, but not for a while. Payloads that big take time, lots of time, to design, fund and build. Elon would do well to pull in the latches and tread water for a few years with the F9/FH and see where the market goes. Unless I miss my guess he will see that the F9/FH will keep him in a profitable business for a very long time by itself. I don't think he'll see a need for the FX or the FXX.

That being said I want to make something clear. I am a big amazing people for Heavy Lift - a huge amazing people. That does not mean however that I am a amazing people for a Heavy Lift Rocket, like the Saturn-V or the Ares-V. That may sound a little strange coming from the co-founder of DIRECT but look at it this way. DIRECT was designed to execute the ESAS mission with a SDHLV *as directed by law*. We set out to execute that Congressional mandate in the most efficient manner possible, *within the bounds of the law*. The Jupiter-246 did that BEAUTIFULLY! The Jupiter is a beautiful HLV and I couldn't be prouder of what we accomplished, but it is certainly not the optimum solution to heavy lift. Why? Because the Jupiter HLV does 2 things sub optimally: (1) it still uses SRB's, which really stinks, figuratively and literally, and (2) it is hard to make really good use of it EXCEPT in its heavy configuration. It shared the same fundamental flaw as the Ares-V, namely that it is essentially a one-trick pony that will be expensive to operate because of a low flight rate. Granted, the J-130, which is afaik still the front runner in the SLS RAC-1 study, is a little easier on this, but it still uses SRB's, which I hate, and there isn't a ton of use for the 70-80 tons it will put into LEO. Oh, to be sure, it will fly, but not at a flight rate that will keep the cost per launch down to the level I would consider to be where the launch costs should be.

I am a fan of heavy lift *capability*, not of a heavy lift *rocket*. From a technical pov, AJAX beats the pants off the Jupiter because of its flexibility and its ability to actually implement what Griffin wanted to do with the Ares 1.5 architecture. He wanted to use the SRB as a CLV and that just wouldn't work out. In addition he needed to have an upper stage on the Ares-V because he couldn't cluster the SRB's around the ET core because of their immense mass. The cluster-SRB LV would have literally crushed the ground around the pad, which we all know is actually a big sandbar. AJAX does not have that restriction. The Atlas-V CCB will easily adapt as a CLV (and in fact regardless of whatever else happens, that *will* happen) and that same CCB can be clustered around the core to incrementally increase the lift capacity of the stack to well beyond what the Ares-V was initially supposed to do, no upper stage needed. And at its minimal configuration it is just a step above the capability of the existing EELV family, complementing them rather than competing with them. The AJAX-440 would be a direct challenge to the FH, lifting only a little more mass to orbit, but at government pricing, which would both enhance and restrict it, depending on the payload. It shares infrastructure, hardware and personnel with the EELVs, driving the cost of the EELV's down. It is efficient as hell because the *entire* capability of any upper stage can be utilized as an fully fueled EDS with spacecraft attached, while driving the cost of the Atlas down to the point where it may actually compete with the F9 on price to orbit on its own. Remember, the $1,000/pound to orbit Elon quoted is based on the full capacity of the FH being divided by the cost of the launch. Unless Elon intends to subsidize his customers, none of them will actually pay that until they actually want to lift a full 50 tons to orbit. If AJAX were adopted, the Atlas-V may very well drop into the competition range with the F9. That would be a sweet thing. I wish SpaceX well, but I don't want the nation's HLV capability to be sole-sourced. A profitable SpaceX FH running on the commercial side with the AJAX running on the government side would be the best of both worlds.

And oh, btw, the AJAX equivilant (AJAX-440) to the Jupiter-130, the RAC-1 preferred configuration, would cost far less to both build and fly than the Jupiter-130. It's amazing how much funding is freed without the solids!
Title: Re: AJAX Launcher
Post by: Lobo on 04/07/2011 08:18 pm
But more time to develop, more money to do so.  You'd need to develop both a first and second stage, rather than repurposing an existing first stage into a core, and using existing components.  The refurbishment costs to LC-39 would remain, the support costs remain, but you'd now have long-poles in development, many more than otherwise.

Think on it, the alternative being suggested is to design a new first stage, new second stage, new engines. 

That is too many potential shortfalls, too many potential traps.  That is what doomed Constellation, too many long poles.  AJAX eliminates that, with just 1 new element, a modified ET.  Even SpaceX is not offering that, Falcon 9 Heavy is a new center stage, new booster stages, and noone knows about the upper stage as of yet.  Also involves new engines as well don't forget. 

Well, you certainly argue a good case.  Don't worry, I'm still an AJAX fan (and to an only slightly lesser degree, a Direct fan). 

Yes, it's a new rocket, and like I said, it probably wouldn't be flying before AJAX or Jupiter could.  The only caviot is F9H -should- be flying before AJAX or Jupiter could, and only have about 18mt less capacity.  Musk says it would be man-rated, so it could start launching Orion as soon as it's ready.  Since we won't have a lunar lander, NEO Mission Module, or anything to do with Mars ready to launch for long after an FX would likely be ready, I don't know that we'd have this delay risk as you describe.  Orion probably won't ready prior to 2016 anyway, right?  So F9H and AJAX would both be ready before ORion would. 
So, what would the gap concern be?  70mt payloads?  Yea, a 70mt payload to LEO could fly sooner with AJAX than with SpaceX.  But a 53mt payload could fly sooner with SpaceX than with AJAX.  So is there anything important that needs to fly in the next 4 years that couldn't fly on F9H, and would need AJAX?
If you take my meaning?
In otherwords, what are the payloads that need 70mt rather than 53mt that can wait for AJAX, but can't wait for FXH? 
Maybe there are some, I'm just curious.
I think we'd have FX before we'd have any type of lunar lander.  And even if not, a 2 or 3 F9H launch architecture can get you 100-150mt into LEO.  You could launch separately if a big enough vehicle to launch them all at once wasn't ready. 
I think a man-rated 53mt LV is the equation changer.  Otherwise, you'd absolutely be right.  F9 is obviously nowhere big enough to lift ORion, and D4H sounds like it'd be difficult to man-rate.  A5H might be a better way to go for trying to lift a crewed ORion, but that's only 30mt.  Without AJAX or Jupiter, you'd be stuck with F9 as your only man-rated launcher, and 25-30mt as your max unmanned lift capacity, which makes it pretty complex to try to do any kind of serious BLEO program. 
So the argument for AJAX or Jupiter (or 5/5) is obvious. 
A cheap, man-rated, 53mt LV, ready to fly in 2 years changes the equation (I think).  It lets you get going not only a little sooner than AJAX or Jupiter, but with ultimately more commonality and flexibility than AJAX.  (cores and engines being used for more than just NASA missions.  With AJAX, the cores and SSME's are only used on NASA HLV launches.  With Jupiter, ad the seg booster to that) 

Just my thoughts.  Obviously there a lot of behind the scenes things you guys know I don't though!  :-)
Title: Re: AJAX Launcher
Post by: Downix on 04/07/2011 09:12 pm
But more time to develop, more money to do so.  You'd need to develop both a first and second stage, rather than repurposing an existing first stage into a core, and using existing components.  The refurbishment costs to LC-39 would remain, the support costs remain, but you'd now have long-poles in development, many more than otherwise.

Think on it, the alternative being suggested is to design a new first stage, new second stage, new engines. 

That is too many potential shortfalls, too many potential traps.  That is what doomed Constellation, too many long poles.  AJAX eliminates that, with just 1 new element, a modified ET.  Even SpaceX is not offering that, Falcon 9 Heavy is a new center stage, new booster stages, and noone knows about the upper stage as of yet.  Also involves new engines as well don't forget. 

Well, you certainly argue a good case.  Don't worry, I'm still an AJAX fan (and to an only slightly lesser degree, a Direct fan). 

Yes, it's a new rocket, and like I said, it probably wouldn't be flying before AJAX or Jupiter could.  The only caviot is F9H -should- be flying before AJAX or Jupiter could, and only have about 18mt less capacity.  Musk says it would be man-rated, so it could start launching Orion as soon as it's ready.  Since we won't have a lunar lander, NEO Mission Module, or anything to do with Mars ready to launch for long after an FX would likely be ready, I don't know that we'd have this delay risk as you describe.  Orion probably won't ready prior to 2016 anyway, right?  So F9H and AJAX would both be ready before ORion would. 
So, what would the gap concern be?  70mt payloads?  Yea, a 70mt payload to LEO could fly sooner with AJAX than with SpaceX.  But a 53mt payload could fly sooner with SpaceX than with AJAX.  So is there anything important that needs to fly in the next 4 years that couldn't fly on F9H, and would need AJAX?
If you take my meaning?
Orions first flight is in late 2013/early 2014, already ordered and getting prepared.  It would be ready for manned flight at the end of 2014.  The issue is lack of a launcher.  F9H may work, but the AJAX plan was to order AVH's.  This was for a few purposes, one, gets Orion in operation sooner.  Two, gets CCB production up ahead of AJAX becoming operational.  If we push forward for F9H, while we could get Orion working, we will not have the CCB production line ramped up for it without added expense.
Quote
In otherwords, what are the payloads that need 70mt rather than 53mt that can wait for AJAX, but can't wait for FXH? 
Maybe there are some, I'm just curious.
That is the crux of any issue for a launcher.  There is no payload for either as a single unit.  There is one for AJAX, however, in being able to loft a DCSS for use for TLI for Orion.  F9H cannot fill that role.
Quote
I think we'd have FX before we'd have any type of lunar lander.  And even if not, a 2 or 3 F9H launch architecture can get you 100-150mt into LEO.  You could launch separately if a big enough vehicle to launch them all at once wasn't ready. 
But we're not going to LEO, are we?  We're going BEO, and that's where the F9H stops looking so good.
Quote
I think a man-rated 53mt LV is the equation changer.  Otherwise, you'd absolutely be right.  F9 is obviously nowhere big enough to lift ORion, and D4H sounds like it'd be difficult to man-rate.  A5H might be a better way to go for trying to lift a crewed ORion, but that's only 30mt.  Without AJAX or Jupiter, you'd be stuck with F9 as your only man-rated launcher, and 25-30mt as your max unmanned lift capacity, which makes it pretty complex to try to do any kind of serious BLEO program. 
So the argument for AJAX or Jupiter (or 5/5) is obvious. 
A cheap, man-rated, 53mt LV, ready to fly in 2 years changes the equation (I think).  It lets you get going not only a little sooner than AJAX or Jupiter, but with ultimately more commonality and flexibility than AJAX.  (cores and engines being used for more than just NASA missions.  With AJAX, the cores and SSME's are only used on NASA HLV launches.  With Jupiter, ad the seg booster to that) 

Just my thoughts.  Obviously there a lot of behind the scenes things you guys know I don't though!  :-)
The core and SSME may themselves be unique, but they share tooling and equipment with other systems, so the cost is shared.  To use an example, Chevrolet makes the Corvette, very expensive, not high volume production car.  But that Corvette shares a lot of systems with other, cheaper, more produced vehicles.  For instance, the LS9 engine it uses has the same tooling as the Vortec engines used in their line of pickup trucks. 
Title: Re: AJAX Launcher
Post by: Lobo on 04/08/2011 12:19 am
Downix, Clogton,

Again, you both make good arguments.  With any luck at least I hope I allowed you to sharpen your arguments for AJAX by asking some questions which others may be asking in the future, if they haven't already.

Thanks for indulging my curiosities!

And yes, a good point about BLEO throw capability.  F9H needs a 2nd stage to get it's payload into LEO right?  thus some of it's propellant is used and the 2nd stage is less capable for throwing mass BLEO?  Is that what you mean when you say the F9H doesn't look as good BLEO?
Where AJAX gets a 2nd stage with payload to circular LEO without any use of the 2nd stage propellant, so it can throw more BLEO?  And the high efficiency of the SSME core allows for that, and is unique to EELV derived kerolox launchers like F9 and Atlas?
Just want to make sure I am understanding your arguments correctly.  :-)
Title: Re: AJAX Launcher
Post by: Downix on 04/08/2011 12:33 am
Downix, Clogton,

Again, you both make good arguments.  With any luck at least I hope I allowed you to sharpen your arguments for AJAX by asking some questions which others may be asking in the future, if they haven't already.

Thanks for indulging my curiosities!

And yes, a good point about BLEO throw capability.  F9H needs a 2nd stage to get it's payload into LEO right?  thus some of it's propellant is used and the 2nd stage is less capable for throwing mass BLEO?  Is that what you mean when you say the F9H doesn't look as good BLEO?
Where AJAX gets a 2nd stage with payload to circular LEO without any use of the 2nd stage propellant, so it can throw more BLEO?  And the high efficiency of the SSME core allows for that, and is unique to EELV derived kerolox launchers like F9 and Atlas?
Just want to make sure I am understanding your arguments correctly.  :-)
You have most of it.  The added bit is that the EDS engine, the RL-10, is also far more efficient than the Merlin-Vac, at a sacrifice of thrust.  For BEO work, isp is king.

The F9 as a first stage offers good throw, as does the Atlas V CCB.  But with AJAX, you now have a high-thrust, high-isp main stage engine, the SSME, which does the majority of the work.  Then, you add once you're in orbit the RL-10 low-thrust but high-isp.  You now have a very potent combination.  Falcon 9's upper stage, however, has to do the work of both the main stage *and* EDS in AJAX, all with an engine which has far less impulse, 346 sec vs the RL-10's 461, over 100 seconds more impulse.
Title: Re: AJAX Launcher
Post by: Zed_Noir on 04/08/2011 07:04 am
The F9 and FH could be topped with the AV US as a high energy 3rd stage/EDS.

Jim pooh-pooh this idea by the way. Paraphrasing "SpaceX will not use the upper stage of another contractor."
Title: Re: AJAX Launcher
Post by: Downix on 04/08/2011 07:13 am
The F9 and FH could be topped with the AV US as a high energy 3rd stage/EDS.

Jim pooh-pooh this idea by the way. Paraphrasing "SpaceX will not use the upper stage of another contractor."
Not really the thread for that, but both of you are quite right.
Title: Re: AJAX Launcher
Post by: baldusi on 04/08/2011 05:30 pm
I was wondering. The extra thrust of the Merlin 1D, with current sized body, would give a very interesting T/W. It should be an alternative booster for AJAX, wouldn't it?
Title: Re: AJAX Launcher
Post by: Downix on 04/08/2011 07:39 pm
I was wondering. The extra thrust of the Merlin 1D, with current sized body, would give a very interesting T/W. It should be an alternative booster for AJAX, wouldn't it?
After the Delta IV and Taurus II first stage it would be.  The D4 still has a better T/W than the Falcon 9, due to the higher isp engines equating into 1/3rd less fuel while it has only 20% less thrust.  Taurus II has performance equal to the Atlas V.  F9 needs more fuel to get the same result, resulting in quicker burnout despite more thrust.  That means the core can't throw quite as much, we'd be loosing performance with it.

The reason Atlas was selected is due to cost.  It would cost less to get the system ready for Atlas, and it would be sooner sooner, which means less overhead costs to support without a system.  Delta IV did not win due to this, if we were going by pure performance, the D4 would have won out due to it's much better T/W and isp.  But it needed so much work to get it ready, and it would have added a long pole in to the whole operation.  Until Delta was ready to fly, we could not have a test flight.  Any delays there, and the date would slip, so more overhead support costs without a flight, more jobs lost.  Atlas, however, could be brought online for it sooner, with test flights in 2014 out of LC-39 with Orion on top of an Atlas V HLV.  For Delta, core design changes for manned operation would mean that any testing of the non-man-rated design would not necessarily reflect the final vehicle, and could be as useless as the Ares I-X flight, so we would be delayed in waiting for those changes before work could begin on the rest of the system, and if those are delayed, there goes the schedule and budget. Delta is a 3 year program to get it ready to serve the role, any single delay of any system, and there went the schedule.

Atlas is a solid, proven design ready for the job.  Atlas's only real issue for man-rating is in the upper stage, and that is already being addressed and should be ready by next year based on the progress with the work.  Which means even if it is delayed, we have two years additional we'd be waiting anyways for Orion.  The HLV form of Atlas is not a huge concern by ULA, and based on the record of Atlas and how the CCB is nearly identical between versions of the rocket (unlike Delta) there should be no delays, and even if there are, we still have a buffer between when AVH would be ready over Orion.  Delta would be coming ready at the same time as Orion, so a delay in either would hurt the program.  We can afford a single delay, not two, and having two items which must be ready together is not a smart way to develop.  Delays often mean design changes, which can ripple down the chain, as we saw with Orion as Ares I had design changes due to failing its performance profile.

SpaceX is a solid company, with a good product.  It needs to be kept from AJAX for the simple reason that it would step on toes, it would not give the advantage needed.  We have tough enemies in ATK.  You need as tough an opponent as you can to fight them, and ULA has those.
Title: Re: AJAX Launcher
Post by: baldusi on 04/09/2011 09:04 pm
I was wondering. The extra thrust of the Merlin 1D, with current sized body, would give a very interesting T/W. It should be an alternative booster for AJAX, wouldn't it?
After the Delta IV and Taurus II first stage it would be.  The D4 still has a better T/W than the Falcon 9, due to the higher isp engines equating into 1/3rd less fuel while it has only 20% less thrust.  Taurus II has performance equal to the Atlas V.
So you could actually do bidding process, and let ULA, Orbital and SpaceX bid to offer the boosters, asking for a given performance and deciding on price. Because then Orbital might have a chance. I know ULA has a lot of clout in Congress. But NASA is such a small part of the budget, and I'm sure that you could say that the booster stage is a commercial offering and thus, NASA can't produce it itself.
Title: Re: AJAX Launcher
Post by: Downix on 04/09/2011 09:09 pm
I was wondering. The extra thrust of the Merlin 1D, with current sized body, would give a very interesting T/W. It should be an alternative booster for AJAX, wouldn't it?
After the Delta IV and Taurus II first stage it would be.  The D4 still has a better T/W than the Falcon 9, due to the higher isp engines equating into 1/3rd less fuel while it has only 20% less thrust.  Taurus II has performance equal to the Atlas V.
So you could actually do bidding process, and let ULA, Orbital and SpaceX bid to offer the boosters, asking for a given performance and deciding on price. Because then Orbital might have a chance. I know ULA has a lot of clout in Congress. But NASA is such a small part of the budget, and I'm sure that you could say that the booster stage is a commercial offering and thus, NASA can't produce it itself.
You can have larger pools than even this.  Aerojet, for instance, could bid with buying engineless CCB's and putting AJ-26's on them.  But that is part of the idea, to make it able to *be* bid on in such a way.
Title: Re: AJAX Launcher
Post by: HappyMartian on 04/12/2011 02:48 am
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 
Now you're thinking like I have for almost a year now.

That's 3 of us :)

I've seen the light...

Yes. I have too! And the light is lovely. 

Cheers!  :)
Title: Re: AJAX Launcher
Post by: Patchouli on 04/12/2011 07:40 pm
Downix,

Just had a thought after yesterday's SpaceX announcement.  I wonder if ULA will see the writing on the wall about the likelyhood of stiff competition going forward from SpaceX on commercial payloads anyway, if not also military payloads.  And think about lobbying hard now for something like AJAX for SLS to try to lock in a "guaranteed" government market for their Atlas CCB's?

With a threat of SpaceX to eat into their LV market it'd be wise for them to lock themselves into NASA's heavy lifter and try to displace ATK. 

Maybe it won't have any effect, but if I were running ULA, and I saw a proposal like AJAX that would lock my product into NASA's rocket for the forseeable future, and I had a young, upstart company nipping at my heals, I'd probably be pulling out all the stops to make that happen. 
Now you're thinking like I have for almost a year now.

Same here ACES is too good a concept to not do.
I'd even push like crazy for an ACES derived lunar lander.
Title: Re: AJAX Launcher
Post by: HappyMartian on 04/13/2011 05:47 am
I'd even push like crazy for an ACES derived lunar lander.

Yep. That would work out nice!

Cheers!
Title: Re: AJAX Launcher
Post by: Lobo on 04/13/2011 10:23 pm
Downix,

I've been corresponding with Steve Piertrobon about SLS and AJAX, and he's of the opinion that the law is pretty specific that SRB's are to be used.
I pointed out the argument about "practicable" phrase, but he pointed me to this link (you might already be aware of this).  Your thoughts on this?

http://www.blackholenews.net/Space/Letter-from-Sen-Nelson-and-Sen-Hutchison-to-NASA-Administrator-Bolden-Regarding-Space-Launch-System-Multi-purpose-Crew-Vehicle/

Specifically from Bill Nelson and Kay Hutchenson:
------------------------------------
Finally, we would like to clarify our intent when stating "to the extent practicable" in the Authorization Act, such as the direction to leverage Shuttle and Constellation capabilities "to the extent practicable" in developing the Space Launch System and the multi-purpose crew vehicle. Federal courts have held that the phrase "to the maximum extent practicable" imposes "a clear duty on [an] agency to fulfill the [relevant] statutory command to the extent that it is feasible or possible*' (Fund for Animals v. Babbitt, 903 F. Supp. 96,107 (D.D.C. 1995) (noting that the phrase "does not permit an agency unbridled discretion"), Further, the Government Accountability Office has determined that "where Congress directs that a [contracting] preference be given to the greatest extent practicable, an agency must either provide the preference or articulate a reasoned explanation of why it is impracticable to do so" (Ocuto Blacktop & Paving Company, Inc., Opinion B-284 1 65, March 1,2000 (holding the Army Corps of Engineers had failed to demonstrate why providing a contract preference to a local business was impracticable)). Thus, in the context of the NASA Authorization Act, we believe that those statutorily directed actions to be performed by NASA "to the maximum extent practicable" or "to the extent practicable," such as the requirement in Section 302 of the law to extend or modify existing contracts, should be carried out, unless the agency can demonstrate why they are infeasible or impossible to perform.

As we noted in a statement yesterday, the NASA Authorization Act of 201 0 that we worked so hard to pass last year is not an optional, advisory document: it is the law. We fought for this legislation because it was the right solution to the extraordinary challenge we face. We look forward to continuing to work with NASA to ensure the vitality of our Nation's space program.

Sincerely,

[signed]

Bill Nelson
Chairman
Subcommittee on Science and Space


[signed]

Kay Bailey Hutchison
Ranking Member
Commerce, Science, and Transportation Committee
Title: Re: AJAX Launcher
Post by: Lobo on 04/13/2011 10:32 pm

Same here ACES is too good a concept to not do.
I'd even push like crazy for an ACES derived lunar lander.


Actually, I really like ULA's ACES plan.  It reduces the number of disposable components by eliminating 1-purpose EDS's, as the CSM/ACES would do the EDS burn for the crew, and the Lander/ACES would do the EDS burn for the lander.  (Or you can have one ACES do the TLI burn for the whole stack).
Both of those ACES modules also do other things.  The CSM/ACES does the TEI burn, and the Lander/ACES does the descent burn.  With a lunar orbit (or L-point) depot, the lander ascender can be made reusable and park there for station keeping.  the CSM can park there during the mission for propellent storage and station keeping. 

Plus your Crew service module, lander descent module, and your depot(s) are all common with ULA's EELV upper stages. 

Yea, I think ACES is too good of a concept to -NOT- do.
Title: Re: AJAX Launcher
Post by: Downix on 04/13/2011 11:40 pm
Downix,

I've been corresponding with Steve Piertrobon about SLS and AJAX, and he's of the opinion that the law is pretty specific that SRB's are to be used.
I pointed out the argument about "practicable" phrase, but he pointed me to this link (you might already be aware of this).  Your thoughts on this?

http://www.blackholenews.net/Space/Letter-from-Sen-Nelson-and-Sen-Hutchison-to-NASA-Administrator-Bolden-Regarding-Space-Launch-System-Multi-purpose-Crew-Vehicle/

Specifically from Bill Nelson and Kay Hutchenson:
------------------------------------
Finally, we would like to clarify our intent when stating "to the extent practicable" in the Authorization Act, such as the direction to leverage Shuttle and Constellation capabilities "to the extent practicable" in developing the Space Launch System and the multi-purpose crew vehicle. Federal courts have held that the phrase "to the maximum extent practicable" imposes "a clear duty on [an] agency to fulfill the [relevant] statutory command to the extent that it is feasible or possible*' (Fund for Animals v. Babbitt, 903 F. Supp. 96,107 (D.D.C. 1995) (noting that the phrase "does not permit an agency unbridled discretion"), Further, the Government Accountability Office has determined that "where Congress directs that a [contracting] preference be given to the greatest extent practicable, an agency must either provide the preference or articulate a reasoned explanation of why it is impracticable to do so" (Ocuto Blacktop & Paving Company, Inc., Opinion B-284 1 65, March 1,2000 (holding the Army Corps of Engineers had failed to demonstrate why providing a contract preference to a local business was impracticable)). Thus, in the context of the NASA Authorization Act, we believe that those statutorily directed actions to be performed by NASA "to the maximum extent practicable" or "to the extent practicable," such as the requirement in Section 302 of the law to extend or modify existing contracts, should be carried out, unless the agency can demonstrate why they are infeasible or impossible to perform.

As we noted in a statement yesterday, the NASA Authorization Act of 201 0 that we worked so hard to pass last year is not an optional, advisory document: it is the law. We fought for this legislation because it was the right solution to the extraordinary challenge we face. We look forward to continuing to work with NASA to ensure the vitality of our Nation's space program.

Sincerely,

[signed]

Bill Nelson
Chairman
Subcommittee on Science and Space


[signed]

Kay Bailey Hutchison
Ranking Member
Commerce, Science, and Transportation Committee
NASA has already submitted how it is infeasable to perform, the report they submitted in February.  That is why they submitted that report with the 5/5 son-of-Ares which would not work.  NASA has been advised the practicable limits have been surpassed, as they are required to per the law.  They now have some flexibility, as they have covered their political posteriors. 

The law is quite clear, the SRB's are to be retained if they can meet the budget and support requirements.  To keep the SRB's would consume, without developing, testing, or building a single unit, $6 billion dollars.  Out of a $12 billion budget, half of it would be gone in an instant just in maintenance costs for a technology no longer in use anywhere else.  So, to the fullest extent Practicable, the SRB's must die, per the authorization law.

The only provision which required SRB's was this one:

Sec 302
(3) TRANSITION NEEDS.—The Administrator shall ensure
critical skills and capabilities are retained, modified, and developed, as appropriate, in areas related to solid and liquid
engines, large diameter fuel tanks, rocket propulsion, and other
ground test capabilities for an effective transition to the follow-
on Space Launch System

As ATK has already released that the skills and capabilities are not dependent on the SLS, with their Liberty proposal (which they stated they will persue independent of SLS) that means that there is no need to marry SRB's to SLS in order to retain critical skills.

The tank and liquid propulsion, however, have no other way in order to be retained, which means that they are required to be in SLS.
Title: Re: AJAX Launcher
Post by: Lobo on 04/14/2011 11:00 pm
NASA has already submitted how it is infeasable to perform, the report they submitted in February.  That is why they submitted that report with the 5/5 son-of-Ares which would not work.  NASA has been advised the practicable limits have been surpassed, as they are required to per the law.  They now have some flexibility, as they have covered their political posteriors. 

The law is quite clear, the SRB's are to be retained if they can meet the budget and support requirements.  To keep the SRB's would consume, without developing, testing, or building a single unit, $6 billion dollars.  Out of a $12 billion budget, half of it would be gone in an instant just in maintenance costs for a technology no longer in use anywhere else.  So, to the fullest extent Practicable, the SRB's must die, per the authorization law.

The only provision which required SRB's was this one:

Sec 302
(3) TRANSITION NEEDS.—The Administrator shall ensure
critical skills and capabilities are retained, modified, and developed, as appropriate, in areas related to solid and liquid
engines, large diameter fuel tanks, rocket propulsion, and other
ground test capabilities for an effective transition to the follow-
on Space Launch System

As ATK has already released that the skills and capabilities are not dependent on the SLS, with their Liberty proposal (which they stated they will persue independent of SLS) that means that there is no need to marry SRB's to SLS in order to retain critical skills.

The tank and liquid propulsion, however, have no other way in order to be retained, which means that they are required to be in SLS.

Interesting.  Thanks Downix.  The intracacies of this makes my head hurt some times.  But when I read that letter from Nelson and Hutchenson, it seemed pretty damning to AJAX.

So, let's see if we get this straight.

Of the most "directly" shuttle derived, you have 4/3 (Direct), and 5/5 (Ares Classic?).
4/3 meets budget, but really can't be grown into 130mt.  And really can't even be grown into 130 short tons unless you upgrade the SRB's to 5-seg, right?
5/5 can be grown to 130mt with an upper stage.  But it probably won't meet the current budget.  right?

So neither of the more "directly" derived options being studied by RAC-1 can meet the NASA Authorization act?

But AJAX could get around the SRB requirement by meeting both budget and growth lift ability requirements, and still retains the liquid components, which -are- "practicable"?

Do I understand where you are coming from with AJAX correctly, and while you feel there's still a strong case for it, and it will be considered?

Alternatively, can 4/3 be chosen, and basically 5/5 with an upper stage be considered a "growth option" for 4/3?  In which case, an SRB LV would meet both budget and future performance of the NASA Authorization act?
And then maybe down the road, the Authorization act is modified to drop the 130 ton growth requirement.  4/3 grows to 4/4 with US, and we have our SLS system going forward.  Is -that- a possibility that threatens AJAX's consideration?
Title: Re: AJAX Launcher
Post by: Downix on 04/14/2011 11:36 pm
NASA has already submitted how it is infeasable to perform, the report they submitted in February.  That is why they submitted that report with the 5/5 son-of-Ares which would not work.  NASA has been advised the practicable limits have been surpassed, as they are required to per the law.  They now have some flexibility, as they have covered their political posteriors. 

The law is quite clear, the SRB's are to be retained if they can meet the budget and support requirements.  To keep the SRB's would consume, without developing, testing, or building a single unit, $6 billion dollars.  Out of a $12 billion budget, half of it would be gone in an instant just in maintenance costs for a technology no longer in use anywhere else.  So, to the fullest extent Practicable, the SRB's must die, per the authorization law.

The only provision which required SRB's was this one:

Sec 302
(3) TRANSITION NEEDS.—The Administrator shall ensure
critical skills and capabilities are retained, modified, and developed, as appropriate, in areas related to solid and liquid
engines, large diameter fuel tanks, rocket propulsion, and other
ground test capabilities for an effective transition to the follow-
on Space Launch System

As ATK has already released that the skills and capabilities are not dependent on the SLS, with their Liberty proposal (which they stated they will persue independent of SLS) that means that there is no need to marry SRB's to SLS in order to retain critical skills.

The tank and liquid propulsion, however, have no other way in order to be retained, which means that they are required to be in SLS.

Interesting.  Thanks Downix.  The intracacies of this makes my head hurt some times.  But when I read that letter from Nelson and Hutchenson, it seemed pretty damning to AJAX.

So, let's see if we get this straight.

Of the most "directly" shuttle derived, you have 4/3 (Direct), and 5/5 (Ares Classic?).
4/3 meets budget, but really can't be grown into 130mt.  And really can't even be grown into 130 short tons unless you upgrade the SRB's to 5-seg, right?
If you limit yourself to two stages + boosters, correct.  There are alternative options even for this, which were explored under the Shuttle.  The ASRM would give better performance than the ATK 5-seg, for example.  Also the addition of GEM-60 monolothic SRB's was studied for the shuttle as well, and that research would be applied here.  A third stage could also do the trick.  The RS-25e program could also focus on boosting the performance to 115%, another option which would again boost the performance.  Yet another study was to abandon re-use of the SRB's and to therefore utilize lighter weight, non-reusable casings, giving yet again a performance boost.  There are more growth options out there than just 5-seg.
Quote
5/5 can be grown to 130mt with an upper stage.  But it probably won't meet the current budget.  right?
Almost assuredly it will not meet the budget needs.
Quote
So neither of the more "directly" derived options being studied by RAC-1 can meet the NASA Authorization act?
We don't know that.  There are yet other options to explore which have not yet been addressed.  Zubrin's Mars Direct discussed one option, using add-on engine pods.  RAC-1 is doing a lot of work, delving into more than just a single option I would imagine.  We presuppose a lot from them.
Quote
But AJAX could get around the SRB requirement by meeting both budget and growth lift ability requirements, and still retains the liquid components, which -are- "practicable"?
Correct.  In addition, AJAX does not preclude the use of solids either.  It is just not on the baseline model or in the critical path.  We're using the Atlas as our primary crew launch vehicle, and Atlas utilizes solids in many of it's configurations.  So, even with SRB's a requirement, we have that covered.
Quote
Do I understand where you are coming from with AJAX correctly, and while you feel there's still a strong case for it, and it will be considered?
That is up to forces outside of my control.
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Alternatively, can 4/3 be chosen, and basically 5/5 with an upper stage be considered a "growth option" for 4/3?  In which case, an SRB LV would meet both budget and future performance of the NASA Authorization act?
Yes, that was part of the sidemount Block growth design put forth by JSC in fact.
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And then maybe down the road, the Authorization act is modified to drop the 130 ton growth requirement.  4/3 grows to 4/4 with US, and we have our SLS system going forward.  Is -that- a possibility that threatens AJAX's consideration?
We'd need to get it in front of people.  Once there, then we let the dice roll where they will.
Title: Re: AJAX Launcher
Post by: Downix on 04/16/2011 07:53 pm
Doing some work on the AJAX budget, to give more detailed numbers.  I've hit upon something interesting as far as costs go and wanted to verify somewhat. 

The estimated costs for the NLS main ET derived stage was to be $194 million per year for 6 years.  The costs for the SWLT came to $178 million per year for 6 years.  Adjusting for inflation, and averaging those costs, I came out to $288 million per year.  Does this seem correct to you all?
Title: Re: AJAX Launcher
Post by: Lobo on 04/18/2011 09:15 pm
Doing some work on the AJAX budget, to give more detailed numbers.  I've hit upon something interesting as far as costs go and wanted to verify somewhat. 

The estimated costs for the NLS main ET derived stage was to be $194 million per year for 6 years.  The costs for the SWLT came to $178 million per year for 6 years.  Adjusting for inflation, and averaging those costs, I came out to $288 million per year.  Does this seem correct to you all?

Sorry, I have no idea.
Title: Re: AJAX Launcher
Post by: sdsds on 04/19/2011 04:30 am
The estimated costs for the NLS main ET derived stage was to be $194 million per year for 6 years.  The costs for the SWLT came to $178 million per year for 6 years.  Adjusting for inflation, and averaging those costs, I came out to $288 million per year.  Does this seem correct to you all?

I'm quite curious about this.  Can you provide a bit of detail on what you envision NASA would get in return for $288 million per year for six years?  Is this the cost to design the core; to create and install and/or refurbish the tooling; to produce one or more units; to conduct ground tests; flight tests?  Etc.

How did USA propose to procure additional Shuttle ET units for CSTS?
Title: Re: AJAX Launcher
Post by: Downix on 04/19/2011 04:45 am
The estimated costs for the NLS main ET derived stage was to be $194 million per year for 6 years.  The costs for the SWLT came to $178 million per year for 6 years.  Adjusting for inflation, and averaging those costs, I came out to $288 million per year.  Does this seem correct to you all?

I'm quite curious about this.  Can you provide a bit of detail on what you envision NASA would get in return for $288 million per year for six years?  Is this the cost to design the core; to create and install and/or refurbish the tooling; to produce one or more units; to conduct ground tests; flight tests?  Etc.

How did USA propose to procure additional Shuttle ET units for CSTS?
In both NLS and SLWT that was for R&D, all tooling mods, and to produce 4 units for ground and flight testing.  All encompassing costs distilled down to the basic.

As for USA's plan, no idea as I did not have access to their documentation.
Title: Re: AJAX Launcher
Post by: sdsds on 04/19/2011 05:01 am
Estimate to produce 7 units using http://cost.jsc.nasa.gov/AMCM.html
(This is likely a gross misuse of the AMCM tool.)

qty: 7
weight: 85600 lb (includes 4x SSME)
mission type: launch vehicle
ioc: 2016
block: 4
difficulty: avg

2004$ in millions Total Cost: 5163
5163 / 6 = $860.5 million per year

But that would include the SSME.  If we subtract out an estimate for those:

5163 - 2370 = 2793
2793 / 6 = $465.5 million per year.
Title: Re: AJAX Launcher
Post by: Downix on 04/19/2011 05:14 am
Estimate to produce 7 units using http://cost.jsc.nasa.gov/AMCM.html
(This is likely a gross misuse of the AMCM tool.)

qty: 7
weight: 85600 lb (includes 4x SSME)
mission type: launch vehicle
ioc: 2016
block: 4
difficulty: avg

2004$ in millions Total Cost: 5163
5163 / 6 = $860.5 million per year

But that would include the SSME.  If we subtract out an estimate for those:

5163 - 2370 = 2793
2793 / 6 = $465.5 million per year.
Very gross use, but not a bad idea.  I'll subtract the SSME's from the core weight (which you are off of):


Quantity   6
Dry Weight (lb.)   112465
Mission Type   Space Transport - Launch Vehicle Stage
IOC Year   2016
Block Number   1
Difficulty   Average


2004$ in millions
Total Cost   5926

So, dividing by 6 years, we get:
$988 million per year.

That is more what I was thinking in my head.  The SLWT and NLS numbers always seemed too low.  I'm bookmarking that site.
Title: Re: AJAX Launcher
Post by: alexw on 04/19/2011 06:07 am
The estimated costs for the NLS main ET derived stage was to be $194 million per year for 6 years.  The costs for the SWLT came to $178 million per year for 6 years.  Adjusting for inflation, and averaging those costs, I came out to $288 million per year.  Does this seem correct to you all?
I'm quite curious about this.  Can you provide a bit of detail on what you envision NASA would get in return for $288 million per year for six years?  Is this the cost to design the core; to create and install and/or refurbish the tooling; to produce one or more units; to conduct ground tests; flight tests?  Etc.
In both NLS and SLWT that was for R&D, all tooling mods, and to produce 4 units for ground and flight testing.  All encompassing costs distilled down to the basic.
     Does that mean the cost of the propulsion structure plus another (12?) brand-new SSMEs, plus development of new avionics plus four sets of that plus four sets of all the auxiliary systems (APUs, hydraulics, some heat rejection) would average $194-$178 = $88 million/yr?
     Sounds rather low indeed. Was NLS assuming none of the SWLT development costs, ie using a LWT-derived structure only?
    -Alex
Title: Re: AJAX Launcher
Post by: Downix on 04/19/2011 12:16 pm
The estimated costs for the NLS main ET derived stage was to be $194 million per year for 6 years.  The costs for the SWLT came to $178 million per year for 6 years.  Adjusting for inflation, and averaging those costs, I came out to $288 million per year.  Does this seem correct to you all?
I'm quite curious about this.  Can you provide a bit of detail on what you envision NASA would get in return for $288 million per year for six years?  Is this the cost to design the core; to create and install and/or refurbish the tooling; to produce one or more units; to conduct ground tests; flight tests?  Etc.
In both NLS and SLWT that was for R&D, all tooling mods, and to produce 4 units for ground and flight testing.  All encompassing costs distilled down to the basic.
     Does that mean the cost of the propulsion structure plus another (12?) brand-new SSMEs, plus development of new avionics plus four sets of that plus four sets of all the auxiliary systems (APUs, hydraulics, some heat rejection) would average $194-$178 = $88 million/yr?
     Sounds rather low indeed. Was NLS assuming none of the SWLT development costs, ie using a LWT-derived structure only?
    -Alex
That was for the core, no engines. The STME was a separate budget line. And the study I found was LWT derived, not SLWT. NLS was cancelled in 1991 and the SLWT program began in 1993.

That also did not include avionics, which was a separate budget entry.
Title: Re: AJAX Launcher
Post by: martin hegedus on 04/19/2011 04:38 pm
I'm not sure of the actual sources where the above SLWT numbers are coming from, so maybe this helps?

http://www.nasa.gov/columbia/foia/index.html

Some of the ET tank contracts are located there.  The NAS8-36200 links seem to be broken.  Maybe someone at NASA can be found to reconnect them, if required.  Or, one can google NAS8-36200
Title: Re: AJAX Launcher
Post by: Downix on 04/19/2011 04:49 pm
I'm not sure of the actual sources where the above SLWT numbers are coming from, so maybe this helps?

http://www.nasa.gov/columbia/foia/index.html

Some of the ET tank contracts are located there.  The NAS8-36200 links seem to be broken.  Maybe someone at NASA can be found to reconnect them, if required.  Or, one can google NAS8-36200

Very handy.

I was using two GAO reports for it, only two years I found numbers for "shuttle tank weight reduction program".  I'll go over these to compare.

I am more comfortable with $1 Bil/year cost for AJAX's development.
Title: Re: AJAX Launcher
Post by: Downix on 04/19/2011 05:17 pm
I'm not sure of the actual sources where the above SLWT numbers are coming from, so maybe this helps?

http://www.nasa.gov/columbia/foia/index.html

Some of the ET tank contracts are located there.  The NAS8-36200 links seem to be broken.  Maybe someone at NASA can be found to reconnect them, if required.  Or, one can google NAS8-36200

Very handy.

I was using two GAO reports for it, only two years I found numbers for "shuttle tank weight reduction program".  I'll go over these to compare.

I am more comfortable with $1 Bil/year cost for AJAX's development.
Ok, after this reading, the original number is correct for just the R&D to CDR, but did not include any test items.  Now I have the rest of the numbers and will adjust accordingly.

I also now know exactly how much an ET costs, I'd severely overestimated the cost to launch.
Title: Re: AJAX Launcher
Post by: baldusi on 04/19/2011 05:52 pm
I also now know exactly how much an ET costs, I'd severely overestimated the cost to launch.
Meaning that the ET turned out to be way more expensive or cheaper than you thought?
Title: Re: AJAX Launcher
Post by: Downix on 04/19/2011 05:59 pm
I also now know exactly how much an ET costs, I'd severely overestimated the cost to launch.
Meaning that the ET turned out to be way more expensive or cheaper than you thought?
Cheaper.
Title: Re: AJAX Launcher
Post by: baldusi on 04/19/2011 06:07 pm
Cheaper.
Could you provide an approximate breakdown of launch costs in percentage?
Like:
Engines,
Structure
ET
Boosters
Fuel
Ground Ops
Integrations
Etc?

I'm very interested in that.
Title: Re: AJAX Launcher
Post by: Downix on 04/19/2011 07:13 pm
Cheaper.
Could you provide an approximate breakdown of launch costs in percentage?
Sure:
Engines: 24.4%
Core: 11.5%
Boosters: 19%
Launch Costs: 11.7%
Flight Ops: 3.7%
Integrations 3%

I have the remainder (Avonics, ground ops, the shroud, support costs, etc) at 26.6% with a 1% misc cost.

I am not including the cost of NASA pensions, health insurance, or the actual mission costs in this, which is included with the shuttles cost breakdowns.
Title: Re: AJAX Launcher
Post by: baldusi on 04/19/2011 07:22 pm
At which flight rate?
Which costs would be more affected by flight rate?
Title: Re: AJAX Launcher
Post by: Downix on 04/19/2011 07:28 pm
At which flight rate?
Which costs would be more affected by flight rate?
I am only aiming at 2/year.  I realistically do not see a scenario to go above 3/year.  All of those will be effected, but not dramatically.  The biggest cost change would be to the 26.6%, which is where the ground ops are.

The reason why a lot of other numbers won't change dramatically is due to the amount of reduced overhead in this approach.  That means that more flights won't effect the prices as much.  It will effect it somewhat, but not as dramatically as with the Shuttle.  Shuttle was intended for a much larger flight rate than we had.  I am aiming with the realization that 2 flights/year is the likely flight rate.
Title: Re: AJAX Launcher
Post by: baldusi on 04/19/2011 07:44 pm
That's 8 Atlas V boosters and 8 RS-25D. That would be about triple current Atlas V launches and an order of magnitude for RS-25D. Yep, you won't go much lower on those items at a higher rate. The nice part is that the RD-180 could be Americanized and it's a great revenue for ULA without using it's RL10 stash. I still can't understand how does it come ULA isn't pushing like mad for AJAX.
Title: Re: AJAX Launcher
Post by: Downix on 04/19/2011 07:46 pm
That's 8 Atlas V boosters and 8 RS-25D. That would be about triple current Atlas V launches and an order of magnitude for RS-25D. Yep, you won't go much lower on those items at a higher rate. The nice part is that the RD-180 could be Americanized and it's a great revenue for ULA without using it's RL10 stash. I still can't understand how does it come ULA isn't pushing like mad for AJAX.
*shrug*  Who knows.  I see the advantage, but convincing others.  ATK is still the 800 lbs gorilla in the room.
Title: Re: AJAX Launcher
Post by: Downix on 04/22/2011 05:01 am
After my umpteenth Orbiter sim of AJAX, I am still in awe over it's throwing capacity.  I have gotten quite good at putting an Orion + DCSS into a nice long ellipse in order to give it an edge to hitting TLI from a 440.

I just wish I was good at 3D modelling so I could make a real model for it.
Title: Re: AJAX Launcher
Post by: baldusi on 04/24/2011 03:27 pm
Downix, you got me thinking about the Zenit not being an ideal LV, but a booster, and the good LV being sort of lacking in T/W. So, you either keep the engine and thrust structure of a booster and shrink the tank, or you get a more powerful engine and stronger thrust structure for a given tank. I'm I right?
If so, wouldn't it be better to design a modular tank section, that can be shortened by (I don't know) 20% easily? Or eat the weight of a thrust structure and add or retire engines according to need? I'm that the Atlas might find easier to shrink the tanks, while a Falcon Block 0 with Merlin 1D might work as a booster. But in a more general consideration, if you go to economies of scales design, small engines seems a better alternative to modular tanks. Strictly from a manufacturing point of view.
Title: Re: AJAX Launcher
Post by: spacenut on 04/24/2011 06:52 pm
In defence of Downix, he used the off the shelf Atlas V so that no changes would be made to this strap on booster.  He only made changes to the core for attach points for the Atlas V's.  This allows the Atlas to continue in production and actually would increase production of Atlas V's for economy of scale.  Lowering costs for both single Atlas V's and for the heavy lift.  Also with 4, 6 or 8 Atlas V's around the core you can dial up the LEO payload you want to get from 70 to over 130 tons.  This satisfies the congressional mandate as well as for anything we wish to launch to the moon or Mars in the future.  All without an upper stage.  No items to contend with in the development path.  Upper stage can be an ACES shared with EELV or larger if needed when the J2X is ever developed.  This is a more flexible path than solids, and less operating expense.  Large solids are only cost effective for probably 6 or more shuttle sized launches a year.  If Atlas V's are used, with only 2 launches a year for the heavy, that is at least 8 Atlas cores to me made if not more for the regular Atlas launches.  40 cores can be made a year at the Decatur, Alabama plant.  Full productivity will be a cost saver, not just for Atlas and AJAX, but also for Delta IV since they are also made at Decatur. 
Title: Re: AJAX Launcher
Post by: Downix on 04/26/2011 08:16 pm
Thanks Spacenut, did a good job putting it into a nut-shell. </badjoke>

In all seriousness, for AJAX to work as minimal changes to the CCB as possible must be done.  Otherwise cost issues will sink it, as it would for any other program.  That means no shrinking of the tank, no adding sensors to the tank, no partial-loading the tank.  You *can* swap out engines, only because Atlas was designed with the ability to do so for if and when a domestic RP-1 engine was available.  But we're not doing that due to cost and time to certify for the first stage.  The third stage we're looking at pushing Atlas Phase II, which has the extra thrust anyways, so is an issue already looked at.  Right now, the focus is initial capability, to meet the timeline.  Once you have that initial capability, then you can concern yourself with future work.
Title: Re: AJAX Launcher
Post by: simonbp on 04/26/2011 11:06 pm
Should point out that the currently-circulating "Phase I/Phase II" plan seems to fit Ajax (or something like it) to a tee; just make Phase II be the Phase I core with RP-1 boosters. And, the extra time would give the opportunity to use something other than off-the-shelf Atlas CCBs...
Title: Re: AJAX Launcher
Post by: clongton on 04/26/2011 11:18 pm
AJAX is *THE* answer to this whole mess.
AJAX is the *PERFECT* answer to this whole mess.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 04/26/2011 11:24 pm
Was wondering if the AJAX paper had been completed yet. Work got the better of me again.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 04/26/2011 11:26 pm
Thanks Spacenut, did a good job putting it into a nut-shell. </badjoke>

In all seriousness, for AJAX to work as minimal changes to the CCB as possible must be done.  Otherwise cost issues will sink it, as it would for any other program.  That means no shrinking of the tank, no adding sensors to the tank, no partial-loading the tank.  You *can* swap out engines, only because Atlas was designed with the ability to do so for if and when a domestic RP-1 engine was available.  But we're not doing that due to cost and time to certify for the first stage.  The third stage we're looking at pushing Atlas Phase II, which has the extra thrust anyways, so is an issue already looked at.  Right now, the focus is initial capability, to meet the timeline.  Once you have that initial capability, then you can concern yourself with future work.

Exactly. Thats why, I thought, the plan was to use a shortened et. Are we moving back to baseline 0 again? (standard et)

Regardless, it seem there is a huge footinthedoor chance here for us.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 04/26/2011 11:29 pm
AJAX is *THE* answer to this whole mess.
AJAX is the *PERFECT* answer to this whole mess.

Nothing is perfect. Nothing.

If this was actually to go forward and this rocket built I have no doubt it would present its many own little quirks as all large machines do.

Its a good solution but not perfect, as far as politics and economics goes. A perfect solution would be if Spacex already had FH online for the price they said. 
Title: Re: AJAX Launcher
Post by: neilh on 04/27/2011 12:02 am
If this was actually to go forward and this rocket built I have no doubt it would present its many own little quirks as all large machines do.

One issue I was wondering about is if there'd be any difficulties in getting the stock LRBs to support the weight of the ET+payload, a role currently carried by the SRBs. I was pretty sure this was previously discussed somewhere earlier in this mega-thread, but can't seem to find it...
Title: Re: AJAX Launcher
Post by: sdsds on 04/27/2011 01:11 am
any difficulties in getting the stock LRBs to support the weight of the ET+payload[?]

Good question; I'm sure Downix will respond with details.

Meanwhile, one major aspect of AJAX to keep in mind is that unlike DIRECT, the core is really a beast quite different from the Shuttle ET.  For AJAX there's no cross-beam between the LH2 and LOX tanks because the booster thrust is transferred to the core down at its base.  That makes the AJAX core really beefy down at the bottom.

Of course your question was about the CCB, not about the core.  Note the CCB is already designed for the role of strap-on booster; that's what makes Atlas V Heavy available for order today.
Title: Re: AJAX Launcher
Post by: Downix on 04/27/2011 02:42 am
If this was actually to go forward and this rocket built I have no doubt it would present its many own little quirks as all large machines do.

One issue I was wondering about is if there'd be any difficulties in getting the stock LRBs to support the weight of the ET+payload, a role currently carried by the SRBs. I was pretty sure this was previously discussed somewhere earlier in this mega-thread, but can't seem to find it...
Simple, they're not.  All of ther weight is supported by the ET in this configuration.  Supporting weight by the CCB's is possible in theory, but studying it, the weight load for different CCB configurations eventually made the core too heavy.  It was better to put the support into the core, rather than passing that to the boosters as DIRECT and the Shuttle do.
Title: Re: AJAX Launcher
Post by: neilh on 04/27/2011 03:04 am
If this was actually to go forward and this rocket built I have no doubt it would present its many own little quirks as all large machines do.

One issue I was wondering about is if there'd be any difficulties in getting the stock LRBs to support the weight of the ET+payload, a role currently carried by the SRBs. I was pretty sure this was previously discussed somewhere earlier in this mega-thread, but can't seem to find it...
Simple, they're not.  All of ther weight is supported by the ET in this configuration.  Supporting weight by the CCB's is possible in theory, but studying it, the weight load for different CCB configurations eventually made the core too heavy.  It was better to put the support into the core, rather than passing that to the boosters as DIRECT and the Shuttle do.

In that case, is the ET brought "down" relative to where it is on STS so it's down at pad level, or is the launch pad modified to support the raised ET?
Title: Re: AJAX Launcher
Post by: Downix on 04/27/2011 03:28 am
If this was actually to go forward and this rocket built I have no doubt it would present its many own little quirks as all large machines do.

One issue I was wondering about is if there'd be any difficulties in getting the stock LRBs to support the weight of the ET+payload, a role currently carried by the SRBs. I was pretty sure this was previously discussed somewhere earlier in this mega-thread, but can't seem to find it...
Simple, they're not.  All of ther weight is supported by the ET in this configuration.  Supporting weight by the CCB's is possible in theory, but studying it, the weight load for different CCB configurations eventually made the core too heavy.  It was better to put the support into the core, rather than passing that to the boosters as DIRECT and the Shuttle do.

In that case, is the ET brought "down" relative to where it is on STS so it's down at pad level, or is the launch pad modified to support the raised ET?
AJAX would use new MLP's over the Shuttle.  50 years of exposure to the Florida air has made the MLP's close to retirement age anyways.  The new MLP's would have the ET actually below the base level, just slightly, much how the Saturn V was positioned on the MLP or Atlas V is today.  This way all exhaust is focused downward during the start-up, enabling the sound suppression system a leg up over what happens with the Shuttle as well as better channeling the exhaust.

The new MLP would also enable rapid rollout, being able to bring the rocket to the pad for same-day launch, much how both Delta and Atlas are handled.  Focus is on rapid turnaround, once you bring it out, you are prepared to launch.  Not roll it out, and launch it months later.  We have a dedicated MLP thread as well.
Title: Re: AJAX Launcher
Post by: Prober on 04/27/2011 03:33 am
hi i see alot of work has gone into AJAX.  Many of the ideas and concepts I agree with.  Couple of major issues you will need to deal with.

1 I do believe deeep down that congress or NASA will fight to keep any solids any future design.  Why was ares1 designed as such?

2 How flexable are you in the design?  My concept is a couple of steps beyond Shuttle C.  Yet it is very close to the main goes of the Energia. I wish to shoot for a full heavy lift system.  The heavy load would be side mounted.

http://k26.com/buran/html/why_mars_.html   Notice on the top left.

Title: Re: AJAX Launcher
Post by: neilh on 04/27/2011 03:35 am
In that case, is the ET brought "down" relative to where it is on STS so it's down at pad level, or is the launch pad modified to support the raised ET?
AJAX would use new MLP's over the Shuttle.  50 years of exposure to the Florida air has made the MLP's close to retirement age anyways.  The new MLP's would have the ET actually below the base level, just slightly, much how the Saturn V was positioned on the MLP or Atlas V is today.  This way all exhaust is focused downward during the start-up, enabling the sound suppression system a leg up over what happens with the Shuttle as well as better channeling the exhaust.

The new MLP would also enable rapid rollout, being able to bring the rocket to the pad for same-day launch, much how both Delta and Atlas are handled.  Focus is on rapid turnaround, once you bring it out, you are prepared to launch.  Not roll it out, and launch it months later.  We have a dedicated MLP thread as well.

Many thanks for the excellent answers, Downix!
Title: Re: AJAX Launcher
Post by: Downix on 04/27/2011 04:07 am
hi i see alot of work has gone into AJAX.  Many of the ideas and concepts I agree with.  Couple of major issues you will need to deal with.

1 I do believe deeep down that congress or NASA will fight to keep any solids any future design.  Why was ares1 designed as such?
Solids have their limits, and we're hitting them.  Ares I is a prime example of management overruling engineering.

But by Solids we really mean ATK, and ATK's support on the hill is a lot weaker today than it was in 2006.
Quote
2 How flexable are you in the design?  My concept is a couple of steps beyond Shuttle C.  Yet it is very close to the main goes of the Energia. I wish to shoot for a full heavy lift system.  The heavy load would be side mounted.

http://k26.com/buran/html/why_mars_.html   Notice on the top left.
Oh hey, love this site.

I'm not against side-mount for-se, but it limits growth potential.  Can't fit 8 boosters around it that way.  In addition, you can make a linear load carrying structure a lot lighter than a side-load carrying structure.  My study of architecture and engineering showed me that back in the 90's.  You will limit future growth through a side-mounted, in my study of the issues.

That being said, it is still possible to use a side-mounted fairing on AJAX as it is, using the support structures used for two of the boosters along with a nose-cap on the tank.

Energia was a smart design, but Russia's neo-Energia design reflects the past few decades of lessons, and is very AJAX-like.
Title: Re: AJAX Launcher
Post by: Lobo on 04/27/2011 03:44 pm
AJAX is *THE* answer to this whole mess.
AJAX is the *PERFECT* answer to this whole mess.

Is there any chance that one of the NASA RAC Teams came to this conclusion too, but decided it wasn't politically viable to go directly there?  And so this was a method of getting there politically?  Come up with an SRB LV using mostly existing hardware and people, and then open up bidding and do an in-depth cost analysis of the proposals knowing that AJAX will come out looking the best option?

Or do they have something else in mind that just by pure chance leaves the door open for AJAX?
Title: Re: AJAX Launcher
Post by: mike robel on 04/27/2011 04:39 pm
I would be surprised if anyone inside NASA is officially pushing AJAX, just like there was no official push for JUPITER/Direct.  I am not so confident, though, as to place money on it.
Title: Re: AJAX Launcher
Post by: baldusi on 04/27/2011 08:59 pm
I seriously doubt it. But basically because AJAX also assumes that you buy a stock Atlas V booster, and do minimum changes. Also assumes an efficient ground ops. They will find they need lots of mods, and those will be too expensive, etc. I'm feeling a pessimist today?
Title: Re: AJAX Launcher
Post by: Prober on 04/27/2011 09:17 pm
why are we shooting for 75 tons vs say 100 tons as a starting point?

Sure Ajax can do it and maybe better thaN you think.  With congress etc. involved wouldn't a 100 ton be a better choice?

Title: Re: AJAX Launcher
Post by: Downix on 04/27/2011 09:57 pm
I seriously doubt it. But basically because AJAX also assumes that you buy a stock Atlas V booster, and do minimum changes. Also assumes an efficient ground ops. They will find they need lots of mods, and those will be too expensive, etc. I'm feeling a pessimist today?
A bit.  I've also done a lot of the research, what changes would be needed.  Lockheed, when they designed the Atlas, had a similar concept to AJAX in their pile, which they called Concept 7 in a report they wrote in 2005.  Unlike Delta, which has very narrow margins requiring each launch configuration to have a slightly different CCB, Atlas has plenty of margin which means the existing CCB can be used in a Heavy, or as strap on boosters, right now.  The key is to make sure you keep the Atlas's need in mind when you build your main body.  This is not an assumption, it's a design rule.  If you cannot build it without changes to the CCB which are already accounted for (example, using strap on SRB's as well as the CCB's, or running the CCB's at 80% throttle vs 100%, or locking down the maneuvering controls, all of which the CCB is capable of right now) then using the Atlas CCB dies, simple as that, and Plan B is pulled out and use the Delta CBC which, due to needing to be modified for every flight configuration already enables the semi-custom configuration needed to be done without serious issue, although at harm to total program cost.  Remember, Delta only lost out to Atlas due to speed and money, not due to capability.  Delta would require additional costs associated with getting the design ready for human flight, a $1.5 billion program on it's own, and as a result test flights of the systems could not begin until  late 2015 instead of mid 2014 as with Atlas.  Having a two and a half year margin to identify faults and correct them is preferable to a one year margin.  Would it work, I am confident it would.  But the margin is too close for my comfort.

You'll find similar compromises no matter which booster it used, from the Zenit to the Falcon.  We evaluated, and based on what we found, the Atlas CCB has the highest likelihood of success.  But it has an advantage in that core changes needed for Atlas can carry over to Delta as well due to the similar design requirements of the EELV program, so there is an immediate Plan B and even the Taurus II first stage as a backup to the backup due to it's similarity to the Atlas CCB in first stage capability.  Falcon and Zenit, however, have very different flight profiles, and the core changes for AJAX do not work as well for them for easy swap-in.  To optimize the core between Atlas, Delta and Taurus requires minor adjustments.  To optimize to Falcon or Zenit would require some serious redesigning of the core, likely with less commonality in the tools which means higher cost and longer time to develop. 

That 2016 ready date is the key, you buy yourself every second you can so when overruns or delays happen, you have margin. 

Although the two-step program could buy some time, I'm not banking on it.  The less we deal with the SRB's the better in my viewpoint.  I'd rather focus on getting a HLV which can meet our demands for the foreseeable future, while also bringing the cost to launch in-line by increasing production of the most expensive component of our EELV fleet, the Atlas CCB. (although increasing Delta's CBC would be of help, it would not be as dramatic a help due to the previously mentioned semi-custom nature of the CBC's)
Title: Re: AJAX Launcher
Post by: Downix on 04/27/2011 10:02 pm
why are we shooting for 75 tons vs say 100 tons as a starting point?

Sure Ajax can do it and maybe better thaN you think.  With congress etc. involved wouldn't a 100 ton be a better choice?

Actually, aiming for a dynamic, scalable design, which goes from 50mT to 130mT.  The baseline configuration happens to be 70mT for simplicities sake, it meets the demand of the authorization Act.  It is no more difficult to build a 100mT version than a 50mT version, you just have differing numbers of CCB's and assemble it to meet your needs.  Similar to how Energia operated, with the M using two boosters, the flight version with 4, and with Vulkan having 8.  But while Energia was limited due to the sheer power of it's boosters to working in such even pairing, with AJAX and it's more even thrust capability you can have more off-balance numbers, enabling you to better custom fit the launch to your need, such as 6 boosters.
Title: Re: AJAX Launcher
Post by: Prober on 04/27/2011 10:42 pm
Question, does using CCBs instead of SRBs affect/remove the Base Heating issue? If so, could a human-rated (non-regen) RS-68A be used instead of SSME?
In theory yes.  However, no such engine at this time exists.  It would also require a larger tank, due to the isp issues, or an upper stage on every payload.  Part of the reason this design works at all is due to the SSME's efficiency.

In the back of my mind the SSME issue is bothering me.   Is there anyway (as a starting point) you can use the whole 3 SSME assembly from the space shuttle?  I recall the the video i watched two weeks ago from one of the project leaders.  The 4th engine added my create more problems than its worth.  Be like designing a new engine IMHO.

Title: Re: AJAX Launcher
Post by: Downix on 04/28/2011 01:52 am
Question, does using CCBs instead of SRBs affect/remove the Base Heating issue? If so, could a human-rated (non-regen) RS-68A be used instead of SSME?
In theory yes.  However, no such engine at this time exists.  It would also require a larger tank, due to the isp issues, or an upper stage on every payload.  Part of the reason this design works at all is due to the SSME's efficiency.

In the back of my mind the SSME issue is bothering me.   Is there anyway (as a starting point) you can use the whole 3 SSME assembly from the space shuttle?  I recall the the video i watched two weeks ago from one of the project leaders.  The 4th engine added my create more problems than its worth.  Be like designing a new engine IMHO.

We've explored that and it can be done, yes.  The reason why using 4 is to buy margin.  Using three the performance would go up, actually, due to not consuming the core fuel as rapidly.  If we can improve the T/W margin, through SSME thrust improvements, weight savings in the core (which I'll admit my estimates are purposefully heavy in order to buy margin), then there would be little issue in returning to 3 SSME.

That being said, I've never seen any scenario where a 4th SSME would prove as difficult as designing a new engine.  The support base for AJAX is not the same as the shuttle.  The loads are different, and it can take more stress than the Shuttles arrangement could.  Honestly, the way I'm drafting this design is to be solid.  I also have drafted alternative ways to mount the engines as well, including a solution to allow a reusable SSME to be reused.  But those are not cost effective at this point.  We just don't have the flight rate to make it cost effective.  We *may* get the Atlas to the point it becomes cost effective for that, and ULA has a system drafted for when that day comes, but that is still far in the future.
Title: Re: AJAX Launcher
Post by: Downix on 04/28/2011 09:52 pm
Ok, until this morning I knew AJAX was less expensive than other options, but not how much less.  As a challenge I did a comparison on AJAX using Falcon 9's instead of Atlas, found a little better performance with the F9's but also discovered how much more expensive it would be to operate, about 30% more per-flight using the F9 over the Atlas, and with additional overhead needs.  It is a nice feeling to know you've picked the right answer. 

*pets the CCB's*
Title: Re: AJAX Launcher
Post by: neilh on 04/28/2011 10:09 pm
Ok, until this morning I knew AJAX was less expensive than other options, but not how much less.  As a challenge I did a comparison on AJAX using Falcon 9's instead of Atlas, found a little better performance with the F9's but also discovered how much more expensive it would be to operate, about 30% more per-flight using the F9 over the Atlas, and with additional overhead needs.  It is a nice feeling to know you've picked the right answer. 

*pets the CCB's*

What cost numbers were you using?
Title: Re: AJAX Launcher
Post by: Downix on 04/29/2011 01:42 am
Ok, until this morning I knew AJAX was less expensive than other options, but not how much less.  As a challenge I did a comparison on AJAX using Falcon 9's instead of Atlas, found a little better performance with the F9's but also discovered how much more expensive it would be to operate, about 30% more per-flight using the F9 over the Atlas, and with additional overhead needs.  It is a nice feeling to know you've picked the right answer. 

*pets the CCB's*

What cost numbers were you using?
I put down a full breakdown on the other thread, but I used the published numbers for both, and then extrapolated the booster cost. I did have to revise after I realized I was underestimating overhead in worst-case scenarios for both designs.  The F9's boosters do come out more expensive than the Atlas's by about 10%.  But the higher cost of Atlas is due in part to having a much more expensive upper stage engine. (Falcon's first stage is approx 57% of the cost, while Atlas's first stage is only 27% once you remove the integration costs)

So, what I came down to wound up neck and neck, with Atlas having a slight edge in the estimated flight rate of 2 per year.  But, the overall cost of Atlas is not reflected in here, AJAX would almost triple Atlas production from 4 cores per year to 12, while Hippogriff would only add 50% production increase from 8 to 12, which means that the benefit for overall launch cost outside of the HLV is greater with AJAX.  Which means greater benefits for the launch community.

The other thread:
http://forum.nasaspaceflight.com/index.php?topic=24974.msg730933#msg730933

But to quote that thread:
Quote
Remember, this is using the Block 3 version of the Falcon 9, which has an early estimated flyaway cost of $57 million, with the heavy form of it having a flyaway cost of $124 million.  This gives us a tool to calculate the booster cost, you take the heavy, minus the core, divide by two, so (124-57)/2 = 33.5, so $33.5 million, right in line with your estimates. 

Let us compare this to the Atlas V cost, using the baseline, but do understand that this is ULA's pricing, which includes integration services and support costs not included in SpaceX's, so please no going "wow that's expensive" as it is including more in the pricetag, and also understand my pricing is from before the PWR price increases, which would effect the upper stage but not the booster so not relevant to this discussion.  The 401 for MAVEN is costing $192 million. The Atlas V Heavy comes in at $264 million.  Now, the Heavy not only has the three CCB but a Dual Engine Centaur as well, which adds $12 million to the cost, so, ($264-192-12)/2 = $30 million per booster.

Now, there is the cost of the SSME, but you're forgetting that this is a volume business, and we have a low volume for launch.  The price break for SSME production I found was 8 per year.  2 launches of 3, as on the Hippogriff 320, and the cost per SSME was approximately 30% higher than 2 launches of 4, eating up the cost benefit of one less SSME.  The estimated costs I have puts the RS-25d at $58 million at 6/year vs $45 million at 8/year. So, a Hippogriff 320 would have $174 million in RS-25d's vs the AJAX 440's $180 million.  The AJAX core is slightly less expensive as well, but only slightly, at $41 million each vs $44 million for Hippogriff, using the estimation system derived from the Shuttle ET costs.

But, none of this is including any overhead costs. While yes, the incidentals for a particular launch are lower for the Hippogriff, it does require some higher support overhead due to lack of shared suppliers.  This is SpaceX's one weakness of being vertically integrated, less sharing to reduce your overhead with.  The horizontal vs Vertical integration is a non-issue, mind you.  Prep the F9 booster in the old Orbiter Processing Bay, roll it over to the VAB for final integration, not a major issue. 

What I calculated out was that for two AJAX 440 launched per year the total direct launcher costs came to $370 million per launch not counting any overhead, integration, etc, while for a Hippogriff 320 it came to $310 million. But, comparing overhead needs, with Atlas it came out to ~$1.2 billion/year, due to those shared costs of Atlas reducing the overhead by that much. For Falcon it came out to ~$1.4 billion. While this may seem small, the edge is still with Atlas at the flight rates I'm expecting. At $60 million difference per-flight, it would take 4 flights to make enough difference, but if we got it to 4 flights, we would see other cost savings start hitting as well which would throw off all of these numbers again.

So, at the expected flight rate of 2 per year, the total launch cost for AJAX comes to ~$1.94 billion vs Hippogriff's ~$2.01 billion.  I know, we're talking $70 million difference here, but the LCROSS mission was $79 million to keep it in perspective.
Title: Re: AJAX Launcher
Post by: Prober on 04/29/2011 02:59 am
How do we plan on promoting Ajax?

Title: Re: AJAX Launcher
Post by: Downix on 04/29/2011 03:45 am
Any and every way we can.
Title: Re: AJAX Launcher
Post by: Prober on 04/29/2011 07:12 am
Any and every way we can.

I have an idea for you to think about that fixs alot of little issues with Ajax and also makes the sale alot easier.

1) Read somewhere that NASA bought a few large friction stir machines.
2) Also read somewhere that NASA wants its "own' engines etc.

The Atlas V is in high demand, Ajax might get rejected for that reason.

Was reading about the Atlas program and came to a winner IMHO the AtlasIIIA. Its man rated, uses the same engines and now retired.  So its
modern, more available and being 10ft dia. allows to add more booster engines to Ajax as needed.

So the key is that the tooling is not being used and might be transfered to where the shuttle tanks are made.  The other site could be the SRB are reworked near the cape.

This could be NASA's booster, and they can improved it.
L?ockhead might even have some pre made in stock
Your thoughts?

Title: Re: AJAX Launcher
Post by: MikeAtkinson on 04/29/2011 07:15 am
The SpaceX website says

F9: $54M - $59.5M (standard launch prices for 2013).
FH: $80M - $125M   (standard launch prices for 2013).

Taking the lower figures in both cases (80-54) / 2 = $13M. It is possible that the low FH figure is for a 1.5 configuration, without upper stage, even so the boosters may cost < $20M.

I'm not saying these figures are right, only that given the figures on the SpaceX website there is a wide range of possible booster costs.

Without actually getting cost data from SpaceX and ULA it is impossible to tell which is the cheaper.


Title: Re: AJAX Launcher
Post by: Prober on 04/29/2011 08:03 am
ATLAS III STAGE 1
Engines: P&W/NPO Energomash RD-180 with two gimbaled chambers
Length: 28.91 m
Diameter: 3.05 m
Dry mass: 13,725 kg
Oxidizer: liquid oxygen
Fuel: RP-1 hydrocarbon
Propellant mass: 183,200 kg
Thrust: 3,827 kN SL
Burn time: 184 s (182 s)

===========================

ATLAS V COMMON CORE BOOSTER (CCB)
Engines: P&W/NPO Energomash RD-180 with two gimbaled chambers
Length: 32.46 m
Diameter: 3.81 m
Dry mass: 20,743 kg (21,173 kg for 55X configuration)
Oxidizer: liquid oxygen
Fuel: RP-1 hydrocarbon
Propellant mass: 284,089 kg
Thrust: 3,827 kN SL
Burn time: 236 s to 252 s

Some numbers to run......



Title: Re: AJAX Launcher
Post by: Downix on 04/29/2011 02:04 pm
The SpaceX website says

F9: $54M - $59.5M (standard launch prices for 2013).
FH: $80M - $125M   (standard launch prices for 2013).

Taking the lower figures in both cases (80-54) / 2 = $13M. It is possible that the low FH figure is for a 1.5 configuration, without upper stage, even so the boosters may cost < $20M.

I'm not saying these figures are right, only that given the figures on the SpaceX website there is a wide range of possible booster costs.

Without actually getting cost data from SpaceX and ULA it is impossible to tell which is the cheaper.

In my experience, if budgeting, use the higher numbers. I also have higher fidelity numbers as well but cannot post them, so using the publically available information for this. Frankly could not be as close as I am if not for one 2013 launch posting their numbers.
Title: Re: AJAX Launcher
Post by: Downix on 04/29/2011 05:26 pm
Any and every way we can.

I have an idea for you to think about that fixs alot of little issues with Ajax and also makes the sale alot easier.

1) Read somewhere that NASA bought a few large friction stir machines.
2) Also read somewhere that NASA wants its "own' engines etc.

The Atlas V is in high demand, Ajax might get rejected for that reason.

Was reading about the Atlas program and came to a winner IMHO the AtlasIIIA. Its man rated, uses the same engines and now retired.  So its
modern, more available and being 10ft dia. allows to add more booster engines to Ajax as needed.

So the key is that the tooling is not being used and might be transfered to where the shuttle tanks are made.  The other site could be the SRB are reworked near the cape.

This could be NASA's booster, and they can improved it.
L?ockhead might even have some pre made in stock
Your thoughts?

Would increase the costs for no reason.  You would improve T/W, enabling the removal of an SSME, but would now need a second assembly line, with the overhead associated with that, and would not have high enough production to get the cost savings needed to make the program viable.  Remember, this is for 2 launches a year, 8 boosters in most scenarios.  That is less than the number ULA makes a year, meaning we can look at ULA's overhead to give a general idea of what these boosters overhead would be, and it's not pretty.

As for saying Atlas V is in high demand, ULA is running the Atlas line at a fraction of capacity.  They built the factory in Alabama to be able to pump out 50 first stages a year.  Between Atlas and Delta, they produce barely 10.  There would need to be a 5 fold increase in demand before there is any issue.  This plan would double their total core production, which would almost make their one shift of operation be fully productive.  Not fully, but almost (it would take 20 cores a year so I understand to make them fully productive). 

If demand grew to the point that there would be a shortfall in Atlas V CCB's, that would be a good thing for this country.  It would mean that US launch rates are at least triple what they are now, assuming ULA got all of those launch orders.  And then we could assess what was an option back when the USAF was concerned for just this reason, if demand outstripped production capacity there was an option to open up another assembly line at Michoud, the factory which makes the Shuttles ET and would be making the core for AJAX.  Reading those documents, that line could produce an additional 15 CCB's per year without any interruptions to ET production (and this is when whey were making 5+ ET's per year).

I do not see a logistical advantage to producing Atlas III cores for this.  The Atlas III was more expensive to build and operate than the Atlas V.  It would require a new assembly line, with new overhead costs, without enough of a launch cost reduction to compensate for it.

The only real issue I did find was RD-180 supply, we could outpace that a lot quicker than we could the CCB's, and using A3's would retain that, so the one real weak spot would not be traded.  But we have plans for that as well with the segment to produce a domestic RP-1 engine, either producing the RD-180 domestically or some other option as discussed above, and purchasing the CCB's sans engine to install them at KSC in the OPF's when we also add the control system, nosecap, and prepare them for installation in the VAB.
Title: Re: AJAX Launcher
Post by: Lobo on 04/29/2011 07:07 pm

As for saying Atlas V is in high demand, ULA is running the Atlas line at a fraction of capacity.  They built the factory in Alabama to be able to pump out 50 first stages a year.  Between Atlas and Delta, they produce barely 10.  There would need to be a 5 fold increase in demand before there is any issue.  This plan would double their total core production, which would almost make their one shift of operation be fully productive.  Not fully, but almost (it would take 20 cores a year so I understand to make them fully productive). 

If demand grew to the point that there would be a shortfall in Atlas V CCB's, that would be a good thing for this country.  It would mean that US launch rates are at least triple what they are now, assuming ULA got all of those launch orders.  And then we could assess what was an option back when the USAF was concerned for just this reason, if demand outstripped production capacity there was an option to open up another assembly line at Michoud, the factory which makes the Shuttles ET and would be making the core for AJAX.  Reading those documents, that line could produce an additional 15 CCB's per year without any interruptions to ET production (and this is when whey were making 5+ ET's per year).


Is there anyone at ULA aware of AJAX high enough up to matter?  To maybe get their lobbiests to start pushing for something AJAX-like for SLS?
Or are they just marching merrily on, oblivious to their financial potential in this design?

Personally, I still kinda like using Falcon boosters.  If for not other reason, than SpaceX seems like a more visionary and nimble company that would love to be part of SLS, and likely have every intention of keeping their costs down to make SLS as affordable as possible for NASA.
Somehow I seriously doubt ULA would have that intention in mind once SLS was married to them, any more than ATK has been since STS was married to them...
Title: Re: AJAX Launcher
Post by: Lobo on 04/29/2011 07:23 pm

So, what I came down to wound up neck and neck, with Atlas having a slight edge in the estimated flight rate of 2 per year.  But, the overall cost of Atlas is not reflected in here, AJAX would almost triple Atlas production from 4 cores per year to 12, while Hippogriff would only add 50% production increase from 8 to 12, which means that the benefit for overall launch cost outside of the HLV is greater with AJAX.  Which means greater benefits for the launch community.


Ack!  We are NOT calling the flagship rocket of the USA "Hippogriff".  No way.  I don't care how much the nerds like the mythological inside baseball of it.  WE don't want a rocket that makes people think of "Hippopotomous"

;-)

I think just referring to it as "AJAX" when we're talking about the stack wtih Atlas CCB's, and "FJAX" when talking about the stack with Falcon CCB's.  If we ever get to a point where this LV is actually being looked at and considered by people who can do something about it, then you can pick which booster you like better and come up with a different name if you want.

:-)

In fact, since AJAX originally stood for "Atlas-Jupiter Advanced eXperimental", and it sounds like the AJAX core would be quite a bit different thant he Jupiter core.  So you probably could drop the "J" from AJAX.  And if you are then leaning towards using Falcon cores, well then the first "A" goes away from "AJAX".

Might just have to come up with a new name for "AJAX" anyway. 
;-)

Although AJAX is short and pithy, and thus a handy name.
Title: Re: AJAX Launcher
Post by: Downix on 04/29/2011 07:46 pm

So, what I came down to wound up neck and neck, with Atlas having a slight edge in the estimated flight rate of 2 per year.  But, the overall cost of Atlas is not reflected in here, AJAX would almost triple Atlas production from 4 cores per year to 12, while Hippogriff would only add 50% production increase from 8 to 12, which means that the benefit for overall launch cost outside of the HLV is greater with AJAX.  Which means greater benefits for the launch community.


Ack!  We are NOT calling the flagship rocket of the USA "Hippogriff".  No way.  I don't care how much the nerds like the mythological inside baseball of it.  WE don't want a rocket that makes people think of "Hippopotomous"

;-)

I think just referring to it as "AJAX" when we're talking about the stack wtih Atlas CCB's, and "FJAX" when talking about the stack with Falcon CCB's.  If we ever get to a point where this LV is actually being looked at and considered by people who can do something about it, then you can pick which booster you like better and come up with a different name if you want.

:-)

In fact, since AJAX originally stood for "Atlas-Jupiter Advanced eXperimental", and it sounds like the AJAX core would be quite a bit different thant he Jupiter core.  So you probably could drop the "J" from AJAX.  And if you are then leaning towards using Falcon cores, well then the first "A" goes away from "AJAX".

Might just have to come up with a new name for "AJAX" anyway. 
;-)

Although AJAX is short and pithy, and thus a handy name.
The J does not necessarily reflect the DIRECT Jupiter you realize.  Chrysler's Space Division built the Jupiter IRBM and Redstone missile, don't forget. Michouds first role for NASA was to utilize the Redstone and Jupiter fuel tanks to manufacture the Saturn IB stage, later the Saturn II stage for the Saturn V rocket.  AJAX builds upon that legacy, of the Saturn as the SuperJupiter, so the name still works.
Title: Re: AJAX Launcher
Post by: Downix on 04/29/2011 07:56 pm

As for saying Atlas V is in high demand, ULA is running the Atlas line at a fraction of capacity.  They built the factory in Alabama to be able to pump out 50 first stages a year.  Between Atlas and Delta, they produce barely 10.  There would need to be a 5 fold increase in demand before there is any issue.  This plan would double their total core production, which would almost make their one shift of operation be fully productive.  Not fully, but almost (it would take 20 cores a year so I understand to make them fully productive). 

If demand grew to the point that there would be a shortfall in Atlas V CCB's, that would be a good thing for this country.  It would mean that US launch rates are at least triple what they are now, assuming ULA got all of those launch orders.  And then we could assess what was an option back when the USAF was concerned for just this reason, if demand outstripped production capacity there was an option to open up another assembly line at Michoud, the factory which makes the Shuttles ET and would be making the core for AJAX.  Reading those documents, that line could produce an additional 15 CCB's per year without any interruptions to ET production (and this is when whey were making 5+ ET's per year).


Is there anyone at ULA aware of AJAX high enough up to matter?  To maybe get their lobbiests to start pushing for something AJAX-like for SLS?
Or are they just marching merrily on, oblivious to their financial potential in this design?

Personally, I still kinda like using Falcon boosters.  If for not other reason, than SpaceX seems like a more visionary and nimble company that would love to be part of SLS, and likely have every intention of keeping their costs down to make SLS as affordable as possible for NASA.
Somehow I seriously doubt ULA would have that intention in mind once SLS was married to them, any more than ATK has been since STS was married to them...
Part of the idea is that the boosters would be purchased in a COTS method over the cost-plus as the SRB's have been.  This fits in with ULA's current operating method.  In addition, AJAX is not "married" to them, just baselining the spec around them.  If ULA's costs grew too much, switching to another booster is more than possible, once the hard work to the tank is done.  Of the US booster options, most are similar to the Atlas for T/W, with only the Falcon having a notably greater T/W.  And it would not even have to be an existing booster, as a replacement would need to be bid.  But you need a flying system first, hence why the initial pairing to the Atlas.  If you notice in my MLP design, I have the exhaust hole open in a particular way to enable more flexibility.  Could use Delta CBC, Taurus II's first stage, Buzz Aldrin's Starbooster concept, lots of options.  But we don't have time to explore every options right now, which is why the focus on getting a system which works now.
Title: Re: AJAX Launcher
Post by: Rocket Science on 04/29/2011 10:02 pm
You know... if you keep this up, you're going to get one of those "who are you guys?" from Leroy Chiao. Which is a good thing!;)
Title: Re: AJAX Launcher
Post by: Prober on 04/29/2011 10:52 pm

If there's show stoppers with SpaceX, I obviously have no qualms with ULA.  Go with the best option I say.  Just asking the questions, that's all.  :-)

ULA has more political clout at the moment as well.  I have to think in terms of politics as well.  SpaceX does not play this game anywhere near as well as ULA does.  Fighting against ATK, as this would inevitably be, you need as many 800 lbs gorillas on your side as possible.

Sorry to disagree with you but ULA will become an 80lb weakling this year.  Austerity trumps them all in FY012
Title: Re: AJAX Launcher
Post by: Downix on 04/29/2011 11:35 pm

If there's show stoppers with SpaceX, I obviously have no qualms with ULA.  Go with the best option I say.  Just asking the questions, that's all.  :-)

ULA has more political clout at the moment as well.  I have to think in terms of politics as well.  SpaceX does not play this game anywhere near as well as ULA does.  Fighting against ATK, as this would inevitably be, you need as many 800 lbs gorillas on your side as possible.

Sorry to disagree with you but ULA will become an 80lb weakling this year.  Austerity trumps them all in FY012

I'm afraid you're buying into a bit of marketing hype there.  LockMart and Boeing both have more lobbying muscle than most people can imagine, with an army of Lobbyists.  This "Age of Austerity" will not diminish their lobbying capacity, but it will require them to be more frugal with their lobbying.  Something in the nature of AJAX plays into this new Austerity, it would make the money used to support ULA go much further. 
Title: Re: AJAX Launcher
Post by: Lobo on 04/29/2011 11:46 pm
Part of the idea is that the boosters would be purchased in a COTS method over the cost-plus as the SRB's have been.  This fits in with ULA's current operating method.  In addition, AJAX is not "married" to them, just baselining the spec around them.  If ULA's costs grew too much, switching to another booster is more than possible, once the hard work to the tank is done.  Of the US booster options, most are similar to the Atlas for T/W, with only the Falcon having a notably greater T/W.  And it would not even have to be an existing booster, as a replacement would need to be bid.  But you need a flying system first, hence why the initial pairing to the Atlas.  If you notice in my MLP design, I have the exhaust hole open in a particular way to enable more flexibility.  Could use Delta CBC, Taurus II's first stage, Buzz Aldrin's Starbooster concept, lots of options.  But we don't have time to explore every options right now, which is why the focus on getting a system which works now.

Understood.  If the core is designed from the jump to allow more boosters than just the Atlas to hook to it, that'd certainly give NASA leverage in the future if/when ULA starts to try to squeeze them. 
By "married" I just mean that Inertia is hard to overcome, especially in government.  Once you go one direction it it sometimes very hard to take a different direction down the road.  FUnding, politics, etc.
That becomes harder if making that change would result in costly LV modifications, more test flight to requalify, etc.  So sometimes you can get "married" via common law.  ;-)

Tauras II has about 70% of the power of Falcon 9 (Merlin 1c) or Atlas V CCB, right?
So how much paylaod to LEO could 4 Taurus II Booster throw compared to Atlas or Falcon?
Title: Re: AJAX Launcher
Post by: Lobo on 04/30/2011 12:23 am

The J does not necessarily reflect the DIRECT Jupiter you realize.  Chrysler's Space Division built the Jupiter IRBM and Redstone missile, don't forget. Michouds first role for NASA was to utilize the Redstone and Jupiter fuel tanks to manufacture the Saturn IB stage, later the Saturn II stage for the Saturn V rocket.  AJAX builds upon that legacy, of the Saturn as the SuperJupiter, so the name still works.

I see your point, but now you are trying to reach a bit to justify it after the fact.  I was there when "AJAX" was born on the forum, and even helped (in a small way) to come up with the name and acronym (on one of the Direct threads if I remember right) 
And what got it started was a discussion of replacing the ATK SRB's on Direct (if Direct were to be chosen as SLS), either because that'd be a safer/more flexible option, or if ATK became a problem in the future with their SRB production.
And because this would basically be a Direct "Jupiter" with "Altlas" CCB LRB's, several of us were kicking around a way to ust the J for Jupiter and "A" for Atlas to call it something other than Jupiter-LRB or whatever people were using to refer to it to distinquish it from the regular SRB Jupiter.  (Which you Downix, obviously grabbed that ball and ran with it!)

So yea, you can go back after the fact and try to come up with something else to make "AJAX" work, but "Atlas" and the Direct "Jupiter" were the genesis of the "J" and one of the "A"s in AJAX.  :-)
But heck, usually the military and NASA seem to both come up with the acronym first, then try to figure out what it stands for.  No reason you can't do it too.  :-)

As long as it's not "Hippogriff", sticking with "AJAX" is fine by me.  I was just trying to ironic.

AJAX is obviously a mythology reference into itself.  And it's more pithy than many Greek mythological heroes/gods such as Odysseus, Diomedes, Hephaestus, etc....which are a bit of a mouthful.
"Achillies" isn't bad, but I don't think anyone wants to name their rocket after even this most famous of Greek heroes because of the obvious reference to having an "Achillies Heel"... if there was ever an actual problem when the rocket, you'd never hear the end of it! heheheheh

Since Saturn and the planets were named after Roman gods, you could be bold enough and call it "Mars", as the rocket that will [hopefully] get us to Mars!  Pithy and bold!  ;-)

Or heck, why are we naming it after Greek and Roman mythology at all.  This will be an American Rocket. Let's name it after American Mythology.  Call it, "Paul Bunyan", "John Henry", "Pecos Bill", "Bigfoot", "Captain America", "Superman", "Iron Man", "The Hulk", or "Batman".
Our comic book superheroes are really our own American Mythology when you think about it.
Besides, how bold and in-your-face would it be to have NASA's flagship rocket called "Captain America"?  We can play the "Team America:  World Police" theme when we launch it.  Our Russian, Japanese, and European partners will love that I'm sure.

But I digress... 

;-)
Title: Re: AJAX Launcher
Post by: mike robel on 04/30/2011 12:45 am
I will tell you why.  Same reason an aircraft carrier should not be named America or United States:

America stuck in the mud
United States blows Up
America sunk
Title: Re: AJAX Launcher
Post by: Downix on 04/30/2011 12:51 am
Part of the idea is that the boosters would be purchased in a COTS method over the cost-plus as the SRB's have been.  This fits in with ULA's current operating method.  In addition, AJAX is not "married" to them, just baselining the spec around them.  If ULA's costs grew too much, switching to another booster is more than possible, once the hard work to the tank is done.  Of the US booster options, most are similar to the Atlas for T/W, with only the Falcon having a notably greater T/W.  And it would not even have to be an existing booster, as a replacement would need to be bid.  But you need a flying system first, hence why the initial pairing to the Atlas.  If you notice in my MLP design, I have the exhaust hole open in a particular way to enable more flexibility.  Could use Delta CBC, Taurus II's first stage, Buzz Aldrin's Starbooster concept, lots of options.  But we don't have time to explore every options right now, which is why the focus on getting a system which works now.

Understood.  If the core is designed from the jump to allow more boosters than just the Atlas to hook to it, that'd certainly give NASA leverage in the future if/when ULA starts to try to squeeze them. 
By "married" I just mean that Inertia is hard to overcome, especially in government.  Once you go one direction it it sometimes very hard to take a different direction down the road.  FUnding, politics, etc.
That becomes harder if making that change would result in costly LV modifications, more test flight to requalify, etc.  So sometimes you can get "married" via common law.  ;-)

Tauras II has about 70% of the power of Falcon 9 (Merlin 1c) or Atlas V CCB, right?
So how much paylaod to LEO could 4 Taurus II Booster throw compared to Atlas or Falcon?
Taurus II has 85% of the thrust, but also has only 85% of the weight of the Atlas V, so it becomes a wash for performance.  We discussed the performance difference between the two on this thread:
http://forum.nasaspaceflight.com/index.php?topic=22340.0

From a T/W ratio (which is the main concern here) the Falcon 9 Block 3 is better than both the Taurus II and Atlas, but has fewer points of commonality.  Delta IV CBC has a similar T/W to the Falcon 9 Block 3 first stage too I should note.
Title: Re: AJAX Launcher
Post by: Prober on 04/30/2011 01:45 am

If there's show stoppers with SpaceX, I obviously have no qualms with ULA.  Go with the best option I say.  Just asking the questions, that's all.  :-)

ULA has more political clout at the moment as well.  I have to think in terms of politics as well.  SpaceX does not play this game anywhere near as well as ULA does.  Fighting against ATK, as this would inevitably be, you need as many 800 lbs gorillas on your side as possible.

Sorry to disagree with you but ULA will become an 80lb weakling this year.  Austerity trumps them all in FY012

I'm afraid you're buying into a bit of marketing hype there.  LockMart and Boeing both have more lobbying muscle than most people can imagine, with an army of Lobbyists.  This "Age of Austerity" will not diminish their lobbying capacity, but it will require them to be more frugal with their lobbying.  Something in the nature of AJAX plays into this new Austerity, it would make the money used to support ULA go much further. 

The DoD cuts will tax Lobbing efforts as it turns to survival mode for high ticket projects.  Meanwhile Boden will do the Administrations bidding.  NASA in the end will have little interest.    The numbers don’t lie and Austerity will trump.
Title: Re: AJAX Launcher
Post by: Downix on 04/30/2011 02:38 am

If there's show stoppers with SpaceX, I obviously have no qualms with ULA.  Go with the best option I say.  Just asking the questions, that's all.  :-)

ULA has more political clout at the moment as well.  I have to think in terms of politics as well.  SpaceX does not play this game anywhere near as well as ULA does.  Fighting against ATK, as this would inevitably be, you need as many 800 lbs gorillas on your side as possible.

Sorry to disagree with you but ULA will become an 80lb weakling this year.  Austerity trumps them all in FY012

I'm afraid you're buying into a bit of marketing hype there.  LockMart and Boeing both have more lobbying muscle than most people can imagine, with an army of Lobbyists.  This "Age of Austerity" will not diminish their lobbying capacity, but it will require them to be more frugal with their lobbying.  Something in the nature of AJAX plays into this new Austerity, it would make the money used to support ULA go much further. 

The DoD cuts will tax Lobbing efforts as it turns to survival mode for high ticket projects.  Meanwhile Boden will do the Administrations bidding.  NASA in the end will have little interest.    The numbers don’t lie and Austerity will trump.
Precisely, in an age of Austerity, cuts will happen.  It is those with lobbying power who will salvage more out of those cuts.  Bolden presented originally a plan focusing on utilizing the EELV's, remember.  It is Congress who pushed the SLS.  This gives us the edge, the more Austerity there is, the stronger the case for AJAX is.
Title: Re: AJAX Launcher
Post by: Lobo on 05/02/2011 03:50 pm
Taurus II has 85% of the thrust, but also has only 85% of the weight of the Atlas V, so it becomes a wash for performance.  We discussed the performance difference between the two on this thread:
http://forum.nasaspaceflight.com/index.php?topic=22340.0


Ok, I'll check that out.  I was just going by the wikipedia entry for Tarus II, which said about 7mt to LEO, compared with around 10mt to LEO for single stick Atlas V and current F9.

Title: Re: AJAX Launcher
Post by: Downix on 05/02/2011 04:32 pm
Taurus II has 85% of the thrust, but also has only 85% of the weight of the Atlas V, so it becomes a wash for performance.  We discussed the performance difference between the two on this thread:
http://forum.nasaspaceflight.com/index.php?topic=22340.0


Ok, I'll check that out.  I was just going by the wikipedia entry for Tarus II, which said about 7mt to LEO, compared with around 10mt to LEO for single stick Atlas V and current F9.

Atlas V has a much better upper stage.  Falcon 9 has more T/W margin and a slightly better upper stage.

If you look at the T2 with liquid upper stage, it is also 10mT.
Title: Re: AJAX Launcher
Post by: madscientist197 on 05/03/2011 11:32 am
I put down a full breakdown on the other thread, but I used the published numbers for both, and then extrapolated the booster cost. I did have to revise after I realized I was underestimating overhead in worst-case scenarios for both designs.  The F9's boosters do come out more expensive than the Atlas's by about 10%.  But the higher cost of Atlas is due in part to having a much more expensive upper stage engine. (Falcon's first stage is approx 57% of the cost, while Atlas's first stage is only 27% once you remove the integration costs)

So, what I came down to wound up neck and neck, with Atlas having a slight edge in the estimated flight rate of 2 per year.  But, the overall cost of Atlas is not reflected in here, AJAX would almost triple Atlas production from 4 cores per year to 12, while Hippogriff would only add 50% production increase from 8 to 12, which means that the benefit for overall launch cost outside of the HLV is greater with AJAX.  Which means greater benefits for the launch community.

The other thread:
http://forum.nasaspaceflight.com/index.php?topic=24974.msg730933#msg730933

While I can't say that you are necessarily wrong, it's a bit dangerous to extrapolate this much from a couple of cost figures (especially cost figures from SpaceX).
Title: Re: AJAX Launcher
Post by: Downix on 05/03/2011 02:37 pm
I put down a full breakdown on the other thread, but I used the published numbers for both, and then extrapolated the booster cost. I did have to revise after I realized I was underestimating overhead in worst-case scenarios for both designs.  The F9's boosters do come out more expensive than the Atlas's by about 10%.  But the higher cost of Atlas is due in part to having a much more expensive upper stage engine. (Falcon's first stage is approx 57% of the cost, while Atlas's first stage is only 27% once you remove the integration costs)

So, what I came down to wound up neck and neck, with Atlas having a slight edge in the estimated flight rate of 2 per year.  But, the overall cost of Atlas is not reflected in here, AJAX would almost triple Atlas production from 4 cores per year to 12, while Hippogriff would only add 50% production increase from 8 to 12, which means that the benefit for overall launch cost outside of the HLV is greater with AJAX.  Which means greater benefits for the launch community.

The other thread:
http://forum.nasaspaceflight.com/index.php?topic=24974.msg730933#msg730933

While I can't say that you are necessarily wrong, it's a bit dangerous to extrapolate this much from a couple of cost figures (especially cost figures from SpaceX).
It is saying a lot, however, when while using cost figures from SpaceX that they remain the more expensive option, yes?
Title: Re: AJAX Launcher
Post by: HappyMartian on 05/04/2011 01:26 pm
I put down a full breakdown on the other thread, but I used the published numbers for both, and then extrapolated the booster cost. I did have to revise after I realized I was underestimating overhead in worst-case scenarios for both designs.  The F9's boosters do come out more expensive than the Atlas's by about 10%.  But the higher cost of Atlas is due in part to having a much more expensive upper stage engine. (Falcon's first stage is approx 57% of the cost, while Atlas's first stage is only 27% once you remove the integration costs)

So, what I came down to wound up neck and neck, with Atlas having a slight edge in the estimated flight rate of 2 per year.  But, the overall cost of Atlas is not reflected in here, AJAX would almost triple Atlas production from 4 cores per year to 12, while Hippogriff would only add 50% production increase from 8 to 12, which means that the benefit for overall launch cost outside of the HLV is greater with AJAX.  Which means greater benefits for the launch community.

The other thread:
http://forum.nasaspaceflight.com/index.php?topic=24974.msg730933#msg730933

While I can't say that you are necessarily wrong, it's a bit dangerous to extrapolate this much from a couple of cost figures (especially cost figures from SpaceX).
It is saying a lot, however, when while using cost figures from SpaceX that they remain the more expensive option, yes?

Well, maybe it has something to do with the RD-180. When I suggested that SpaceX might consider making use of RD-180s not too many folks agreed with me...  ;)

Cheers!
Title: Re: AJAX Launcher
Post by: baldusi on 05/04/2011 02:45 pm
It is saying a lot, however, when while using cost figures from SpaceX that they remain the more expensive option, yes?
May be you should qualify that a bit. You said that the marginal price was cheaper, but the overhead price was higher due to less synergies with other gvt spendings, right?
Title: Re: AJAX Launcher
Post by: Downix on 05/04/2011 02:49 pm
It is saying a lot, however, when while using cost figures from SpaceX that they remain the more expensive option, yes?
May be you should qualify that a bit. You said that the marginal price was cheaper, but the overhead price was higher due to less synergies with other gvt spendings, right?
I was referring to just the booster cost itself, the F9 Block III first stage is 10% more expensive than the Atlas V's CCB. 

Of course to be fair, the Atlas V Phase II is estimated to be more expensive, while enabling the same kinds of reduction in SSME's and boosters.
Title: Re: AJAX Launcher
Post by: baldusi on 05/04/2011 03:14 pm
It is saying a lot, however, when while using cost figures from SpaceX that they remain the more expensive option, yes?
May be you should qualify that a bit. You said that the marginal price was cheaper, but the overhead price was higher due to less synergies with other gvt spendings, right?
I was referring to just the booster cost itself, the F9 Block III first stage is 10% more expensive than the Atlas V's CCB. 

Of course to be fair, the Atlas V Phase II is estimated to be more expensive, while enabling the same kinds of reduction in SSME's and boosters.
Could you put a table on the first post comparing AJAX, AJAX-F and/or AJAX-D and AJAX-T and AJAX-II (atlas V phase II)?

I know that AJAX-F is:
AJAX-F
Overhead: 1.4B
Conf - LEO - Cost
320 - 72mT - 310M
340 - 94mT - 376M?
360 - 121 mT - 442M?
380 - 144 mT - 508M?

AJAX
Overhead: 1.2B
440 - ?? - 370M
460 - ?? - 430M
480 - ?? - 490M

Etc?
One small detail, you said that the cost of the RS-25D was 58M at 6/yr and 45M at 8/yr. I understand thus, that the RS-25 has an overhead of 312M and a marginal cost of 6M per engine. Does that seems right?
Title: Re: AJAX Launcher
Post by: MikeAtkinson on 05/04/2011 03:58 pm
I was referring to just the booster cost itself, the F9 Block III first stage is 10% more expensive than the Atlas V's CCB. 

I'm trying to understand the booster costs.

Are these costs direct quotes from SpaceX and ULA for boosters for this application?

Are they general costs for the boosters or are they for boosters specifically designed/integrated/qualified for AJAX?

Have you computed them in some way based on launch costs (perhaps using non-public information?

Do the costs include support from SpaceX and ULA for integration and launch? If they do, how are the support costs calculated?

Are the costs for any design changes, integration and qualification included in the cost of the boosters or are they subsumed into the general AJAX development costs?

What assumptions have been made about cost growth between now and the FOC (2017?) of AJAX?

I realise that you might not be able to answer all these in detail due to confidential information.
Title: Re: AJAX Launcher
Post by: sdsds on 05/04/2011 04:07 pm
you said that the cost of the RS-25D was 58M at 6/yr and 45M at 8/yr. I understand thus, that the RS-25 has an overhead of 312M and a marginal cost of 6M per engine. Does that seems right?

If you're looking for a linear model of reality, go for it.  Just don't expect reality to match a linear approximation!  Reality almost certainly has discontinuities; the exact quantities where those discontinuities would be visible in quoted prices is presumably not public information, and might have changed over time.  If a customer negotiated today for a production run of four or six engines identical to Block II SSME, the price per engine might easily be $72M or more.  If that same customer entered into a multi-year contract for many more engines, and were willing to tolerate some differences between the engines delivered and Block II SSME, the customer might be able to negotiate a considerably lower price.  Per engine prices of $36M have been mentioned.

I have previously suggested one pricing model:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=22266.0;attach=282639
Title: Re: AJAX Launcher
Post by: Downix on 05/04/2011 04:25 pm
I was referring to just the booster cost itself, the F9 Block III first stage is 10% more expensive than the Atlas V's CCB. 

I'm trying to understand the booster costs.

Are these costs direct quotes from SpaceX and ULA for boosters for this application?
For SpaceX's prices I used their proposed pricing for the F9H.  For ULA I used the cost of three existing missions (two for 2012, one for 2013).  So, one is "we hope it will be this price" and the other is "this is the price someone has already paid" with the known cost of the unflown Heavy paired against it.
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Are they general costs for the boosters or are they for boosters specifically designed/integrated/qualified for AJAX?
The point of AJAX is to be off-the-shelf as much as possible.  Basically pulling the boosters off the assembly line before they are integrated with an upper stage.  Any work beyond this is handled at KSC during the integration process.  With the AJAX core design for Atlas anyways, there is no need for modifications due to the Atlas' design and margins.  It has plenty of wiggle room for what we need.  If you went with the Delta version, then there would be a larger operational cost due to the changes.  Falcon is an unknown, due to how little information SpaceX has released.
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Have you computed them in some way based on launch costs (perhaps using non-public information?
For Atlas V, it is paid for launch costs.  For the Falcon 9 Block III, this is impossible as there has been no launches of the Block III yet, nor will there be until 2013 at the earliest, so the proposed pricing on SpaceX's website has been used. I did not adjust SpaceX's prices for any growth, unlike ULA's which based on 2012/2013 known pricing for ordered missions.
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Do the costs include support from SpaceX and ULA for integration and launch? If they do, how are the support costs calculated?
ULA does include that in it's costs.  So I understand it, SpaceX does not include that in the cost it gives out.  As for calculating out support costs for ULA, I compared the pricing with and without the center module using another launch to subtract from.  Most of the integration and launch costs will be the same between one with and without the Heavy's CCB's if you compare the Heavy's documentations, proposal to the DoD, and current ULA documentation on it.
[/quote]
Are the costs for any design changes, integration and qualification included in the cost of the boosters or are they subsumed into the general AJAX development costs?
[/quote]
There are no design changes for the boosters, which is one of the points of AJAX, to use them off-the-shelf as it were.  Instead the core was adjusted to integrate to the boosters.  Qualification needs vary depending on the particular booster.  For the baseline, using Atlas V, the Qualification will be paired with Orion flight testing on Atlas V Heavy.  Integration is part of the general AJAX development cost.
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What assumptions have been made about cost growth between now and the FOC (2017?) of AJAX?
Right now I am using FY12 dollar units, and FY12's budget breakdown.  The reason being is that FY12 is looking to have the largest price jump, due to the shutdown of the Shuttle program hurting the supply chain.  Which means the majority of cost increases will occur in the next 12 months.  By working on this baseline, once AJAX starts development it would actually push prices back down by increasing the production rate again, restoring it to Shuttle-era levels, so that once launch time happens, it will be, through cost growth, back to FY12 levels.
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I realise that you might not be able to answer all these in detail due to confidential information.
Answered what I could.
Title: Re: AJAX Launcher
Post by: Downix on 05/04/2011 04:31 pm
It is saying a lot, however, when while using cost figures from SpaceX that they remain the more expensive option, yes?
May be you should qualify that a bit. You said that the marginal price was cheaper, but the overhead price was higher due to less synergies with other gvt spendings, right?
I was referring to just the booster cost itself, the F9 Block III first stage is 10% more expensive than the Atlas V's CCB. 

Of course to be fair, the Atlas V Phase II is estimated to be more expensive, while enabling the same kinds of reduction in SSME's and boosters.
Could you put a table on the first post comparing AJAX, AJAX-F and/or AJAX-D and AJAX-T and AJAX-II (atlas V phase II)?

I know that AJAX-F is:
AJAX-F
Overhead: 1.4B
Conf - LEO - Cost
320 - 72mT - 310M
340 - 94mT - 376M?
360 - 121 mT - 442M?
380 - 144 mT - 508M?

AJAX
Overhead: 1.2B
440 - ?? - 370M
460 - ?? - 430M
480 - ?? - 490M

Etc?
One small detail, you said that the cost of the RS-25D was 58M at 6/yr and 45M at 8/yr. I understand thus, that the RS-25 has an overhead of 312M and a marginal cost of 6M per engine. Does that seems right?
The RS-25 can get as low as $36 mil per unit, if we could get it to 16 engines.  But, as sdsds pointed out, all of this depends on a lot of things.  I used worst case scenarios for my pricing, so as to maximize the buffer in my budget.  So I have the pricing for one-off construction, rather than multi-year contracts, for instance.  I do not presume what a multi-year would run, that would be nonsense for me to even try and presume. 

Your estimate for overhead is off, however, as the cost of a single RS-25D is $80 mil.

*edit* typo
Title: Re: AJAX Launcher
Post by: baldusi on 05/04/2011 04:32 pm
you said that the cost of the RS-25D was 58M at 6/yr and 45M at 8/yr. I understand thus, that the RS-25 has an overhead of 312M and a marginal cost of 6M per engine. Does that seems right?

If you're looking for a linear model of reality, go for it.  Just don't expect reality to match a linear approximation!  Reality almost certainly has discontinuities; the exact quantities where those discontinuities would be visible in quoted prices is presumably not public information, and might have changed over time.  If a customer negotiated today for a production run of four or six engines identical to Block II SSME, the price per engine might easily be $72M or more.  If that same customer entered into a multi-year contract for many more engines, and were willing to tolerate some differences between the engines delivered and Block II SSME, the customer might be able to negotiate a considerably lower price.  Per engine prices of $36M have been mentioned.

I have previously suggested one pricing model:
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=22266.0;attach=282639
That's not exactly an ongoing model, that's a particular case. And of course that reality is hardly ever linear, but in economics aproximate is good enough. For example, an R-squared of .55 is the norm in econometrics. In fact, if you get  0.95 is veeeeery suspicious. You might always improve the cost and/or performance of the engine. That's why engineers are paid. But you have to plan for the upper bound. If you go above that you now somebody is doing something wrong.
You might say, for example, that you have to invest a certain amount on tooling at first. If you want to linealize that, take a loan of fixed payments. You obviously have a maximum capacity, and going over that requires further expenses (like new building, taking a new shift, or extra machines). And machines have a useful life, so once your total output (regardless of time) goes above certain level, you have to buy new one, which might not be available by the time you need them. Now, do you really want to do all that analysis, and be probably wrong in the end anyways because somebody got a great idea or somebody did something wrong? Or isn't it simpler to take a lineal approach and add a contingency margin?
Title: Re: AJAX Launcher
Post by: baldusi on 05/04/2011 04:39 pm
The RS-25 can get as low as $36 mil/year, if we could get it to 16 engines.  But, as sdsds pointed out, all of this depends on a lot of things.  I used worst case scenarios for my pricing, so as to maximize the buffer in my budget.  So I have the pricing for one-off construction, rather than multi-year contracts, for instance.  I do not presume what a multi-year would run, that would be nonsense for me to even try and presume. 

Your estimate for overhead is off, however, as the cost of a single RS-25D is $80 mil.

Can you get at least eight different amounts? Then we can actually use an estimator with a certain confidence level.

In any case I was more interested in the payload of the AJAX since I forgot how much would it lift  :(
Title: Re: AJAX Launcher
Post by: Downix on 05/04/2011 04:52 pm
The RS-25 can get as low as $36 mil/year, if we could get it to 16 engines.  But, as sdsds pointed out, all of this depends on a lot of things.  I used worst case scenarios for my pricing, so as to maximize the buffer in my budget.  So I have the pricing for one-off construction, rather than multi-year contracts, for instance.  I do not presume what a multi-year would run, that would be nonsense for me to even try and presume. 

Your estimate for overhead is off, however, as the cost of a single RS-25D is $80 mil.

Can you get at least eight different amounts? Then we can actually use an estimator with a certain confidence level.

In any case I was more interested in the payload of the AJAX since I forgot how much would it lift  :(
It's not a linear growth, the overhead needs for a single engine is different than for 6, so I understand. 

The key right now is not the total payloads, but the targeted. The senate guidelines are for 70mT, hence the focus on that.  For the 70mT number, you have the AJAX-440, AJAX/P2-220, AJAX/D-340 and AJAX/F-320. (not using a special number for the Taurus II because it's virtually identical to the Atlas baseline in all estimations I've run) 
Title: Re: AJAX Launcher
Post by: baldusi on 05/04/2011 06:03 pm
The key right now is not the total payloads, but the targeted. The senate guidelines are for 70mT, hence the focus on that.  For the 70mT number, you have the AJAX-440, AJAX/P2-220, AJAX/D-340 and AJAX/F-320. (not using a special number for the Taurus II because it's virtually identical to the Atlas baseline in all estimations I've run) 
Ok, that's the baseline, but you also need a 130mT (or 122mT) growth option. The AJAX/F-380 does that. The -480? The P2-240? You'd be talking about IMLEO in {-481,F-381,etc} case, right?
Title: Re: AJAX Launcher
Post by: Downix on 05/04/2011 06:05 pm
The key right now is not the total payloads, but the targeted. The senate guidelines are for 70mT, hence the focus on that.  For the 70mT number, you have the AJAX-440, AJAX/P2-220, AJAX/D-340 and AJAX/F-320. (not using a special number for the Taurus II because it's virtually identical to the Atlas baseline in all estimations I've run) 
Ok, that's the baseline, but you also need a 130mT (or 122mT) growth option. The AJAX/F-380 does that. The -480? The P2-240? You'd be talking about IMLEO in {-481,F-381,etc} case, right?
For the 130mT, you'd have AJAX-480, AJAX/F-380, AJAX/D-360 and AJAX/P2-260.
Title: Re: AJAX Launcher
Post by: discovery_fan on 05/05/2011 11:29 am
One issue I was wondering about is if there'd be any difficulties in getting the stock LRBs to support the weight of the ET+payload, a role currently carried by the SRBs. I was pretty sure this was previously discussed somewhere earlier in this mega-thread, but can't seem to find it...
Quote
Simple, they're not.  All of ther weight is supported by the ET in this configuration.  Supporting weight by the CCB's is possible in theory, but studying it, the weight load for different CCB configurations eventually made the core too heavy.  It was better to put the support into the core, rather than passing that to the boosters as DIRECT and the Shuttle do.

Sorry, I'm not sure if this was allready answered, but I was not able to find an answer:

If the liquid booster are not able to support the weight of the stack on the ground, how are they able to support the weight post T-0?

Once the stack lifts from the pad, the boosters "boost" or push the stack upwards and downrange.
Even with more force than on ground (because we are talking 2-3 g's compared to 1g on the ground, additional dynamic prerssure and drag come also to minid) - right?
That is the reason boosters are there. I mean right after T-0 the boosters push the stack (or help to push) with so much intensity that it accelerates with 2-3g against its own weight and the aerodynamic forces. That forces have to be larger then to support the weight on ground - are they not? 
They don't just fly along with the stack, they are the driving force on the stack, otherwise there would not be any use for them.

Are CCBs able to withstand that forces on a HLV unmodified?
If yes, why can't they support the weight of the stack on ground?
Title: Re: AJAX Launcher
Post by: Downix on 05/05/2011 02:35 pm
One issue I was wondering about is if there'd be any difficulties in getting the stock LRBs to support the weight of the ET+payload, a role currently carried by the SRBs. I was pretty sure this was previously discussed somewhere earlier in this mega-thread, but can't seem to find it...
Quote
Simple, they're not.  All of ther weight is supported by the ET in this configuration.  Supporting weight by the CCB's is possible in theory, but studying it, the weight load for different CCB configurations eventually made the core too heavy.  It was better to put the support into the core, rather than passing that to the boosters as DIRECT and the Shuttle do.

Sorry, I'm not sure if this was allready answered, but I was not able to find an answer:

If the liquid booster are not able to support the weight of the stack on the ground, how are they able to support the weight post T-0?

Once the stack lifts from the pad, the boosters "boost" or push the stack upwards and downrange.
Even with more force than on ground (because we are talking 2-3 g's compared to 1g on the ground, additional dynamic prerssure and drag come also to minid) - right?
That is the reason boosters are there. I mean right after T-0 the boosters push the stack (or help to push) with so much intensity that it accelerates with 2-3g against its own weight and the aerodynamic forces. That forces have to be larger then to support the weight on ground - are they not? 
They don't just fly along with the stack, they are the driving force on the stack, otherwise there would not be any use for them.

Are CCBs able to withstand that forces on a HLV unmodified?
If yes, why can't they support the weight of the stack on ground?
I never said they couldn't.  I said that the ground weight distribution for enabling CCB support became the issue, for the simplest methods for handling that increased the weight of the core more than to have the core handle the weight on the ground.  The CCB's can support the weight, it's the core that became the issue for that layout.
Title: Re: AJAX Launcher
Post by: Prober on 05/05/2011 03:10 pm
The RS-25 can get as low as $36 mil/year, if we could get it to 16 engines.  But, as sdsds pointed out, all of this depends on a lot of things.  I used worst case scenarios for my pricing, so as to maximize the buffer in my budget.  So I have the pricing for one-off construction, rather than multi-year contracts, for instance.  I do not presume what a multi-year would run, that would be nonsense for me to even try and presume. 

Your estimate for overhead is off, however, as the cost of a single RS-25D is $80 mil.

Can you get at least eight different amounts? Then we can actually use an estimator with a certain confidence level.

In any case I was more interested in the payload of the AJAX since I forgot how much would it lift  :(

Did you include the RS-68B Regen Upgrade costs to a Phase II Ajax?
 
 
Title: Re: AJAX Launcher
Post by: baldusi on 05/05/2011 03:20 pm
Did you include the RS-68B Regen Upgrade costs to a Phase II Ajax?
 
 

Phase II means Atlas V Phase II. Which uses dual RD-181 on a 5m core (Delta 4 tooling).
Title: Re: AJAX Launcher
Post by: Downix on 05/05/2011 04:29 pm
Did you include the RS-68B Regen Upgrade costs to a Phase II Ajax?
 
 

Phase II means Atlas V Phase II. Which uses dual RD-181 on a 5m core (Delta 4 tooling).
Or single RD-172, PWR has stated they could produce that also.  Or a single AR-1000 as yet another option.
Title: Re: AJAX Launcher
Post by: Downix on 05/05/2011 04:29 pm
The RS-25 can get as low as $36 mil/year, if we could get it to 16 engines.  But, as sdsds pointed out, all of this depends on a lot of things.  I used worst case scenarios for my pricing, so as to maximize the buffer in my budget.  So I have the pricing for one-off construction, rather than multi-year contracts, for instance.  I do not presume what a multi-year would run, that would be nonsense for me to even try and presume. 

Your estimate for overhead is off, however, as the cost of a single RS-25D is $80 mil.

Can you get at least eight different amounts? Then we can actually use an estimator with a certain confidence level.

In any case I was more interested in the payload of the AJAX since I forgot how much would it lift  :(

Did you include the RS-68B Regen Upgrade costs to a Phase II Ajax?

No, for it does not use them.
Title: Re: AJAX Launcher
Post by: spacenut on 05/05/2011 04:43 pm
AJAX/P2-260?  Does this mean 2 RS-25 engine on core with 6 Phase II boosters?  This would be 12 RD-180 engines right? 
Title: Re: AJAX Launcher
Post by: 2552 on 05/05/2011 04:52 pm
Quote
Do the costs include support from SpaceX and ULA for integration and launch? If they do, how are the support costs calculated?

ULA does include that in it's costs.  So I understand it, SpaceX does not include that in the cost it gives out.

The Falcon 9 User's Guide (http://www.spacex.com/Falcon9UsersGuide_2009.pdf) says the price does include payload integration:

Quote from: page 7
1.6.2.  Pricing
The standard price per launch for Falcon 9 Launch Vehicles can be found here (http://www.spacex.com/falcon9.php#pricing_and_performance)2.  Pricing includes range, standard payload integration and third party liability insurance.
Title: Re: AJAX Launcher
Post by: sdsds on 05/05/2011 05:02 pm
AJAX/P2-260?  Does this mean 2 RS-25 engine on core with 6 Phase II boosters?

Yes, it's a fascinating configuration because the lower engine count makes the core look a bit more like a conventional upper stage.  Every kg of core engine mass saved is a kg of payload delivered.  So then what's the wet mass of two SSME at burnout?  Also would the reduced core stage mass give AJAX/P2-260 acceptable performance to higher energy orbits, e.g. GTO, even without an upper stage?
Title: Re: AJAX Launcher
Post by: Downix on 05/05/2011 05:04 pm
Quote
Do the costs include support from SpaceX and ULA for integration and launch? If they do, how are the support costs calculated?

ULA does include that in it's costs.  So I understand it, SpaceX does not include that in the cost it gives out.

The Falcon 9 User's Guide (http://www.spacex.com/Falcon9UsersGuide_2009.pdf) says the price does include payload integration:

Quote from: page 7
1.6.2.  Pricing
The standard price per launch for Falcon 9 Launch Vehicles can be found here (http://www.spacex.com/falcon9.php#pricing_and_performance)2.  Pricing includes range, standard payload integration and third party liability insurance.
Interesting.  Then something does not add up with other, published costs.

In addition, the integration is not something that can be pre-priced like that.  Some systems, like Irridium satellites, are fairly simple to integrate.  Others, such as the JWST, are incredibly complex to integrate.  The launch cost above is half the integration cost alone for one system I've worked with.  And that system was fairly tame by integration standards.
Title: Re: AJAX Launcher
Post by: Downix on 05/05/2011 05:14 pm
AJAX/P2-260?  Does this mean 2 RS-25 engine on core with 6 Phase II boosters?

Yes, it's a fascinating configuration because the lower engine count makes the core look a bit more like a conventional upper stage.  Every kg of core engine mass saved is a kg of payload delivered.  So then what's the wet mass of two SSME at burnout?  Also would the reduced core stage mass give AJAX/P2-260 acceptable performance to higher energy orbits, e.g. GTO, even without an upper stage?
Well, the SSME's themselves are not "wet" don't forget.  But each one is 3,177 kg.  And yes, it would still have the performance for higher energy orbits.  Truth be, the reason why we have so many SSME's on AJAX is due to T/W issues, not due to the need for the actual thrust in mid-to-late flight.  The P2 Atlas core has enough T/W margin that you no longer need more than the 2 SSME's to reach similar performance.

But this is long, long in the future.  By my best guess, work on P2 would not begin until 2020.
Title: Re: AJAX Launcher
Post by: Downix on 05/05/2011 05:15 pm
AJAX/P2-260?  Does this mean 2 RS-25 engine on core with 6 Phase II boosters?  This would be 12 RD-180 engines right? 
Right, or 6 RD-172's, depending on which option ULA uses.  I suspect the RD-180 will remain, as then mass production scale would improve the cost per-engine.
Title: Re: AJAX Launcher
Post by: baldusi on 05/05/2011 06:21 pm
AJAX/P2-260?  Does this mean 2 RS-25 engine on core with 6 Phase II boosters?  This would be 12 RD-180 engines right? 
Right, or 6 RD-172's, depending on which option ULA uses.  I suspect the RD-180 will remain, as then mass production scale would improve the cost per-engine.
That's what I thought. One of the big costs of launchers are the engines. The russians seems to have standarized on the RD-180 (RUS-M) and RD-191 (Angara) for the future. The Zenit will probably be replaced by the Angara, so they may phase it out (not to mention, that would retire the Ukranians as competitors). In any case all three have something like 70% of commonality.
I don't think ULA would retire the phase I. So they would need two engines types, at a really low rate for the RD-172, and they wouldn't really gain much from the 172. At least the RD-171M (the latest) has slightly less T/W and isp than the RD-180.
Title: Re: AJAX Launcher
Post by: Downix on 05/05/2011 06:39 pm
AJAX/P2-260?  Does this mean 2 RS-25 engine on core with 6 Phase II boosters?  This would be 12 RD-180 engines right? 
Right, or 6 RD-172's, depending on which option ULA uses.  I suspect the RD-180 will remain, as then mass production scale would improve the cost per-engine.
That's what I thought. One of the big costs of launchers are the engines. The russians seems to have standarized on the RD-180 (RUS-M) and RD-191 (Angara) for the future. The Zenit will probably be replaced by the Angara, so they may phase it out (not to mention, that would retire the Ukranians as competitors). In any case all three have something like 70% of commonality.
I don't think ULA would retire the phase I. So they would need two engines types, at a really low rate for the RD-172, and they wouldn't really gain much from the 172. At least the RD-171M (the latest) has slightly less T/W and isp than the RD-180.
I am not so certain that the Phase I would remain.  One of the goals of Phase II is to unify construction tooling between Atlas and Delta.  Retaining Phase I would continue keeping the higher upkeep for no good reason.  Phase II's smallest configuration is just a hair above the Atlas V 402 capability, and ULA does offer the Delta IV Medium at the 401's capability, so there is no loss if Phase I is phased out.
Title: Re: AJAX Launcher
Post by: baldusi on 05/05/2011 07:11 pm
I am not so certain that the Phase I would remain.  One of the goals of Phase II is to unify construction tooling between Atlas and Delta.  Retaining Phase I would continue keeping the higher upkeep for no good reason.  Phase II's smallest configuration is just a hair above the Atlas V 402 capability, and ULA does offer the Delta IV Medium at the 401's capability, so there is no loss if Phase I is phased out.
But the smallest Phase II does use a single RD-180 engine. So I still think they would be better off with dual RD-180 than single RD-172. BTW, if SpaceX is successful competing, the need for the Delta 4 is not great. In fact, if they could make the RD-180 in the USA, there would be no reason.
Title: Re: AJAX Launcher
Post by: Lobo on 05/05/2011 09:38 pm
I am not so certain that the Phase I would remain.  One of the goals of Phase II is to unify construction tooling between Atlas and Delta.  Retaining Phase I would continue keeping the higher upkeep for no good reason.  Phase II's smallest configuration is just a hair above the Atlas V 402 capability, and ULA does offer the Delta IV Medium at the 401's capability, so there is no loss if Phase I is phased out.
But the smallest Phase II does use a single RD-180 engine. So I still think they would be better off with dual RD-180 than single RD-172. BTW, if SpaceX is successful competing, the need for the Delta 4 is not great. In fact, if they could make the RD-180 in the USA, there would be no reason.

Yea, I've pondered this too.  For a long time, there were only to quasi-commercial American LV providers.  Boeing and LM.  Delta and Atlas.  The US military spread their contracts between them to keep them both going so they had redundancy, and not be stuck without an LV in case there was a problem with one LV like they were after the Challenger accident, when it was policy that all military payloads would be launched on the shuttles. 
Then they merged into ULA, but needed to retain the two separate LV's so the US military had redudancy.  But it sounds like since then, cost have really been going up, because ULA was really a monopoly on the US tax payers, and they could write their own tickets.  With the advent of SpaceX's F9 and Orbital T2, if successful, very shortly there will be two legitimate competators for those government payload contracts.  Competition is always good.  Always. And forces suppliers to improve and refine their products to be competative. 
Since the government won't need ULA to maintain two LV's any more by arranging their contracts to support both LV's, I would think ULA will want to streamline their own process as SpaceX and Orbital start to gain traction (sounds like SpaceX is already getting those inroads).

That's how I understand it anyway, with my pretty limited knowledge of such things.  Just applying basic principles of free-market economics to it.
(Correct me if I'm wrong please). 
And I could see that ULA would drop the 5m delta alltogether to focus on the more flexible Atlas.  (Unless ULA wanted to disolve, and Boeing and LM would compete against each other again with Delta and Atlas...but I kinda doubt that'd happen at this point).
For the same 5m diameter, Atlas can lift about 3X as much payload (Phase 2).  I'm not sure how much two RD-180's cost (Russian and PWR versions) vs. a single PWR RS68, but the price of the rest of your booster will be about the same.  (Anyone know the cost of the PWR RS68, the estimated cost per unit of a PWR RD-180, and the cost of a Russian RD-180?)
The core and tankage and plumbing should be about the same price.  So your basic cost different will be engines.
And whether they are the Russian RD-180's, or PWR doing mass production, it should be cheaper per engine, by a decent amount, than the RS-68 at it's relatively low production rate.

So, here's the advantages for ULA to dump Delta, and probably eventually AV, and develop AVP2, as I see it.
1)  AVP2 would use existing Delta tooling, right?  SO you'd just basically take over the existing production line for it.
2)  You streamline to just one engine, used by both AV (until you maybe retire it too) and AVP2.
3)  By retiring AV, you can streamline on just one producting line.
4)  You can retire D4H, as AVP2 will cover that performance and then some.
5)  The RD-180 engine weighs 1mt less than the RS-68, and generates about 200,000 lbf more thrust as seal level.  I'm assuming that's why a single twin engine AVP2 can lift more than a D4H?  If there's a single engine variant of the AVP2 that can lift about what an AV-402 can, then there's no cost advantage of a single stick D4, as it has the same 5m diameter, single engine AVP2 can do the same lift, for about the same price as a single engine, 5m dia Delta 4.
6)  Sounds like Atlas and RD-180 are fairly easier to human-rate than Delta and RS-68.  So you can human rate them and make it available for NASA and private human flight.  CST-100 becomes an obvious choice as it's Boeing.  But a twin engine AVP2 can loft a full Orion to LEO too.
7)  Only need to maintain one LC at Canaveral and one LC at VAFB then.

So unless there's some reason to keep Delta and RS-68 around that I'm not aware of, seems like if I were emperor of ULA, I'd be scrapping D4 and converting it to AVP2 ASAP.  I'd rework the contract with PWR to start work on a man-rated RD-180, and have it ready by the time I'd used up my stock of Ruskie RD-180's, and be looking to maybe launch crews.  (Possibly even buying some more Russian ones to use for a lower-cost cargo commercial customer option...a "bargin" option if you don't care about it being Russian made)
Then when that was built, tested, and flying, I'd axe the AV production line, and transfer those assets (when applicable) to ramping up AVP2 production.  So everything rolls off one 5m line, and uses one common engine, and I'd go to just one common upper stage for everything.
And then I'd direct all the lobbiests and politica leverage at my disposal to do a media blitz for AJAX, flying with Atlas LRB's.  Starting with Phase 1, transistioning to Phase 2.  I'd propose it to NASA and twist every arm I could, and send my minions out to all the media outlets [that would care about NASA and the HSF program] and bang the drum for AJAX.  Outlining simple and clearly all of the benefits over the current SRB derived options.  I'd throw out "budgetary" numbers showing how much money AJAX would save the US taxpayer vs. any SRB option that'd involve a new crawler, etc.  Even if my budgetary numbers were pretty "optimistic".  ;-)  Hey, Elon's not the only guy that can come out aggressive and be optimistic on his promises and costs.

And if possible I'd dissolve all of the labor unions involved in ULA citing the necessity to streamline.  That might be hard or impossible on an established entity like ULA...but if you wanted to compete against young, dynamic companies, sometimes you need to rock the boat.

But that's just me...  ;-)
Title: Re: AJAX Launcher
Post by: baldusi on 05/05/2011 10:54 pm
As I understand it NROL won't launch anything with a Russian built engine. And now a days, I don't know who will invest the billions of P2 development. If I'm not mistaken, nowadays they are developing the EDS and the Common Centaur.
Title: Re: AJAX Launcher
Post by: Joris on 05/05/2011 10:59 pm
As I understand it NROL won't launch anything with a Russian built engine.

5 NROL payloads have flown aboard Atlas V,and 1 aboard a Atlas III.

That is six payloads flown aboard a rocket that used a Russian build engine, the RD-180.
Title: Re: AJAX Launcher
Post by: Downix on 05/05/2011 11:13 pm
And in this case it would be a US built engine.
Title: Re: AJAX Launcher
Post by: Prober on 05/06/2011 01:56 am
Working with Russia might be very hard in the near future.  They are now starting to use their existing N-33 engines.  It's very very possible engines produced in Russia and worked on in the USA will become very expensive, for alot of reasons. 
 
The US airforce has some interesting engine work in the pipeline.  Looks like the only real game in town (sad).  From the recent papers I found it looks like the J2-X might have had a military use.   
 
 
Title: Re: AJAX Launcher
Post by: Joris on 05/06/2011 08:22 am
Working with Russia might be very hard in the near future.  They are now starting to use their existing N-33 engines.  It's very very possible engines produced in Russia and worked on in the USA will become very expensive, for alot of reasons. 


The two new Russian rocket-families, Angara and Rus-M, will both use members of the RD-170 family. Namely the RD-180 and RD-191.

And Soyuz-1 is quite some time away, IMHO.
Title: Re: AJAX Launcher
Post by: Downix on 05/06/2011 02:45 pm
Working with Russia might be very hard in the near future.  They are now starting to use their existing N-33 engines.  It's very very possible engines produced in Russia and worked on in the USA will become very expensive, for alot of reasons. 


The two new Russian rocket-families, Angara and Rus-M, will both use members of the RD-170 family. Namely the RD-180 and RD-191.

And Soyuz-1 is quite some time away, IMHO.
The Soyuz-2-1v uses the NK-33A.  I believe that is what is being referenced.

If we were smart, we would not produce the RD-180, but the AR-1000 proposed by PWR or the Aerojet AJ-26 domestically.  Either option would fulfill the needs, but also enable us to fully state that it's not a Russian engine, even if it's origin and initial designwork were Russian in origin.  I know some politicians, even if we produce RD-180's here, would still decry that the US had dropped to just producing a foreign engine.
Title: Re: AJAX Launcher
Post by: baldusi on 05/06/2011 06:43 pm
Working with Russia might be very hard in the near future.  They are now starting to use their existing N-33 engines.  It's very very possible engines produced in Russia and worked on in the USA will become very expensive, for alot of reasons. 


The two new Russian rocket-families, Angara and Rus-M, will both use members of the RD-170 family. Namely the RD-180 and RD-191.

And Soyuz-1 is quite some time away, IMHO.
The Soyuz-2-1v uses the NK-33A.  I believe that is what is being referenced.

If we were smart, we would not produce the RD-180, but the AR-1000 proposed by PWR or the Aerojet AJ-26 domestically.  Either option would fulfill the needs, but also enable us to fully state that it's not a Russian engine, even if it's origin and initial designwork were Russian in origin.  I know some politicians, even if we produce RD-180's here, would still decry that the US had dropped to just producing a foreign engine.
The Soyuz-1-1v is supposed to flight this year with an academic satellite. So it's not that far. And this year might see two Taurus II. That would be five engines out of the stock in the first year of use. We know that the CRS will use 18 AJ-26 (demo + 8 missions).
I love the AJ-26, but the AR-1000 is more logical for multi engine allergic clients. Personally, I think part of the secret of SpaceX's prices are rates. If you don't fly enough, make the engines small enough to have to make many. The AJ-26 would wall beautifully there. Imagina a 5 x AJ-26 Atlas Phase II. At six Atlas launches per year that would make 30 engines. A nice rate of production!
Title: Re: AJAX Launcher
Post by: Downix on 05/06/2011 06:46 pm
Working with Russia might be very hard in the near future.  They are now starting to use their existing N-33 engines.  It's very very possible engines produced in Russia and worked on in the USA will become very expensive, for alot of reasons. 


The two new Russian rocket-families, Angara and Rus-M, will both use members of the RD-170 family. Namely the RD-180 and RD-191.

And Soyuz-1 is quite some time away, IMHO.
The Soyuz-2-1v uses the NK-33A.  I believe that is what is being referenced.

If we were smart, we would not produce the RD-180, but the AR-1000 proposed by PWR or the Aerojet AJ-26 domestically.  Either option would fulfill the needs, but also enable us to fully state that it's not a Russian engine, even if it's origin and initial designwork were Russian in origin.  I know some politicians, even if we produce RD-180's here, would still decry that the US had dropped to just producing a foreign engine.
The Soyuz-1-1v is supposed to flight this year with an academic satellite. So it's not that far. And this year might see two Taurus II. That would be five engines out of the stock in the first year of use. We know that the CRS will use 18 AJ-26 (demo + 8 missions).
I love the AJ-26, but the AR-1000 is more logical for multi engine allergic clients. Personally, I think part of the secret of SpaceX's prices are rates. If you don't fly enough, make the engines small enough to have to make many. The AJ-26 would wall beautifully there. Imagina a 5 x AJ-26 Atlas Phase II. At six Atlas launches per year that would make 30 engines. A nice rate of production!
Now you're thinking.  And if we can get the production rate up enough, it would be more affordable for the Russians to buy US made AJ-26's than to restart production domestically, putting the shoe on the other foot as it were.
Title: Re: AJAX Launcher
Post by: baldusi on 05/06/2011 07:02 pm
Now you're thinking.  And if we can get the production rate up enough, it would be more affordable for the Russians to buy US made AJ-26's than to restart production domestically, putting the shoe on the other foot as it were.
ITAR would prevent that :(. I know that Aerojet could just sell them the same part's that are originals and let them produce the rest. But I don't think ITAR allows to export the technology, even to the original developed. ???
Title: Re: AJAX Launcher
Post by: Downix on 05/06/2011 07:16 pm
Now you're thinking.  And if we can get the production rate up enough, it would be more affordable for the Russians to buy US made AJ-26's than to restart production domestically, putting the shoe on the other foot as it were.
ITAR would prevent that :(. I know that Aerojet could just sell them the same part's that are originals and let them produce the rest. But I don't think ITAR allows to export the technology, even to the original developed. ???
That would be an interesting argument to make. 
Title: Re: AJAX Launcher
Post by: baldusi on 05/06/2011 07:33 pm
Now you're thinking.  And if we can get the production rate up enough, it would be more affordable for the Russians to buy US made AJ-26's than to restart production domestically, putting the shoe on the other foot as it were.
ITAR would prevent that :(. I know that Aerojet could just sell them the same part's that are originals and let them produce the rest. But I don't think ITAR allows to export the technology, even to the original developed. ???
That would be an interesting argument to make. 
Whoever enforces ITAR could say that they are actually denying the capability by making further fabrication uneconomical  :-\
On the positive side, if they can get upto 5 engines in a 5m core, they could have 2, 3 and 4 versions also (I don't think 1 could have enough thrust for anything). That might make the need for solids significantly reduced, at the cost of higher qualification work and more complicated GNC. I think I'm falling in love :p
The Taurus is 3.9m, so they would need close to 6m to put five AJ-26.  But the nice part is to design 2, 3 and 4 engined versions. That would allow a smooth system only changing the thrust structure and tank's length.
Title: Re: AJAX Launcher
Post by: martin hegedus on 05/10/2011 01:54 am
Now you're thinking.  And if we can get the production rate up enough, it would be more affordable for the Russians to buy US made AJ-26's than to restart production domestically, putting the shoe on the other foot as it were.
ITAR would prevent that :(. I know that Aerojet could just sell them the same part's that are originals and let them produce the rest. But I don't think ITAR allows to export the technology, even to the original developed. ???

ITAR states that certain technologies need an export license.  ITAR does not, in and of itself, prevent export.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/10/2011 04:32 am
it looks like iv got alot of catching up to do. Hopefully in the next week or so I will get on here and read the entire thread over again cover to cover. Find out what I have missed.
Title: Re: AJAX Launcher
Post by: Downix on 05/11/2011 11:35 pm
Working on a baseball reference card, and for it I made an ESAS-like diagram.  So thought to put that on here.  I have the basic booster, and a few US options, Centaur w/ Orion, DCSS w/ Orion, ACES w/ ACES-SM Orion and ACES w/ ACES lander, to give an idea.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/11/2011 11:42 pm
Looks good... lets bend some metal!
Title: Re: AJAX Launcher
Post by: mike robel on 05/12/2011 12:12 am
Gasp!  It looks like your playing with LEGOS!  Or worse.  :)
Title: Re: AJAX Launcher
Post by: martin hegedus on 05/12/2011 02:51 am
Cool, your outer mold line looks reasonable.  One more suggestion.  Again, just cautionary.  If the angle where the payload fairing meets the LAS tower is similar to ARES, or less (i.e. nose is blunter) another fairing may need to be added between the LAS tower and PLF, i.e. blend it in.  You can use ARES I or 1X as an example.  The reason is that a recirculation region may develop between the LAS tower and the fairing causing additional non-linearities.

I like the biconic ET nose since it makes separation predictable/testable, the slanted in CCB nose caps to minimize aero issues as you cluster the CCBs, and the minimal boat tail on the ET to make back end aero predictable.
Title: Re: AJAX Launcher
Post by: Downix on 05/12/2011 02:55 am
Cool, your outer mold line looks reasonable.  One more suggestion.  Again, just cautionary.  If the angle where the payload fairing meets the LAS tower is similar to ARES, or less (i.e. nose is blunter) another fairing may need to be added between the LAS tower and PLF, i.e. blend it in.  You can use ARES I or 1X as an example.  The reason is that a recirculation region may develop between the LAS tower and the fairing causing additional non-linearities.

I like the biconic ET nose since it makes separation predictable/testable, the slanted in CCB nose caps to minimize aero issues as you cluster the CCBs, and the minimal boat tail on the ET to make back end aero predictable.

I was figuring to use the Ares I LAS as/is, as it's already very late in development.  Looking, there is no space between it and the Orion itself.
Title: Re: AJAX Launcher
Post by: martin hegedus on 05/12/2011 03:34 am
Cool, your outer mold line looks reasonable.  One more suggestion.  Again, just cautionary.  If the angle where the payload fairing meets the LAS tower is similar to ARES, or less (i.e. nose is blunter) another fairing may need to be added between the LAS tower and PLF, i.e. blend it in.  You can use ARES I or 1X as an example.  The reason is that a recirculation region may develop between the LAS tower and the fairing causing additional non-linearities.

I like the biconic ET nose since it makes separation predictable/testable, the slanted in CCB nose caps to minimize aero issues as you cluster the CCBs, and the minimal boat tail on the ET to make back end aero predictable.

I was figuring to use the Ares I LAS as/is, as it's already very late in development.  Looking, there is no space between it and the Orion itself.

Between was the wrong word to use.  When you look at the side view of the Ares I, there is a fairing that blends in the LAS tower to the Ogive nose.  Not sure of all the ins and outs, it may have structural purposes.  But it also prevents a ring vortex forming at the junction of the base of the LAS tower and the Ogive.  The earlier Ares designs, DAC 1, had this issue.  See "Status, Plans and Initial Results for Ares 1 Crew Launch Vehicle Aerodynamics" at ntrs.  It's towards the end of the paper and called "LAS Flow Anomaly."  It's the same phenomena that occurs with drag reduction aero spikes.

In the case of the Saturn V, the LAS tower sits on a milk stool.  The openness of the milk stool will prevent the formation of the ring vortex.  The Soyuz does not have a fairing, but maybe the angle of the capsule is steep enough not to warrant it or they factored it into the design.  However, if you have the ring vortex, you may need to spend more time in the WT.

If you are using the Ares LAS as is, then I guess you'll be using that fairing also, so no problem.
Title: Re: AJAX Launcher
Post by: Downix on 05/12/2011 04:25 pm
Cool, your outer mold line looks reasonable.  One more suggestion.  Again, just cautionary.  If the angle where the payload fairing meets the LAS tower is similar to ARES, or less (i.e. nose is blunter) another fairing may need to be added between the LAS tower and PLF, i.e. blend it in.  You can use ARES I or 1X as an example.  The reason is that a recirculation region may develop between the LAS tower and the fairing causing additional non-linearities.

I like the biconic ET nose since it makes separation predictable/testable, the slanted in CCB nose caps to minimize aero issues as you cluster the CCBs, and the minimal boat tail on the ET to make back end aero predictable.

I was figuring to use the Ares I LAS as/is, as it's already very late in development.  Looking, there is no space between it and the Orion itself.

Between was the wrong word to use.  When you look at the side view of the Ares I, there is a fairing that blends in the LAS tower to the Ogive nose.  Not sure of all the ins and outs, it may have structural purposes.  But it also prevents a ring vortex forming at the junction of the base of the LAS tower and the Ogive.  The earlier Ares designs, DAC 1, had this issue.  See "Status, Plans and Initial Results for Ares 1 Crew Launch Vehicle Aerodynamics" at ntrs.  It's towards the end of the paper and called "LAS Flow Anomaly."  It's the same phenomena that occurs with drag reduction aero spikes.

In the case of the Saturn V, the LAS tower sits on a milk stool.  The openness of the milk stool will prevent the formation of the ring vortex.  The Soyuz does not have a fairing, but maybe the angle of the capsule is steep enough not to warrant it or they factored it into the design.  However, if you have the ring vortex, you may need to spend more time in the WT.

If you are using the Ares LAS as is, then I guess you'll be using that fairing also, so no problem.

The main reason for using the Ares LAS as/is is three fold:

1) Don't have time to R&D
2) Don't have money to R&D
3) Needs to be ready for first crewed flights in 2014.

The Ares LAS as it is, frankly, is overkill for every abort scenario we've come up with, on both AJAX and on Ares V HLV.  And I mean overkill on an order of magnitude.  It was meant to pull Orion away from an exploding SRB.  Both AJAX and Atlas are less explosive than the SRB would be, so in all abort scenarios I've studied, the Ares LAS has 40% more capability than is needed.  I consider that a good thing, I'd rather have more capability, than "just right" because in case of design changes or growth you will eat away at that margin, as what happened with Ares.
Title: Re: AJAX Launcher
Post by: martin hegedus on 05/12/2011 05:07 pm
Cool, your outer mold line looks reasonable.  One more suggestion.  Again, just cautionary.  If the angle where the payload fairing meets the LAS tower is similar to ARES, or less (i.e. nose is blunter) another fairing may need to be added between the LAS tower and PLF, i.e. blend it in.  You can use ARES I or 1X as an example.  The reason is that a recirculation region may develop between the LAS tower and the fairing causing additional non-linearities.

I like the biconic ET nose since it makes separation predictable/testable, the slanted in CCB nose caps to minimize aero issues as you cluster the CCBs, and the minimal boat tail on the ET to make back end aero predictable.

I was figuring to use the Ares I LAS as/is, as it's already very late in development.  Looking, there is no space between it and the Orion itself.

Between was the wrong word to use.  When you look at the side view of the Ares I, there is a fairing that blends in the LAS tower to the Ogive nose.  Not sure of all the ins and outs, it may have structural purposes.  But it also prevents a ring vortex forming at the junction of the base of the LAS tower and the Ogive.  The earlier Ares designs, DAC 1, had this issue.  See "Status, Plans and Initial Results for Ares 1 Crew Launch Vehicle Aerodynamics" at ntrs.  It's towards the end of the paper and called "LAS Flow Anomaly."  It's the same phenomena that occurs with drag reduction aero spikes.

In the case of the Saturn V, the LAS tower sits on a milk stool.  The openness of the milk stool will prevent the formation of the ring vortex.  The Soyuz does not have a fairing, but maybe the angle of the capsule is steep enough not to warrant it or they factored it into the design.  However, if you have the ring vortex, you may need to spend more time in the WT.

If you are using the Ares LAS as is, then I guess you'll be using that fairing also, so no problem.

The main reason for using the Ares LAS as/is is three fold:

1) Don't have time to R&D
2) Don't have money to R&D
3) Needs to be ready for first crewed flights in 2014.

The Ares LAS as it is, frankly, is overkill for every abort scenario we've come up with, on both AJAX and on Ares V HLV.  And I mean overkill on an order of magnitude.  It was meant to pull Orion away from an exploding SRB.  Both AJAX and Atlas are less explosive than the SRB would be, so in all abort scenarios I've studied, the Ares LAS has 40% more capability than is needed.  I consider that a good thing, I'd rather have more capability, than "just right" because in case of design changes or growth you will eat away at that margin, as what happened with Ares.

Sorry, I'm confused.  Are you addressing a topic I brought up?  I didn't question your use of the LAS as is.  For me, when I looked at your drawing above, and granted it is a low fidelity drawing (and meant to be that way), the fact that the LAS tower goes straight into the tip of the biconic nose fairing caught my attention.  Unfortunately I don't have any other drawings to go by.  So I thought I would mention it.
Title: Re: AJAX Launcher
Post by: Downix on 05/12/2011 05:10 pm
Cool, your outer mold line looks reasonable.  One more suggestion.  Again, just cautionary.  If the angle where the payload fairing meets the LAS tower is similar to ARES, or less (i.e. nose is blunter) another fairing may need to be added between the LAS tower and PLF, i.e. blend it in.  You can use ARES I or 1X as an example.  The reason is that a recirculation region may develop between the LAS tower and the fairing causing additional non-linearities.

I like the biconic ET nose since it makes separation predictable/testable, the slanted in CCB nose caps to minimize aero issues as you cluster the CCBs, and the minimal boat tail on the ET to make back end aero predictable.

I was figuring to use the Ares I LAS as/is, as it's already very late in development.  Looking, there is no space between it and the Orion itself.

Between was the wrong word to use.  When you look at the side view of the Ares I, there is a fairing that blends in the LAS tower to the Ogive nose.  Not sure of all the ins and outs, it may have structural purposes.  But it also prevents a ring vortex forming at the junction of the base of the LAS tower and the Ogive.  The earlier Ares designs, DAC 1, had this issue.  See "Status, Plans and Initial Results for Ares 1 Crew Launch Vehicle Aerodynamics" at ntrs.  It's towards the end of the paper and called "LAS Flow Anomaly."  It's the same phenomena that occurs with drag reduction aero spikes.

In the case of the Saturn V, the LAS tower sits on a milk stool.  The openness of the milk stool will prevent the formation of the ring vortex.  The Soyuz does not have a fairing, but maybe the angle of the capsule is steep enough not to warrant it or they factored it into the design.  However, if you have the ring vortex, you may need to spend more time in the WT.

If you are using the Ares LAS as is, then I guess you'll be using that fairing also, so no problem.

The main reason for using the Ares LAS as/is is three fold:

1) Don't have time to R&D
2) Don't have money to R&D
3) Needs to be ready for first crewed flights in 2014.

The Ares LAS as it is, frankly, is overkill for every abort scenario we've come up with, on both AJAX and on Ares V HLV.  And I mean overkill on an order of magnitude.  It was meant to pull Orion away from an exploding SRB.  Both AJAX and Atlas are less explosive than the SRB would be, so in all abort scenarios I've studied, the Ares LAS has 40% more capability than is needed.  I consider that a good thing, I'd rather have more capability, than "just right" because in case of design changes or growth you will eat away at that margin, as what happened with Ares.

Sorry, I'm confused.  Are you addressing a topic I brought up?  I didn't question your use of the LAS as is.  For me, when I looked at your drawing above, and granted it is a low fidelity drawing (and meant to be that way), the fact that the LAS tower goes straight into the tip of the biconic nose fairing caught my attention.  Unfortunately I don't have any other drawings to go by.  So I thought I would mention it.

Ah, got it.  And yes, it's quite low-fidelity. 
Title: Re: AJAX Launcher
Post by: Downix on 05/12/2011 07:17 pm
I've been figuring out a flight test system for AJAX a bit.  I think I may have a solution.

I realized if the Buttresses were built, but not attached to the tank, along with the boat-tail, it would be possible to cradle them around ET-94, installing Buttresses from AJAX, with two of them modified to fit up to the tanks ET support.  This would enable a flight test without a full tank manufacture to be done. The tank itself would be overweight so there would be some performance loss.  But then we would be able to then perform an AJAX 440 mission sooner.  I would not just do a dummy launch, but a full on mission launch.  My suggestion for a mission would be to launch two Centaur with the extended duration package and refueling system, one with the sunshield installed.  Then you could push the sunshielded Centaur to EML1, then do testing of refueling.  Good, cheap mission which the AJAX would enable, and a way to do it with the heavier ET-94 tank.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/12/2011 10:25 pm
Any thoughts on using MLAS?

http://www.nasaspaceflight.com/2007/12/mlas-the-alternative-orion-launch-abort-system-gains-momentum/
Title: Re: AJAX Launcher
Post by: Downix on 05/12/2011 11:19 pm
Any thoughts on using MLAS?

http://www.nasaspaceflight.com/2007/12/mlas-the-alternative-orion-launch-abort-system-gains-momentum/
Last time I checked, MLAS was still a paper project.  Remember, bird in the hand vs two in the bush.  MLAS may be superior, but when comparing to the Orbital designed LAS which is already fully developed and is in late testing, we just don't have the time or money to devote to yet another change.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/12/2011 11:30 pm
Any thoughts on using MLAS?

http://www.nasaspaceflight.com/2007/12/mlas-the-alternative-orion-launch-abort-system-gains-momentum/
Last time I checked, MLAS was still a paper project.  Remember, bird in the hand vs two in the bush.  MLAS may be superior, but when comparing to the Orbital designed LAS which is already fully developed and is in late testing, we just don't have the time or money to devote to yet another change.
I understand... they did flight test it. I'm sure you just don't recall it with all you are taking on.
Have a look at the video
Regards
Robert
http://www.nasa.gov/centers/wallops/missions/mlas.html
Title: Re: AJAX Launcher
Post by: Downix on 05/12/2011 11:35 pm
Any thoughts on using MLAS?

http://www.nasaspaceflight.com/2007/12/mlas-the-alternative-orion-launch-abort-system-gains-momentum/
Last time I checked, MLAS was still a paper project.  Remember, bird in the hand vs two in the bush.  MLAS may be superior, but when comparing to the Orbital designed LAS which is already fully developed and is in late testing, we just don't have the time or money to devote to yet another change.
I understand... they did flight test it. I'm sure you just don't recall it with all you are taking on.
Have a look at the video
Regards
Robert
http://www.nasa.gov/centers/wallops/missions/mlas.html
Hey, if it's ready to go, welcome aboard.  I'm just focused on not spending money on developing that is not needed, if MLAS would do that, great.  If the Orbital LAS would do that, great.  Whichever one is used is unimportant in the grand scheme of things.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/13/2011 12:06 am
A fellow pragmatist... That's it, keep your eye on the prize!!
Title: Re: AJAX Launcher
Post by: clongton on 05/13/2011 01:52 am
If it ain't broke then don't fix it! :)
Title: Re: AJAX Launcher
Post by: Downix on 05/13/2011 02:44 am
If it ain't broke then don't fix it! :)
Precisely.

After all of this discussion of utilizing the Falcon for AJAX, and the J-2X evolution and future growth options, the more I am convinced that the main Atlas based design is the right direction.  While, yes, with Falcon you get some edge, you also now have more risks, and don't have the direct-to-130mT capability to ease some politicians (that darn 9 engines on the Falcon core). 

However, after the J-2X dissection of today I do think that the J-2X could be a solid engine for ACES, if the tap-cycle higher-impulse form is developed, with the gas generator version working as an interim step.  And if it doesn't work, you still have the super-efficient RL-10 to use.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/16/2011 11:34 pm
Are you familiar with the Uragan? I think you know where I am going with this....
Regards
Robert
Title: Re: AJAX Launcher
Post by: Downix on 05/16/2011 11:42 pm
Are you familiar with the Uragan? I think you know where I am going with this....
Regards
Robert
I'll assume you mean the "Energia II" or "Vulkan" or "Herkules", the 8-Zenit version of the Energia.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/16/2011 11:47 pm
Are you familiar with the Uragan? I think you know where I am going with this....
Regards
Robert
I'll assume you mean the "Energia II" or "Vulkan" or "Herkules", the 8-Zenit version of the Energia.
Very good, perhaps a glimpse of the future?;)
Title: Re: AJAX Launcher
Post by: Jason1701 on 05/17/2011 01:36 am
Are you familiar with the Uragan? I think you know where I am going with this....
Regards
Robert
I'll assume you mean the "Energia II" or "Vulkan" or "Herkules", the 8-Zenit version of the Energia.

No, 4-Zenit, but with flyback core and boosters.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/17/2011 12:28 pm
Are you familiar with the Uragan? I think you know where I am going with this....
Regards
Robert
I'll assume you mean the "Energia II" or "Vulkan" or "Herkules", the 8-Zenit version of the Energia.

No, 4-Zenit, but with flyback core and boosters.
Energia II for now... since you asked...:)
The reusable Energia variant with flyback boosters and core stage:
http://www.buran.ru/images/jpg/gk175-2.jpg
http://www.buran.ru/images/jpg/gk175-5.jpg
http://www.buran.ru/images/jpg/gk175-1.jpg
http://www.buran.ru/images/jpg/buran-t.jpg
http://www.buran.ru/images/jpg/gk175-4.jpg
http://www.buran.ru/images/jpg/uragan1m.jpg
http://www.buran.ru/images/jpg/uragan3m.jpg
http://www.buran.ru/images/jpg/uragan4m.jpg



Title: Re: AJAX Launcher
Post by: Downix on 05/19/2011 02:09 am
Ok, get paid friday, def getting L2...
Title: Re: AJAX Launcher
Post by: Jim on 05/19/2011 03:17 am
Any thoughts on using MLAS?

http://www.nasaspaceflight.com/2007/12/mlas-the-alternative-orion-launch-abort-system-gains-momentum/
Last time I checked, MLAS was still a paper project.  Remember, bird in the hand vs two in the bush.  MLAS may be superior, but when comparing to the Orbital designed LAS which is already fully developed and is in late testing, we just don't have the time or money to devote to yet another change.
I understand... they did flight test it. I'm sure you just don't recall it with all you are taking on.
Have a look at the video
Regards
Robert
http://www.nasa.gov/centers/wallops/missions/mlas.html

That was not a test of a valid abort system., much like Ares I-X wasn't a valid test of Ares I.  They found out they couldn't manifold the abort motors for the money allocated so they changed the goals. Motors,not abort motors, were place in a skirt below the capsule and ballast was place on the capsule simulate burn out abort motors.  The test was of the unpowered portion of the flight, after burnout of the launch motors.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/20/2011 12:11 am
Downix, was wondering if AJAX has a website yet as the direct team did? If not, would be interested to know when it would be possible to make one.
Title: Re: AJAX Launcher
Post by: Downix on 05/20/2011 12:18 am
Downix, was wondering if AJAX has a website yet as the direct team did? If not, would be interested to know when it would be possible to make one.
I keep meaning to spend a weekend putting one together.  I don't want to make the mistakes DIRECT did with it, however.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/20/2011 12:20 am
I understand, look forward to it :)
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/20/2011 12:31 am
You might want to take a page from von Braun’s. He used the influence of the media to get his point of view across thrrough self promotion. With all the media's attention with the end of shuttle, I'm sure they are looking for stories right now. Don't miss this opportunity for the free press. Strike while the iron is still hot...
Regards
Robert
 http://www.thespacereview.com/article/1006/1
Title: Re: AJAX Launcher
Post by: Downix on 05/20/2011 03:26 am
Hmm... perhaps.

I was pondering doing a space blog, but it would be weird to discuss my own ideas.
Title: Re: AJAX Launcher
Post by: Joris on 05/20/2011 11:16 am
Hmm... perhaps.

I was pondering doing a space blog, but it would be weird to discuss my own ideas.

That would be great. Perhaps even spread the AJAX-concept?
Title: Re: AJAX Launcher
Post by: 2552 on 05/20/2011 12:24 pm
Hmm... perhaps.

I was pondering doing a space blog, but it would be weird to discuss my own ideas.

That sounds like a great idea actually. It looks like the domain http://ajaxlauncher.com/ is not taken, maybe you could use that for it?
Title: Re: AJAX Launcher
Post by: Downix on 05/20/2011 01:03 pm
Hmm... perhaps.

I was pondering doing a space blog, but it would be weird to discuss my own ideas.

That sounds like a great idea actually. It looks like the domain http://ajaxlauncher.com/ is not taken, maybe you could use that for it?
You want to bet? I've had that for almost a year now.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/20/2011 01:15 pm
Hmm... perhaps.

I was pondering doing a space blog, but it would be weird to discuss my own ideas.
Might I suggest you get in touch with Miles O'Brian. He knows the media, is an expert spokesperson and has contacts.
Rergards
Robert
Title: Re: AJAX Launcher
Post by: Downix on 05/20/2011 01:34 pm
Hmm... perhaps.

I was pondering doing a space blog, but it would be weird to discuss my own ideas.
Might I suggest you get in touch with Miles O'Brian. He knows the media, is an expert spokesperson and has contacts.
Rergards
Robert
I assume you mean the Journalist.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/20/2011 01:41 pm
Hmm... perhaps.

I was pondering doing a space blog, but it would be weird to discuss my own ideas.
Might I suggest you get in touch with Miles O'Brian. He knows the media, is an expert spokesperson and has contacts.
Rergards
Robert
I assume you mean the Journalist.
Yup, that's the guy...
Title: Re: AJAX Launcher
Post by: Downix on 05/20/2011 02:09 pm
Ok, de-parked ajaxlauncher.com and moved it to my host.  Currently it is set to 403.  This weekend I will put up a website "coming soon" page.
Title: Re: AJAX Launcher
Post by: Downix on 05/22/2011 07:51 am
While getting the website set up, I came up with this picture, which pretty much sums up the whole situation right now.  We have a big blank rocket-shaped hole, and we need to fill it.
Title: Re: AJAX Launcher
Post by: clongton on 05/22/2011 01:12 pm
While getting the website set up, I came up with this picture, which pretty much sums up the whole situation right now.  We have a big blank rocket-shaped hole, and we need to fill it.

HEY! That looks like AJAX!
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/22/2011 01:16 pm
Stealth Rocket!!
Title: Re: AJAX Launcher
Post by: HappyMartian on 05/22/2011 01:50 pm
I love the AJAX picture! Keep up the great work!  ;)

Cheers!


Edited.
Title: Re: AJAX Launcher
Post by: Downix on 05/22/2011 03:48 pm
I love the AJAX picture! Keep up the great work!  ;)

Cheers!


Edied.
Would look better with a real AJAX on it...
Title: Re: AJAX Launcher
Post by: Downix on 05/22/2011 06:39 pm
And if anyone wants to mock my photoshop skills
Title: Re: AJAX Launcher
Post by: alexw on 05/22/2011 07:15 pm
THAT PICTURE IS SHOPPED I CAN TELL FROM SOME OF THE PIXELS AND FROM HAVING SEEN QUITE A FEW SHOPS IN MY LIFE
Title: Re: AJAX Launcher
Post by: simonbp on 05/22/2011 07:55 pm
THAT PICTURE IS SHOPPED I CAN TELL FROM SOME OF THE PIXELS AND FROM HAVING SEEN QUITE A FEW SHOPS IN MY LIFE

Beat me to it!

Here's a few Quick 'n Dirty renders from pieces I already had laying around, using a four-fold symmetry on the base; will fix with something better soon.
Title: Re: AJAX Launcher
Post by: Prober on 05/22/2011 08:33 pm
Hmm... perhaps.

I was pondering doing a space blog, but it would be weird to discuss my own ideas.

That sounds like a great idea actually. It looks like the domain http://ajaxlauncher.com/ is not taken, maybe you could use that for it?
You want to bet? I've had that for almost a year now.

I like the way you think ahead.  Ajax is in good hands.
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/22/2011 11:46 pm
Out of my way, I'll drive that sucker to the pad...
Title: Re: AJAX Launcher
Post by: Lobo on 05/23/2011 03:41 pm
THAT PICTURE IS SHOPPED I CAN TELL FROM SOME OF THE PIXELS AND FROM HAVING SEEN QUITE A FEW SHOPS IN MY LIFE

Now we know where those phony pictures of the lunar landings came from!
Title: Re: AJAX Launcher
Post by: Downix on 05/23/2011 05:50 pm
Incidentally, that shroud design is something I'd discovered while researching shroud technologies made by ATK.  It's a composite material, weighs 1/4 that of the Atlas V shroud per cm^2, and can withstand the pressures of launch.  It's drawback is that it cannot be stored long-term, and begins breaking down 8-12 weeks after manufacture.
Title: Re: AJAX Launcher
Post by: baldusi on 05/23/2011 06:43 pm
So you have a problem like Endeavour's and you need a new shroud? How much does it degrades (like in how long does it equals current shrouds?). Besides, where would they build that beast? I guess Utah is out of the question.
Title: Re: AJAX Launcher
Post by: Downix on 05/23/2011 07:02 pm
So you have a problem like Endeavour's and you need a new shroud? How much does it degrades (like in how long does it equals current shrouds?). Besides, where would they build that beast? I guess Utah is out of the question.
No idea, I did not say to use it, just that I'd discovered it.  It was novel enough to be interesting.  Plus, got a good sample of the color in order to render this.

And the factory that builds this is in Maryland IIRC.
Title: Re: AJAX Launcher
Post by: HappyMartian on 05/24/2011 01:06 am
...

Here's a few Quick 'n Dirty renders from pieces I already had laying around, using a four-fold symmetry on the base; will fix with something better soon.

Great job!

Cheers!
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/24/2011 04:41 am
Just got back, spent some time around Michoud assembly facility. Seemed rather quiet for most of the week which is kinda sad, reminds of how much they are scaling things back.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/24/2011 04:44 am
What I came back to:

Amazing STS 134 flyabout video, images
Heat Shield Cleared!
Soyuz landed
Downix and co. attempting to fake the moon land-I mean what.........
Something resembling a Saturn 5 with an et stuck to it and what appear to be two strangely topped off atlas boosters....
Keith Cowing on the radio talking about Noaa getting shorted the bucks for new weather sats
Tornados
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/24/2011 04:53 am
Taken from another thread, but it should be posted here:

2)  If using SSME's, you'd need at least 5 to have enough T/W ratio.  5 or 6 SSME core concepts I've seen, like the one Boeing had, didn't have very good preformance to LEO, given the cost of the core redesign, and all of those SSME's. 
...
So that's why that concept never really get that far.  By the time you redesign the tank, and add the extra SSME's, you'd probably not be far away from a J130 in price and effort, and a J130 can get like twice the mass to LEO as a slick core design.
A core-only design powered by six SSMEs should be able to lift Congress's 70 "tons" (63.5 "tonnes") to LEO if it was fitted with a proper upper stage.  J-2X would be needed instead of SRBs.   

 - Ed Kyle
I'd sooner have J-2X over SRB's.

such a waste, give me a good F-1 heheh
Honestly, I wouldn't and I'll tell you why.  The F-1 is a beast, but for RP-1 an engine such as the TR-107, RS-84, AR-1000 or AJ-24 crushes it for efficiency.  More efficiency means less fuel needed, means you don't need as big of an engine to do the same job.

Id rather have: Rs84, Raptor, Upcoming larger Merlicn 1-C derivative (Merlin X)

What we don't need: SRBS, J2X


I actually would like to point out that I am fed up with SRBS at this point and I will tell you why:

I heard from a friend who worked at the agency until recently (and since I am relying on word alone I take it with a grain of salt) that on a shuttle mission sometime between 07 and now (forget which one but I think it was 124 or 119) something happened regarding one of the srbs. Regarding which mission  it may have been 118, again I don't remember the number (curses be to my brain). Anyway, he told me they had some sort of burn through issue on one of the joint gaskets......again. Seems unthinkable with all the changes made after challenger right? Again I take this with a grain of salt but in all honestly I have lost alot of faith in SRBS as a safe means to orbit. They are:

Toxic
Expensive
Heavy
Vibrate like crazy
Potentially STILL unsafe

I think we should be done with the dam things, IMHO.

P.S: If anyone else heard about this occurrence or remembers the mission number and any other details please let me know (honestly do not remember much of our conversation, was really tired at the time.)
Title: Re: AJAX Launcher
Post by: Downix on 05/24/2011 07:04 am
I am in agreement about the SRB's.  However, I have softened my position on the J-2X after studying it in more detail.  J-2X as it is now, no, the RL-10 is better.  *however*, the current J-2X is a result of Ares I, and it's need for more thrust.  They swapped out the tap-out cycle generator with the gas generator off of the RS-68, increasing the thrust, but loosing the isp.  So, if they restored the tap-out, the J-2X actually gives the RL-10 a run for its money as an EDS.
Title: Re: AJAX Launcher
Post by: RanulfC on 05/24/2011 09:08 pm
What we don't need: SRBS, ...

I actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
Unfortunatly, "Congress" (recall that it's also the opposite of "Progress" but I DEgress :) ) doesn't agree and in fact mandates their use in the SLS...

I think I'll be glad on leaving Utah in the next year or so... I think it's degrading my brain :)

Randy
Title: Re: AJAX Launcher
Post by: Downix on 05/24/2011 09:11 pm
What we don't need: SRBS, ...

I actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
Unfortunatly, "Congress" (recall that it's also the opposite of "Progress" but I DEgress :) ) doesn't agree and in fact mandates their use in the SLS...

I think I'll be glad on leaving Utah in the next year or so... I think it's degrading my brain :)

Randy
Already discussed, no, the law does not mandate their use in the SLS.  The terminology has been gone over by lawyers, there is no mandate for RSRB's, period.
Title: Re: AJAX Launcher
Post by: Downix on 05/25/2011 06:24 am
Alright, ajaxlauncher.com's template and framework is in.  I'll be setting up content controls shortly, and getting documentation up there. 
Title: Re: AJAX Launcher
Post by: RanulfC on 05/25/2011 01:05 pm
What we don't need: SRBS, ...

I actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
Unfortunatly, "Congress" (recall that it's also the opposite of "Progress" but I DEgress :) ) doesn't agree and in fact mandates their use in the SLS...

I think I'll be glad on leaving Utah in the next year or so... I think it's degrading my brain :)

Randy
Already discussed, no, the law does not mandate their use in the SLS.  The terminology has been gone over by lawyers, there is no mandate for RSRB's, period.
::::grin::: While the "law" may not "mandate" or even mention them, "Politically" the SLS depends on them any concept presented by NASA to Congress will not likely pass muster without them. Utah was guaranteed them and unfortunately (for those of us who’d much rather have LRBs or LOX/Kero work) they have the support of the rest of Congress for various and sundry reasons which will lead to RSRBs continuing to be made and used.

They may NOT be "mandated" legally in-writing, they ARE however "mandated" per Congressional default and most NASA will be forced to use them on whatever design they adopt.

Randy
Title: Re: AJAX Launcher
Post by: Rocket Science on 05/25/2011 01:26 pm
When it comes to rocket design "there are the laws of physics and then there are the physical laws".
Regards
Robert
Title: Re: AJAX Launcher
Post by: Downix on 05/25/2011 02:19 pm
What we don't need: SRBS, ...

I actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
Unfortunatly, "Congress" (recall that it's also the opposite of "Progress" but I DEgress :) ) doesn't agree and in fact mandates their use in the SLS...

I think I'll be glad on leaving Utah in the next year or so... I think it's degrading my brain :)

Randy
Already discussed, no, the law does not mandate their use in the SLS.  The terminology has been gone over by lawyers, there is no mandate for RSRB's, period.
::::grin::: While the "law" may not "mandate" or even mention them, "Politically" the SLS depends on them any concept presented by NASA to Congress will not likely pass muster without them. Utah was guaranteed them and unfortunately (for those of us who’d much rather have LRBs or LOX/Kero work) they have the support of the rest of Congress for various and sundry reasons which will lead to RSRBs continuing to be made and used.

They may NOT be "mandated" legally in-writing, they ARE however "mandated" per Congressional default and most NASA will be forced to use them on whatever design they adopt.

Randy
Half of the Utah group lost re-election. The remaining member is now in political turmoil due to his ties to ATK and is facing a primary challenger which will make his ability to apply pressure far reduced.

Also, there is a way to retain Utah, even grow it, while eliminating the solids.
Title: Re: AJAX Launcher
Post by: RanulfC on 05/25/2011 09:29 pm
Not to get to far off topic but ONE out of THREE and the "new" guy is onboard with ATK already. He's "solidly" (excuse the pun but HE used it in an interview :) ) behind the rest of the Utah delegation on pushing solids.

While there may be a way to "grow" Utah vis-a-vis the SLS the largest factor may end up being the DoD who do NOT want ATK out of the large solid motor industry.

Randy
Title: Re: AJAX Launcher
Post by: PahTo on 05/25/2011 09:34 pm

Then let DoD pay for SRBs/SRMs out of their budget, or slice that budget and give it to NASA.
Title: Re: AJAX Launcher
Post by: Downix on 05/25/2011 10:08 pm
Not to get to far off topic but ONE out of THREE and the "new" guy is onboard with ATK already. He's "solidly" (excuse the pun but HE used it in an interview :) ) behind the rest of the Utah delegation on pushing solids.

While there may be a way to "grow" Utah vis-a-vis the SLS the largest factor may end up being the DoD who do NOT want ATK out of the large solid motor industry.

Randy
That may be, but the DoD also does not utilize large segmented solids, but large monolithic solids.  Different kettle of fish, as it were.  They do not want those solids messed with, which loss of the RSRB does not effect beyond the incidental costs.  This can be compensated for with only slight re-shuffling of resources and the agreement for ground rules for other options for ATK to enjoy.

For instance, the Liberty.  CCDev does not need a new rocket, but there are groups which do in the particular weight category it operates in.  It is solid for LEO, not as good for BEO operations.  Delta does not fit well into this weight category, and Atlas is better at BEO with the launcher offered in this category.  The issue I have with Liberty is the presumption of operation from LC-39.  I would strongly encourage Liberty development and utilization, but to operate it out of LC-36, which currently lacks a customer, LC-46 where ATK already operates a launch vehicle and could be upgraded to handle the Liberty, or Wallops which is well set up for the flexible launch scenario Liberty offers.  By my estimates, the number of launches available per year Liberty could be competitive for gaining the contract of is between 15-20, with the Liberty's suggested pricetag making it competitive even when compared against the Proton and Zenit launchers.  It also would pair well with the reborn Athena launchers, giving ATK a range of craft with a competitive pricetag for a myriad of missions.  In addition, it would offer up redundancy for CCDev over the Atlas launcher (Falcon of course being focused for SpaceX's Dragon, so the ability for corporate fiddling to harm a competitor making them less ideal for other companies).  It also avoids the ITAR issues which have caused some satellite operators headaches. 

If ATK could gain even 4 of those launches per year for the Liberty, and four more for Athena, it would bring their costs in-line for the DoD, while also offering the DoD more options for their own launch needs.  This would also give them an opportunity to reduce their own overhead as well, as part of the issue is in the use of the segmented SRB for the shuttle has set requirements, which operating the Liberty and Athena would not have. 
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/25/2011 11:49 pm
What we don't need: SRBS, ...

I actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
Unfortunatly, "Congress" (recall that it's also the opposite of "Progress" but I DEgress :) ) doesn't agree and in fact mandates their use in the SLS...

I think I'll be glad on leaving Utah in the next year or so... I think it's degrading my brain :)

Randy
Already discussed, no, the law does not mandate their use in the SLS.  The terminology has been gone over by lawyers, there is no mandate for RSRB's, period.
::::grin::: While the "law" may not "mandate" or even mention them, "Politically" the SLS depends on them any concept presented by NASA to Congress will not likely pass muster without them. Utah was guaranteed them and unfortunately (for those of us who’d much rather have LRBs or LOX/Kero work) they have the support of the rest of Congress for various and sundry reasons which will lead to RSRBs continuing to be made and used.

They may NOT be "mandated" legally in-writing, they ARE however "mandated" per Congressional default and most NASA will be forced to use them on whatever design they adopt.

Randy

Quote
and most NASA will be forced to use them on whatever design they adopt.


Thats what I am afraid of. We shall see........
Title: Re: AJAX Launcher
Post by: Zed_Noir on 05/26/2011 05:09 am
Apparently Masten is going to operate LC-36 for sub-orbital flights according to SpaceRef article.

http://www.spaceref.com/news/viewpr.html?pid=33593 (http://www.spaceref.com/news/viewpr.html?pid=33593)
Title: Re: AJAX Launcher
Post by: Downix on 05/26/2011 05:23 am
Very good.  ATK still operates out of LC-46, and studying the design it would not be difficult to grow the assembly building to the required size to operate the Liberty.
Title: Re: AJAX Launcher
Post by: Downix on 05/26/2011 07:13 am
While thumbing through the ESAS, I was surprised to notice a lift vehicle in there, LV28.  8.4m core with RS-68, with Atlas V boosters.  In the report they mentioned intentionally not researching this with SSME's.  But even with RS-68, it is delivering almost 70 tonnes to LEO.

Just an interesting note.
Title: Re: AJAX Launcher
Post by: RanulfC on 05/26/2011 08:54 pm
Not to get to far off topic but ONE out of THREE and the "new" guy is onboard with ATK already. He's "solidly" (excuse the pun but HE used it in an interview :) ) behind the rest of the Utah delegation on pushing solids.

While there may be a way to "grow" Utah vis-a-vis the SLS the largest factor may end up being the DoD who do NOT want ATK out of the large solid motor industry.

Randy
That may be, but the DoD also does not utilize large segmented solids, but large monolithic solids.  Different kettle of fish, as it were.  They do not want those solids messed with, which loss of the RSRB does not effect beyond the incidental costs.  This can be compensated for with only slight re-shuffling of resources and the agreement for ground rules for other options for ATK to enjoy.

For instance, the Liberty.  CCDev does not need a new rocket, but there are groups which do in the particular weight category it operates in.  It is solid for LEO, not as good for BEO operations.  Delta does not fit well into this weight category, and Atlas is better at BEO with the launcher offered in this category.  The issue I have with Liberty is the presumption of operation from LC-39.  I would strongly encourage Liberty development and utilization, but to operate it out of LC-36, which currently lacks a customer, LC-46 where ATK already operates a launch vehicle and could be upgraded to handle the Liberty, or Wallops which is well set up for the flexible launch scenario Liberty offers.  By my estimates, the number of launches available per year Liberty could be competitive for gaining the contract of is between 15-20, with the Liberty's suggested pricetag making it competitive even when compared against the Proton and Zenit launchers.  It also would pair well with the reborn Athena launchers, giving ATK a range of craft with a competitive pricetag for a myriad of missions.  In addition, it would offer up redundancy for CCDev over the Atlas launcher (Falcon of course being focused for SpaceX's Dragon, so the ability for corporate fiddling to harm a competitor making them less ideal for other companies).  It also avoids the ITAR issues which have caused some satellite operators headaches. 

If ATK could gain even 4 of those launches per year for the Liberty, and four more for Athena, it would bring their costs in-line for the DoD, while also offering the DoD more options for their own launch needs.  This would also give them an opportunity to reduce their own overhead as well, as part of the issue is in the use of the segmented SRB for the shuttle has set requirements, which operating the Liberty and Athena would not have. 
I'll cross my fingers and hope you're right, however "I" am not the one(s) who need to hear this stuff and the one(s) who DO are not listening it seems....

The "logic" is wrapped up in continued production of the SRSRB AS justification in and of themselves. I'll note that ATK has been trying to "sell" various LV versions of everything from single-segment to full-up RSRB "boosters" since the mid-90s with no takers and "Liberty" doesn't strike me as being much more viable than "Constellation-Ares-1" was despite the claims. Still one can hope...

Randy
Title: Re: AJAX Launcher
Post by: Downix on 05/26/2011 10:09 pm

I'll cross my fingers and hope you're right, however "I" am not the one(s) who need to hear this stuff and the one(s) who DO are not listening it seems....

The "logic" is wrapped up in continued production of the SRSRB AS justification in and of themselves. I'll note that ATK has been trying to "sell" various LV versions of everything from single-segment to full-up RSRB "boosters" since the mid-90s with no takers and "Liberty" doesn't strike me as being much more viable than "Constellation-Ares-1" was despite the claims. Still one can hope...

Randy
The crux of the issue, need to get this to the right ears.

ATK's various SRB ideas before kept failing to pass the completeness test in my experience.  They always gambled on rapid innovation, new technologies to pull their dreams out of the fire.  Liberty does as well, but not as badly as Ares I did.  Ares I needed all new everything.  Liberty, well, the Ares I first stage is just about ready, so not new although underperforming for Ares' intended role.  The Ariane upper stage and engine are the concerns, they are not designed for this configuration.  *but*, studying them, it is not a game breaker.  The Ariane's core is supported on the sides, not the base, but a simple reinforced load-transfer framework solves that.  The Vulcain 2 engine as it is requires ground-start, is a bit trickier. Based on what I've found in researching it, enabling it to start at atmosphere is not an engineering challenge, as the majority of the systems for start are already incorporated into the engine already, namely the turbopump ignition solids and gas generator solids.  As a result, this is not a game-breaker by any stretch.  Studying the design for the thrust chamber igniters, those would not be difficult to incorporate into the system, and ATK offers a solution to that with the required weight properties already.

In short, it's a good partnership, they each provide something the other one needs.
Title: Re: AJAX Launcher
Post by: Jason1701 on 05/26/2011 10:53 pm
I like ajaxlauncher.com. For the sake of professionalism, could you correct the "it's" error in the site's first paragraph?
Title: Re: AJAX Launcher
Post by: Downix on 05/26/2011 11:38 pm
I like ajaxlauncher.com. For the sake of professionalism, could you correct the "it's" error in the site's first paragraph?
Fixed.  Also tweaking the banner logo a bit, not as clean as I'd like it.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/27/2011 12:13 am
I like ajaxlauncher.com. For the sake of professionalism, could you correct the "it's" error in the site's first paragraph?
Fixed.  Also tweaking the banner logo a bit, not as clean as I'd like it.

just sent an account creation request whenever you get a chance.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/27/2011 12:21 am
it apparently will not let me view any of the content unless I am a user.

"Access denied"   >:(
Title: Re: AJAX Launcher
Post by: Downix on 05/27/2011 12:49 am
Dang, everyone jumped on at once!  It's a manual process for now until I get all of the information sorted into "good to release" and "not ready for prime time" and can automate the process.
Title: Re: AJAX Launcher
Post by: Downix on 05/27/2011 12:56 am
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.
Title: Re: AJAX Launcher
Post by: luke strawwalker on 05/27/2011 01:00 am
While getting the website set up, I came up with this picture, which pretty much sums up the whole situation right now.  We have a big blank rocket-shaped hole, and we need to fill it.

You're going to have a lot of boiloff on the pad with that all-black paint scheme aren't you?? LOL:) 

Or is that the DOD version?? Hehehe...

Cool pic.  Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: mike robel on 05/27/2011 01:03 am
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.

mkrobel is me of course!
Title: Re: AJAX Launcher
Post by: Downix on 05/27/2011 01:09 am
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.

mkrobel is me of course!
Ok.  (if you only knew how many times I referenced your Shuttle Saturn model to folk)

I deleted your redundant account there Final.
Title: Re: AJAX Launcher
Post by: luke strawwalker on 05/27/2011 01:15 am
Site looks really nice...

Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/27/2011 01:20 am
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.

Hate to break it to you but I messed it up the first time I tried. You need to unblock FinalFrontier1 not FinalFrontier. The "Final Frontier" one has the incorrect email address so I won't get the verification email when you unblock. Keep typing .net instead of .com  >:(
Title: Re: AJAX Launcher
Post by: FinalFrontier on 05/27/2011 01:21 am
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.

mkrobel is me of course!
Ok.  (if you only knew how many times I referenced your Shuttle Saturn model to folk)

I deleted your redundant account there Final.

The redundant one was the one with the right email address (the only one that could have worked) You deleted the working one x.x
Title: Re: AJAX Launcher
Post by: Downix on 05/27/2011 01:29 am
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.

mkrobel is me of course!
Ok.  (if you only knew how many times I referenced your Shuttle Saturn model to folk)

I deleted your redundant account there Final.

The redundant one was the one with the right email address (the only one that could have worked) You deleted the working one x.x
I fixed your email address in it.
Title: Re: AJAX Launcher
Post by: Downix on 05/27/2011 03:48 pm
Now I have geoallegrezza also on the list of people awaiting to have their accounts turned on.  I do not know whom this is either.
Title: Re: AJAX Launcher
Post by: Prober on 05/28/2011 06:17 pm
Not sure if you saw this or not ...but we might have another way to get and Ajax type built, maybe even cheaper.

http://forum.nasaspaceflight.com/index.php?topic=25305.msg0#new

http://www.parabolicarc.com/2011/05/27/ukrainian-rocket-fly-florida/

If they can manufacture their own engines its the way around the Russian engine problem.



Title: Re: AJAX Launcher
Post by: Downix on 05/28/2011 07:53 pm
Not sure if you saw this or not ...but we might have another way to get and Ajax type built, maybe even cheaper.

http://forum.nasaspaceflight.com/index.php?topic=25305.msg0#new

http://www.parabolicarc.com/2011/05/27/ukrainian-rocket-fly-florida/

If they can manufacture their own engines its the way around the Russian engine problem.
Those aren't RD-171's in there.  Those are AJ-26's!!
Title: Re: AJAX Launcher
Post by: seeya later navigator on 05/29/2011 10:36 am
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.
Hi Downix,

I'm just an avid follower of this post who could not resist the chance of more info on the Ajax Launcher. It's like a habit that needs to be fixed. I'm very hopefull that this system is built soon. But will it? Is it too obviously the right thing to do that it will not find any backing. We need more detail on this proposed Launcher to be in circulation.
Title: Re: AJAX Launcher
Post by: clongton on 05/29/2011 01:51 pm
It's a sad statement to NASA's credibility when so many people seem to agree that something like AJAX is the best way forward for any SDHLV and then state that the reason they believe NASA won't do it is precisely because it is the best way forward.
Title: Re: AJAX Launcher
Post by: Downix on 05/29/2011 06:31 pm
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.
Hi Downix,

I'm just an avid follower of this post who could not resist the chance of more info on the Ajax Launcher. It's like a habit that needs to be fixed. I'm very hopefull that this system is built soon. But will it? Is it too obviously the right thing to do that it will not find any backing. We need more detail on this proposed Launcher to be in circulation.
Alright, I'll unblock you to the basic area.  (need to get more information on-site, but need to finish a project first I've put off for months first)
Title: Re: AJAX Launcher
Post by: Proponent on 05/31/2011 04:39 am
Which of the RAC-3 concepts appears closes to AJAX, and how does it differ?
Title: Re: AJAX Launcher
Post by: Downix on 05/31/2011 04:41 am
Which of the RAC-3 concepts appears closes to AJAX, and how does it differ?
The RAC-3 are not the closest.  RAC-2 Option 4 is actually the closest, with an 8.4m ET tank, LH2 engines, and an upgrade path to Atlas CCB's.
Title: Re: AJAX Launcher
Post by: Downix on 05/31/2011 02:15 pm
Ok, just put a "What is AJAX" page up.  It's fully public, not requiring a login.

This whole authentication thing is getting old, however.  I'll add a way to automate the process a bit, and add another tier to allow for more customizable content access.

I'm also working on getting the whole paper up on there, and will be opening it up for certain people to go over, and give suggestions.
Title: Re: AJAX Launcher
Post by: Lobo on 06/03/2011 04:34 pm
Downix,

Dunno if this has already been asked, so my appologies if it has.   But if LRB CCB boosters were to be chosen for SLS, could RS-68 ablative nozzle engines survive that base heating environment?
They can't with SRB's, but I don't know if the LRB's exhaust is just as hot, or if it would be cooler, allowing for the the RS-68 to be used.  The RS-68 would still need to be man-rated, but NASA planned on doing that anyway with the original CxP before the base heating became an issue.
If the RS-68 didn't need to evolve into a regen cooled design, and could stay ablative, then maybe that would be a better way to go rather than RS25E's?

Just didn't know if the LRB's would provide the same base load heating problems that the SRB's did.
Title: Re: AJAX Launcher
Post by: Downix on 06/03/2011 04:40 pm
Downix,

Dunno if this has already been asked, so my appologies if it has.   But if LRB CCB boosters were to be chosen for SLS, could RS-68 ablative nozzle engines survive that base heating environment?
They can't with SRB's, but I don't know if the LRB's exhaust is just as hot, or if it would be cooler, allowing for the the RS-68 to be used.  The RS-68 would still need to be man-rated, but NASA planned on doing that anyway with the original CxP before the base heating became an issue.
If the RS-68 didn't need to evolve into a regen cooled design, and could stay ablative, then maybe that would be a better way to go rather than RS25E's?

Just didn't know if the LRB's would provide the same base load heating problems that the SRB's did.
Yes, the RS-68 would survive due to the much less hostile environment, but then you would need another stage due to the RS-68 being useless for orbital insertion, running out of fuel far too early.

The RS-68 regen was studied, and found as expensive as the RS-25E while having lower performance.

So, to go RS-68 you would wind up requiring more engines, which would increase the costs.
Title: Re: AJAX Launcher
Post by: Lobo on 06/03/2011 05:09 pm
Yes, the RS-68 would survive due to the much less hostile environment, but then you would need another stage due to the RS-68 being useless for orbital insertion, running out of fuel far too early.

The RS-68 regen was studied, and found as expensive as the RS-25E while having lower performance.

So, to go RS-68 you would wind up requiring more engines, which would increase the costs.

Ahhh, yea.  Forgot about that aspect of it.  Yea, then it makes much more sense to go with the RS-25E's to keep the basic SSTO concept (if you consider the CCB's part of the first stage). 

Have you heard anything lately new about something AJAX-like getting any consideration by the poweres that be?
Title: Re: AJAX Launcher
Post by: Downix on 06/03/2011 05:16 pm
Yes, the RS-68 would survive due to the much less hostile environment, but then you would need another stage due to the RS-68 being useless for orbital insertion, running out of fuel far too early.

The RS-68 regen was studied, and found as expensive as the RS-25E while having lower performance.

So, to go RS-68 you would wind up requiring more engines, which would increase the costs.

Ahhh, yea.  Forgot about that aspect of it.  Yea, then it makes much more sense to go with the RS-25E's to keep the basic SSTO concept (if you consider the CCB's part of the first stage). 

Have you heard anything lately new about something AJAX-like getting any consideration by the poweres that be?
If you look at the RAC studies, you'll find several block evolutions that looks pretty darn similar.

But that's about it.  I really need to figure out a way past Shelby's assistants.
Title: Re: AJAX Launcher
Post by: Prober on 06/03/2011 06:00 pm
Downix,

Dunno if this has already been asked, so my appologies if it has.   But if LRB CCB boosters were to be chosen for SLS, could RS-68 ablative nozzle engines survive that base heating environment?
They can't with SRB's, but I don't know if the LRB's exhaust is just as hot, or if it would be cooler, allowing for the the RS-68 to be used.  The RS-68 would still need to be man-rated, but NASA planned on doing that anyway with the original CxP before the base heating became an issue.
If the RS-68 didn't need to evolve into a regen cooled design, and could stay ablative, then maybe that would be a better way to go rather than RS25E's?

Just didn't know if the LRB's would provide the same base load heating problems that the SRB's did.
Yes, the RS-68 would survive due to the much less hostile environment, but then you would need another stage due to the RS-68 being useless for orbital insertion, running out of fuel far too early.

The RS-68 regen was studied, and found as expensive as the RS-25E while having lower performance.

So, to go RS-68 you would wind up requiring more engines, which would increase the costs.

Has any ablative nozzle been man rated yet?  Would think at this time it might be viewed as adding risk?
Title: Re: AJAX Launcher
Post by: Downix on 06/03/2011 06:17 pm
Downix,

Dunno if this has already been asked, so my appologies if it has.   But if LRB CCB boosters were to be chosen for SLS, could RS-68 ablative nozzle engines survive that base heating environment?
They can't with SRB's, but I don't know if the LRB's exhaust is just as hot, or if it would be cooler, allowing for the the RS-68 to be used.  The RS-68 would still need to be man-rated, but NASA planned on doing that anyway with the original CxP before the base heating became an issue.
If the RS-68 didn't need to evolve into a regen cooled design, and could stay ablative, then maybe that would be a better way to go rather than RS25E's?

Just didn't know if the LRB's would provide the same base load heating problems that the SRB's did.
Yes, the RS-68 would survive due to the much less hostile environment, but then you would need another stage due to the RS-68 being useless for orbital insertion, running out of fuel far too early.

The RS-68 regen was studied, and found as expensive as the RS-25E while having lower performance.

So, to go RS-68 you would wind up requiring more engines, which would increase the costs.

Has any ablative nozzle been man rated yet?  Would think at this time it might be viewed as adding risk?
Actually yes, the ascent engine for the Apollo LM was ablative, not just the nozzle but the combustion chamber as well.
Title: Re: AJAX Launcher
Post by: Lobo on 06/03/2011 07:00 pm

Has any ablative nozzle been man rated yet?  Would think at this time it might be viewed as adding risk?

I believe the LEM engines were ablatively cooled.  And they'd have had to be man-rated, right?

Are theUS H-1 engine, F-1 engine, or J2 engine (Used For Saturn 1B and V) or Russian RD-117, RD-118, or RD-0124 engines (used for Soyuz) ablative or regeneratively cooled?  I tried to look them up online but couldn't find any reference to ablative or regeneratively cooled.
Other than the Shuttle, these are the only LV's that have launched humans into space in the past 40 years.
Would the Shuttle SRB's be considered ablative?
Title: Re: AJAX Launcher
Post by: notherspacexfan on 06/04/2011 12:42 pm
http://spacenews.com/launch/110603-aerojet-teledyne-brown-form-propulsion-alliance.html

It looks like the stink aerojet has been making about competitive bidding of the SLS booster contract is about LRBs.

“We’ve been talking with NASA about doing some liquid boosters with kerosene engines for the [SLS] heavy launch vehicle,” Geveden said in a June 3 phone interview. “Aerojet has a history there with their AJ26 engine.”
Title: Re: AJAX Launcher
Post by: Downix on 06/04/2011 04:56 pm
http://spacenews.com/launch/110603-aerojet-teledyne-brown-form-propulsion-alliance.html

It looks like the stink aerojet has been making about competitive bidding of the SLS booster contract is about LRBs.

“We’ve been talking with NASA about doing some liquid boosters with kerosene engines for the [SLS] heavy launch vehicle,” Geveden said in a June 3 phone interview. “Aerojet has a history there with their AJ26 engine.”

*breaths a bit of a sigh* Ok, now I can put that doc on ajaxlauncher.com.  I'll put it up in a bit.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 06/04/2011 07:03 pm
Got the email back from the website but it did not contain a password. It said a password would be forthcoming in another email.

 ???
Title: Re: AJAX Launcher
Post by: Prober on 06/04/2011 07:58 pm
http://spacenews.com/launch/110603-aerojet-teledyne-brown-form-propulsion-alliance.html

It looks like the stink aerojet has been making about competitive bidding of the SLS booster contract is about LRBs.

“We’ve been talking with NASA about doing some liquid boosters with kerosene engines for the [SLS] heavy launch vehicle,” Geveden said in a June 3 phone interview. “Aerojet has a history there with their AJ26 engine.”


Another Interesting development.

Title: Re: AJAX Launcher
Post by: Downix on 06/04/2011 09:53 pm
Got the email back from the website but it did not contain a password. It said a password would be forthcoming in another email.

 ???
It should be the password you set it at. 

I need to fix that automated registration bit.  Ok, focusing on that now.
Title: Re: AJAX Launcher
Post by: Lobo on 06/06/2011 04:02 pm
Hey,
Our fearless leader Downix gets an honorable mention here:

http://www.nasaspaceflight.com/2011/06/sls-decision-nasa-two-phase-approach/

"A “non official” proposal of using liquid boosters on the HLV was created by a NSF forum member Nate Downes, which cites the liquid option as advantageous due to the simplicity of handling, superior impulse and the logistical advantages of pad fueling simply, which enables a wider range of missions for the same cost.  ATK appear to be fully aware their long-term role in SLS is not set in stone and have been busy providing costings and options to both the Marshall teams and “people in power” in Washington, DC."

(I assume Nate Downes in Downix?)

So Mr. Downes, is there any word on ULA trying to make a play to get Atlas CCB's on SLS?  That seems so ripe for the plucking, I can't believe they aren't in there with an army of lobbiests twisting arms of the "people in power" in Washington DC.  I know you linked the article on Aerojet wanting to compete for it, But does Aeroject have a whole booster like an Atlas CCB core?  or just an engine?   What are they proposing for the core itself?
Title: Re: AJAX Launcher
Post by: Downix on 06/06/2011 05:37 pm
Hey,
Our fearless leader Downix gets an honorable mention here:

http://www.nasaspaceflight.com/2011/06/sls-decision-nasa-two-phase-approach/

"A “non official” proposal of using liquid boosters on the HLV was created by a NSF forum member Nate Downes, which cites the liquid option as advantageous due to the simplicity of handling, superior impulse and the logistical advantages of pad fueling simply, which enables a wider range of missions for the same cost.  ATK appear to be fully aware their long-term role in SLS is not set in stone and have been busy providing costings and options to both the Marshall teams and “people in power” in Washington, DC."

(I assume Nate Downes in Downix?)

So Mr. Downes, is there any word on ULA trying to make a play to get Atlas CCB's on SLS?  That seems so ripe for the plucking, I can't believe they aren't in there with an army of lobbiests twisting arms of the "people in power" in Washington DC.  I know you linked the article on Aerojet wanting to compete for it, But does Aeroject have a whole booster like an Atlas CCB core?  or just an engine?   What are they proposing for the core itself?

I honestly assumed people would have googled Downix and known my name long before now.  Been using the handle since the mid-90's when I was a Linux developer.

Beyond that, I can't answer anything else of your questions.  What little I do know was given with a promise of confidentiality, so keeping Mum.  I am, however, still working on this.
Title: Re: AJAX Launcher
Post by: Lobo on 06/06/2011 11:52 pm
Hey,
Our fearless leader Downix gets an honorable mention here:

http://www.nasaspaceflight.com/2011/06/sls-decision-nasa-two-phase-approach/

"A “non official” proposal of using liquid boosters on the HLV was created by a NSF forum member Nate Downes, which cites the liquid option as advantageous due to the simplicity of handling, superior impulse and the logistical advantages of pad fueling simply, which enables a wider range of missions for the same cost.  ATK appear to be fully aware their long-term role in SLS is not set in stone and have been busy providing costings and options to both the Marshall teams and “people in power” in Washington, DC."

(I assume Nate Downes in Downix?)

So Mr. Downes, is there any word on ULA trying to make a play to get Atlas CCB's on SLS?  That seems so ripe for the plucking, I can't believe they aren't in there with an army of lobbiests twisting arms of the "people in power" in Washington DC.  I know you linked the article on Aerojet wanting to compete for it, But does Aeroject have a whole booster like an Atlas CCB core?  or just an engine?   What are they proposing for the core itself?

I honestly assumed people would have googled Downix and known my name long before now.  Been using the handle since the mid-90's when I was a Linux developer.

Beyond that, I can't answer anything else of your questions.  What little I do know was given with a promise of confidentiality, so keeping Mum.  I am, however, still working on this.

Ok, gotcha.  Been trying to be good about not disussing L2 stuff over here myself.  Sometimes hard when interesting things come along over there though.  I'm sure it's the same for you.  heheheh
But since Chris posted that article above, I figured it was ok to mention what was included in it's content anyway.  :-)

Anyway, hopefully you've heard some promising things, because I'm pretty much all-in on the LRB's at this point.  Even if it is ULA.  (I know the Atlas cores come out as the best fit, but ULA just seems pretty ready to charge up the wazzu like ATK.  So other options like F9 or some other core would actually make me feel a little more optimisitc.  :-)  ).

One last question, if you can answer it, is overall, generally speaking, if LRB's were to get a really fair and hard look for SLS, how much of an issue, really, would the RD-180 engines be for the Atlas CCB's, or Aerojet's AJ26 engines, being Russian designed and built engines?
And even if the plan is to use the existing inventory, and transition to US built RD-180's or AJ26's, the existing operational hardware is Russian, and that's what you are basing your program off of.

I heard it'd be a huge deal for NASA's flagship LV carrying US astronauts...and obviously 20 years ago or more that'd be the case.  But I don't think the average American really cares that much any more.  Russia is more of a pain in the rear than the Big Red Menace the Soviets were.  So would politicans care that much, really?
Just wondering if it's as big of a deal as some people on the forum make it out to be.  Several have said things to the effect that, "No Flagship NASA LV will every fly with Russian engines on it".   Just wondering how accurate that is?
Title: Re: AJAX Launcher
Post by: Downix on 06/06/2011 11:55 pm
Hey,
Our fearless leader Downix gets an honorable mention here:

http://www.nasaspaceflight.com/2011/06/sls-decision-nasa-two-phase-approach/

"A “non official” proposal of using liquid boosters on the HLV was created by a NSF forum member Nate Downes, which cites the liquid option as advantageous due to the simplicity of handling, superior impulse and the logistical advantages of pad fueling simply, which enables a wider range of missions for the same cost.  ATK appear to be fully aware their long-term role in SLS is not set in stone and have been busy providing costings and options to both the Marshall teams and “people in power” in Washington, DC."

(I assume Nate Downes in Downix?)

So Mr. Downes, is there any word on ULA trying to make a play to get Atlas CCB's on SLS?  That seems so ripe for the plucking, I can't believe they aren't in there with an army of lobbiests twisting arms of the "people in power" in Washington DC.  I know you linked the article on Aerojet wanting to compete for it, But does Aeroject have a whole booster like an Atlas CCB core?  or just an engine?   What are they proposing for the core itself?

I honestly assumed people would have googled Downix and known my name long before now.  Been using the handle since the mid-90's when I was a Linux developer.

Beyond that, I can't answer anything else of your questions.  What little I do know was given with a promise of confidentiality, so keeping Mum.  I am, however, still working on this.

Ok, gotcha.  Been trying to be good about not disussing L2 stuff over here myself.  Sometimes hard when interesting things come along over there though.  I'm sure it's the same for you.  heheheh
But since Chris posted that article above, I figured it was ok to mention what was included in it's content anyway.  :-)

Anyway, hopefully you've heard some promising things, because I'm pretty much all-in on the LRB's at this point.  Even if it is ULA.  (I know the Atlas cores come out as the best fit, but ULA just seems pretty ready to charge up the wazzu like ATK.  So other options like F9 or some other core would actually make me feel a little more optimisitc.  :-)  ).

One last question, if you can answer it, is overall, generally speaking, if LRB's were to get a really fair and hard look for SLS, how much of an issue, really, would the RD-180 engines be for the Atlas CCB's, or Aerojet's AJ26 engines, being Russian designed and built engines?
And even if the plan is to use the existing inventory, and transition to US built RD-180's or AJ26's, the existing operational hardware is Russian, and that's what you are basing your program off of.

I heard it'd be a huge deal for NASA's flagship LV carrying US astronauts...and obviously 20 years ago or more that'd be the case.  But I don't think the average American really cares that much any more.  Russia is more of a pain in the rear than the Big Red Menace the Soviets were.  So would politicans care that much, really?
Just wondering if it's as big of a deal as some people on the forum make it out to be.  Several have said things to the effect that, "No Flagship NASA LV will every fly with Russian engines on it".   Just wondering how accurate that is?
There are other options even over the RD-180 and AJ-26.  As a stop-gap while a proper engine is built could use a cluster of RS-27A's, or pull out those handful of F-1's or H-1's sitting in Michoud. Could pull out some LR-87's.  We *have* engines.  I baselined the RD-180 for initial testing just for simplicities sake to enable a proper domestic RP-1 engine to be built.
Title: Re: AJAX Launcher
Post by: Rocket Science on 06/07/2011 12:05 am
I really don't think the average U.S. citizen really cares about the use of a Russian engine. We are going to spend the next few years buying rides on their rockets. It would be more a political football. I doubt Americans are going to run out in the street in rage...:)
Title: Re: AJAX Launcher
Post by: Lobo on 06/07/2011 12:12 am
There are other options even over the RD-180 and AJ-26.  As a stop-gap while a proper engine is built could use a cluster of RS-27A's, or pull out those handful of F-1's or H-1's sitting in Michoud. Could pull out some LR-87's.  We *have* engines.  I baselined the RD-180 for initial testing just for simplicities sake to enable a proper domestic RP-1 engine to be built.

That's good to know, but that would bring up another problem.
If you had a stop-gap engine configuration on an Atlas, Taurus, or Falcon core, that'd basically be a new LV.  A new "booster" anyway. 
Then sometime there after, you switch to another engine.  Can NASA do that for anything less than a King's ransom?  Would that be a little like the "2-Phase" approach for SLS that Bolden just shot down?
I mean, yea, that's an option of the folks making the decision have their heart set on RP-1 LRB's, and are just figuring a way to be more politicaly palatable.  But it sounds like if anything, their heart is set on "heritage" SRB's.  Or at least that's got the most inertia, and you have to overcome that inertia to do something else.  And saying you could throw some temp engines on cores to test SLS, just to have to put new engines on cores and have to re-test SLS, might not overcome that inertia.

But, you skillfully dodged my question.  Would using RD-180's or AJ26's really be that big of a deal?  They are the more obivous choice if you are looking at Atlas cores or Taurus cores, as they are in great supply, and a US made one could be transitioned to if those stockpiles started running down, because the proper licensing is there.  If you are dusting off old fossils like the F-1, there's very little chance of transitioning to a new US made F-1 because PWR would pretty much need to create a whole new engine to do a current F-1.  So the logical choice would be using an engine that you can just stick with if the testing checks out from the start.  At least IMO anyway.

So, it would seem if you want to overcome the SRB inertia, you want to bring the best and most simple plan to the table.  That'd be using Atlas, Taurus, or Falcon9 CCB's.  And if you are using Atlas or Taurus, their engine of base design is a Russian engine.  And the most simple plan is you start with that engine, and stick with it if it tests out so you don't need to qualify new booster configurations later, for the extra money and effort.

F9 has US built engines, but it obviously has it's own issues with the sheer number of engines 4 or more CCB's would have to ignite.  And the other things you mentioned that'd be the F9 not your first choice for CCB's.

Hey, to me, it matters not a whit.  IF we are going to burn up a bunch of Ruskie engines until we start making our own version, fine by me.
But I'm just curious if most of the powers that be feel similar, or if they are really hung up on the Ruskie engine thing?
Title: Re: AJAX Launcher
Post by: Downix on 06/07/2011 01:59 am
There are other options even over the RD-180 and AJ-26.  As a stop-gap while a proper engine is built could use a cluster of RS-27A's, or pull out those handful of F-1's or H-1's sitting in Michoud. Could pull out some LR-87's.  We *have* engines.  I baselined the RD-180 for initial testing just for simplicities sake to enable a proper domestic RP-1 engine to be built.

That's good to know, but that would bring up another problem.
If you had a stop-gap engine configuration on an Atlas, Taurus, or Falcon core, that'd basically be a new LV.  A new "booster" anyway. 
Depends on the nature of the configuration.  There are avenues which limit this as an issue.
Quote
Then sometime there after, you switch to another engine.  Can NASA do that for anything less than a King's ransom?  Would that be a little like the "2-Phase" approach for SLS that Bolden just shot down?
Yes, it can be. As for being like the 2-phase approach, that approach required a new core design, this does not, it's an engine upgrade.
Quote
I mean, yea, that's an option of the folks making the decision have their heart set on RP-1 LRB's, and are just figuring a way to be more politicaly palatable.  But it sounds like if anything, their heart is set on "heritage" SRB's.  Or at least that's got the most inertia, and you have to overcome that inertia to do something else.  And saying you could throw some temp engines on cores to test SLS, just to have to put new engines on cores and have to re-test SLS, might not overcome that inertia.
You have to do that with the RS-25 in any case, new construction vs warehoused engines, so a non-argument.
Quote
But, you skillfully dodged my question.  Would using RD-180's or AJ26's really be that big of a deal?  They are the more obivous choice if you are looking at Atlas cores or Taurus cores, as they are in great supply, and a US made one could be transitioned to if those stockpiles started running down, because the proper licensing is there.  If you are dusting off old fossils like the F-1, there's very little chance of transitioning to a new US made F-1 because PWR would pretty much need to create a whole new engine to do a current F-1.  So the logical choice would be using an engine that you can just stick with if the testing checks out from the start.  At least IMO anyway.
No, it's not that big of a deal.  The AJ-26 has been listed as majority US at this point, for instance.
Quote
So, it would seem if you want to overcome the SRB inertia, you want to bring the best and most simple plan to the table.  That'd be using Atlas, Taurus, or Falcon9 CCB's.  And if you are using Atlas or Taurus, their engine of base design is a Russian engine.  And the most simple plan is you start with that engine, and stick with it if it tests out so you don't need to qualify new booster configurations later, for the extra money and effort.

F9 has US built engines, but it obviously has it's own issues with the sheer number of engines 4 or more CCB's would have to ignite.  And the other things you mentioned that'd be the F9 not your first choice for CCB's.

Hey, to me, it matters not a whit.  IF we are going to burn up a bunch of Ruskie engines until we start making our own version, fine by me.
But I'm just curious if most of the powers that be feel similar, or if they are really hung up on the Ruskie engine thing?
If we want RP-1 engines, we must do warehoused engines of one sort or another for testing.  It is easier to use the RD-180, but other options do exist.
Title: Re: AJAX Launcher
Post by: MarekCyzio on 06/07/2011 02:08 pm
I really don't think the average U.S. citizen really cares about the use of a Russian engine. We are going to spend the next few years buying rides on their rockets. It would be more a political football. I doubt Americans are going to run out in the street in rage...:)

http://en.rian.ru/russia/20110511/163977154.html

I have nothing against Russia subsidizing our space program.
Title: Re: AJAX Launcher
Post by: Rocket Science on 06/07/2011 05:01 pm
I really don't think the average U.S. citizen really cares about the use of a Russian engine. We are going to spend the next few years buying rides on their rockets. It would be more a political football. I doubt Americans are going to run out in the street in rage...:)

http://en.rian.ru/russia/20110511/163977154.html

I have nothing against Russia subsidizing our space program.
Hey, I might get one of those for my front lawn..lol The Russians are not that dumb, they'll just make up it by increasing the cost of the rides on the Soyuz.
Regards
Robert
Title: Re: AJAX Launcher
Post by: Lobo on 06/07/2011 09:36 pm

If we want RP-1 engines, we must do warehoused engines of one sort or another for testing.  It is easier to use the RD-180, but other options do exist.

Yea, I just have to think that even some of the stubborn old politicians might give in if it's understood that existing RD-180 engines will only be used for texsting and perhaps "Block 0" AJAX-440, base unit.  Sort of an argument that, "We have them, they are reliable and well understood, and so while we are developing a new Launch system, they would be one less unknown, and make development that much faster.  Once the new LV is flying and is getting a history and we are getting flight data, we can then swap over to the US made version at that time.  NASA Astronauts will be flying on an all-US built LV for the duration of the SLS program.  We're just using some existing Russian-built inventory for the testing and early phases."

Out of curiosity, how much work would there be to a Taurus 2 to get it man-rated?  As I understand, the F9 (with Merlin 1) will already be for Dragon, and the Atlas will be very easy to man-rate (plus they'll probably man rate it regardless for CST-100 and Dreamchaser)
Taurus 2 is designed more as a unmanned cargo launcher though isn't it?  Would there be any issues with it completing for a potential LRB contract?

Title: Re: AJAX Launcher
Post by: Lobo on 06/07/2011 09:40 pm
One other question.

With AJAX, are all of the booster gimbaled?  Or just the RS25's on the core?
Title: Re: AJAX Launcher
Post by: Downix on 06/07/2011 09:42 pm

If we want RP-1 engines, we must do warehoused engines of one sort or another for testing.  It is easier to use the RD-180, but other options do exist.

Yea, I just have to think that even some of the stubborn old politicians might give in if it's understood that existing RD-180 engines will only be used for texsting and perhaps "Block 0" AJAX-440, base unit.  Sort of an argument that, "We have them, they are reliable and well understood, and so while we are developing a new Launch system, they would be one less unknown, and make development that much faster.  Once the new LV is flying and is getting a history and we are getting flight data, we can then swap over to the US made version at that time.  NASA Astronauts will be flying on an all-US built LV for the duration of the SLS program.  We're just using some existing Russian-built inventory for the testing and early phases."

Out of curiosity, how much work would there be to a Taurus 2 to get it man-rated?  As I understand, the F9 (with Merlin 1) will already be for Dragon, and the Atlas will be very easy to man-rate (plus they'll probably man rate it regardless for CST-100 and Dreamchaser)
Taurus 2 is designed more as a unmanned cargo launcher though isn't it?  Would there be any issues with it completing for a potential LRB contract?

So I understand it, the Taurus 2 as/is is not man-ratable due to the upper stage.  *however* the liquid upper stage can be made human-rateable.  For it competing for an LRB contract, no issues at all that I can see, as it's issues for human-rating have to do with the upper stage, not the first.
Title: Re: AJAX Launcher
Post by: Downix on 06/07/2011 09:43 pm
One other question.

With AJAX, are all of the booster gimbaled?  Or just the RS25's on the core?
Just the core.  Simplifies the control system.
Title: Re: AJAX Launcher
Post by: Lobo on 06/07/2011 09:59 pm
One other question.

With AJAX, are all of the booster gimbaled?  Or just the RS25's on the core?
Just the core.  Simplifies the control system.

If there was an in flight engine failure of a booster, could the RS25's gimbal enough to keep the stack pointed up for abort?  (as opposed to it wheeling over) 
Title: Re: AJAX Launcher
Post by: Downix on 06/07/2011 10:07 pm
One other question.

With AJAX, are all of the booster gimbaled?  Or just the RS25's on the core?
Just the core.  Simplifies the control system.

If there was an in flight engine failure of a booster, could the RS25's gimbal enough to keep the stack pointed up for abort?  (as opposed to it wheeling over) 
The system still has throttle control.  In case of booster failure, all boosters would throttle down, or even shut off depending on how serious the failure was.
Title: Re: AJAX Launcher
Post by: baldusi on 06/07/2011 10:14 pm
Plus, the four booster configuration has a 50% that a given booster failure will be on the paired boosters. In which case the problem of control would be greatly simplified. In the other case, couldn't the RD-180 be gimbaled out to go with the CG (or aerodynamic centre, I don't know which would be the correct one)? So the gimbaling of the booster's is a simple case of which ones are not activated?
Title: Re: AJAX Launcher
Post by: Lobo on 06/08/2011 12:13 am
Downix,

I was reading some of your comments over on the thread about 2-Phase being rejected.  And you were saying something about the RS-25E's being different beasts than the current SSME's.  Could you expand a little on that?
Maybe a brief summary of the costs stavings, and performance increases, technological upgrades, and production streamlining of the RS25E over the current version?  And what needs to be done to get them rolling off the assembly line at PWR?  (YOu indicated that they could be ready much faster than people think?)
And how all of that would effect AJAX when switching from the current stock of SSME's in the initial phase and test to the RS25E's?

It sounds as those RS25 is the sure winner for SLS.  AS it says, "RS-25 or RS-68", except that the RS-68 can't survive the base heat loading if SRB's are still used for boosters, right?
And even if LRB's are chosen, you still don't really want RS-68's because they can't get the payload to LEO without an upper stage?   So that pretty much makes the RS25 the winner either way, right?  Which means there will be an RS-25E sooner or later.  So now I'm more currious about how it will be different than the current SSME (RS-25D?) but I'm unable to find much info on them online.
Also, you mention the J2X helping the RS25E.  How does that fit in and what do you see the future of the J2X with an AJAX-SLS?

Thanks a bunch.
Title: Re: AJAX Launcher
Post by: baldusi on 06/08/2011 02:43 pm
And even if LRB's are chosen, you still don't really want RS-68's because they can't get the payload to LEO without an upper stage?   So that pretty much makes the RS25 the winner either way, right?  Which means there will be an RS-25E sooner or later.

You assume too much common sense.
Title: Re: AJAX Launcher
Post by: clongton on 06/08/2011 04:03 pm
And even if LRB's are chosen, you still don't really want RS-68's because they can't get the payload to LEO without an upper stage?   So that pretty much makes the RS25 the winner either way, right?  Which means there will be an RS-25E sooner or later.

You assume too much common sense.

Not common sense; legislation.
The Authorization Act requires a minimum of 70 tons to LEO without an upper stage.
Title: Re: AJAX Launcher
Post by: baldusi on 06/08/2011 04:59 pm
And even if LRB's are chosen, you still don't really want RS-68's because they can't get the payload to LEO without an upper stage?   So that pretty much makes the RS25 the winner either way, right?  Which means there will be an RS-25E sooner or later.

You assume too much common sense.

Not common sense; legislation.
The Authorization Act requires a minimum of 70 tons to LEO without an upper stage.

Common sense in implementing an RS-25E program only with what's already developed to get the maximum cost saving for the least investment, while getting a nice performance boost. I'd bet a whole new program will be started.
Title: Re: AJAX Launcher
Post by: clongton on 06/08/2011 08:04 pm
And even if LRB's are chosen, you still don't really want RS-68's because they can't get the payload to LEO without an upper stage?   So that pretty much makes the RS25 the winner either way, right?  Which means there will be an RS-25E sooner or later.

You assume too much common sense.

Not common sense; legislation.
The Authorization Act requires a minimum of 70 tons to LEO without an upper stage.

Common sense in implementing an RS-25E program only with what's already developed to get the maximum cost saving for the least investment, while getting a nice performance boost. I'd bet a whole new program will be started.

Lobo's point was that RS-68 couldn't be used because it required an upper stage to get the 70 ton minimum to LEO therefore the RS-25 wins because it doesn't need the upper stage. So between the 2 candidates, RS-25 wins over RS-68, not because it's common sense but because the legislation *requires* that the 70 ton minimum payload must reach LEO without an upper stage. That was my point.
Title: Re: AJAX Launcher
Post by: Lampyridae on 06/09/2011 08:18 am
As a first stage engine, the RS-25's high isp is better optimised for BEO payloads though.
Title: Re: AJAX Launcher
Post by: Joris on 06/09/2011 11:54 am
As a first stage engine, the RS-25's high isp is better optimised for BEO payloads though.

It's because it's the last stage engine.
Title: Re: AJAX Launcher
Post by: Lobo on 06/09/2011 06:01 pm
And even if LRB's are chosen, you still don't really want RS-68's because they can't get the payload to LEO without an upper stage?   So that pretty much makes the RS25 the winner either way, right?  Which means there will be an RS-25E sooner or later.

You assume too much common sense.

Not common sense; legislation.
The Authorization Act requires a minimum of 70 tons to LEO without an upper stage.

Common sense in implementing an RS-25E program only with what's already developed to get the maximum cost saving for the least investment, while getting a nice performance boost. I'd bet a whole new program will be started.

Lobo's point was that RS-68 couldn't be used because it required an upper stage to get the 70 ton minimum to LEO therefore the RS-25 wins because it doesn't need the upper stage. So between the 2 candidates, RS-25 wins over RS-68, not because it's common sense but because the legislation *requires* that the 70 ton minimum payload must reach LEO without an upper stage. That was my point.

Bingo.  From both a common sense standpoint, and a legislation standpoint.  If the RS-68 can't get 70mt into LEO without an upper stage, then it doesn't meat the Congress mandate. 
Beyond that, even if they changed the mandate wording, but kept SRB's, you can't use RS-68's because they won't survive the base heating environment.
And even if you switch to LRB's, so that the RS-68's can probably survive the base heating environment, they aren't man-rated, and it sounds like it's a bit of a chore to man rate them. 
And even if you do man rate them, and incur that extra development cost and project lead time, you will still need to develop an upper stage to get anything into LEO.  Which means even more cost and lead time up front, before anything even gets off the ground. 
And even if you do all of that, the RS-68 isn't "Shuttle heritage" as the RS25 is.  So you have to justify why you aren't using shuttle heritage liquid engines "where practicable".   If I understand it all correctly.

There's a pretty strong case of going with LRB's over shuttle "heritage" SRB's, in terms of commonality, safety, flexibility, and growth potential, but when the RS25 beats the RS68 in pretty much every metric except maybe long term cost per unit (I think the ablative version of the RS68 will always be a little cheaper than the RS25E could be made to be), but even that cost difference is very minimal in the overall cost per launch, especially if you are only using 2 or 3 engines per core.  Very minor compared to all of the other things the RS25 gives you.
And the LRB's have another card up their sleave besides commonality, flexibility, safety, and growth, as I understand it, ATK can't make the actual shuttle SRB's any more.  We have the existing casings, and that's it.  They've geared up for the 5-seg Ares style now.  And while that's "heritage" to the shuttle SRB, it's not the shuttle SRB.
Then I've been hearing about new ATK proposals recently for new SRB's that are composite, with different fuel mixtures, to save money.  Likely this would be expendable rather than reusable (although no one seems to know that for sure).  These SRB's would basically be all new, and no more "shuttle heritage" than Atlas CCB's.

So, sounds like unless ATK can start rolling out old shuttle 4-seg boosters again, or at the very least, the Ares 5-seg, or the Ares 5-seg with the middle segment removed, they won't be shuttle heritage either.  But I think those options are pretty spendy, which is why I think they've been coming to the table with some other options that's been reported to be "impressive" from a cost standpoint.

That's how I understand all that Downix and Co. have reported thus far on the situation anyway.
Title: Re: AJAX Launcher
Post by: Lobo on 06/09/2011 11:29 pm
Here's a question for both Downix and Chuck,

If the RS-68 isn't a good engine to get to LEO without an upper stage, how was Direct 1.0 and 2.0 planning to get the J-120 to LEO?
As I understand, Direct switch to the SSME for Direct 3.0, but that was mainly due to CxP looking to go to it after it started to look like the RS-68 wasn't going to survive the heating environment with the SRB's, unless evolved to a regen version, which would eliminate the "low-cost" advantage of them.
But I don't recall hearing anything about the RS-68 having issues getting the non-upper stage version of Jupiter to LEO.

What happened there?
Title: Re: AJAX Launcher
Post by: Downix on 06/10/2011 02:06 am
Here's a question for both Downix and Chuck,

If the RS-68 isn't a good engine to get to LEO without an upper stage, how was Direct 1.0 and 2.0 planning to get the J-120 to LEO?
As I understand, Direct switch to the SSME for Direct 3.0, but that was mainly due to CxP looking to go to it after it started to look like the RS-68 wasn't going to survive the heating environment with the SRB's, unless evolved to a regen version, which would eliminate the "low-cost" advantage of them.
But I don't recall hearing anything about the RS-68 having issues getting the non-upper stage version of Jupiter to LEO.

What happened there?
DIRECT 1.0 used the RS-68 Regen proposal, which was to have much better ISP.  DIRECT 2.0 used only 2 RS-68's so would have had enough fuel to perform it's role. 

Any engine can get a capsule to orbit if you have enough fuel for it.
Title: Re: AJAX Launcher
Post by: Lampyridae on 06/10/2011 07:08 am
As a first stage engine, the RS-25's high isp is better optimised for BEO payloads though.

It's because it's the last stage engine.

True. Although a last stage engine that's lit first.  :D
Title: Re: AJAX Launcher
Post by: Lobo on 06/10/2011 05:34 pm
Here's a question for the forum to kick around.

AJAX's numbering system.  IT was good for when AJAX itself was being "developed" here, to denote various configurations of engines/boosters/upper stage engines.  But now that the design is pretty well fleshed out and polished up by Downix, I'm just curious if a different numbering system should be used for the "finished product" as it were.
Meaning, typically, when you have a numbering system like that, it's to denote variables. Take The Atlas numbering system for example.
First digit is PLF diameter
Second digit is number of SRB's
Third digit is number of upper stage engines.

All of those are variable options. Meaning the next Atlas launch could be an Atlas V-552, and the next launch after that could be an Atlas V-401, the next launch could be a 512, and then next could be a 411.
The numbering system doesn't denote any constants, like number of engines on the core.  There's always one RD-180.

Direct had a numbering system that was a bit redundant.
First digit is number of stages
Second digit is number of core engines
third digit is number of upper stage engines.

The first number was sort of redundant because if there was any number other than "0" for the 3rd digit, then you know it was a two-stage config.
And even denoting the number of upper stage engines was perhaps not the best way to do it.  IT was good when discussing the concept of Jupiter that was being fleshed out, because there were 4 options for engines on a new purpose built upper stage.  1=J2X, 6=RL10, 4=RL60, etc.
But once NASA might have selection which upper stage engine to use, it would have become unecessary, because the Upper stage would -always- have that number of engines.  It would no longer be an optional variable. 
It would still have two options for core engines, but not really in a sense, because the variant without an upper stage would always have 3 core engines, and the variant with an upper stage would always have 4 core stages.
So, if Direct had been chosen verbatim by NASA for SLS, you really could get by with just
Jupiter-1
Jupiter-2
That would tell you all you needed to know.  Jupiter 1 would always be a J-130, and a Jupiter-2 would always be a J-246, or J-241, or J-244, depending on what was decided on for the upper stage engines.

Take Saturn V for example.  [As I understand it] the V denotied 5 core first stage engines of the Saturn C family that would have different F1's.
The Saturn C5 was the only one ever built, so it was Shortened to "Saturn V".  But there might have been a "Saturn IV" and a "Saturn III" if the family had been fully developed.
and there was no numbering systme to denote the number of J2's on the 2nd or 3rd stages, because there were -always- 5 J2's on the 2nd stage and -always- 1 J2 on the 3rd stage.
So really the only variable would have been the number of F1's on the first stage, so that was the only number in the model.
(Please correct me if I messed up the Saturn's history, it's a bit hard to understand).

So, we get to AJAX.
Sounds like the number of core engines really isn't a variable.  Id's start with 4 of the existing RS25D's, but then transition to 3 RS25E's after CCB engine future upgrades (if I understand correctly).
But Block 0 will always have 4 engines, and a Block 1 would always have 3 engines.  Once you transition, you will never come back to 3 core engines.  So it's not really a variable.  (again, please correct me if I misunderstand that).  It's an evolution.  So is the first digit really necessary?
The 2nd digit is the number of CCB's, and since the BEAUTY of AJAX is that that is variable depending on the mission, obvioulsy that number needs to stay.
The 3rd digit is the number of engines on the upper stage.  This presents some issues because the argument -for- AJAX is it is a SSTO LV without the need for an upper stage to get to LEO.  So it can carry multiple upper stages as part of the payload.  DCSS, Centaur, ACES, or some type of upper stage that's integrated into the payload like for a planetary probe or something.  So...1)  should there be -any- denotation for the an upper stage, since that's technically part of the paylaod (AJAX is SSTO regardless of if a EDS is on it or not), and 2)  is denoting the number of upper stage engines useful?
Can you accurately get by with just an:
"AJAX-3", or "AJAX-4", or "AJAX-6".  (I guess there is no 8 CCB variant any more?)
For a Moon Mission, do you want to say you are launching an AJAX-461?  Or that you are launching an AJAX-6, with a crew and an EDS (whichever one it is).  But a new ISS segment might use the -exact- same AJAX.  An AJAX-6.  Just with no EDS.  And that's how AJAX is different that Jupiter. Jupiter would use a J-241 or a lunar mission, and a J-130 for a LEO.  AJAX would have the same number of core engines, and the same number of CCB's (depending on the lift requirement for the LEO mission).  It doesn't matter to AJAX if there's an EDS attached to the payload or not.  Jupiter needs a 2nd stage burn to LEO in a J241 config.  A J240 couldn't get to LEO from what I understand.  That's why the JUS is part of the LV, rather than divorced from it like AJAX.

If you wanted to address the upper stage in some way, you could go Direct's route and add a "1" or a "2" to the beginning to denote 1 stage or 2 stage.  "AJAX-14" for example, or "AJAX-26".  As the number of actual engines on the Centaur or DCSS might not be that important when talking about AJAX itself.
Or you could put the 1 or 2 at the end.  And AJAX-41 or AJAX-62.
However, if you thought the number of RL10's or possibly J2X's (if a newer variant of that is develped and used, which Downix has mentioned) was valuable, instead of 1 or 2 for stage, you could put a "0" there for no upper stage at all, or a 1 or 2 or 4 depending on the upper stage engines.  So an AJAX-40 would have no upper stage, but an AJAX-42 would have an upper stage with two engines.  You could take it one further and Denote which upper stage is being used with a letter.  C=Centaur, A=ACES, D=DCSS, etc.
So an AJAX-42C would have 4 CCB's, a Centaur upper stage with 2 engines.
But would AJAX -really- be using various upper stages if it was adopted as SLS?  Or would it really on use one.  Say DCSS at first, then ACES when ACES is developed (which as part of Downix's AJAX plan, so let's assume if AJAX is adopted, ACES will be developed). 
In reality, would it use all three as options?  Or would it settle on one at first (DCSS or Centaur, which even has performence most compatible with AJAX), then go exclusively with ACES once ACES is developed?  I mean, ACES would be developed to replace both DCSS and Centaur, right?  So would the type of upper stage really be an option?  Or again, an evolutionary step?
And if ACES is developed, there might still be RL10 versions of it for Atlas and Delta (as a single J2X, even the variant Downix has talked about, might be too much for say an Atlas 401 launch.  Wouldn't that still want just one or two RL10's?), but AJAX would probably always use the J2X version of ACES, due to it's super heavy lift. So at that point, would there every be any config flying on AJAX other than a single J2X engine ACES upper stage?  If so, is denoting the number of engines imporant?

Anyway, I'm sure I've completely over-thought this issue, but it got me thinking, so I thought I'd stick it on the AJAX general thread for people's thoughts.

Personally, I think we can sorta drop the last digit entirely, since when we discuss AJAX, we are pretty much just discussing the core, RS25's, and CCB's.  In all of these pages, I've not heard the number of engines on the upper stage every discussed as important.  When AJAX varants are noted, there seems to always be a "0" at that last digit.  Which obviously is very different than all the threads about Direct in which upper stage engines are discussed at length.  Mainly because Direct needed a purpose built upper stage, which was part of the LV itself.
If you want to keep the last digit, just make it a "0" for no upper stage, LEO AJAX, and a "1" for an upper stage, regardless of type.  Or a "1" for no upper stage (LV is 1-stage), or a "2" for an upper stage of any time (LV is 2-stage).

However, while we are still just kicking around a concept, we could keep the number of core engines in the model to just clarify.  But that maybe could be dropped if AJAX was ever actually implimented, as it would be unnecessary if the number of engines was always the same for every launch of the latest evolution of AJAX.
So, for the time being, we can have an AJAX-440, or AJAX-460, or AJAX-461, etc.  Later than would be just an AJAX-40, or AJAX-61.  Or even just an AJAX-4, or an AJAX-6, as the EDS is divorced from AJAX.

Or maybe I'm pondering something no one cares about, and should be pondering something else.  That's entirely possible too.  ;-)
Title: Re: AJAX Launcher
Post by: Lobo on 06/10/2011 09:04 pm
Downix,

Something else.  You've mentioned ULA's lunar exploration proposal and how AJAX could support that architecture (without the need for Depots initially).  And that through AJAX, ACES is developed, which helps create a high performance upper stage for Delta and Atals, as well as AJAX.  And then you have the keystone in place for an affordable lunar architecture.   You also have a pretty low cost option for Orion's service module as well.
So, would an ACES lander and an ACES Orion service module use the RL-10's that were in ULA's paper?  Or would they maybe use the J2X if developed as you've described (lower thurst but higher ISP).
So might there just be a single J2X on the ACES/Orion, and the ACES/Altair?  How would that compare with the 4 RL10's ULA outlined in their paper?
Title: Re: AJAX Launcher
Post by: Downix on 06/10/2011 09:11 pm
Downix,

Something else.  You've mentioned ULA's lunar exploration proposal and how AJAX could support that architecture (without the need for Depots initially).  And that through AJAX, ACES is developed, which helps create a high performance upper stage for Delta and Atals, as well as AJAX.  And then you have the keystone in place for an affordable lunar architecture.   You also have a pretty low cost option for Orion's service module as well.
So, would an ACES lander and an ACES Orion service module use the RL-10's that were in ULA's paper?  Or would they maybe use the J2X if developed as you've described (lower thurst but higher ISP).
So might there just be a single J2X on the ACES/Orion, and the ACES/Altair?  How would that compare with the 4 RL10's ULA outlined in their paper?
It depends a lot on the political situation.  I did discover that there is a method to constructing the thrust-support mount which can handle both 2 RL-10 and a J-2X without weight penalty, so it is more than possible to make a single system which can use both.  With the J-2X so close, it would make sense for ACES, in whatever form it takes, to take advantage of multiple engine options.

RL-10 makes a lot of sense for some applications, J-2X in others.  For a lander or Service Module, RL-10 all the way due to it's restart and throttling capability.  For EDS work, J-2X is pretty darned good.  It is good to offer flexibility.
Title: Re: AJAX Launcher
Post by: Lobo on 06/10/2011 10:27 pm

RL-10 makes a lot of sense for some applications, J-2X in others.  For a lander or Service Module, RL-10 all the way due to it's restart and throttling capability.  For EDS work, J-2X is pretty darned good.  It is good to offer flexibility.

Interesting. 
So if let's say ACES was built, and the ACES based lunar architecture was adopted and used with AJAX, how would that work in general, in your view?
I think ULA planned to have the ACES/Orion to do it's own TLI burn, then refuel at a lunar depot, and then do it's TEI burn.  So it would be it's own EDS.  Same for ACES/Altair.  And that was kind of the beauty of their proposal as you can remove the separate EDS.
So would you add an ACES EDS with J2X back to that architecture?  Then have ACES/ORion and ACES/Altair with the RL-10's?

How would you launch your hardware?  Two launch?  One super-heavy AJAX?  (AJAX-460, 112mt to LEO).   With a stack of an ACES-41 EDS with J2X (that's about 45mt fully fueled).  Above that, ACES/Altair (fully or partially fueled?  That's push 50mt fully fueled).  That leaves about 18mt for Orion and a partially fueled ACES/SM?
That might be doable, as the ACES/SM only needs to do the TEI burn for Orion from lunar orbit, and that doesn't take much.
Or would you just do away with the EDS, use RL10's ACES stages, launch two AJAX-440's, which would put up a fully fueld ACES/Altair, and a fully fueled ACES/ORion.  They dock in LEO, and Orion does the TLI burn for the stack and the TEI burn for ORion.  ACES/Atair does the LOI burn and the descent burn.  Would they have enough fuel for those maneuvers?

Maybe put a J2X on ORion/ACES, as it'd probably only do 2 burns.  TLI and TEI.  J2X could be started twice, right?  ACES/Atair would need to do smaller burns and throttle during descent, so sounds like you'd want RL10's for sure there.

Anyway, just curious.  :-)  Sorry to pester.
Title: Re: AJAX Launcher
Post by: Lobo on 06/10/2011 10:31 pm
It depends a lot on the political situation.  I did discover that there is a method to constructing the thrust-support mount which can handle both 2 RL-10 and a J-2X without weight penalty, so it is more than possible to make a single system which can use both.  With the J-2X so close, it would make sense for ACES, in whatever form it takes, to take advantage of multiple engine options.

That's cool.  A niced added bit of flexibility for ACES.  So it can be used with J2X for the most efficient EDS, and with RL-10's smaller payloads or as a lunar lander descent stage.
Yet another reason it'd be great to develop ACES!
Title: Re: AJAX Launcher
Post by: Lobo on 06/22/2011 09:40 pm
Downix,

Did you calculate performance of AJAX with AJ26 engines (say on Taurus II CCB) for the LRB's.  I think I remember you saying you looked at Taurus/AJ26 boosters, Atlas/RD180 boosters, and Falcon/M-1 engines for LRB options, and Atlas/RD180 came out with the best technical and political considerations, but did you post any performance info on the options other than Atlas/RD180?  I looked back like 10 pages and couldn't find it, so I figured I'd check before I kept looking.

Just curious.  Thanks.

-
Title: Re: AJAX Launcher
Post by: Downix on 06/22/2011 09:50 pm
Downix,

Did you calculate performance of AJAX with AJ26 engines (say on Taurus II CCB) for the LRB's.  I think I remember you saying you looked at Taurus/AJ26 boosters, Atlas/RD180 boosters, and Falcon/M-1 engines for LRB options, and Atlas/RD180 came out with the best technical and political considerations, but did you post any performance info on the options other than Atlas/RD180?  I looked back like 10 pages and couldn't find it, so I figured I'd check before I kept looking.

Just curious.  Thanks.

-
I did on the old Jupiter w/ LRB thread, before this thing even had a name.  The performance was almost identical to the Atlas w/ CCB, within 200kg.
Title: Re: AJAX Launcher
Post by: Lobo on 06/22/2011 10:03 pm
Downix,

Did you calculate performance of AJAX with AJ26 engines (say on Taurus II CCB) for the LRB's.  I think I remember you saying you looked at Taurus/AJ26 boosters, Atlas/RD180 boosters, and Falcon/M-1 engines for LRB options, and Atlas/RD180 came out with the best technical and political considerations, but did you post any performance info on the options other than Atlas/RD180?  I looked back like 10 pages and couldn't find it, so I figured I'd check before I kept looking.

Just curious.  Thanks.

-
I did on the old Jupiter w/ LRB thread, before this thing even had a name.  The performance was almost identical to the Atlas w/ CCB, within 200kg.

Ok, cool.  Thanks.  I know you'd said you'd looked at them all.  Just didn't recall seeing any actual performance info.

So, a quick follow up question, if using two AJ26's per booster rather than one RD180, would there be any engine out capabiltiy on say an AJAX-440?  Since an engine failure would be 1/8 of our booster power, rather tahn 1/4.  Or would an AJ26 failure after launch result in a crew abort?
Title: Re: AJAX Launcher
Post by: Lobo on 06/22/2011 10:15 pm
I did on the old Jupiter w/ LRB thread, before this thing even had a name.  The performance was almost identical to the Atlas w/ CCB, within 200kg.

If you still have those stats laying around some where, that might be good info for the AJAX website....  For all the booster options you've looked at.
Title: Re: AJAX Launcher
Post by: Downix on 06/22/2011 11:42 pm
Downix,

Did you calculate performance of AJAX with AJ26 engines (say on Taurus II CCB) for the LRB's.  I think I remember you saying you looked at Taurus/AJ26 boosters, Atlas/RD180 boosters, and Falcon/M-1 engines for LRB options, and Atlas/RD180 came out with the best technical and political considerations, but did you post any performance info on the options other than Atlas/RD180?  I looked back like 10 pages and couldn't find it, so I figured I'd check before I kept looking.

Just curious.  Thanks.

-
I did on the old Jupiter w/ LRB thread, before this thing even had a name.  The performance was almost identical to the Atlas w/ CCB, within 200kg.

Ok, cool.  Thanks.  I know you'd said you'd looked at them all.  Just didn't recall seeing any actual performance info.

So, a quick follow up question, if using two AJ26's per booster rather than one RD180, would there be any engine out capabiltiy on say an AJAX-440?  Since an engine failure would be 1/8 of our booster power, rather tahn 1/4.  Or would an AJ26 failure after launch result in a crew abort?
I've not done that much research into it, honestly.  In theory I suppose it would, but at this time not prepared to do the full breakdown.
Title: Re: AJAX Launcher
Post by: baldusi on 06/23/2011 05:21 pm
So, a quick follow up question, if using two AJ26's per booster rather than one RD180, would there be any engine out capabiltiy on say an AJAX-440?  Since an engine failure would be 1/8 of our booster power, rather tahn 1/4.  Or would an AJ26 failure after launch result in a crew abort?

Current AJ26, would need three to match an RD-180 thrust. The proposed AJ26-500 could use just two. In any case, if you use the engines on boosters, and you turn off one engine, you'd have to turn off an engine on the opposite booster, to avoid having a fuel difference. So if you have just two boosters, you're in trouble. If, instead, you have eight, you'd loose about 12.5% of your booster's thrust (the core would still go on).
Title: Re: AJAX Launcher
Post by: Downix on 06/23/2011 05:48 pm
So, a quick follow up question, if using two AJ26's per booster rather than one RD180, would there be any engine out capabiltiy on say an AJAX-440?  Since an engine failure would be 1/8 of our booster power, rather tahn 1/4.  Or would an AJ26 failure after launch result in a crew abort?

Current AJ26, would need three to match an RD-180 thrust. The proposed AJ26-500 could use just two. In any case, if you use the engines on boosters, and you turn off one engine, you'd have to turn off an engine on the opposite booster, to avoid having a fuel difference. So if you have just two boosters, you're in trouble. If, instead, you have eight, you'd loose about 12.5% of your booster's thrust (the core would still go on).
Not true.  2 AJ-26's produce 3,265kN (S.L.), or 3,630kN (Vac).  Compare to the RD-180's 3,830kN (S.L) or 4150kN (S.L.).  While yes, it is lower, it is not 33% lower, it is only 14% lower.  Add to it the weight difference of three metric tons for just the engines (including the added vectoring equipment needed for the AJ-26 which is not needed on the RD-180) and we wind up with an actual contributed thrust loss of 8%.  Now, add to it the fuel consumption rate for both engines, and you wind up very similar results.  You would have a worse T/W for ground-lift as the only drawback.  But this is if we use them on the same Atlas V CCB.  If we use them on the Taurus II's first stage, which is lighter than the Atlas CCB by 46 metric tons, then the performance loss is more than offset by the lighter system.

Remember, it's not Thrust that counts, it's applied thrust.  The weight of the launcher needs to be subtracted from the total thrust to give the surplus, the amount of thrust you can generate to overcome the inertia and pressure forces.  While the AJ-26 may not have as much thrust, that does not mean that it requires more engines to do the job if the rest of the system for it is lighter as well.
Title: Re: AJAX Launcher
Post by: Lobo on 06/23/2011 08:58 pm
Downix,

So, if there were no political considerations, just practical and technical ones, what would be your dream configuration of engines and boosters?
ULA's Atlas/RD-180?  Or was that just the most politcally likely?

If you were made SLS Czar tomorrow with complete authority over it, which way would you go?
Title: Re: AJAX Launcher
Post by: Downix on 06/23/2011 09:22 pm
Downix,

So, if there were no political considerations, just practical and technical ones, what would be your dream configuration of engines and boosters?
ULA's Atlas/RD-180?  Or was that just the most politcally likely?

If you were made SLS Czar tomorrow with complete authority over it, which way would you go?
It's the most politically likely.  I originally wanted the Taurus II, and if other things happen, could still happen.  But I am a pragmatist first and foremost, and Atlas has the cards in that regards.
Title: Re: AJAX Launcher
Post by: baldusi on 06/23/2011 09:30 pm
Downix,

So, if there were no political considerations, just practical and technical ones, what would be your dream configuration of engines and boosters?
ULA's Atlas/RD-180?  Or was that just the most politcally likely?

If you were made SLS Czar tomorrow with complete authority over it, which way would you go?
It's the most politically likely.  I originally wanted the Taurus II, and if other things happen, could still happen.  But I am a pragmatist first and foremost, and Atlas has the cards in that regards.

But was ever Taurus II designed to be a booster? Not that    Yuzhnoye would have any problem designing it as such :P
But if it needed a redesign, then you'd be actually very close to designing a Taurus II Heavy.
Title: Re: AJAX Launcher
Post by: Downix on 06/23/2011 10:02 pm
Downix,

So, if there were no political considerations, just practical and technical ones, what would be your dream configuration of engines and boosters?
ULA's Atlas/RD-180?  Or was that just the most politcally likely?

If you were made SLS Czar tomorrow with complete authority over it, which way would you go?
It's the most politically likely.  I originally wanted the Taurus II, and if other things happen, could still happen.  But I am a pragmatist first and foremost, and Atlas has the cards in that regards.

But was ever Taurus II designed to be a booster? Not that    Yuzhnoye would have any problem designing it as such :P
But if it needed a redesign, then you'd be actually very close to designing a Taurus II Heavy.
From what I understand, it shares a majority of pieces with the Zenit, which has already been used as a booster.
Title: Re: AJAX Launcher
Post by: baldusi on 06/24/2011 02:33 am
Downix,

So, if there were no political considerations, just practical and technical ones, what would be your dream configuration of engines and boosters?
ULA's Atlas/RD-180?  Or was that just the most politcally likely?

If you were made SLS Czar tomorrow with complete authority over it, which way would you go?
It's the most politically likely.  I originally wanted the Taurus II, and if other things happen, could still happen.  But I am a pragmatist first and foremost, and Atlas has the cards in that regards.

But was ever Taurus II designed to be a booster? Not that    Yuzhnoye would have any problem designing it as such :P
But if it needed a redesign, then you'd be actually very close to designing a Taurus II Heavy.
From what I understand, it shares a majority of pieces with the Zenit, which has already been used as a booster.
Yuzhnoye designed the tanking and piping, but I think a booster needs some special structural design. It would need some hard points to attach to the core, the structural requirements might be slightly different due to the aerodynamic pressure and it needs to be designed to separate safely from the core, for example. I understand that taking precaution to add those reinforcements wouldn't complicate performance, but might increase design cost. But given that they already have designed a booster, it might be actually more expensive to actually take away those design decisions. Time to ask Dr Elias.
Title: Re: AJAX Launcher
Post by: Lobo on 06/24/2011 03:44 pm
So, perhaps to get some clarification for me on this Taurus II/AJ26 config, Aerojet will make the AJ26, who actually builds the Taurus II CCB?  Orbital, or Yuzhnoye?  (a name I've only just head of, who is Yuzhnoye?)
I thought Orbital was building the Taurus II CCB.  Or are they just buying it from Yuzhnoye and integrating it with the AJ26 purchased from Aerojet?

PS:  appologies in advance for not being in the know on this insider stuff.  ;-)
Title: Re: AJAX Launcher
Post by: baldusi on 06/24/2011 04:12 pm
So, perhaps to get some clarification for me on this Taurus II/AJ26 config, Aerojet will make the AJ26, who actually builds the Taurus II CCB?  Orbital, or Yuzhnoye?  (a name I've only just head of, who is Yuzhnoye?)
I thought Orbital was building the Taurus II CCB.  Or are they just buying it from Yuzhnoye and integrating it with the AJ26 purchased from Aerojet?

PS:  appologies in advance for not being in the know on this insider stuff.  ;-)

Read here:
http://www.orbital.com/TaurusII/Suppliers/
http://www.yuzhnoye.com/index.php?lang=en
http://www.yuzhmash.com/en/

Yuzhnoye SDO is the Ukranian design bureau that designed the Cyclone and the Zenit families, the Dnepr and many others. They work very closely with the heavy industry manufacturer Yuzhmash (also Ukranian), which builds the a fore mentioned LV. Orbital Sciences are the masters of outsourcing. So, when they needed to design the tank and piping of the Taurus II they outsourced that work to Yuzhnoye and the manufacturing to Yuzhmash.
The core of the Taurus II looks suspiciously similar to the Zenit first stage. Which would be logical to be made using the same tooling. All the rest of the equipment and mechanism inside, are different, as I understand it (apu, ECU, engines, avionics, etc.). But since the techniques for making the structural design of the Zenit were thought as a dual use launcher or booster, it wouldn't take a great leap of faith to think that it might be easy to adapt the core structure as a booster.

Title: Re: AJAX Launcher
Post by: Lobo on 06/24/2011 04:36 pm
Ok, thanks for the update.  I learn something new every day around here.  :-)

So, would there be any political issues with using a Ruskie built CCB?  Seems like there was consternation about Ruskie build RD180's being used on US-Build Atlas V CCB's, if they were to be used on SLS.
Title: Re: AJAX Launcher
Post by: baldusi on 06/24/2011 04:59 pm
Ok, thanks for the update.  I learn something new every day around here.  :-)

So, would there be any political issues with using a Ruskie built CCB?  Seems like there was consternation about Ruskie build RD180's being used on US-Build Atlas V CCB's, if they were to be used on SLS.

First, is Ukrainian built, not Russian. And second, is not the CCB, but the tank and piping of the first stage. The rest, from avionics to second stage, actuators and fairing are all American.
If I'm not mistaken, there was a COTS requirement of the LV being US built. And it's usually considered as a percentage of money that stays in the US vs the amount that goes to foreign suppliers.
The AJ26 cost around 1M to Aerojet, and they sell it for something like 5M, so they are considered American. I don't know how much does Yuzhmash charges Orbital, but I think they charge 15M for the whole Zenit second stage (fully integrated), so I seriously doubt that they would charge more than 5M to 7M for the tanks and piping of the Taurus II. Considering the cost of the launch should be significantly more than that, and the avionics and second stage is from US you can't say that it isn't American (by a thin margin, thou).
Cygnus has a far higher share made by non US companies, though.
Title: Re: AJAX Launcher
Post by: Downix on 06/24/2011 05:18 pm
Too add to the discussion of US-made bits, Yuzhnoye is apparently looking at a production capability within the US as well:

http://forum.nasaspaceflight.com/index.php?topic=25305.0

And yes, the Taurus II looks incredibly similar to Zenit, it would be logical if at least some sharing had happened.
Title: Re: AJAX Launcher
Post by: Prober on 06/25/2011 07:33 pm
So, perhaps to get some clarification for me on this Taurus II/AJ26 config, Aerojet will make the AJ26, who actually builds the Taurus II CCB?  Orbital, or Yuzhnoye?  (a name I've only just head of, who is Yuzhnoye?)
I thought Orbital was building the Taurus II CCB.  Or are they just buying it from Yuzhnoye and integrating it with the AJ26 purchased from Aerojet?

PS:  appologies in advance for not being in the know on this insider stuff.  ;-)

Read here:
http://www.orbital.com/TaurusII/Suppliers/
http://www.yuzhnoye.com/index.php?lang=en
http://www.yuzhmash.com/en/

Yuzhnoye SDO is the Ukranian design bureau that designed the Cyclone and the Zenit families, the Dnepr and many others. They work very closely with the heavy industry manufacturer Yuzhmash (also Ukranian), which builds the a fore mentioned LV. Orbital Sciences are the masters of outsourcing. So, when they needed to design the tank and piping of the Taurus II they outsourced that work to Yuzhnoye and the manufacturing to Yuzhmash.
The core of the Taurus II looks suspiciously similar to the Zenit first stage. Which would be logical to be made using the same tooling. All the rest of the equipment and mechanism inside, are different, as I understand it (apu, ECU, engines, avionics, etc.). But since the techniques for making the structural design of the Zenit were thought as a dual use launcher or booster, it wouldn't take a great leap of faith to think that it might be easy to adapt the core structure as a booster.



Just thought I would add the Zenit booster engine was designed from the start with the idea of 10 uses.  The NK-33 was expendable. 

Title: Re: AJAX Launcher
Post by: Downix on 06/25/2011 08:19 pm
So, perhaps to get some clarification for me on this Taurus II/AJ26 config, Aerojet will make the AJ26, who actually builds the Taurus II CCB?  Orbital, or Yuzhnoye?  (a name I've only just head of, who is Yuzhnoye?)
I thought Orbital was building the Taurus II CCB.  Or are they just buying it from Yuzhnoye and integrating it with the AJ26 purchased from Aerojet?

PS:  appologies in advance for not being in the know on this insider stuff.  ;-)

Read here:
http://www.orbital.com/TaurusII/Suppliers/
http://www.yuzhnoye.com/index.php?lang=en
http://www.yuzhmash.com/en/

Yuzhnoye SDO is the Ukranian design bureau that designed the Cyclone and the Zenit families, the Dnepr and many others. They work very closely with the heavy industry manufacturer Yuzhmash (also Ukranian), which builds the a fore mentioned LV. Orbital Sciences are the masters of outsourcing. So, when they needed to design the tank and piping of the Taurus II they outsourced that work to Yuzhnoye and the manufacturing to Yuzhmash.
The core of the Taurus II looks suspiciously similar to the Zenit first stage. Which would be logical to be made using the same tooling. All the rest of the equipment and mechanism inside, are different, as I understand it (apu, ECU, engines, avionics, etc.). But since the techniques for making the structural design of the Zenit were thought as a dual use launcher or booster, it wouldn't take a great leap of faith to think that it might be easy to adapt the core structure as a booster.



Just thought I would add the Zenit booster engine was designed from the start with the idea of 10 uses.  The NK-33 was expendable. 


This is not actually true. The NK-33 was a reusable design in order for them to perform test after test on it.  There is at least one reusable rocket which planned to use them, the K-1.
Title: Re: AJAX Launcher
Post by: tnphysics on 07/03/2011 02:21 pm
Any benefits to reusing the boosters?

Also, what about reusing the core like was planned with the fully reusable Energia?
Title: Re: AJAX Launcher
Post by: Downix on 07/03/2011 05:43 pm
Any benefits to reusing the boosters?

Also, what about reusing the core like was planned with the fully reusable Energia?
You need a much higher flight rate to make reuse economically viable.  Frankly, we just don't have enough payload to make it work unless we were to launch everything in 1 ton increments.

Now, one thing which can be made economically viable is recoverable engines.  In the AJAX paper I have on L2 I discuss the option of recovering the SSME's, and ULA has a paper on recovery of the Atlas V's main engine.  The rest of the system, not viable, but those can be made cost-effective far simpler.
Title: Re: AJAX Launcher
Post by: Lampyridae on 07/04/2011 07:28 am
Quote
Cooke’s directorate, which will be merged into Gerstenmaier’s in a pending reorganization, is pushing a shift to hydrocarbon-fueled booster engines for the heavy-lift SLS. Administrator Charles Bolden has accepted and forwarded to the White House for final approval a recommendation that there be an eventual competition for liquid-fueled strap-on boosters after initial use of solid fuel to help get the all-cryogenic SLS main stage off the ground, as it evolves toward the targeted 130-metric-ton lift capacity Congress desires (AW&ST June 20, p. 38).

Don't know if you saw this article. It's on page 2.

http://www.aviationweek.com/aw/generic/story.jsp?id=news/awst/2011/07/04/AW_07_04_2011_p56-341403.xml&headline=Shuttle%27s%20Lessons%20Will%20Endure%20For%20Decades&channel=awst
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/05/2011 04:17 pm
Any benefits to reusing the boosters?

Also, what about reusing the core like was planned with the fully reusable Energia?


Yeah honestly both of those would probably raise costs. Expendable is the way to go.
Title: Re: AJAX Launcher
Post by: Downix on 07/05/2011 09:31 pm
Quote
Cooke’s directorate, which will be merged into Gerstenmaier’s in a pending reorganization, is pushing a shift to hydrocarbon-fueled booster engines for the heavy-lift SLS. Administrator Charles Bolden has accepted and forwarded to the White House for final approval a recommendation that there be an eventual competition for liquid-fueled strap-on boosters after initial use of solid fuel to help get the all-cryogenic SLS main stage off the ground, as it evolves toward the targeted 130-metric-ton lift capacity Congress desires (AW&ST June 20, p. 38).

Don't know if you saw this article. It's on page 2.

http://www.aviationweek.com/aw/generic/story.jsp?id=news/awst/2011/07/04/AW_07_04_2011_p56-341403.xml&headline=Shuttle%27s%20Lessons%20Will%20Endure%20For%20Decades&channel=awst
Yes I did, and was pleasantly surprised by it.
Title: Re: AJAX Launcher
Post by: Lobo on 07/09/2011 05:31 pm
Downix,

Quick question.  Are there any technological advantages to SRB's over LRB's?
I'm aware of all the tech advantages of LRB's, but other than political considerations, are there any actual advantages that could be argued for the SRB?  Some area it's better that than LRB's?
Title: Re: AJAX Launcher
Post by: Downix on 07/09/2011 07:18 pm
Downix,

Quick question.  Are there any technological advantages to SRB's over LRB's?
I'm aware of all the tech advantages of LRB's, but other than political considerations, are there any actual advantages that could be argued for the SRB?  Some area it's better that than LRB's?
Long term storage paired with instant use options.  No need to fuel it first. 

I'll admit, that capability made Ares I interesting for me, the ability to have a unit ready to launch at all times, in case of an emergency crew rescue.  However, it was paired with a cryogenic upper stage, which threw that out the window.  I still think they should have gone for hypergolic or kerolox, for this reason.  Imagine always having a launcher sitting on an MLP, in a protective shelter in the dead-end of the Crawlerway (the way which was to lead to the more northern pads, but wound up never built out).  If there was anything, it rolls out and is launched as quickly as you can get it to the pad and the crawler away.

SRB's also have a very high thrust, even if they lack impulse.  For initial segments of the flight, that is very important.  You can also pre-program the flight burn through various techniques of SRB development, optimizing the thrust for the segment of flight you are in, and so long as you construct it properly you will get the same results every single time.
Title: Re: AJAX Launcher
Post by: sdsds on 07/09/2011 07:38 pm
Are there any technological advantages to SRB's over LRB's?

Long term storage paired with instant use options.

Extremely reliable ignition.
Title: Re: AJAX Launcher
Post by: kraisee on 07/09/2011 08:09 pm
4-seg SRB has an extensive proven flight history of 220 back-to-back human-rated units since the fixes following the last failure.

5-seg does not have this.

Ross.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/09/2011 08:40 pm
4-seg SRB has an extensive proven flight history of 220 back-to-back human-rated units since the fixes following the last failure.

5-seg does not have this.

Ross.
Which is why when a 5 segment is ultimately announced to be the baseline choice for SLS I am not going to be keen on supporting.


I will be honest I just flat out do not like SRBS, in my mind they have always been:
1. Inherently more expensive
2. Inherently harder to handle (due to the toxic fuels)
3. Inherently less safe (due to the inter case sealing system of the pressure vessel).


I have and always will think that liquid boosters are superior. That's why if the politics were in our favor I would prefer to see AJAX or a similarly liquid boosted SLS configuration. But sadly they are not.
Title: Re: AJAX Launcher
Post by: neilh on 07/09/2011 11:52 pm
I have and always will think that liquid boosters are superior. That's why if the politics were in our favor I would prefer to see AJAX or a similarly liquid boosted SLS configuration. But sadly they are not.

I actually wonder if part of the reason for the delay in SLS announcement is that the political winds may be shifting in favor of liquid-boosted SLS from the start (instead of solid-boosted with a liquid-boosted competition several years after).
Title: Re: AJAX Launcher
Post by: clongton on 07/10/2011 12:12 am
I have and always will think that liquid boosters are superior. That's why if the politics were in our favor I would prefer to see AJAX or a similarly liquid boosted SLS configuration. But sadly they are not.

I actually wonder if part of the reason for the delay in SLS announcement is that the political winds may be shifting in favor of liquid-boosted SLS from the start (instead of solid-boosted with a liquid-boosted competition several years after).

I would not be opposed to this.
Title: Re: AJAX Launcher
Post by: sdsds on 07/10/2011 12:28 am
if the politics were in our favor I would prefer to see AJAX or a similarly liquid boosted SLS configuration. But sadly they are not.

I actually wonder if part of the reason for the delay in SLS announcement is that the political winds may be shifting in favor of liquid-boosted SLS from the start (instead of solid-boosted with a liquid-boosted competition several years after).

Maybe within the context of a sole-source RSRM contract, one interpretation of "independent cost estimate" is "price negotiation."  Having a viable alternative design (e.g. using the Atlas CCB or Delta CBC) should help keep that kind of independent cost estimate reasonable.
Title: Re: AJAX Launcher
Post by: clongton on 07/10/2011 12:32 am
if the politics were in our favor I would prefer to see AJAX or a similarly liquid boosted SLS configuration. But sadly they are not.

I actually wonder if part of the reason for the delay in SLS announcement is that the political winds may be shifting in favor of liquid-boosted SLS from the start (instead of solid-boosted with a liquid-boosted competition several years after).

Maybe within the context of a sole-source RSRM contract, one interpretation of "independent cost estimate" is "price negotiation."  Having a viable alternative design (e.g. using the Atlas CCB or Delta CBC) should help keep that kind of independent cost estimate reasonable.

RD-180 vs. RS-68. Man-rated vs. non-man-rated. If they go with the Atlas-V CCB then they will also have a CLV to boot.
Title: Re: AJAX Launcher
Post by: sdsds on 07/10/2011 02:50 am
Maybe within the context of a sole-source RSRM contract, one interpretation of "independent cost estimate" is "price negotiation."  Having a viable alternative design (e.g. using the Atlas CCB or Delta CBC) should help keep that kind of independent cost estimate reasonable.

RD-180 vs. RS-68. Man-rated vs. non-man-rated.

Yes, it might be quite difficult to make RS-68 into an engine rated for human spaceflight.  But it would be even more difficult to make RD-180 into an engine that had American heritage.

Technical considerations vs. political considerations.  I don't feel qualified to predict which would hold sway.  I do know that if ATK were dead set on protecting their booster monopoly they would not hesitate to wave the flag and call an Atlas CCB booster unpatriotic.
Title: Re: AJAX Launcher
Post by: luke strawwalker on 07/10/2011 03:59 am
if the politics were in our favor I would prefer to see AJAX or a similarly liquid boosted SLS configuration. But sadly they are not.

I actually wonder if part of the reason for the delay in SLS announcement is that the political winds may be shifting in favor of liquid-boosted SLS from the start (instead of solid-boosted with a liquid-boosted competition several years after).

Maybe within the context of a sole-source RSRM contract, one interpretation of "independent cost estimate" is "price negotiation."  Having a viable alternative design (e.g. using the Atlas CCB or Delta CBC) should help keep that kind of independent cost estimate reasonable.

RD-180 vs. RS-68. Man-rated vs. non-man-rated. If they go with the Atlas-V CCB then they will also have a CLV to boot.

Agree completely.  RS-68 would need manrating and it wasn't designed for it, so it'll be a big job.  RD-180 is derived from a manrated engine, so much easier.  Manrating Delta IV as a booster would be problematical (so we've been told all along) whereas manrating Atlas V for booster duties would be considerably simpler (so it's been said). 

Atlas V Heavy would make a good CLV as well for MPCV/Orion, if desired. 

I'm hoping against hope that this is actually what's going on behind the scenes... SRB's mean high costs, because that infrastructure is shared with NOBODY and NASA must pay the bill all by themselves.  Using LRB's in the form of Atlas boosters (ala AJAX) is a win/win by increasing flight rates of Atlas V and thereby lowering costs for ALL users, NASA included.  Cost sharing is what's gonna make this thing affordable, not clinging to the SRB's of which NASA is sole user...

Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: luke strawwalker on 07/10/2011 04:01 am
Maybe within the context of a sole-source RSRM contract, one interpretation of "independent cost estimate" is "price negotiation."  Having a viable alternative design (e.g. using the Atlas CCB or Delta CBC) should help keep that kind of independent cost estimate reasonable.

RD-180 vs. RS-68. Man-rated vs. non-man-rated.

Yes, it might be quite difficult to make RS-68 into an engine rated for human spaceflight.  But it would be even more difficult to make RD-180 into an engine that had American heritage.

Technical considerations vs. political considerations.  I don't feel qualified to predict which would hold sway.  I do know that if ATK were dead set on protecting their booster monopoly they would not hesitate to wave the flag and call an Atlas CCB booster unpatriotic.

More unpatriotic than flying on Russian boosters in Russian capsules lofted by Russian engines for the foreseeable future?? 

Rather hollow IMHO. 

We can allow folks to wave the flag and wag the dog, or we can come up with an affordable way to do this... not both. 

Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: neilh on 07/10/2011 09:28 am
if the politics were in our favor I would prefer to see AJAX or a similarly liquid boosted SLS configuration. But sadly they are not.

I actually wonder if part of the reason for the delay in SLS announcement is that the political winds may be shifting in favor of liquid-boosted SLS from the start (instead of solid-boosted with a liquid-boosted competition several years after).

Maybe within the context of a sole-source RSRM contract, one interpretation of "independent cost estimate" is "price negotiation."  Having a viable alternative design (e.g. using the Atlas CCB or Delta CBC) should help keep that kind of independent cost estimate reasonable.

RD-180 vs. RS-68. Man-rated vs. non-man-rated. If they go with the Atlas-V CCB then they will also have a CLV to boot.

I also wonder how the Aerojet-Teledyne Brown liquid boosters which Sen. Shelby seems to favor play into all of this.
Title: Re: AJAX Launcher
Post by: clongton on 07/10/2011 11:49 am
RD-180 vs. RS-68. Man-rated vs. non-man-rated. If they go with the Atlas-V CCB then they will also have a CLV to boot.

I also wonder how the Aerojet-Teledyne Brown liquid boosters which Sen. Shelby seems to favor play into all of this.

The AJ-26-500 would make a fine LRB engine, there can be no doubt. But the advantage that the Atlas-V CCB (RD-180) would have is that it powers the 1st stage of a man-ratable LV because the upper stage is also powered by a man-ratable engine, the RL-10. This enables the Atlas-V to actually be used to launch manned spacecraft by itself, serving triple duty; (1) the CCB as the SLS LRB, (2) DoD LV and (3) NASA and Commercial Crew CLV.

The Taurus II, powered by the AJ-26 on the other hand has a Castor solid rocket motor for the upper stage and could not be utilized in the role of CLV, disqualifying itself from that critical 3rd role. Even if the Taurus were upgraded to the AJ-26-500, the solid upper stage would still disqualify it from that role.

Being able to multi-purpose the LRB to launch both NASA *and* Commercial Crew as well as serving the DoD and the SLS HLV is the icing on the cake provided by the Atlas-V CCB. It is what would have driven the cost of the entire system down thru the floor. It is what *should* have been used for the CxP Crew Launch Vehicle in lieu of the Ares-I. It would have actually made Administrator Griffin's CxP 1.5 architecture work very, very nicely. The Atlas-V would have been the ".5" in the 1.5 architecture. What makes this so attractive is that the Atlas-V CCB *remains  the SAME*, completely unchanged when it is used in any of those 3 roles. This configuration was actually in the ESAS Appendix-6 and traded extremely well. The only reason it  was not selected is because it was not an ATK solid.  Had Dr. Griffin authorized this route, it is very likely that Orion would already be doing test flights on the Atlas-V Heavy, providing an extremely smooth transition between STS and CxP. There would have been no gap in American access to the ISS and the HLV would be well on its way to operational status already.

Now we could substitute the AJ-26-500 for the RD-180 on NASA-purposed missions and that would work very well for the LRB role, but unless the USAF were willing to gradually replace the RD-180  on *all* Atlas-V's, replenishing the inventory with the Aerojet engine instead of more RD-180's, we would completely loose the synergy that the Atlas-V CCB brings to the equation. Personally I think that would be a very smart move on the part of the USAF, but that is not my decision to make.
Title: Re: AJAX Launcher
Post by: neilh on 07/10/2011 07:02 pm
Thanks Chuck, that seems like a pretty good assessment of things.
Title: Re: AJAX Launcher
Post by: Downix on 07/10/2011 07:13 pm
I would add two addendums to Chuck's well said piece.

1) A Taurus 2 with a new upper stage could fill a CLV role, but that would add critical development onto the path, something unwanted.

2) Even if we have to use CCB's w/ a different enging, there would still be some cost reduction, just not as great.  It could be done as an immediate solution in order to demonstrate to the USAF beforehand that it can be operated without interference with their existing systems.  I do feel that once the CCB's are demonstrated with a domestic engine, the USAF will likely evaluate, if not switch outright to the solution.  Knowing them, however, they would want it perfected on NASA's dime first.
Title: Re: AJAX Launcher
Post by: Lobo on 07/11/2011 03:11 am
I would add two addendums to Chuck's well said piece.

1) A Taurus 2 with a new upper stage could fill a CLV role, but that would add critical development onto the path, something unwanted.

2) Even if we have to use CCB's w/ a different enging, there would still be some cost reduction, just not as great.  It could be done as an immediate solution in order to demonstrate to the USAF beforehand that it can be operated without interference with their existing systems.  I do feel that once the CCB's are demonstrated with a domestic engine, the USAF will likely evaluate, if not switch outright to the solution.  Knowing them, however, they would want it perfected on NASA's dime first.

Obviously you guys know way more about this than I do, but from what I understand, the Atlas V CCB was designed for multiple engines?  It just happens to be using the RD-180 now, but it could just as easily use two AJ26's? 
Assuming SLS was AJAX based, and used Atlas CCB's with RD-180's, would ULA assembled the CCB's with engines and then ship them to the VAB?  Or would the CCB and engines be shipped separately to the VAB and assembled there.  If so, I don't know how much of an issue it would really be from a "synergy" point of view.  If NASA is assembling the CCB's with the engines at the VAB, then it should be about the same regardless of if they are using one RD-180 or two AJ26's.  If they use RD-180's, then they are sharing with DoD/ULA, and if they use AJ26's, then they are sharring with Orbital/COTS on the engines as well as DOD/ULA on the CCB.  Not to mention The AJ26-500's would be US made.
(Although, I suppose if PWR made the US version of the RD-180, the same could be said for that, right?)

So, if the Atlas CCB's were used, would it really matter if it used AJ26's or RD-180's from a synergy and sharing standpoint?
Besides, if you wanted to use an Atlas Heavy for a crew lifter, ULA hasn't built one yet, so it's not like you are taking a flying LV and swapping out the engines and having to re-cert it.  The Atlas heavy would probably be flying for the first time for NASA to lift a crewed Orion regardless of what engines it has, so it doesn't really matter if it's flying with AJ26's.  right?  Going to be a new LV regardless. 

If I'm missing something here, let me know.

 
Title: Re: AJAX Launcher
Post by: Zed_Noir on 07/11/2011 03:29 am
IMO replacing the RD-180 with AJ-26 on the Atlas V CCB means you are making a new LV. The DoD might be hesitant to test a new LV with their payloads.
Title: Re: AJAX Launcher
Post by: Lobo on 07/11/2011 03:33 am
I have and always will think that liquid boosters are superior. That's why if the politics were in our favor I would prefer to see AJAX or a similarly liquid boosted SLS configuration. But sadly they are not.

I actually wonder if part of the reason for the delay in SLS announcement is that the political winds may be shifting in favor of liquid-boosted SLS from the start (instead of solid-boosted with a liquid-boosted competition several years after).

I would not be opposed to this.

my fingers are crossed for this too.
Title: Re: AJAX Launcher
Post by: Lobo on 07/11/2011 03:40 am
Are there any technological advantages to SRB's over LRB's?

Long term storage paired with instant use options.

Extremely reliable ignition.

Thanks.

But the genesis of my question was if there were any good tech arguments for SRB's that ATK could be pushing against an LRB challenger, other than just pushing with their political weight and lobbiests?

Two of the tech arguments for that people answered me with, "reliable ignition" and "proven track record (4-seg shuttle type)", I'd think they'd be easily rebutted with  1)  LRB's can be shut down if there's an ignition problem and 2) Atlas/RD-180's have a pretty good track record too.  So those don't seem like things that are definate advantages over LRB's, which is what I was if there were.
For example, an advantage of LRB's is they can be fueled at that pad, that means 1) safer assembly in the VAB, 2)  Safer transportation to KSC, and to the pad, and on the pad prior to launch, 3) less burden on the existing crawler or any new crawler that might someday replace it.
Those are 3 distinct advantages that SRB's have no equivalent of.  All they can do is their best to compensate for those disadvantages. 
So anything like that for SRB's?

Not to mention, since you can shut the LRB's down if there's a problem, there's never a chance that you can get one side lighting without the other side, like you risked with the Shuttle on every launch, and would with SLS on every launch.  (so it was good that they ignite reliably!  One failure would have been disasterous). 

Even long term storage and instant readiness arguments sorta fall away, as pointed out, because any SRB vehicle would still need liquid engines, either on an upper stage like Aries 1 or Liberty, or on the core like Ares V.
So you have long term storage of a liquid engine, and pad fueling anyway.

So, any other definitive tech advantages of SRB's?  LRB's seem to have many over SRB's...what's the counter punch?
Title: Re: AJAX Launcher
Post by: Lobo on 07/11/2011 03:53 am
IMO replacing the RD-180 with AJ-26 on the Atlas V CCB means you are making a new LV. The DoD might be hesitant to test a new LV with their payloads.

DoD wouldn't be.  They'd still use Atlas with RD-180 with no change.  NASA (or ULA) would be assembling the Atlas CCB's with the AJ26 engines.

I guess I look at it like this.  Atlas CCB's used as a booster, would be, in a way a new system, as they've never been used like that before (Atlas 5 Heavy has never flown, and even if they had, they'd never have been used with a big hydrolox core like SLS).  And Atlas CCB's used in a heavy config to lift Orion have never been used like that before, and they'd be a "new system" in effect too.  So they'll be new either way, regardless of what engine they are used with.
Now granted, they'll be "less new" if they use RD-180, and they'll be better understood.  But they'd only be used for NASA, and wouldn't effect DoD or other ULA unmanned paylaods if the AJ26's were used.  They could still use the off-the-shelf Ruskie engines as always.
Title: Re: AJAX Launcher
Post by: marsavian on 07/11/2011 03:55 pm
So SLS is starting out as a SRB booster rocket with the possibility of going LRB booster rocket down the line. What about a hybrid where the final SLS configuration can be either SRB or LRB or both. ATK/Aerojet can compete for the two SRB slots while SpaceX/PWR/Teledyne compete for two LRB slots in the other two 90 degrees apart slots. So you could have a basic SSME core with two LRB (50mT),  with two SRB (90mT), with two SRB and two LRB (130mT) all of which is not including the extra 30mT payload given by a J-2X upper stage. Truly modular in giving a wide range of payload capability to NASA and all companies and technologies get to compete and give the best booster price to NASA on a continual basis. How does that all sound, could NASA build a base vehicle to cope with all these SRB/LRB configurations and possibilities ?
Title: Re: AJAX Launcher
Post by: kirghizstan on 07/11/2011 04:06 pm
So SLS is starting out as a SRB booster rocket with the possibility of going LRB booster rocket down the line. What about a hybrid where the final SLS configuration can be either SRB or LRB or both. ATK/Aerojet can compete for the two SRB slots while SpaceX/PWR/Teledyne compete for two LRB slots in the other two 90 degrees apart slots. So you could have a basic SSME core with two LRB (50mT),  with two SRB (90mT), with two SRB and two LRB (130mT) all of which is not including the extra 30mT payload given by a J-2X upper stage. Truly modular in giving a wide range of payload capability to NASA and all companies and technologies get to compete and give the best booster price to NASA on a continual basis. How does that all sound, could NASA build a base vehicle to cope with all these SRB/LRB configurations and possibilities ?

interesting idea, what would be the lift capabilities of a 4ssme, 2 solid booster, 2 liquid booster config.  obviously it adds a bit of complexity for fueling, but just for Sh**s and Giggles i'm curious. 
Title: Re: AJAX Launcher
Post by: clongton on 07/11/2011 04:26 pm
AJAX should *not* be configured for both LRB and SRB; it's flight rate is too low to support that economically. For SRB's ATK and Aerojet would not be able to split share their revenue with an LRB because if that without making the SRB too expensive to ever use. The booster needs to be either solid or liquid, not both.
Title: Re: AJAX Launcher
Post by: marsavian on 07/11/2011 04:31 pm
So SLS is starting out as a SRB booster rocket with the possibility of going LRB booster rocket down the line. What about a hybrid where the final SLS configuration can be either SRB or LRB or both. ATK/Aerojet can compete for the two SRB slots while SpaceX/PWR/Teledyne compete for two LRB slots in the other two 90 degrees apart slots. So you could have a basic SSME core with two LRB (50mT),  with two SRB (90mT), with two SRB and two LRB (130mT) all of which is not including the extra 30mT payload given by a J-2X upper stage. Truly modular in giving a wide range of payload capability to NASA and all companies and technologies get to compete and give the best booster price to NASA on a continual basis. How does that all sound, could NASA build a base vehicle to cope with all these SRB/LRB configurations and possibilities ?

interesting idea, what would be the lift capabilities of a 4ssme, 2 solid booster, 2 liquid booster config.  obviously it adds a bit of complexity for fueling, but just for Sh**s and Giggles i'm curious. 

Without an upper stage, somewhere in the SLS 130mT area I guess.
Title: Re: AJAX Launcher
Post by: Downix on 07/11/2011 04:34 pm
AJAX should *not* be configured for both LRB and SRB; it's flight rate is too low to support that economically. For SRB's ATK and Aerojet would not be able to split share their revenue with an LRB because if that without making the SRB too expensive to ever use. The booster needs to be either solid or liquid, not both.

Indeed, we just cannot afford such a solution on the budget levels we're looking at.
Title: Re: AJAX Launcher
Post by: kirghizstan on 07/11/2011 04:40 pm
AJAX should *not* be configured for both LRB and SRB; it's flight rate is too low to support that economically. For SRB's ATK and Aerojet would not be able to split share their revenue with an LRB because if that without making the SRB too expensive to ever use. The booster needs to be either solid or liquid, not both.

i made sure not to call it a good idea, i actually think it is an awful idea, just trying to get a sense of performance of the vechile that poster proposed.
Title: Re: AJAX Launcher
Post by: marsavian on 07/11/2011 04:50 pm
Politically though it's a great idea satisfying everyone so expect it in a few years as the SLS Mark II ;).
Title: Re: AJAX Launcher
Post by: kraisee on 07/11/2011 07:34 pm
Politically though it's a great idea satisfying everyone so expect it in a few years as the SLS Mark II ;).

And with insufficient budget, it would be canceled after a few years.

Ross.
Title: Re: AJAX Launcher
Post by: baldusi on 07/11/2011 07:57 pm
You got me thinking. May be not segmented solids. But what about some refurbished ICBM? There must be a lot of Pacekeeper first stages available. What if you adapted them to the "stock" AJAX 461? It wouldn't do very good on LEO, but it should have a very respectable GTO performance. Specially if paired with a Centaur or DCSS. And it would use a lot of stuff that's costing to keep stored.
Title: Re: AJAX Launcher
Post by: Lobo on 07/11/2011 11:52 pm
AJAX should *not* be configured for both LRB and SRB; it's flight rate is too low to support that economically. For SRB's ATK and Aerojet would not be able to split share their revenue with an LRB because if that without making the SRB too expensive to ever use. The booster needs to be either solid or liquid, not both.

Not to mention the extra logistics of getting your boosters from two different suppliers in two different locations, as well as the additional pad issues (supporting hydrolox, kerolox, and solid and igniting them all) and the mix of handling both in the VAB.
Seems like a hybrid car.  It has all the headaches of an IC engine that an electric wouldn't have, but it still has those heavy and expensive batteries like an electric car.  It has to live with both drawbacks, pays for two powertrains, and gets the mass penalty for two powertrains too.  and what do you get out of it?  A little better efficiency over a gasoline engine (diesel cars get the same mileage as hybrids), and better range over an EV.
Go one or the other, and maximize it.
Title: Re: AJAX Launcher
Post by: sdsds on 07/12/2011 03:35 am
May be not segmented solids. But what about some refurbished ICBM? There must be a lot of Pacekeeper first stages available.

The Peacekeeper first stage is readily available as the Castor 120.  Used on Minotaur, Taurus XL, etc.

http://space.skyrocket.de/doc_lau_fam/peacekeeper.htm
Title: Re: AJAX Launcher
Post by: luke strawwalker on 07/12/2011 04:16 am
AJAX should *not* be configured for both LRB and SRB; it's flight rate is too low to support that economically. For SRB's ATK and Aerojet would not be able to split share their revenue with an LRB because if that without making the SRB too expensive to ever use. The booster needs to be either solid or liquid, not both.

Exactly right...

If you wanted to make the thing COMPLETELY unaffordable you couldn't hardly find a better way to do it than have BOTH solids AND liquid boosters for it...

I wonder if this is part of what's delaying all this-- If you optimize the SLS core vehicle NOW, early in the design phase, for SRB's, then you lock in a lot of things that will be VERY hard (expensive) to change later on if you decide to switch to LRB's (load paths, attach scarring, etc).  IF (and that's a big IF) the idea of competing LRB's vs. SRB's is genuine, then the time to do it would be NOW.  Do the trades, then make the call, and go with it.  Optimize your core vehicle ONCE for whichever booster you chose, and avoid the expense and difficulty of switching booster types and then having to do a bunch of stuff to rework the core and work around the differences you can't feasibly/economically change when switching from one booster type to the other...

I'd bet my bottom dollar that whatever booster the first SLS launches with (assuming it survives to ever launch and isn't canceled first) will be the same booster that the last one flies on when the program is canceled or retired... just like with shuttle (slight improvements and Challenger redesign notwithstanding).  Remember, pressure-fed LRB's and ASRM were proposed and even worked on for shuttle but all for naught... 135 launched with basically the same old 4 segment SRB's they've used all along (with slight improvements and the Challenger O-ring redesign)

Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: marsavian on 07/12/2011 07:18 am
Politically though it's a great idea satisfying everyone so expect it in a few years as the SLS Mark II ;).

And with insufficient budget, it would be canceled after a few years.

Ross.

Maybe but a HLV that theoretically subsidized both DoD (SRBs) and commercial (LRBs) as well as providing a > 150mT capacity in its most powerful iteration could have a lot of political support from just about everyone except the Tea Party that could just see it supported financially over the longer haul. The RS-25/J-2X work would also subsidize PWR RL-10s. The main problem with a HLV is not technical or financial but finding a specification that can survive changes of political control every 2/4 years.
Title: Re: AJAX Launcher
Post by: Downix on 07/12/2011 04:48 pm
Watching the Committee today gave me hope, the discussions of liquid boosters especially.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/12/2011 04:58 pm
Watching the Committee today gave me hope, the discussions of liquid boosters especially.

Same here. There was alot of interest in alternate booster technology.

Maybe AJAX ends up being SLS after all :D
Title: Re: AJAX Launcher
Post by: sdsds on 07/12/2011 05:03 pm
Watching the Committee today gave me hope, the discussions of liquid boosters especially.

There was also repeated emphasis on developing a domestic kerolox engine technology.  This might imply solutions like AJAX which use the foreign RD-180 would face non-trivial opposition.

If it were affordable, NASA could do SLS phase I (as J-130) now and at the same time support domestic kerolox booster engine development.  That would allow an all American AJAX clone to compete for SLS phase II.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/12/2011 05:05 pm
Watching the Committee today gave me hope, the discussions of liquid boosters especially.

There was also repeated emphasis on developing a domestic kerolox engine technology.  This might imply solutions like AJAX which use the foreign RD-180 would face non-trivial opposition.

If it were affordable, NASA could do SLS phase I (as J-130) now and at the same time support domestic kerolox booster engine development.  That would allow an all American AJAX clone to compete for SLS phase II.

This is good news, IMO could solve alot of problems by becoming a Compromise rocket with the WH attitude vs. the Congressional attitude as well as commercial vs. government launch advocates.
Title: Re: AJAX Launcher
Post by: Downix on 07/12/2011 05:11 pm
Watching the Committee today gave me hope, the discussions of liquid boosters especially.

There was also repeated emphasis on developing a domestic kerolox engine technology.  This might imply solutions like AJAX which use the foreign RD-180 would face non-trivial opposition.

If it were affordable, NASA could do SLS phase I (as J-130) now and at the same time support domestic kerolox booster engine development.  That would allow an all American AJAX clone to compete for SLS phase II.
If you'd recall, AJAX used the RD-180 for test flights, to get going sooner, while domestic kerolox production was ramped up.  Which means no need for an SLS Phase I using SRB, just one using RD-180 while AJ-500 or AR-1000 or whatever gets put into production.
Title: Re: AJAX Launcher
Post by: Lobo on 07/12/2011 05:13 pm
Watching the Committee today gave me hope, the discussions of liquid boosters especially.

Why, what was discussed?
Title: Re: AJAX Launcher
Post by: sdsds on 07/12/2011 05:19 pm
AJAX used the RD-180 for test flights

Maybe that idea of using Russian built engines -- even temporarily -- is a non-starter for SLS, and thus is the fatal flaw of the AJAX thinking.  We assumed that because USAF/EELV/Atlas can use it, that SLS could use it too.  It doesn't look that way after today's hearing!
Title: Re: AJAX Launcher
Post by: Lobo on 07/12/2011 05:25 pm

Maybe but a HLV that theoretically subsidized both DoD (SRBs) and commercial (LRBs) as well as providing a > 150mT capacity in its most powerful iteration could have a lot of political support from just about everyone except the Tea Party that could just see it supported financially over the longer haul. The RS-25/J-2X work would also subsidize PWR RL-10s. The main problem with a HLV is not technical or financial but finding a specification that can survive changes of political control every 2/4 years.

Why do you think the "Tea Party" wouldn't support it?  Conservatives are often among the most ardent supporters of NASA and US HSF.  Two of the hardest core right wing pundits, Sean Hannity and Mark Levin, have been recently advocating increasing funding to NASA and paying for it by cutting bloated government spending from other areas. And you don't get much more "tea party" than them.  Regardless of what people think about them on everything else, they are big NASA supporters.
Conservatives are usually the most abhored to having to relying on the Russians for US access to space, and thus wanting to rectify that as quickly as possible...they think it's humiliating among other things.  They usually don't view NASA as "wasteful spending" like they do in many other areas of government.  They view NASA as a shining example of American Exceptionalism, and like to foster that.
Not all obviously, but many.  Many more than you'll usually find among the far Left.
Title: Re: AJAX Launcher
Post by: Downix on 07/12/2011 05:37 pm
AJAX used the RD-180 for test flights

Maybe that idea of using Russian built engines -- even temporarily -- is a non-starter for SLS, and thus is the fatal flaw of the AJAX thinking.  We assumed that because USAF/EELV/Atlas can use it, that SLS could use it too.  It doesn't look that way after today's hearing!
In that case plan B, the AJ-26, which has been certified as a US engine due to the amount of rebuilding it has undergone.
Title: Re: AJAX Launcher
Post by: Lobo on 07/12/2011 06:00 pm
Watching the Committee today gave me hope, the discussions of liquid boosters especially.

Why, what was discussed?

Nevermind, I was pointed through the live thread covering it and perused it.  Looked kinda like a cluster-f*ck.  There was some talk about LRB's though, that was encouraging.
Title: Re: AJAX Launcher
Post by: sdsds on 07/12/2011 11:19 pm
We assumed that because USAF/EELV/Atlas can use [RD-180], that SLS could use it too.  It doesn't look that way after today's hearing!
In that case plan B, the AJ-26, which has been certified as a US engine due to the amount of rebuilding it has undergone.

Certified as a US component from a procurement perspective is not the same as being a US component from a political perspective.  Using rebuilt NK-33 engines with "AJ-26" painted on the side might not send the right message, even if it was done only during the time Aerojet was transitioning to domestic production.  But who can say for sure?

Downix let me ask a non-rhetorical question, i.e. one where I truly have no clue about the correct answer.  Why did LM choose Delta-IV Heavy over Atlas-V Heavy as their preferred launcher for the OFT-1 Orion flight?
Title: Re: AJAX Launcher
Post by: Downix on 07/12/2011 11:27 pm
We assumed that because USAF/EELV/Atlas can use [RD-180], that SLS could use it too.  It doesn't look that way after today's hearing!
In that case plan B, the AJ-26, which has been certified as a US engine due to the amount of rebuilding it has undergone.

Certified as a US component from a procurement perspective is not the same as being a US component from a political perspective.  Using rebuilt NK-33 engines with "AJ-26" painted on the side might not send the right message, even if it was done only during the time Aerojet was transitioning to domestic production.  But who can say for sure?

Downix let me ask a non-rhetorical question, i.e. one where I truly have no clue about the correct answer.  Why did LM choose Delta-IV Heavy over Atlas-V Heavy as their preferred launcher for the OFT-1 Orion flight?
If the AJ-26 is prohibited, so would be the RS-68, which has a similar percentage of cost as foreign sourced, primarily from Mitsubishi.  As the RS-68 was baselined for Ares V, this is a non-argument.

As for why Delta IV, I assume due to access and readiness. I have other theories as well, but nothing I would care to state publically.
Title: Re: AJAX Launcher
Post by: baldusi on 07/13/2011 12:14 am
We assumed that because USAF/EELV/Atlas can use [RD-180], that SLS could use it too.  It doesn't look that way after today's hearing!
In that case plan B, the AJ-26, which has been certified as a US engine due to the amount of rebuilding it has undergone.

Certified as a US component from a procurement perspective is not the same as being a US component from a political perspective.  Using rebuilt NK-33 engines with "AJ-26" painted on the side might not send the right message, even if it was done only during the time Aerojet was transitioning to domestic production.  But who can say for sure?

Downix let me ask a non-rhetorical question, i.e. one where I truly have no clue about the correct answer.  Why did LM choose Delta-IV Heavy over Atlas-V Heavy as their preferred launcher for the OFT-1 Orion flight?
If the AJ-26 is prohibited, so would be the RS-68, which has a similar percentage of cost as foreign sourced, primarily from Mitsubishi.  As the RS-68 was baselined for Ares V, this is a non-argument.

As for why Delta IV, I assume due to access and readiness. I have other theories as well, but nothing I would care to state publically.
If it was the only with the necessary performance (please remember that LM signed the deal knowing the performance of the RS-68A upgrade), it was probably the cheapest option. The other being the full development and manufacturing of the Atlas V Heavy. It wouldn't only be a huge extra expense, it would almost kill the Delta IV from ULA.
Title: Re: AJAX Launcher
Post by: kraisee on 07/13/2011 12:21 am
If the AJ-26 is prohibited, so would be the RS-68, which has a similar percentage of cost as foreign sourced, primarily from Mitsubishi.  As the RS-68 was baselined for Ares V, this is a non-argument.

As for why Delta IV, I assume due to access and readiness. I have other theories as well, but nothing I would care to state publically.

You're addressing the excuses, not the underlying issues.

Most members of Congress grew up during the cold war and from their very first breaths, learned to dislike everything to do with the Soviets.   This became a fundamental part of their entire childhood experience and will remain with them until the day they die.

That's the underlying reason for not wanting to use any Russian hardware for NASA's new Flagship Program. The rest is just smoke, mirrors and semi-plausible excuses used to justify this dislike. In other words: Politics.

Unfortunately AJ-26, irrelevant of its "branding", still suffers from this same issue.   No matter how many parts are changed, or produced in the US, the simple fact remains that the design originated as the Soviet NK-33/43, which themselves originated from the NK-15.

RS-68 may have foreign parts, but the anti-Japanese dislike effectively stopped after WW-II and the Japanese were never involved in the Cold War.   That antipathy has now been forgotten and so the Japanese parts are in a separate class of 'friendly' partners.

I'm personally a very big fan of the Russian technology in both RD-180 and NK-33/43 -- they are truly *great* engines.

But you, and many others here, fail to realize that politics cares not one damn for technical merits.

Politics is an extremely unpleasant and messy business primarily run by deep emotions and cold hard cash.   Because the AJ-26 design still originated in Russia, you're going to have no greater luck with it, than with RD-180 -- for precisely the same reason.

You can try to ignore this fundamental fact as much as you wish, but until the majority of members within the US Congress are too old to remember the Cold War, the Russian engines are *N*E*V*E*R* going to be allowed to power NASA's Flagship Program.

NASA's Flagship Program is first and foremost a worldwide demonstration of American expertise.   US Congress members will therefore not want this program to earn a worldwide reputation of "Powered by Russian Technology".   Period.


An RS-68/A based booster would have been politically acceptable.

Ross.
Title: Re: AJAX Launcher
Post by: Lobo on 07/13/2011 07:38 pm
If the AJ-26 is prohibited, so would be the RS-68, which has a similar percentage of cost as foreign sourced, primarily from Mitsubishi.  As the RS-68 was baselined for Ares V, this is a non-argument.

As for why Delta IV, I assume due to access and readiness. I have other theories as well, but nothing I would care to state publically.

You're addressing the excuses, not the underlying issues.

Most members of Congress grew up during the cold war and from their very first breaths, learned to dislike everything to do with the Soviets.   This became a fundamental part of their entire childhood experience and will remain with them until the day they die.

That's the underlying reason for not wanting to use any Russian hardware for NASA's new Flagship Program. The rest is just smoke, mirrors and semi-plausible excuses used to justify this dislike. In other words: Politics.

Unfortunately AJ-26, irrelevant of its "branding", still suffers from this same issue.   No matter how many parts are changed, or produced in the US, the simple fact remains that the design originated as the Soviet NK-33/43, which themselves originated from the NK-15.

RS-68 may have foreign parts, but the anti-Japanese dislike effectively stopped after WW-II and the Japanese were never involved in the Cold War.   That antipathy has now been forgotten and so the Japanese parts are in a separate class of 'friendly' partners.

I'm personally a very big fan of the Russian technology in both RD-180 and NK-33/43 -- they are truly *great* engines.

But you, and many others here, fail to realize that politics cares not one damn for technical merits.

Politics is an extremely unpleasant and messy business primarily run by deep emotions and cold hard cash.   Because the AJ-26 design still originated in Russia, you're going to have no greater luck with it, than with RD-180 -- for precisely the same reason.

You can try to ignore this fundamental fact as much as you wish, but until the majority of members within the US Congress are too old to remember the Cold War, the Russian engines are *N*E*V*E*R* going to be allowed to power NASA's Flagship Program.

NASA's Flagship Program is first and foremost a worldwide demonstration of American expertise.   US Congress members will therefore not want this program to earn a worldwide reputation of "Powered by Russian Technology".   Period.


An RS-68/A based booster would have been politically acceptable.

Ross.

Ross,

I'll preface this by saying I have no direct knowlegde of how big of a deal "Ruskie Engines on NASA's Flagship Rocket" will be to members of Congress and the President.
I've asked this question around this forum of people with much more knowledge than I do (including you!) and got a mixed bag of answers.
But the more I pay attention, and the more I use my noodle to think about it, the more I come to the conclusion that I don't think it'll be a very big issue.  Esspecially if the engine is branded as a US made Aerojet AJ26. 
My reasoning is thus:
1)  I don't think the current President gives a flying rip about NASA, or US HSF, or Russian hardware in general.  I think if our rocket was built fully by Russia, and shipped to KSC for launch by barge, and had Russian letters on it with a Russian flag emblem, I doubt POTUS would care personally, as long as it was cheaper.  He'd say something about this "historic period of international cooperation between Cold Ward rivals".  He's already admitted he doesn't believe in American Exceptionalism any more than any other citizen of any other country feels that way about their own country.
2)  While some in Congress would balk at it, (guys like Nelson, Shelby, etc)  the majority won't care, and know less about NASA than your average 4th grader.  They have other pet projects than NASA, as evidenced by our current political state, and the cluster f*ck going on right now. There's 535 members of congress.  If 20 or 30 of them have an issue with it, it's still a tiny minority.  The of those that have an issue with it, those are the tiny minority that actually give a damn about US HSF, and they will probably see the flip side...that SLS using LRB, even if based on a Russian design, if built, would be the superior LV and actually get us back into space.  The balkers will be the only ones with enough technical interest to also see the advantages of using them.  Especially if there's some "political grey area" in that they would still be technically built in the US, and especially if that transitions to an evolved engine down the road that's more fully US planned and built.  Or that another all-US engine could be upgraded too if one became available.  (Merlin 2 or similar). 
In short, likely, the ones that probably would care most about the engines being Ruskie-based, are also the ones who care the most about NASA and would see the flip side of their advantages (since there's no fully US-made kerolox engine that's available any time soon).
Sounds like Shelby already likes the idea of Aerojet's AJ26 based LRB...which supports my thoery.  I'm sure he's well aware of what it's based on.
3)  Obviosly most in Congress don't care all that much about us relying on-working with- or using Russian hardware, because they don't seem to be willing to do much about the upcomming gap, where we'll be relying fully 100% on the Russians for our manned space access.  If there was more interest and urgency in Congress about that, rather than just some half-hearted squalking, I'd think maybe you were right.  But there doesn't seem to be.

So, in short, the technical advantages of LRB's on SLS are vast and numorous.  I have yet to figure out any technical reason to go with SRB's again.  So the only reason to go with SRB's is political.
Assuming NASA would go with LRB's based on their technical merit, and then sell it on that, and that they'll be either US built AJ26's or US built RD-180's (by PWR), (or heck, even Falcon 9 LRB's using Merlins...if SpaceX gets in), Where it's not brought really mentioned about the Russian connection, then it's really up to POTUS and Congress if they squalk about it.  We already know POTUS won't care, and highly likely that a majority in the House and Senate won't care (IMHO).
And it's likely the general public won't know or care (IMHO).  And even if they find out about it, they are already used to things being "international" and "cooperative".  Foreign built USS segments, supply ships by Russia, ESA, and Japan already.  Multi-national astronauts flying on the Shuttle and manning the ISS.
The perception and attitude just isn't the same as it used to be.
If the rocket says "USA" and "NASA" on it, and it's launching and doing things, the public won't care if some parts are based on a Russian design, or if the pumps were made in Japan, or some electronics were made in Germany, etc.

Anyway, that's just my 2 cents.  And yes, I am a supporter of LRB, so maybe it's a little wishful thinking, but as of yet, I just haven't seen the interest or political will from the players that matter, to make me think they'll care much, and make that a deal-breaker.  They certainly don't seem too concerned that we are about to rely on the Ruskies for EVERYTHING, not just their concept for an engine on a booster.
As long as there's a bandaid over the "Made in the USSR" logo, it'll pass the public, POTUS, and majority of Congress's passing interest.

PS:  If there would be anyone making a stink about it, it'll probably be the handfull of Senators and Representative that ATK has influence over via jobs in their districts.  They might points a yell, "Commie!".  But there should be just as many standing up against that that stand to gain jobs in -their- districts.  Everyone else will shrug and say, "Whatever...when's the football game on?"
So the push and push back would probably be mostly in the relm of politicians with a job stack one way or the other.  Which would be the case even if the LRB's were 100% US built and there was no Russian consideration.  It's just one extra card the ATK people (and maybe SpaceX if they were to try to compete for it...obviously ULA couldn't use it) could try to play to strengthen their hand to keep their hardware on SLS.

But, of course, I could be horribly wrong.  ;-)
Title: Re: AJAX Launcher
Post by: fotoguzzi on 07/13/2011 11:30 pm
I'm as anti-Soviet as the next guy. My only reservation would be that I would want the ability to produce the entire engine in America. I recall that Jim said that the U. S. could reverse-engineer the special coatings on the RD-180 engine and thereby construct the entire engine inhouse.

Once that ability was demonstrated, I would not be too unhappy with purchasing complete engines from Russia for a flagship project.

Modify: remove words; change word
Title: Re: AJAX Launcher
Post by: Downix on 07/13/2011 11:35 pm
I'm as anti-Soviet as the next guy. My only reservation would be that I would want the ability to produce the entire engine in America. I recall that Jim said that the U. S. could reverse-engineer the special coatings on the RD-180 engine and thereby construct the entire engine inhouse.

Once that ability was demonstrated, I would not be too unhappy with purchasing complete engines from Russia for a flagship project.

Modify: remove words; change word
We already have that from Aerojet with their AJ-500, which is based on the AJ-26.
Title: Re: AJAX Launcher
Post by: clongton on 07/14/2011 04:43 pm
Birthday Party!

This thread is exactly a year old today.
It was started July 14, 2010.
Happy Birthday AJAX!
May you have many more.
Title: Re: AJAX Launcher
Post by: Lurker Steve on 07/14/2011 05:34 pm
If the AJ-26 is prohibited, so would be the RS-68, which has a similar percentage of cost as foreign sourced, primarily from Mitsubishi.  As the RS-68 was baselined for Ares V, this is a non-argument.

As for why Delta IV, I assume due to access and readiness. I have other theories as well, but nothing I would care to state publically.

You're addressing the excuses, not the underlying issues.

Most members of Congress grew up during the cold war and from their very first breaths, learned to dislike everything to do with the Soviets.   This became a fundamental part of their entire childhood experience and will remain with them until the day they die.

That's the underlying reason for not wanting to use any Russian hardware for NASA's new Flagship Program. The rest is just smoke, mirrors and semi-plausible excuses used to justify this dislike. In other words: Politics.

Unfortunately AJ-26, irrelevant of its "branding", still suffers from this same issue.   No matter how many parts are changed, or produced in the US, the simple fact remains that the design originated as the Soviet NK-33/43, which themselves originated from the NK-15.

RS-68 may have foreign parts, but the anti-Japanese dislike effectively stopped after WW-II and the Japanese were never involved in the Cold War.   That antipathy has now been forgotten and so the Japanese parts are in a separate class of 'friendly' partners.

I'm personally a very big fan of the Russian technology in both RD-180 and NK-33/43 -- they are truly *great* engines.

But you, and many others here, fail to realize that politics cares not one damn for technical merits.

Politics is an extremely unpleasant and messy business primarily run by deep emotions and cold hard cash.   Because the AJ-26 design still originated in Russia, you're going to have no greater luck with it, than with RD-180 -- for precisely the same reason.

You can try to ignore this fundamental fact as much as you wish, but until the majority of members within the US Congress are too old to remember the Cold War, the Russian engines are *N*E*V*E*R* going to be allowed to power NASA's Flagship Program.

NASA's Flagship Program is first and foremost a worldwide demonstration of American expertise.   US Congress members will therefore not want this program to earn a worldwide reputation of "Powered by Russian Technology".   Period.


An RS-68/A based booster would have been politically acceptable.

Ross.

Ross,

I'll preface this by saying I have no direct knowlegde of how big of a deal "Ruskie Engines on NASA's Flagship Rocket" will be to members of Congress and the President.
I've asked this question around this forum of people with much more knowledge than I do (including you!) and got a mixed bag of answers.
But the more I pay attention, and the more I use my noodle to think about it, the more I come to the conclusion that I don't think it'll be a very big issue.  Esspecially if the engine is branded as a US made Aerojet AJ26. 
My reasoning is thus:
1)  I don't think the current President gives a flying rip about NASA, or US HSF, or Russian hardware in general.  I think if our rocket was built fully by Russia, and shipped to KSC for launch by barge, and had Russian letters on it with a Russian flag emblem, I doubt POTUS would care personally, as long as it was cheaper.  He'd say something about this "historic period of international cooperation between Cold Ward rivals".  He's already admitted he doesn't believe in American Exceptionalism any more than any other citizen of any other country feels that way about their own country.
2)  While some in Congress would balk at it, (guys like Nelson, Shelby, etc)  the majority won't care, and know less about NASA than your average 4th grader.  They have other pet projects than NASA, as evidenced by our current political state, and the cluster f*ck going on right now. There's 535 members of congress.  If 20 or 30 of them have an issue with it, it's still a tiny minority.  The of those that have an issue with it, those are the tiny minority that actually give a damn about US HSF, and they will probably see the flip side...that SLS using LRB, even if based on a Russian design, if built, would be the superior LV and actually get us back into space.  The balkers will be the only ones with enough technical interest to also see the advantages of using them.  Especially if there's some "political grey area" in that they would still be technically built in the US, and especially if that transitions to an evolved engine down the road that's more fully US planned and built.  Or that another all-US engine could be upgraded too if one became available.  (Merlin 2 or similar). 
In short, likely, the ones that probably would care most about the engines being Ruskie-based, are also the ones who care the most about NASA and would see the flip side of their advantages (since there's no fully US-made kerolox engine that's available any time soon).
Sounds like Shelby already likes the idea of Aerojet's AJ26 based LRB...which supports my thoery.  I'm sure he's well aware of what it's based on.
3)  Obviosly most in Congress don't care all that much about us relying on-working with- or using Russian hardware, because they don't seem to be willing to do much about the upcomming gap, where we'll be relying fully 100% on the Russians for our manned space access.  If there was more interest and urgency in Congress about that, rather than just some half-hearted squalking, I'd think maybe you were right.  But there doesn't seem to be.

So, in short, the technical advantages of LRB's on SLS are vast and numorous.  I have yet to figure out any technical reason to go with SRB's again.  So the only reason to go with SRB's is political.
Assuming NASA would go with LRB's based on their technical merit, and then sell it on that, and that they'll be either US built AJ26's or US built RD-180's (by PWR), (or heck, even Falcon 9 LRB's using Merlins...if SpaceX gets in), Where it's not brought really mentioned about the Russian connection, then it's really up to POTUS and Congress if they squalk about it.  We already know POTUS won't care, and highly likely that a majority in the House and Senate won't care (IMHO).
And it's likely the general public won't know or care (IMHO).  And even if they find out about it, they are already used to things being "international" and "cooperative".  Foreign built USS segments, supply ships by Russia, ESA, and Japan already.  Multi-national astronauts flying on the Shuttle and manning the ISS.
The perception and attitude just isn't the same as it used to be.
If the rocket says "USA" and "NASA" on it, and it's launching and doing things, the public won't care if some parts are based on a Russian design, or if the pumps were made in Japan, or some electronics were made in Germany, etc.

Anyway, that's just my 2 cents.  And yes, I am a supporter of LRB, so maybe it's a little wishful thinking, but as of yet, I just haven't seen the interest or political will from the players that matter, to make me think they'll care much, and make that a deal-breaker.  They certainly don't seem too concerned that we are about to rely on the Ruskies for EVERYTHING, not just their concept for an engine on a booster.
As long as there's a bandaid over the "Made in the USSR" logo, it'll pass the public, POTUS, and majority of Congress's passing interest.

PS:  If there would be anyone making a stink about it, it'll probably be the handfull of Senators and Representative that ATK has influence over via jobs in their districts.  They might points a yell, "Commie!".  But there should be just as many standing up against that that stand to gain jobs in -their- districts.  Everyone else will shrug and say, "Whatever...when's the football game on?"
So the push and push back would probably be mostly in the relm of politicians with a job stack one way or the other.  Which would be the case even if the LRB's were 100% US built and there was no Russian consideration.  It's just one extra card the ATK people (and maybe SpaceX if they were to try to compete for it...obviously ULA couldn't use it) could try to play to strengthen their hand to keep their hardware on SLS.

But, of course, I could be horribly wrong.  ;-)

The average US congressman / senator may not care much about the cold war, but they do care about jobs. Heck, they might even think that Pratt & Whitney is getting enough federal funding with the F-35 sole-source engine contract. A perfect solution would be if the Russians did something like Toyota / Honda, and opened a manufacturing facility in the US for building a new RD-180 sized engine. Maybe this brand-new facility is located in Alabama, Florida, or Utah. 
Title: Re: AJAX Launcher
Post by: Downix on 07/14/2011 05:39 pm

The average US congressman / senator may not care much about the cold war, but they do care about jobs. Heck, they might even think that Pratt & Whitney is getting enough federal funding with the F-35 sole-source engine contract. A perfect solution would be if the Russians did something like Toyota / Honda, and opened a manufacturing facility in the US for building a new RD-180 sized engine. Maybe this brand-new facility is located in Alabama, Florida, or Utah. 

Already happening, in a way.  Aerojet already announced that they would be building an updated version of the NK-33 within the US, in Huntsville Alabama.  Their updated AJ-26 can replace the RD-180 easily enough (the AJ-26 was one of the engines which was studied for the Atlas V, in fact).
Title: Re: AJAX Launcher
Post by: Lobo on 07/14/2011 07:33 pm

The average US congressman / senator may not care much about the cold war, but they do care about jobs. Heck, they might even think that Pratt & Whitney is getting enough federal funding with the F-35 sole-source engine contract. A perfect solution would be if the Russians did something like Toyota / Honda, and opened a manufacturing facility in the US for building a new RD-180 sized engine. Maybe this brand-new facility is located in Alabama, Florida, or Utah. 

Already happening, in a way.  Aerojet already announced that they would be building an updated version of the NK-33 within the US, in Huntsville Alabama.  Their updated AJ-26 can replace the RD-180 easily enough (the AJ-26 was one of the engines which was studied for the Atlas V, in fact).

Yea, my comments above were based on thing like this that I've gleened from this thread and many other threads, as well as much my observation of the current POTUS and Congress.  IF this was 1992 adn the Cold War was still fresh in every Congressman's and American citizen's mind, I could see an engine even -based- on a Soviet design as being a non-starter.  But that was then and this is now.  And although I hate to say it, at times I think we could pick up my local phone book, and pick 536 names out of it it at random, and replace all of Congress and POTUS with them, and at least do no worse than we're doing now.  So with the exception of a few congress people that are interested in NASA and US HSF, I doubt most of the rest with figure out or care that the engines are -based- on a Soviet design, if they are being "built" in Alabama by Aerojet, or wherever in the US they'd be built by PWR (RD180). 
Especially if their production equals jobs in those districts.
If the plan was to use off-the shelf Russian engines like PWR and ULA use for the current Atlas, I could see some more grumbling about that. 
But when the question is asked, "Where would the engines be built of SLS where to go with an LRB configuration",
Answer, "Huntsville, AL...where X-number of employees will be hired for that increased production".
"Isn't the AJ-500 engine an old Soviet engine?"
"No sir, it uses some parts built in Russia, but the engine is a a new engine designed and assembled in Huntsville."
"So can it really be considered to be 'Built in the USA'?"
"Yes sir, it has enough US made parts and the assembly is in the US to be considered US made.  Most US built engines use some components built in other countries.  That is nothing unusual".
"Ok, next issue..."

But again, maybe that's a bit of wishful thinking on my part.  ;-)
Title: Re: AJAX Launcher
Post by: Downix on 07/14/2011 07:37 pm

The average US congressman / senator may not care much about the cold war, but they do care about jobs. Heck, they might even think that Pratt & Whitney is getting enough federal funding with the F-35 sole-source engine contract. A perfect solution would be if the Russians did something like Toyota / Honda, and opened a manufacturing facility in the US for building a new RD-180 sized engine. Maybe this brand-new facility is located in Alabama, Florida, or Utah. 

Already happening, in a way.  Aerojet already announced that they would be building an updated version of the NK-33 within the US, in Huntsville Alabama.  Their updated AJ-26 can replace the RD-180 easily enough (the AJ-26 was one of the engines which was studied for the Atlas V, in fact).

Yea, my comments above were based on thing like this that I've gleened from this thread and many other threads, as well as much my observation of the current POTUS and Congress.  IF this was 1992 adn the Cold War was still fresh in every Congressman's and American citizen's mind, I could see an engine even -based- on a Soviet design as being a non-starter.  But that was then and this is now.  And although I hate to say it, at times I think we could pick up my local phone book, and pick 536 names out of it it at random, and replace all of Congress and POTUS with them, and at least do no worse than we're doing now.  So with the exception of a few congress people that are interested in NASA and US HSF, I doubt most of the rest with figure out or care that the engines are -based- on a Soviet design, if they are being "built" in Alabama by Aerojet, or wherever in the US they'd be built by PWR (RD180). 
Especially if their production equals jobs in those districts.
If the plan was to use off-the shelf Russian engines like PWR and ULA use for the current Atlas, I could see some more grumbling about that. 
But when the question is asked, "Where would the engines be built of SLS where to go with an LRB configuration",
Answer, "Huntsville, AL...where X-number of employees will be hired for that increased production".
"Isn't the AJ-500 engine an old Soviet engine?"
"No sir, it uses some parts built in Russia, but the engine is a a new engine designed and assembled in Huntsville."
"So can it really be considered to be 'Built in the USA'?"
"Yes sir, it has enough US made parts and the assembly is in the US to be considered US made.  Most US built engines use some components built in other countries.  That is nothing unusual".
"Ok, next issue..."

But again, maybe that's a bit of wishful thinking on my part.  ;-)
If you notice the wording of all of the announcements, they never say it *is* the NK-33, just "based on" the NK-33.  With Aerojet's history, can also say it is "based on" the LR-87 which powered the Titan missile for it's entire operational life, or the AJ-10 which powered the Shuttle's OMS system for it's entire operational life.  While the new engine may have more systems "based on" the NK-33 than the others, the know-how from these older engines will not be ignored in the production of the AJ-500.  Experience is always used I've often times found out.
Title: Re: AJAX Launcher
Post by: Lobo on 07/14/2011 07:49 pm
If you notice the wording of all of the announcements, they never say it *is* the NK-33, just "based on" the NK-33.  With Aerojet's history, can also say it is "based on" the LR-87 which powered the Titan missile for it's entire operational life, or the AJ-10 which powered the Shuttle's OMS system for it's entire operational life.  While the new engine may have more systems "based on" the NK-33 than the others, the know-how from these older engines will not be ignored in the production of the AJ-500.  Experience is always used I've often times found out.

I guess it's probably like one of those T-Bucket roadsters you see running around in the summer time with the loud pipes and the big fat rear tires and big engines.  Well, they are "based on" a Model T Ford.  But they aren't a Model T Ford any more.

And Ironically...

http://www.tbucketplans.com/2011/07/05/high-performance-machines-meet-for-last-goodbye-on-pad-39a/
Title: Re: AJAX Launcher
Post by: 93143 on 07/14/2011 08:32 pm
...wow.  I didn't know they had those cameras...
Title: Re: AJAX Launcher
Post by: kch on 07/14/2011 09:27 pm
Could someone give an explanation of what Ajax is and how it compares to Jupiter?  Is it a competitor to Direct or is it more or less a modification of the Jupiter?  Not much on google and there doesn't seem to be a website for it.  From what I've gathered so far it has a narrower core booster and uses LRB's instead of SRB's.  It has the advantage over Jupiter in that It can strap on four boosters instead of two, and shares more common parts with EELV. 

You've come to the right site!  Here's a good place to start reading:

http://forum.nasaspaceflight.com/index.php?topic=22266.0

When you've finished reading that one ( ;) ), there are more threads to be found here (19 pages of links at this time):

Heavy Lift Launch Vehicle (HLV/SLS)
http://forum.nasaspaceflight.com/index.php?board=37.0

Read the ones with AJAX in the title first, then browse through the others -- you'll find useful / interesting bits in many of them.

Oh, yes -- "welcome to NSF!"  :)
Title: Re: AJAX Launcher
Post by: Downix on 07/14/2011 09:44 pm
Could someone give an explanation of what Ajax is and how it compares to Jupiter?  Is it a competitor to Direct or is it more or less a modification of the Jupiter?  Not much on google and there doesn't seem to be a website for it.  From what I've gathered so far it has a narrower core booster and uses LRB's instead of SRB's.  It has the advantage over Jupiter in that It can strap on four boosters instead of two, and shares more common parts with EELV. 
it does not have a narrower core, it has a shorter core, done by assembling the fuel tanks with less of the rings found in the ET as it is in the Shuttle. The opposite approach to the original Ares V, which added more rings to stretch the tank.  18% smaller to be exact.  The reason why is twofold.  One, less weight at lift off to compensate for the LRB's lower initial thrust.  Two, the LRB's burn almost twice as long as the SRB's, so the SSME's are throttled down for almost two minutes longer, so they burn less fuel. 

It is not so much a competitor as an alternative arrangement.

As for advantages, you can add more boosters, but you're not limited to just 4.  You can strap anywhere from 2 to 8 Atlas V boosters around the core, which gives you incredible amounts of lift, surpassing the largest configuration of the Ares V..  You can therefore scale it to suit your needs.  Lifting 70 tons, build it one way.  Lifting 120, another.  "Dial a Rocket" as it were, same as you do for the EELV's.  It also, if paired with the Atlas V HLV for crew lift, enables a continuation of the Constellations 1.5 architecture, which itself was a smart idea (not depending on the crew lifter for cargo as well) but the implementation of which for Constellation was lacking. 

By doing this, thanks to the SSME's high efficiency, you do not need a combination EDS/Upper Stage, as with Ares V.  Instead you can use an off-the-shelf orbital stage, such as the Delta Common Second Stage or Common Centaur, to serve as the EDS, with the AJAX core putting it directly into the target parking orbit.  Which means even more commonality with the EELV's than just the boosters.
Title: Re: AJAX Launcher
Post by: Downix on 07/15/2011 04:16 am
So, its only drawback would be political, with ATK being taken out of the the picture.  Is there an estimated timetable for first test flight if Ajax were selected?
Depends on what you consider a test flight.  30-36 months to first booster test, on an Atlas V, 12 months after that for full up AJAX test. (I like being conservative in timetables and cost to buy margin)
Title: Re: AJAX Launcher
Post by: clongton on 07/18/2011 05:18 pm
The stars are aligning.
http://www.nasaspaceflight.com/2011/07/nasa-ula-saa-complete-human-rating-atlas-v/
Title: Re: AJAX Launcher
Post by: luke strawwalker on 07/18/2011 07:11 pm
The stars are aligning.
http://www.nasaspaceflight.com/2011/07/nasa-ula-saa-complete-human-rating-atlas-v/

Yes this is certainly good news for something like AJAX wouldn't it??

Ya know, a year ago I would NEVER have imagined there would be talk of LRB's-- the very fact that LRB's are now at least "being talked about" is a pretty interesting development.  Maybe it's just a ploy to "put the skeer" into ATK, threatening them with the possible replacement of their beloved SRB's with LRB's after the early test flights establish SDHLV (SLS of whatever flavor).  BUT, maybe, just maybe, it's something more...

HR Atlas V would be the first necessity for an AJAX vehicle, correct??  So this would be good news for an AJAX type vehicle.  Personally, having looked at things, I think that AJAX is a MUCH MUCH better fit for SLS requirements than 5/5.  SRB's are maxed out, and the ONLY way to get more than minor incremental improvement is to TOTALLY rework them into something completely new, like the high pressure steel lined composite overlaid cases, which is going to be TERRIFICALLY expensive, and STILL result in something that's basically maxed out when done, with no upgradability.  The support infrastructure is maxed out already.  If you want flexibility, ala "dial a rocket", then LRB's are the ONLY way to go.  SRB's are a 'one trick pony'. 

Could this POSSIBLY, just POSSIBLY, be the reason that HQ is dragging out the SLS announcement as long as possible??  Could they be trying to 'gather the forces' necessary to face down the inevitable ATK lobbyist induced Congressional blowback from showing that SRB needs to go and LRB's take their place, by virtue of an SRB-based SLS being too expensive (which it inevitably WILL prove to be IMHO).  That would certainly fit with their "commercial based" approach MUCH better than SRB SLS would... cost sharing with 'commercial' on SLS by using ULA LRB's would certainly make SLS more palatable to the Admin.  One thing's for sure-- they're gonna have to be loaded for bear if dumping SRB's is a serious proposal-- because ATK's gonna put up a fight... BUT, if they have the numbers and with Congress DESPERATE for an SLS (ANY SLS) then this might JUST get NASA HQ/Admin the leverage they need...

OTOH, anytime a question is posed about the future of Michoud and Louisiana, the response is invariably nebulous and "standard reassuring response"... With any SDLV core vehicle being most assuredly built at Michoud, seems that if LRB's were the plan for an SDLV core vehicle, they could be a LITTLE more reassuring...

Probably reading too much into it... sometimes a cigar is just a cigar... LOL:) 

Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: Downix on 07/18/2011 08:15 pm
" Once the avalanche has started, it's too late for the pebbles to vote." -- Ambassador Kosh from Babylon 5.
Title: Re: AJAX Launcher
Post by: clongton on 07/19/2011 01:31 am
Roll baby roll!
Title: Re: AJAX Launcher
Post by: Lampyridae on 07/19/2011 12:48 pm
"And so it begins...
Title: Re: AJAX Launcher
Post by: Lobo on 07/19/2011 04:09 pm
Interesting article.

But, before all of us AJAX fans get too excited, I read it to be in relation to ULA launching COTS providers which will need man-rating for their crew launches.
Sierra and Blue Origin and Boeing are the real drivers here (I can't imagine Boeing putting CST-100 on anything other than a ULA rocket, as Boeing is half of that consortium).  When you have 3 commercial customers looking to launch on your rocket, there's good incentive to provide it as needed.  I think the proposals we've already seen from NASA and ULA about using KSC for launching Atlas with various capsules on it ties in there as well.

Of couse, it's certainly doesn't hurt AJAX's position.  In fact, makes it stronger.  But it's not perfect.  Sounds like all of the COTS folks will be using the Atlas with the RD-180 engine.  If Aerojet is the only provider offering LRB options for SLS, then they may or may not be using the Atlas V CCB.  And an Atlas V CCB with two AJ26 or AJ500 engine won't quite be the same bestie that ULA is man-rating for the COTS folks.
So I suppose the question I have, is when ULA man-rates the Atlas V with RD-180, how much different would be be to put different engines there and keep the man rating as a booster?  What are the issue/challenges there?

I didn't read anything in there about LRB's, so I don't want to read too much into this.  But, to be wildly optimistic, yea, maybe NASA dragging out final announcement of SLS because they are looking harder at LRB's?  Maybe Aerojet's making a compelling case? Maybe ULA and SpaceX are in there too, we just haven't heard about it publically yet? (as in, they have their lobbiests in there working NASA, but having submitted any official proposals yet).  And maybe that additional pushings is getting some attention in NASA?  (The technical case is certainly a hugely compelling one). 
Who is John Galt?
Title: Re: AJAX Launcher
Post by: clongton on 07/19/2011 05:10 pm
Interesting article.

But, before all of us AJAX fans get too excited, I read it to be in relation to ULA launching COTS providers which will need man-rating for their crew launches.
Sierra and Blue Origin and Boeing are the real drivers here (I can't imagine Boeing putting CST-100 on anything other than a ULA rocket, as Boeing is half of that consortium).  When you have 3 commercial customers looking to launch on your rocket, there's good incentive to provide it as needed.  I think the proposals we've already seen from NASA and ULA about using KSC for launching Atlas with various capsules on it ties in there as well.

Of course, it's certainly doesn't hurt AJAX's position.  In fact, makes it stronger.  But it's not perfect.  Sounds like all of the COTS folks will be using the Atlas with the RD-180 engine.  If Aerojet is the only provider offering LRB options for SLS, then they may or may not be using the Atlas V CCB.  And an Atlas V CCB with two AJ26 or AJ500 engine won't quite be the same bestie that ULA is man-rating for the COTS folks.
So I suppose the question I have, is when ULA man-rates the Atlas V with RD-180, how much different would be be to put different engines there and keep the man rating as a booster?  What are the issue/challenges there?

I didn't read anything in there about LRB's, so I don't want to read too much into this.  But, to be wildly optimistic, yea, maybe NASA dragging out final announcement of SLS because they are looking harder at LRB's?  Maybe Aerojet's making a compelling case? Maybe ULA and SpaceX are in there too, we just haven't heard about it publically yet? (as in, they have their lobbyists in there working NASA, but having submitted any official proposals yet).  And maybe that additional pushing is getting some attention in NASA?  (The technical case is certainly a hugely compelling one). 
Who is John Galt?


In actual fact this is working in our favor. AJAX has *ALWAYS* promoted the use of its LRB as a crew launcher for both Commercial and for NASA. The synergy that creates with ULA and commercial is one of the major selling points of the program.

As for the AJ-500 vs. the RD-180, I do not see that as a problem. ULA has a healthy inventory of RD-180's on hand. I would expect the Atlas-V going forward to continue to use them. During that time Aerojet would be bringing the AJ-500 on line and the engine should be ready to test fly before the RD-180 inventory is exhausted. It would not be a difficult thing to arrange with the USAF to use up the RD-180 inventory without replenishment and simply begin using the AJ-500 in its place. That has a lot going for it.

The RD-180 is a Russian engine while the AJ-500 would be an American engine.
The RD-180 is a single turbine 2-chamber engine producing 861k lbs thrust at sea level.
The AJ-500 replacement would be a 2-engine 1-chamber drop-in replacement producing 1,000,000 lbs of thrust at sea level.

The 2-engine AJ-500 replacement arrangement is in reality the natural successor to the 2-chamber RD-180. It is more powerful, built with modern methods and quality control and is a domestic engine. It's the perfect replacement and actually makes the Atlas-V better than it currently is.
Title: Re: AJAX Launcher
Post by: Lobo on 07/19/2011 09:55 pm

In actual fact this is working in our favor. AJAX has *ALWAYS* promoted the use of its LRB as a crew launcher for both Commercial and for NASA. The synergy that creates with ULA and commercial is one of the major selling points of the program.

As for the AJ-500 vs. the RD-180, I do not see that as a problem. ULA has a healthy inventory of RD-180's on hand. I would expect the Atlas-V going forward to continue to use them. During that time Aerojet would be bringing the AJ-500 on line and the engine should be ready to test fly before the RD-180 inventory is exhausted. It would not be a difficult thing to arrange with the USAF to use up the RD-180 inventory without replenishment and simply begin using the AJ-500 in its place. That has a lot going for it.

The RD-180 is a Russian engine while the AJ-500 would be an American engine.
The RD-180 is a single turbine 2-chamber engine producing 861k lbs thrust at sea level.
The AJ-500 replacement would be a 2-engine 1-chamber drop-in replacement producing 1,000,000 lbs of thrust at sea level.

The 2-engine AJ-500 replacement arrangement is in reality the natural successor to the 2-chamber RD-180. It is more powerful, built with modern methods and quality control and is a domestic engine. It's the perfect replacement and actually makes the Atlas-V better than it currently is.


I'm with you buddy.  I really, REALLY hope this is once piece of the puzzle falling into place which will result in:
1)  AJAX-like SLS with LRB's (preferrably Atlas CCB's with AJ500 engines)
2)  Atlas Launching COTS Capsules.
3)  Atlas Heavy launching Crewed Orion for LEO missions.
4)  KSC being used as a multi-purpose spaceport like it was designed, launching crewed Dragon-F9's, FH's, CST-100-Atlas, Dreamchaser-Atlas, and SLS.

It seems to be, but I'm skeptical...as in I've gotten pretty cynical over the past few years.
Title: Re: AJAX Launcher
Post by: Lobo on 07/19/2011 10:04 pm

As for the AJ-500 vs. the RD-180, I do not see that as a problem. ULA has a healthy inventory of RD-180's on hand. I would expect the Atlas-V going forward to continue to use them. During that time Aerojet would be bringing the AJ-500 on line and the engine should be ready to test fly before the RD-180 inventory is exhausted. It would not be a difficult thing to arrange with the USAF to use up the RD-180 inventory without replenishment and simply begin using the AJ-500 in its place. That has a lot going for it.

The RD-180 is a Russian engine while the AJ-500 would be an American engine.
The RD-180 is a single turbine 2-chamber engine producing 861k lbs thrust at sea level.
The AJ-500 replacement would be a 2-engine 1-chamber drop-in replacement producing 1,000,000 lbs of thrust at sea level.

The 2-engine AJ-500 replacement arrangement is in reality the natural successor to the 2-chamber RD-180. It is more powerful, built with modern methods and quality control and is a domestic engine. It's the perfect replacement and actually makes the Atlas-V better than it currently is.


Ok, I have some questions about this.

1)  Would ULA be opposed for any reason to putting AJ500's on their Atlas CCB's for SLS?  When they've been estabilishing their good track record with RD180's?  Would there be resistance to "messing" with their rocket?
2)  If AJ500's on Atlas CCB's were chosen, would ULA only use them for SLS LRB's?  (And stick with RD-180's for COTS-crew, commercial-unmanned, and government-unmanned) Or would they transition from RD-180's and go exclusively with AJ500's?  What would PWR do about that?

3)  What are some likely scenarios about how it might play out if LRB's are chosen for SLS?
Title: Re: AJAX Launcher
Post by: baldusi on 07/19/2011 10:06 pm
The AJ-500 supposedly would be another HR engine. It has better T/W and isp than the RD-180. Being American and if it has all that's needed, (APU compatibility and such), after extensive testing, ULA should have a problem with it. In fact, it might help them go back to Energomash and tell them to get an even nicer price on RD-180 or they would switch. At least, that's my guess.
Title: Re: AJAX Launcher
Post by: Lobo on 07/19/2011 10:37 pm
Chuck,

I have a quick question I was hoping you can answer.  Could a J-130 put a payload into circular LEO without needing an upper stage like AJAX can?  (assume ullage motors would be needed to deorbit the core in either case).
I assume it can, as there was a lot of Direct documentation that showed it putting cargo into LEO, but after thinking about it, I think those payloads showed some propulsive vehicle as the payload which may have done it's own circ burn.  Orion + MPLM, ORion + Altair, etc.
As I understand Downix, because of the longer burn times of AJAX LRB's, it can put it's full payload into circular LEO with no need of an upper stage.  (and that payload is variable by adding LRB's, so no upper stage is ever needed for LEO payload placement).
Can a J-130 do that too?
Title: Re: AJAX Launcher
Post by: luke strawwalker on 07/20/2011 03:31 am

In actual fact this is working in our favor. AJAX has *ALWAYS* promoted the use of its LRB as a crew launcher for both Commercial and for NASA. The synergy that creates with ULA and commercial is one of the major selling points of the program.

As for the AJ-500 vs. the RD-180, I do not see that as a problem. ULA has a healthy inventory of RD-180's on hand. I would expect the Atlas-V going forward to continue to use them. During that time Aerojet would be bringing the AJ-500 on line and the engine should be ready to test fly before the RD-180 inventory is exhausted. It would not be a difficult thing to arrange with the USAF to use up the RD-180 inventory without replenishment and simply begin using the AJ-500 in its place. That has a lot going for it.

The RD-180 is a Russian engine while the AJ-500 would be an American engine.
The RD-180 is a single turbine 2-chamber engine producing 861k lbs thrust at sea level.
The AJ-500 replacement would be a 2-engine 1-chamber drop-in replacement producing 1,000,000 lbs of thrust at sea level.

The 2-engine AJ-500 replacement arrangement is in reality the natural successor to the 2-chamber RD-180. It is more powerful, built with modern methods and quality control and is a domestic engine. It's the perfect replacement and actually makes the Atlas-V better than it currently is.


Any links to where I can get more info on this "AJ-500"??  More info please... this is a new one by me... :) 

Thanks and later! OL JR :)
Title: Re: AJAX Launcher
Post by: Downix on 07/20/2011 03:37 am

In actual fact this is working in our favor. AJAX has *ALWAYS* promoted the use of its LRB as a crew launcher for both Commercial and for NASA. The synergy that creates with ULA and commercial is one of the major selling points of the program.

As for the AJ-500 vs. the RD-180, I do not see that as a problem. ULA has a healthy inventory of RD-180's on hand. I would expect the Atlas-V going forward to continue to use them. During that time Aerojet would be bringing the AJ-500 on line and the engine should be ready to test fly before the RD-180 inventory is exhausted. It would not be a difficult thing to arrange with the USAF to use up the RD-180 inventory without replenishment and simply begin using the AJ-500 in its place. That has a lot going for it.

The RD-180 is a Russian engine while the AJ-500 would be an American engine.
The RD-180 is a single turbine 2-chamber engine producing 861k lbs thrust at sea level.
The AJ-500 replacement would be a 2-engine 1-chamber drop-in replacement producing 1,000,000 lbs of thrust at sea level.

The 2-engine AJ-500 replacement arrangement is in reality the natural successor to the 2-chamber RD-180. It is more powerful, built with modern methods and quality control and is a domestic engine. It's the perfect replacement and actually makes the Atlas-V better than it currently is.


Any links to where I can get more info on this "AJ-500"??  More info please... this is a new one by me... :) 

Thanks and later! OL JR :)
It's the name for a US built form of the AJ-26.
Title: Re: AJAX Launcher
Post by: sdsds on 07/20/2011 04:58 am
ULA has a healthy inventory of RD-180's on hand. I would expect the Atlas-V going forward to continue to use them. During that time Aerojet would be bringing the AJ-500 on line and the engine should be ready to test fly before the RD-180 inventory is exhausted.

Inventory?  Sure there's some, but PWR is also taking semi-regular deliveries of RD-180 engines newly manufactured by Energomash, yes?

Quote
It would not be a difficult thing to arrange with the USAF to use up the RD-180 inventory without replenishment and simply begin using the AJ-500 in its place.

Price.  Can AJ-500 really compete with RD-180?  How low would Energomash go to prevent its competition from getting a foothold?
Title: Re: AJAX Launcher
Post by: Downix on 07/20/2011 05:06 am
ULA has a healthy inventory of RD-180's on hand. I would expect the Atlas-V going forward to continue to use them. During that time Aerojet would be bringing the AJ-500 on line and the engine should be ready to test fly before the RD-180 inventory is exhausted.

Inventory?  Sure there's some, but PWR is also taking semi-regular deliveries of RD-180 engines newly manufactured by Energomash, yes?
So I understand it, no.  They place large orders, then run from the warehouse for a period.
Quote
Quote
It would not be a difficult thing to arrange with the USAF to use up the RD-180 inventory without replenishment and simply begin using the AJ-500 in its place.

Price.  Can AJ-500 really compete with RD-180?  How low would Energomash go to prevent its competition from getting a foothold?
There is about to be an RD-180 shortage, with two new vehicles coming online which will be using the same tooling and components, namely the Rus-M and Angara.  They may not have a choice.
Title: Re: AJAX Launcher
Post by: baldusi on 07/20/2011 01:10 pm
The Angara will (hopefully) start testing next year with the one core version. And then the five core version. Since the RD-191 is (basically) half an RD-180, that should be roughly equivalent to three or four extra RD-180 in the next two years. Nothing terrible, I would say.
The Rus-M is still in early phases of design. What's more, the spaceport where it should launch is still years from being usable. Not to mention that they didn't even started to work on the pad. It would use an RD-180V, which from what I could get, is an RD-180 with extra human rating equipment.
In any case I don't think Energomash will have a significant demand of the RD-180V and RD-191 for the next three to five years. The real issue might be the RD-170. It uses almost twice the resources of the RD-180, and they really can use all that they build. Specially now that Sea Launch is restarting its operations.
In any case, if the AJ-500 works, and is Americanized, Energomash might not have a chance. I'm speculating on two ways that the AJ-500 might get it's power boost. Obviously it would require a new turbopump. But what are the chances the Aerojet actually implements TAN on them? If it gets to 500klbf by using TAN, starting from the already lightest and more efficient rocket design, could it reach 200 T/W? Could it improve the vac isp above the already amazing 331s?
The other idea is that if they make it a 500klbf stock, and then add TAN, they might increase it's thrust enough to actually power an Atlas V with a single such engine. Pure speculation, though.
Title: Re: AJAX Launcher
Post by: marsavian on 07/21/2011 06:44 pm
Hmmm, everybody wants to use the AJ-500 it seems ;)

Reusable Booster System High Thrust Main Engine

https://www.fbo.gov/index?s=opportunity&mode=form&id=277854b461bb2a53fafa41bb44b25787&tab=core&_cview=1
Title: Re: AJAX Launcher
Post by: Lobo on 07/22/2011 05:32 pm
Hmmm, everybody wants to use the AJ-500 it seems ;)

Reusable Booster System High Thrust Main Engine

https://www.fbo.gov/index?s=opportunity&mode=form&id=277854b461bb2a53fafa41bb44b25787&tab=core&_cview=1

Interesting...

-------------------
a. The contractor must possess and demonstrate to the Government full engine ownership of all design and production intellectual property rights to support domestic production without end use restrictions
b. Engine propellants must be LOX/RP
c. Sea level thrust 300 - 500-klbs
d. Sea level thrust to weight > 85
e. Sea level Isp > 300 seconds
a. Vacuum Isp > 330 seconds
b. Engine reuse threshold of 10 missions with another 10 missions after overhaul
c. High reusable engine reliability with minimal per flight touch labor
d. Engine must operate at throttle levels down to 50% rated thrust
e. In-flight restart capability is of significant interest
------------------

Does the AJ26 or AJ500 conform to all of these parameters?   Is it 50% throttleable?  Could it be reused 10 times?  Can it be restarted in flight?

They say they are specifically looking for an engine to replace the RD-180.  Any idea as to why and what the significance of that statement is?  Does the USAF want to get away from launching their payloads on 100% Russian build engines?
Title: Re: AJAX Launcher
Post by: Downix on 07/22/2011 05:40 pm
Hmmm, everybody wants to use the AJ-500 it seems ;)

Reusable Booster System High Thrust Main Engine

https://www.fbo.gov/index?s=opportunity&mode=form&id=277854b461bb2a53fafa41bb44b25787&tab=core&_cview=1

Interesting...

-------------------
a. The contractor must possess and demonstrate to the Government full engine ownership of all design and production intellectual property rights to support domestic production without end use restrictions
b. Engine propellants must be LOX/RP
c. Sea level thrust 300 - 500-klbs
d. Sea level thrust to weight > 85
e. Sea level Isp > 300 seconds
a. Vacuum Isp > 330 seconds
b. Engine reuse threshold of 10 missions with another 10 missions after overhaul
c. High reusable engine reliability with minimal per flight touch labor
d. Engine must operate at throttle levels down to 50% rated thrust
e. In-flight restart capability is of significant interest
------------------

Does the AJ26 or AJ500 conform to all of these parameters?   Is it 50% throttleable?  Could it be reused 10 times?  Can it be restarted in flight?

They say they are specifically looking for an engine to replace the RD-180.  Any idea as to why and what the significance of that statement is?  Does the USAF want to get away from launching their payloads on 100% Russian build engines?
Yes -- 48%-108% for the AJ-26 as it is.
Yes -- Some samples have been reused far more than just 10.
Yes -- There is a restart/airstart system for them
Title: Re: AJAX Launcher
Post by: baldusi on 07/22/2011 06:04 pm
Hmmm, everybody wants to use the AJ-500 it seems ;)

Reusable Booster System High Thrust Main Engine

https://www.fbo.gov/index?s=opportunity&mode=form&id=277854b461bb2a53fafa41bb44b25787&tab=core&_cview=1

Interesting...

-------------------
a. The contractor must possess and demonstrate to the Government full engine ownership of all design and production intellectual property rights to support domestic production without end use restrictions
b. Engine propellants must be LOX/RP
c. Sea level thrust 300 - 500-klbs
d. Sea level thrust to weight > 85
e. Sea level Isp > 300 seconds
a. Vacuum Isp > 330 seconds
b. Engine reuse threshold of 10 missions with another 10 missions after overhaul
c. High reusable engine reliability with minimal per flight touch labor
d. Engine must operate at throttle levels down to 50% rated thrust
e. In-flight restart capability is of significant interest
------------------

Does the AJ26 or AJ500 conform to all of these parameters?   Is it 50% throttleable?  Could it be reused 10 times?  Can it be restarted in flight?

They say they are specifically looking for an engine to replace the RD-180.  Any idea as to why and what the significance of that statement is?  Does the USAF want to get away from launching their payloads on 100% Russian build engines?
Yes -- 48%-108% for the AJ-26 as it is.
Yes -- Some samples have been reused far more than just 10.
Yes -- There is a restart/airstart system for them
Do we know if the 500 of the AJ-500 is at sea level or vacuum? Because an AJ-26 @ 108% would give like 425klbf in vacuum. Which would only be 17.5% short of 500.

There's another engine that fits the criteria perfectly, and it's going to be really mass produced in the next five years: the RD-191. Since AMROSS has the rights for the RD-180, it wouldn't be a stretch of imagination that they present the RD-191. If the Angara picks up and you add 2 per Atlas V the production will be in the 40 to 60 engines per year! Think about the scale of production!
Title: Re: AJAX Launcher
Post by: Downix on 07/22/2011 06:57 pm
Hmmm, everybody wants to use the AJ-500 it seems ;)

Reusable Booster System High Thrust Main Engine

https://www.fbo.gov/index?s=opportunity&mode=form&id=277854b461bb2a53fafa41bb44b25787&tab=core&_cview=1

Interesting...

-------------------
a. The contractor must possess and demonstrate to the Government full engine ownership of all design and production intellectual property rights to support domestic production without end use restrictions
b. Engine propellants must be LOX/RP
c. Sea level thrust 300 - 500-klbs
d. Sea level thrust to weight > 85
e. Sea level Isp > 300 seconds
a. Vacuum Isp > 330 seconds
b. Engine reuse threshold of 10 missions with another 10 missions after overhaul
c. High reusable engine reliability with minimal per flight touch labor
d. Engine must operate at throttle levels down to 50% rated thrust
e. In-flight restart capability is of significant interest
------------------

Does the AJ26 or AJ500 conform to all of these parameters?   Is it 50% throttleable?  Could it be reused 10 times?  Can it be restarted in flight?

They say they are specifically looking for an engine to replace the RD-180.  Any idea as to why and what the significance of that statement is?  Does the USAF want to get away from launching their payloads on 100% Russian build engines?
Yes -- 48%-108% for the AJ-26 as it is.
Yes -- Some samples have been reused far more than just 10.
Yes -- There is a restart/airstart system for them
Do we know if the 500 of the AJ-500 is at sea level or vacuum? Because an AJ-26 @ 108% would give like 425klbf in vacuum. Which would only be 17.5% short of 500.
No clue, but I would assume vacuum.  Most companies focus on that numbers.

Aerojet's already participated in upgrades similar to this, with the SSME Block III program, which took an engine design which began life running at 380 klbf and had it running at 512 klbf.  I suspect this would be the same process, optimizing the chamber and nozzle around modern processes along with some other manufacturing upgrades such as the laser etched preburner and simplified turbopump manufacturing process.
Quote
There's another engine that fits the criteria perfectly, and it's going to be really mass produced in the next five years: the RD-191. Since AMROSS has the rights for the RD-180, it wouldn't be a stretch of imagination that they present the RD-191. If the Angara picks up and you add 2 per Atlas V the production will be in the 40 to 60 engines per year! Think about the scale of production!
Perhaps, we shall see what happens.
Title: Re: AJAX Launcher
Post by: Lobo on 07/22/2011 07:06 pm
Yes -- 48%-108% for the AJ-26 as it is.
Yes -- Some samples have been reused far more than just 10.
Yes -- There is a restart/airstart system for them

Sweet.  So Downix, what's your speculation on such an RFI?  Looks like Aerjet's engine is about the only US engine that would fit that.

SpaceX's Merlin 1 is too small, their Merlin 2 is too big. 

Doesn't seem like it'd make much sense for the RD-191, a Russian built engine, to replace the RD-180, another Russian build engine.
Or does PWR plan to build a US made RD-191 soon?

Seems like the AJ26/500 is the only thing that could fit there.  Is this RFI written around the AJ engine? (government Spec's are often written with a particular piece of equipment in mind, and the spec's are written around it, but they techhnically have to keep it open to competative bids.  I've delt with that many times in my line of work)
Or is it just a coincidence that it looks like there's just one engine that can fit this?
What are the implications of this?
Title: Re: AJAX Launcher
Post by: Downix on 07/22/2011 07:37 pm
Yes -- 48%-108% for the AJ-26 as it is.
Yes -- Some samples have been reused far more than just 10.
Yes -- There is a restart/airstart system for them

Sweet.  So Downix, what's your speculation on such an RFI?  Looks like Aerjet's engine is about the only US engine that would fit that.

SpaceX's Merlin 1 is too small, their Merlin 2 is too big. 

Doesn't seem like it'd make much sense for the RD-191, a Russian built engine, to replace the RD-180, another Russian build engine.
Or does PWR plan to build a US made RD-191 soon?

Seems like the AJ26/500 is the only thing that could fit there.  Is this RFI written around the AJ engine? (government Spec's are often written with a particular piece of equipment in mind, and the spec's are written around it, but they techhnically have to keep it open to competative bids.  I've delt with that many times in my line of work)
Or is it just a coincidence that it looks like there's just one engine that can fit this?
What are the implications of this?
I can actually name a few other options for this range, but the Aerojet design does hit it very well.  I would not go so far as to say that they wrote it around it, but I would not rule that out either.
Title: Re: AJAX Launcher
Post by: baldusi on 07/22/2011 07:51 pm
RP-1 engines with over 300s isp a sea Level and 330s vacuum? Which ones?
Title: Re: AJAX Launcher
Post by: knotnic on 07/22/2011 09:01 pm
Also from the FBO posting (attached Q&As):
Quote
Question:
“SpaceX requests that XR clarifies whether they are requesting information on existing engines, a system that can be evolved with minimal challenges, or if responses including engines that are at a concept development stage are acceptable responses."

Answer:
XR is interested in obtaining information on existing engine systems that satisfy the published RFI requirements.  Modifications of existing engine systems are acceptable as long as they initially meet the minimum thrust level defined in the RFI.  Significant proposed increases in existing engine thrust levels are considered new engine development and are therefore not applicable under this RFI.  Proposed engine modifications that meet the intent of the RFI requires an accompanying estimated cost/schedule necessary to achieve published RFI requirements.

XR is not interested at this time in obtaining information under this specific RFI on new "clean sheet" engine development concepts.

and

Quote
Question:
The notice says “XR is seeking an existing engine system, not a future developmental concept” and SpaceX would like to understand if XR is interested in engines we are currently designing and planning to build for other customers.

Answer:
XR is interested in existing rocket propulsion systems that satisfy, or could potentially satisfy with modifications, the specifications published in the RFI.

Question:
Second, SpaceX would like to ask whether a response that offered both RP and methane propellant (possibly with fly-off testing) would be an acceptable response.

Answer:
XR is requesting existing engine information that addresses published RFI requirements.

Question:
Also, if there is additional technical data that you can provide we would appreciate it so that we can provide the best response possible for XR.

Answer:
There is no additional engine technical data at this time.

Question:
Aerojet has a question concerning the page size restriction of 8.5 X 11.  We have one page depicting the program schedule which would be best displayed and viewable in an 11 X 17 format.  Aerojet requests permission to display this one page in 11 X 17 format.  The remaining 24 pages will be 8.5 X 11.

Answer:
It is ok for Aerojet to submit their schedule in a 11X17 format.

So it's not OK for SpaceX to propose an uprating or alternate fuel effort; it is OK for Aerojet to submit their product brochure.  Draw your own conclusions.
Title: Re: AJAX Launcher
Post by: Downix on 07/22/2011 09:02 pm
Also from the FBO posting (attached Q&As):
Quote
Question:
“SpaceX requests that XR clarifies whether they are requesting information on existing engines, a system that can be evolved with minimal challenges, or if responses including engines that are at a concept development stage are acceptable responses."

Answer:
XR is interested in obtaining information on existing engine systems that satisfy the published RFI requirements.  Modifications of existing engine systems are acceptable as long as they initially meet the minimum thrust level defined in the RFI.  Significant proposed increases in existing engine thrust levels are considered new engine development and are therefore not applicable under this RFI.  Proposed engine modifications that meet the intent of the RFI requires an accompanying estimated cost/schedule necessary to achieve published RFI requirements.

XR is not interested at this time in obtaining information under this specific RFI on new "clean sheet" engine development concepts.

and

Quote
Question:
The notice says “XR is seeking an existing engine system, not a future developmental concept” and SpaceX would like to understand if XR is interested in engines we are currently designing and planning to build for other customers.

Answer:
XR is interested in existing rocket propulsion systems that satisfy, or could potentially satisfy with modifications, the specifications published in the RFI.

Question:
Second, SpaceX would like to ask whether a response that offered both RP and methane propellant (possibly with fly-off testing) would be an acceptable response.

Answer:
XR is requesting existing engine information that addresses published RFI requirements.

Question:
Also, if there is additional technical data that you can provide we would appreciate it so that we can provide the best response possible for XR.

Answer:
There is no additional engine technical data at this time.

Question:
Aerojet has a question concerning the page size restriction of 8.5 X 11.  We have one page depicting the program schedule which would be best displayed and viewable in an 11 X 17 format.  Aerojet requests permission to display this one page in 11 X 17 format.  The remaining 24 pages will be 8.5 X 11.

Answer:
It is ok for Aerojet to submit their schedule in a 11X17 format.

So it's not OK for SpaceX to propose an uprating or alternate fuel effort; it is OK for Aerojet to submit their product brochure.  Draw your own conclusions.
Yes, they want existing engines which run on RP-1 and meet the performance profile.
Title: Re: AJAX Launcher
Post by: baldusi on 07/22/2011 09:13 pm
May I remind you that current Merlin design:
1) Can't get close to the necessary isp (vac nor sl).
2) Would need two to three times more thrust.
3) Can't throttle (but Merlin Vac can). If it could be made to throttle, it might not even meet the T/W requirement.
You can't say that there were partial because they asked for the best technical solution currently available.

I have my theory of why they are willing to put with two (or even three) engines in the Atlas V. It might happen that a Phase II Atlas V might work with 1.2Mlbf to 1.75Mlbf at SL, depending on length. So the "short" version might use three or four engines, and the "long" version four to five. This, obviously, is pure speculation.
The other is that they have an idea of the future RLV that could use smaller engines. May be because it's going to be smaller, or simply because they want it to fly it back with a single engine out of five, for example.
Title: Re: AJAX Launcher
Post by: Lobo on 07/23/2011 12:12 am
May I remind you that current Merlin design:
1) Can't get close to the necessary isp (vac nor sl).
2) Would need two to three times more thrust.
3) Can't throttle (but Merlin Vac can). If it could be made to throttle, it might not even meet the T/W requirement.
You can't say that there were partial because they asked for the best technical solution currently available.

I have my theory of why they are willing to put with two (or even three) engines in the Atlas V. It might happen that a Phase II Atlas V might work with 1.2Mlbf to 1.75Mlbf at SL, depending on length. So the "short" version might use three or four engines, and the "long" version four to five. This, obviously, is pure speculation.
The other is that they have an idea of the future RLV that could use smaller engines. May be because it's going to be smaller, or simply because they want it to fly it back with a single engine out of five, for example.

Sounds like Merlin and Merlin 2 are/would be great for what SpaceX wants to do with F9, FH (with Merlin1 then merlin 2), and a potential FX. 
But they aren't a good fit for what the USAF might have in mind for Atlas V CCB and a possible reusable booster.  Sounds like the AJ is the best fit.

This begs a few question though.

1)  The USAF is looking at a reusable booster system?  As a stand alone system for launching EELV class payloads?  (If so, why would they want to replace the RD-180?  Unless it can't be reused or restarted?)

2)  Or does this have anything to do with an LRB-SLS system, with reusable boosters, like the SRB's are "reusable".  As in, "we like LRB's on SLS, but the opponets tout the reusability of the SRB's, so can we do a reusable LRB?"   But it doesn't really make sense for the USAF to be issuing that RFI, right?  WOuldnt' that be from NASA or something?

Any relation?  Or is this a purely independant request by the USAF to develop a potentially reusable Atlas V system?
Title: Re: AJAX Launcher
Post by: clongton on 07/23/2011 10:29 am
So it's not OK for SpaceX to propose an uprating or alternate fuel effort; it is OK for Aerojet to submit their product brochure.  Draw your own conclusions.

A comprehensive schedule, perhaps in Gant format, cannot be clearly shown on A-size sheets - it's too complex. I always print my schedules on B-size sheets (11x17) for that reason. Printing IMS sheets is usually done on B-size sheets or larger, industry wide, for the same reason.
Title: Re: AJAX Launcher
Post by: luke strawwalker on 07/29/2011 11:13 pm
So with a 21 year wait to get SLS up and running, how many decades would it take for AJAX?? 

Got to believe it would be a LITTLE quicker...

(still can't believe what I've read over there...) 

Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: Downix on 07/30/2011 07:04 pm
So with a 21 year wait to get SLS up and running, how many decades would it take for AJAX?? 

Got to believe it would be a LITTLE quicker...

(still can't believe what I've read over there...) 

Later!  OL JR :)
Assuming all is go by Jan 1st, could be flying by end of 2015.
Title: Re: AJAX Launcher
Post by: Will on 07/30/2011 08:07 pm
Is there a site that gives the proposed specifications and performance of AJAX in one place?
Title: Re: AJAX Launcher
Post by: Arthur on 07/30/2011 08:20 pm
We are working on a paper giving the full details at this time.  When it is ready, we will be posting it here.
Any update on this?
Title: Re: AJAX Launcher
Post by: Downix on 07/30/2011 09:59 pm
I have the current working paper up for peer review under L2:

http://forum.nasaspaceflight.com/index.php?topic=25432.0
Title: Re: AJAX Launcher
Post by: sdsds on 07/30/2011 11:19 pm
I would like to see the estimation methodology used to generate the projected AJAX core mass.  This is because in my opinion AJAX now needs to be assessed in the context of the reported SLS-1 mission, not the context of the Authorization requirements per se.  AJAX seems like it should compete well in this, since its mass at core burnout should be less than the mass of a stretched core....

I would also like to see more detailed analysis of how the tooling and work cells at Michoud would be used to build an ET-diameter core, shrunk rather than stretched, without the interstage thrust beam but with added structure to carry thrust from below.  Again, this would enable some possibly insightful comparisons to the SLS-1 reference design!
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/30/2011 11:49 pm
I have the current working paper up for peer review under L2:

http://forum.nasaspaceflight.com/index.php?topic=25432.0

Is that up on the website as well (or will it be)?

Cannot wait to see it!

I just gotta say, its been a long time getting to this point from AJAX being just an idea to an actual, doable, concept, and while there is still much to be done I want to thank the entire AJAX team for a great job on this project particularly Downix, the man who came up with the design.


That said, I think there is a real, major, opportunity starting to show here for AJAX to step into the political void. This is mainly because the SLS design, as announced, takes so bloody long to execute, if AJAX can be introduced as a time and budget saving solution to lawmakers and NASA alike, it could potentially be a live saver in an otherwise hopeless situation.
Title: Re: AJAX Launcher
Post by: Downix on 07/31/2011 04:50 pm
I would like to see the estimation methodology used to generate the projected AJAX core mass.  This is because in my opinion AJAX now needs to be assessed in the context of the reported SLS-1 mission, not the context of the Authorization requirements per se.  AJAX seems like it should compete well in this, since its mass at core burnout should be less than the mass of a stretched core....

I would also like to see more detailed analysis of how the tooling and work cells at Michoud would be used to build an ET-diameter core, shrunk rather than stretched, without the interstage thrust beam but with added structure to carry thrust from below.  Again, this would enable some possibly insightful comparisons to the SLS-1 reference design!
I have a rough page on that made, but am working to clean it up, with diagrams to display how it works. 

Basically, I took the existing ET components, added them up, modified when needed, then took the NLS figures for pieces which were missing in the design, had three vendors give estimated weights for the new customized components (took the heaviest of the three) and added 15% to give margin.  Truth is, my estimates for AJAX's weight is higher than I know it will be, because I know estimates can be off, and even a slight off on one end can mean major increases later on, so I bought myself margin.

The paper will use all of the components listed in order to better display it.
Title: Re: AJAX Launcher
Post by: JohnnySokko on 07/31/2011 05:28 pm
No offense to Chris or Nasaspaceflight.com, but why on L2, shouldn't this be as freely accessible as possible?
Title: Re: AJAX Launcher
Post by: Arthur on 07/31/2011 05:40 pm
I want to see it all too, but L2 (to which I have no access) IS a better place for a Peer Review before going public.
Title: Re: AJAX Launcher
Post by: clongton on 07/31/2011 05:45 pm
No offense to Chris or Nasaspaceflight.com, but why on L2, shouldn't this be as freely accessible as possible?

No, because with all respect to the general NSF membership, it is important to limit *initial* comments, criticisms and suggestions to where most of the pros hang out, L2. We did the same with DIRECT. Don't worry. It will see its day on the public side.
Title: Re: AJAX Launcher
Post by: Downix on 07/31/2011 06:49 pm
Right now working on the appendices, the data charts and such.  Need to still locate an artist for some pretty rendering... 8)
Title: Re: AJAX Launcher
Post by: FinalFrontier on 07/31/2011 07:32 pm
Right now working on the appendices, the data charts and such.  Need to still locate an artist for some pretty rendering... 8)

Antonio ;)
Title: Re: AJAX Launcher
Post by: Jason1701 on 08/01/2011 12:47 am
Do you have plans to write an AJAX article on Wikipedia?
Title: Re: AJAX Launcher
Post by: Downix on 08/01/2011 02:22 am
Do you have plans to write an AJAX article on Wikipedia?
In theory I could I suppose.  Would it be considered above trivial?
Title: Re: AJAX Launcher
Post by: sdsds on 08/01/2011 02:34 am
Do you have plans to write an AJAX article on Wikipedia?
In theory I could I suppose.  Would it be considered above trivial?

Almost anything we wrote would be considered "original work" which is not accepted for Wikipedia content.  What Chris Bergin wrote about it on the news side of the site could be used in Wikipedia.  But that tiny bit of admissible material would likely make the topic appear trivial to other Wikipedia editors.

I suggest attempting to gather material on SLS liquid boosters in general, and mentioning AJAX in that context.
Title: Re: AJAX Launcher
Post by: deltaV on 08/01/2011 02:35 am
Do you have plans to write an AJAX article on Wikipedia?
In theory I could I suppose.  Would it be considered above trivial?
I doubt AJAX would meet notability criteria as is. I would wait until it has a public face beyond just a forum thread before creating a WP page.
Title: Re: AJAX Launcher
Post by: Prober on 08/04/2011 02:52 am
Hmmm, everybody wants to use the AJ-500 it seems ;)

Reusable Booster System High Thrust Main Engine

https://www.fbo.gov/index?s=opportunity&mode=form&id=277854b461bb2a53fafa41bb44b25787&tab=core&_cview=1 (https://www.fbo.gov/index?s=opportunity&mode=form&id=277854b461bb2a53fafa41bb44b25787&tab=core&_cview=1)

Interesting...

-------------------
a. The contractor must possess and demonstrate to the Government full engine ownership of all design and production intellectual property rights to support domestic production without end use restrictions
b. Engine propellants must be LOX/RP
c. Sea level thrust 300 - 500-klbs
d. Sea level thrust to weight > 85
e. Sea level Isp > 300 seconds
a. Vacuum Isp > 330 seconds
b. Engine reuse threshold of 10 missions with another 10 missions after overhaul
c. High reusable engine reliability with minimal per flight touch labor
d. Engine must operate at throttle levels down to 50% rated thrust
e. In-flight restart capability is of significant interest
------------------

Does the AJ26 or AJ500 conform to all of these parameters?   Is it 50% throttleable?  Could it be reused 10 times?  Can it be restarted in flight?

They say they are specifically looking for an engine to replace the RD-180.  Any idea as to why and what the significance of that statement is?  Does the USAF want to get away from launching their payloads on 100% Russian build engines?
Yes -- 48%-108% for the AJ-26 as it is.
Yes -- Some samples have been reused far more than just 10.
Yes -- There is a restart/airstart system for them
Do we know if the 500 of the AJ-500 is at sea level or vacuum? Because an AJ-26 @ 108% would give like 425klbf in vacuum. Which would only be 17.5% short of 500.

There's another engine that fits the criteria perfectly, and it's going to be really mass produced in the next five years: the RD-191. Since AMROSS has the rights for the RD-180, it wouldn't be a stretch of imagination that they present the RD-191. If the Angara picks up and you add 2 per Atlas V the production will be in the 40 to 60 engines per year! Think about the scale of production!

Think AMROSS is done?
 
 
Title: Re: AJAX Launcher
Post by: Rocket Science on 08/05/2011 07:32 pm
Nate,
Just curious… I’ve been looking around and couldn’t locate any info so far. Did anyone ever consider a re-engine of the Atlas V with a single F-1 engine? Thought you might have an opinion on it.
Robert
Title: Re: AJAX Launcher
Post by: Downix on 08/05/2011 07:53 pm
Nate,
Just curious… I’ve been looking around and couldn’t locate any info so far. Did anyone ever consider a re-engine of the Atlas V with a single F-1 engine? Thought you might have an opinion on it.
Robert

Too low an impulse.  Even with the added thrust, you would wind up running out of fuel too soon, and could not make it to orbit.
Title: Re: AJAX Launcher
Post by: Rocket Science on 08/05/2011 07:56 pm
Nate,
Just curious… I’ve been looking around and couldn’t locate any info so far. Did anyone ever consider a re-engine of the Atlas V with a single F-1 engine? Thought you might have an opinion on it.
Robert

Too low an impulse.  Even with the added thrust, you would wind up running out of fuel too soon, and could not make it to orbit.
Twin side by side tanks feeding single engine?
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 08/05/2011 07:58 pm
A question has been rattling around in my head for a few days.. if you went with a 6 or 8 booster configuration AJAX and only used 1(or possibly 2?) SSME on the core, could you do a direct TLI or TMI with no Upper Stage?  If so, how much could you inject? Would this configuration provide benefits with a DIVHUS?
Title: Re: AJAX Launcher
Post by: Downix on 08/05/2011 08:02 pm
A question has been rattling around in my head for a few days.. if you went with a 6 or 8 booster configuration AJAX and only used 1(or possibly 2?) SSME on the core, could you do a direct TLI or TMI with no Upper Stage?  If so, how much could you inject? Would this configuration provide benefits with a DIVHUS?
I looked at it informally, no hard numbers.  It had ok performance, but not enough of a jump to validate things further over the three engine core if you throttle them down as needed.
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 08/05/2011 08:13 pm
A question has been rattling around in my head for a few days.. if you went with a 6 or 8 booster configuration AJAX and only used 1(or possibly 2?) SSME on the core, could you do a direct TLI or TMI with no Upper Stage?  If so, how much could you inject? Would this configuration provide benefits with a DIVHUS?
I looked at it informally, no hard numbers.  It had ok performance, but not enough of a jump to validate things further over the three engine core if you throttle them down as needed.

So you're saying it could not inject anything(or not enough to be useful) through TLI or TMI without an Upper Stage?
Title: Re: AJAX Launcher
Post by: Downix on 08/05/2011 08:51 pm
A question has been rattling around in my head for a few days.. if you went with a 6 or 8 booster configuration AJAX and only used 1(or possibly 2?) SSME on the core, could you do a direct TLI or TMI with no Upper Stage?  If so, how much could you inject? Would this configuration provide benefits with a DIVHUS?
I looked at it informally, no hard numbers.  It had ok performance, but not enough of a jump to validate things further over the three engine core if you throttle them down as needed.

So you're saying it could not inject anything(or not enough to be useful) through TLI or TMI without an Upper Stage?
No, I am saying it would not inject significantly more than what the 3-engine core could.
Title: Re: AJAX Launcher
Post by: TrueBlueWitt on 08/06/2011 05:33 am
A question has been rattling around in my head for a few days.. if you went with a 6 or 8 booster configuration AJAX and only used 1(or possibly 2?) SSME on the core, could you do a direct TLI or TMI with no Upper Stage?  If so, how much could you inject? Would this configuration provide benefits with a DIVHUS?
I looked at it informally, no hard numbers.  It had ok performance, but not enough of a jump to validate things further over the three engine core if you throttle them down as needed.

So you're saying it could not inject anything(or not enough to be useful) through TLI or TMI without an Upper Stage?
No, I am saying it would not inject significantly more than what the 3-engine core could.

Interesting, I always thought of AJAX without any Upper Stage as only delivering it's payload to LEO.
Title: Re: AJAX Launcher
Post by: WulfTheSaxon on 08/06/2011 06:36 am
A question has been rattling around in my head for a few days.. if you went with a 6 or 8 booster configuration AJAX and only used 1(or possibly 2?) SSME on the core, could you do a direct TLI or TMI with no Upper Stage?  If so, how much could you inject? Would this configuration provide benefits with a DIVHUS?
I looked at it informally, no hard numbers.  It had ok performance, but not enough of a jump to validate things further over the three engine core if you throttle them down as needed.

So you're saying it could not inject anything(or not enough to be useful) through TLI or TMI without an Upper Stage?
No, I am saying it would not inject significantly more than what the 3-engine core could.

Interesting, I always thought of AJAX without any Upper Stage as only delivering it's payload to LEO.

Depending on how I calculate it, an AJAX 380 seems to get around 10 tonnes to TLI with Schilling’s. Not really enough to do anything useful, unless you’re interested in a one-way trip.  :P

Speaking of which, it would be great to have the necessary numbers to run Schilling’s on AJAX all in one place…
Title: Re: AJAX Launcher
Post by: baldusi on 08/06/2011 02:57 pm
Incidentally, shouldn't the SLS Act have specified "a 70tn to LEO capability evolvable to 65tn to TLI/GSO or so?".
BTW, Dowmix, could you add the performance to LEO,GTO and TLI for the AJAX 430,440 and 460 to the first post? For easy reference.
Title: Re: AJAX Launcher
Post by: Proponent on 08/08/2011 03:41 am
Incidentally, shouldn't the SLS Act have specified "a 70tn to LEO capability evolvable to 65tn to TLI/GSO or so?".

That certainly would have been a bit less irrational, although the idea of legislation specifying payload capabilities remains non-sensical.
Title: Re: AJAX Launcher
Post by: Lobo on 08/09/2011 07:08 pm
Downix,

So, has there been progress (that you can share) about getting AJAX in front of the right people to be considered?  Instead of SRB's for the first 4 flights of SLS?

Just wondering what chances are that they might go with the -obvious- choice of LRB's right from the jump, rather than screwing around with new ATK SRB's for just a few flights.
The tentative SLS plan is a little disheartening, but they do have the opetion at least for LRB's on SLS-5.  I suppose that's something...
Title: Re: AJAX Launcher
Post by: Downix on 08/10/2011 12:24 am
Downix,

So, has there been progress (that you can share) about getting AJAX in front of the right people to be considered?  Instead of SRB's for the first 4 flights of SLS?

Just wondering what chances are that they might go with the -obvious- choice of LRB's right from the jump, rather than screwing around with new ATK SRB's for just a few flights.
The tentative SLS plan is a little disheartening, but they do have the opetion at least for LRB's on SLS-5.  I suppose that's something...
Some, right now waiting for the right documents.  *twiddling thumbs*
Title: Re: AJAX Launcher
Post by: Lobo on 08/10/2011 03:46 pm
Downix,

So, has there been progress (that you can share) about getting AJAX in front of the right people to be considered?  Instead of SRB's for the first 4 flights of SLS?

Just wondering what chances are that they might go with the -obvious- choice of LRB's right from the jump, rather than screwing around with new ATK SRB's for just a few flights.
The tentative SLS plan is a little disheartening, but they do have the opetion at least for LRB's on SLS-5.  I suppose that's something...
Some, right now waiting for the right documents.  *twiddling thumbs*

Are you waiting to receive the right documents from someone?  Or waiting to get the right documents prepared so you can send them to someone?
Title: Re: AJAX Launcher
Post by: Downix on 08/10/2011 07:16 pm
Downix,

So, has there been progress (that you can share) about getting AJAX in front of the right people to be considered?  Instead of SRB's for the first 4 flights of SLS?

Just wondering what chances are that they might go with the -obvious- choice of LRB's right from the jump, rather than screwing around with new ATK SRB's for just a few flights.
The tentative SLS plan is a little disheartening, but they do have the opetion at least for LRB's on SLS-5.  I suppose that's something...
Some, right now waiting for the right documents.  *twiddling thumbs*

Are you waiting to receive the right documents from someone?  Or waiting to get the right documents prepared so you can send them to someone?
Checking my mailbox daily...
Title: Re: AJAX Launcher
Post by: Downix on 08/10/2011 07:54 pm
A question has been rattling around in my head for a few days.. if you went with a 6 or 8 booster configuration AJAX and only used 1(or possibly 2?) SSME on the core, could you do a direct TLI or TMI with no Upper Stage?  If so, how much could you inject? Would this configuration provide benefits with a DIVHUS?
I looked at it informally, no hard numbers.  It had ok performance, but not enough of a jump to validate things further over the three engine core if you throttle them down as needed.

So you're saying it could not inject anything(or not enough to be useful) through TLI or TMI without an Upper Stage?
No, I am saying it would not inject significantly more than what the 3-engine core could.

Interesting, I always thought of AJAX without any Upper Stage as only delivering it's payload to LEO.

Depending on how I calculate it, an AJAX 380 seems to get around 10 tonnes to TLI with Schilling’s. Not really enough to do anything useful, unless you’re interested in a one-way trip.  :P

Speaking of which, it would be great to have the necessary numbers to run Schilling’s on AJAX all in one place…
I'll be adding those numbers to the first page.

What I calculated brought AJAX to between 14 and 30 metric tons to direct TLI, depending on other conditions.
Title: Re: AJAX Launcher
Post by: baldusi on 08/10/2011 08:12 pm
What I calculated brought AJAX to between 14 and 30 metric tons to direct TLI, depending on other conditions.
That's without upper stage?  :o
Title: Re: AJAX Launcher
Post by: Downix on 08/10/2011 08:14 pm
What I calculated brought AJAX to between 14 and 30 metric tons to direct TLI, depending on other conditions.
That's without upper stage?  :o
Yes.
Title: Re: AJAX Launcher
Post by: clongton on 08/10/2011 08:32 pm
Now this is interesting.
The AJAX-380, (NO upper stage) can directly inject between 14 and 30 metric tonnes thru TLI, depending on other conditions.

Ok look at this:
Apollo 15 Command Module: 5.820 metric tonnes
Apollo 15 Service Module:   24.523 metric tonnes
Apollo 15 Lunar Module:      16.600 metric tonnes
-----------------------------------------------------------------------
Injected mass thru TLI:        46.943 metric tonnes

It would appear that the AJAX-380 is a good launch vehicle for Direct Inject to TLI. But that's more than we really want to do with a single launch. Knowing that the AJAX could easily put the CSM into LEO, we can do this:

2-Launch architecture:
An Atlas-V could easily put the 16.6 metric tonne Lunar Module into LEO for the CSM to dock with.
So we launch the LM on an Atlas-V.
We launch the CSM on the AJAX-380.
They dock in LEO and depart for the moon.

We go to the moon with no upper stage on the AJAX!!! :)
The Lunar Stack (CSM/LM) would be all hypergolic.

If we decide we want a bigger spacecraft, CSM, Lunar Module or both, we put an upper stage on the AJAX. The Atlas-V can already handle a bigger LM. We have mission growth options!

Nate: This scenario could have flown Apollo 15 with margin to spare.
Nate: Time to define Apollo-2, using the AJAX instead of the Saturn.
Title: Re: AJAX Launcher
Post by: Downix on 08/10/2011 09:51 pm
Now this is interesting.
The AJAX-380, (NO upper stage) can directly inject between 14 and 30 metric tonnes thru TLI, depending on other conditions.

Ok look at this:
Apollo 15 Command Module: 5.820 metric tonnes
Apollo 15 Service Module:   24.523 metric tonnes
Apollo 15 Lunar Module:      16.600 metric tonnes
-----------------------------------------------------------------------
Injected mass thru TLI:        46.943 metric tonnes

It would appear that the AJAX-380 is a good launch vehicle for Direct Inject to TLI. But that's more than we really want to do with a single launch. Knowing that the AJAX could easily put the CSM into LEO, we can do this:

2-Launch architecture:
An Atlas-V could easily put the 16.6 metric tonne Lunar Module into LEO for the CSM to dock with.
So we launch the LM on an Atlas-V.
We launch the CSM on the AJAX-380.
They dock in LEO and depart for the moon.

We go to the moon with no upper stage on the AJAX!!! :)
The Lunar Stack (CSM/LM) would be all hypergolic.

If we decide we want a bigger spacecraft, CSM, Lunar Module or both, we put an upper stage on the AJAX. The Atlas-V can already handle a bigger LM. We have mission growth options!

Nate: This scenario could have flown Apollo 15 with margin to spare.
Nate: Time to define Apollo-2, using the AJAX instead of the Saturn.
The only issue I can see for this is that you can't restart the AJAX's engines, making docking with the LEM incredibly difficult.  It would be far simpler to lift a DCSS with it as an EDS, and dock with the LEM before that performs the TLI.
Title: Re: AJAX Launcher
Post by: luke strawwalker on 08/10/2011 10:04 pm
Now this is interesting.
The AJAX-380, (NO upper stage) can directly inject between 14 and 30 metric tonnes thru TLI, depending on other conditions.

Ok look at this:
Apollo 15 Command Module: 5.820 metric tonnes
Apollo 15 Service Module:   24.523 metric tonnes
Apollo 15 Lunar Module:      16.600 metric tonnes
-----------------------------------------------------------------------
Injected mass thru TLI:        46.943 metric tonnes

It would appear that the AJAX-380 is a good launch vehicle for Direct Inject to TLI. But that's more than we really want to do with a single launch. Knowing that the AJAX could easily put the CSM into LEO, we can do this:

2-Launch architecture:
An Atlas-V could easily put the 16.6 metric tonne Lunar Module into LEO for the CSM to dock with.
So we launch the LM on an Atlas-V.
We launch the CSM on the AJAX-380.
They dock in LEO and depart for the moon.

We go to the moon with no upper stage on the AJAX!!! :)
The Lunar Stack (CSM/LM) would be all hypergolic.

If we decide we want a bigger spacecraft, CSM, Lunar Module or both, we put an upper stage on the AJAX. The Atlas-V can already handle a bigger LM. We have mission growth options!

Nate: This scenario could have flown Apollo 15 with margin to spare.
Nate: Time to define Apollo-2, using the AJAX instead of the Saturn.
The only issue I can see for this is that you can't restart the AJAX's engines, making docking with the LEM incredibly difficult.  It would be far simpler to lift a DCSS with it as an EDS, and dock with the LEM before that performs the TLI.

Yeah, how would that work shutting down the core engines??  I don't get it.  You shut down your SSME's you can't start them again... or are you talking about a core powered by clustered J-2X?? 

The only way I could see this working is to launch the lander direct on Atlas to TLI as well, simultaneously with the AJAX and then the two rendezvousing and docking after core vehicle disposal after the TLI maneuver is completed... but that would seem to be an EXTREMELY tricky manuever not likely to ever get approval... and certainly not desirable...

Later!  OL JR :)
Title: Re: AJAX Launcher
Post by: baldusi on 08/10/2011 10:09 pm
What about a LOR? Can you send a crasher stage and ascend stage within a 30tn budget (minus whatever is needed for LOI)? Can you make a LDS (Lunar Return Stage) plus a return capsule for 30tn (again, minus whatever is needed for LOI)? If so, you can do such mission in just two AJAX launches. I don't know if it would be cheaper than actually putting an US or using a depot architecture. But it should be possible. After all, Apollo made it with 45tn. Granted, it would require two dockings (or an EVA + docking).
Title: Re: AJAX Launcher
Post by: clongton on 08/10/2011 10:25 pm
The only issue I can see for this is that you can't restart the AJAX's engines, making docking with the LEM incredibly difficult.  It would be far simpler to lift a DCSS with it as an EDS, and dock with the LEM before that performs the TLI.

Nope. The Atlas-V sends the LM into LEO and the restartable Centaur does the circularization burn. Ajax injects the CSM into an elliptical LEO and the CSM does its own circularization burn, then rendezvous and docks with the LM. Then the docked stack departs for the moon with a burn of the LM engine,  the same way it was supposed to happen for Ares (eyeballs out), sporting drop tanks designed specifically for that burn.

Edit:cleaned up the wording a little bit.
Title: Re: AJAX Launcher
Post by: Downix on 08/10/2011 10:28 pm
The only issue I can see for this is that you can't restart the AJAX's engines, making docking with the LEM incredibly difficult.  It would be far simpler to lift a DCSS with it as an EDS, and dock with the LEM before that performs the TLI.

Nope. The Atlas-V sends the LM into LEO and the restartable Centaur does the circularization burn. Ajax injects the CSM into an elliptical LEO and the CSM does its own circularization burn, then rendezvous and docks with the LM, the same way it was supposed to happen for Ares. Then the docked stack departs for the moon with a burn of the LM engine, sporting drop tanks designed specifically for that burn.
That works.

And you realize that this is an opposite to the Constellation method.
Title: Re: AJAX Launcher
Post by: Lobo on 08/10/2011 11:30 pm
The only issue I can see for this is that you can't restart the AJAX's engines, making docking with the LEM incredibly difficult.  It would be far simpler to lift a DCSS with it as an EDS, and dock with the LEM before that performs the TLI.

Nope. The Atlas-V sends the LM into LEO and the restartable Centaur does the circularization burn. Ajax injects the CSM into an elliptical LEO and the CSM does its own circularization burn, then rendezvous and docks with the LM. Then the docked stack departs for the moon with a burn of the LM engine,  the same way it was supposed to happen for Ares (eyeballs out), sporting drop tanks designed specifically for that burn.

Edit:cleaned up the wording a little bit.

Maybe you could, but why would you?

Couldn't you just take an AJAX-462 (2 RL-10's on DCSS?)  Or AJAX-464 (4 RL10's on an ACES-41).
That'd get like 112mt into LEO (Block 1 AJAX can do 120mt per Downix), Saturn V scale lift to LEO, and then the CSM and LM could be put through TLI with DCSS or ACES acting like the S-IVB.
Is there a reason you'd do an AJAX 360 and an Atlas V with upper stage, rather than that?
Seems like doing it all with one AJAX, you have 6 Atlas CCB's, 1 core, 4 RS25's, and one EELV-US.  And minimal orbital dockings, just an Apollo like maneuver in LEO to dock the CSM with the LM sitting on the EELV-US.   Logistics are just a single launch.

If you do it in two launches, you have 7 Atlas CCB's, 3 RS25's, 1 core, and one EELV-US (partially fueled).  And your logistics are harder, as you have to launch the crew to rendezvous with the LM that was launched separately.  Not to mention the logistics of two launches close together.

So what's the advantage of the two launchers vs. just one heavy AJAX launch?
Title: Re: AJAX Launcher
Post by: Rocket Science on 08/22/2011 05:52 pm
Hey Nate,
Do you have any updates that you could share with us at this time. :)
Robert
Title: Re: AJAX Launcher
Post by: Downix on 08/22/2011 06:25 pm
Hey Nate,
Do you have any updates that you could share with us at this time. :)
Robert

Got derailed with waiting for some papers, tired of waiting so began crunching the numbers for the Delta IV form to include in the Appendix, using the new form Delta. (new engine + common core)
Title: Re: AJAX Launcher
Post by: Rocket Science on 08/23/2011 11:03 pm
Hey Nate,
Do you have any updates that you could share with us at this time. :)
Robert

Got derailed with waiting for some papers, tired of waiting so began crunching the numbers for the Delta IV form to include in the Appendix, using the new form Delta. (new engine + common core)
Thanks Nate,
Looking forward to see the final product :)
Robert
Title: Re: AJAX Launcher
Post by: Downix on 12/10/2011 12:35 am
At the NASA Future Forum today I carried some of these to give out if requested, and thought this thread could use a little love.
Title: Re: AJAX Launcher
Post by: Rocket Science on 12/10/2011 12:44 am
Looking good... :)
Title: Re: AJAX Launcher
Post by: clongton on 12/10/2011 02:00 pm
Love accepted :)
Title: Re: AJAX Launcher
Post by: baldusi on 12/10/2011 02:18 pm
You are too nice. You're competing with Sharks. Go get a "casual" talk to those likely to be more friendly to your ideas. Then invite the rest to the talk.
Title: Re: AJAX Launcher
Post by: spacenut on 12/13/2011 02:37 pm
Probably need to talk to ULA.  They might have enough push to get it through. 
Title: Re: AJAX Launcher
Post by: RocketmanUS on 12/23/2011 06:37 am
To keep the core and booster engines the same-
Using 4 or 6 booster with a (3) RD-180 powered core.
What would the core diameter be? Can it be 8.4 m same as shuttle ET just shorter?
What would the mass to 130x130 nm 28 degree be ( for 4 booster and for 6 boosters )?

Using same engines should help keep cost down.
Title: Re: AJAX Launcher
Post by: FinalFrontier on 12/23/2011 07:21 am
At the NASA Future Forum today I carried some of these to give out if requested, and thought this thread could use a little love.


Beautiful :D Glad to see the finished product at last.
Title: Re: AJAX Launcher
Post by: fotoguzzi on 12/24/2011 06:38 pm
At the NASA Future Forum today I carried some of these to give out if requested, and thought this thread could use a little love.
Sorry to be dense, but is there not something missing from the lineup?
Title: Re: AJAX Launcher
Post by: Downix on 12/24/2011 06:57 pm
At the NASA Future Forum today I carried some of these to give out if requested, and thought this thread could use a little love.
Sorry to be dense, but is there not something missing from the lineup?
Not certain what you mean.
Title: Re: AJAX Launcher
Post by: Jason1701 on 12/24/2011 10:36 pm
When will the paper be out?
Title: Re: AJAX Launcher
Post by: Downix on 02/02/2012 12:38 pm
Just so everyone knows, I haven't dropped off the face of the earth, nor forgotten AJAX.  I had a personal tragedy happen recently.  My step-father, the man who raised me from the time I was 8 months old, passed away recently.  It's shaken me up, and my mothers just about fallen apart as he was her rock for 35 years.  I am getting myself together, and will be more active again now.
Title: Re: AJAX Launcher
Post by: kcrick on 02/02/2012 01:37 pm
Just so everyone knows, I haven't dropped off the face of the earth, nor forgotten AJAX.  I had a personal tragedy happen recently.  My step-father, the man who raised me from the time I was 8 months old, passed away recently.  It's shaken me up, and my mothers just about fallen apart as he was her rock for 35 years.  I am getting myself together, and will be more active again now.

Very sad to hear that. My prayers are with you. Glad to see you back.
Title: Re: AJAX Launcher
Post by: baldusi on 02/02/2012 02:32 pm
My condolences.  Cherish the good memories, live to keep making him proud.
Title: Re: AJAX Launcher
Post by: Lobo on 02/02/2012 10:17 pm
Just so everyone knows, I haven't dropped off the face of the earth, nor forgotten AJAX.  I had a personal tragedy happen recently.  My step-father, the man who raised me from the time I was 8 months old, passed away recently.  It's shaken me up, and my mothers just about fallen apart as he was her rock for 35 years.  I am getting myself together, and will be more active again now.

Very sad to hear that. My prayers are with you. Glad to see you back.

X2

May God be with you and your family during this time...
Title: Re: AJAX Launcher
Post by: Rocket Science on 02/02/2012 10:23 pm
My condolences Nate to you and your family. I will keep you in my thoughts and prayers. Take the time you need....
Title: Re: AJAX Launcher
Post by: Downix on 03/28/2012 07:07 pm
FYI everyone, I'll be in Florida next week, if anyone wants to meet up for coffee.
Title: Re: AJAX Launcher
Post by: HappyMartian on 03/29/2012 01:51 pm
FYI everyone, I'll be in Florida next week, if anyone wants to meet up for coffee.

Coffee and Florida always sound good to me! But, I'm half a world away...

Take care and God Bless!

Title: Re: AJAX Launcher
Post by: Lobo on 08/21/2012 04:03 pm
Downix,

Don't know tha this is the ideal forum for this question, but...

Any idea what Block 1B SLS would do with two F9 v1.1 boosters on each side mated to a strongback?
I'll assume the FH outboard boosters SpaceX is designing could mate right to a strongback as they would the central FH core. 

I'm thinking this could be a reasonable LRB replacement for the 5-seg SRB's after all of the casings have flown, but without needing the Block 2 core upgrades that the more powerful Advanced Boosters will need top handle the increased loads.  A pair of F9 v1.1 would be just about 2.8M lb (vac) thrust each with longer burn times than SRB's and better isp (although not as good of isp as RD-180).  So two should actually be pretty close to the 5-seg, where two Atlas V CCB's would probably be a little under powered, and Block 1B would loose capacity.
[/quote]
Title: Re: AJAX Launcher
Post by: RocketmanUS on 12/07/2012 04:02 am
Global HLV.

Russia supplies U.S. with RD-180's.
Russia supplies parts to the ESA ATV.
Both U.S. and Russia have had a HLV launch pad. ESA should be able to have on at their South America launch site.

All three could make the boosters. Both U.S. and Russia have made large cores ( stages, tanks ) before. Using materials and ways to make the tanks ( stages ) that are common among all three anyone of them or all of them could make the tanks ( stages ). U.S. could also make the RD-180's if there was a high enough production need.


To keep the core and booster engines the same-
Using 2 to 6 booster each having one RD-180 and a core with up to (4) RD-180's.

Would be a dial a rocket. Core would not have to be 8.4m diameter but would need to be at least 5m diameter.

Add US as needed.

If one launch location had weather problems then could use another location and or increased flight rates for the year.

Boosters could be used as a stand alone rocket with their own US.

We need lower cost and not high ISP and performance in the boosters and core. However the U.S. and EDS is were we need the high ISP and performance. So removing RS-25, super light weight expensive tanks to lower cost and put that in the EDS and US. ( without US have a kick stage OMS to put payload into orbit.

What could we see in mass to 130x130 nm 28 degree from the Cape with such a configuration?

Possible Japan and China could be partners too. Why compete with the HLV when they each can design their own HLV? When they could combine their effort and save money were it is needed on mission hardware for the missions each wants.

Team work for the HLV and have the competition on the space hardware.
Using same engines on booster and core would help keep cost down.
Title: Re: AJAX Launcher
Post by: Arthur on 03/25/2013 10:27 pm
When will the paper be out?
So did the Ajax Paper ever make it into the public realm?
Title: Re: AJAX Launcher
Post by: llanitedave on 03/26/2013 02:34 am

Possible Japan and China could be partners too. Why compete with the HLV when they each can design their own HLV? When they could combine their effort and save money were it is needed on mission hardware for the missions each wants.


Japan and China are just about as likely to be partners as are Israel and Iran.
Title: Re: AJAX Launcher
Post by: Hyperion5 on 03/26/2013 05:15 pm
Downix,

Don't know tha this is the ideal forum for this question, but...

Any idea what Block 1B SLS would do with two F9 v1.1 boosters on each side mated to a strongback?
I'll assume the FH outboard boosters SpaceX is designing could mate right to a strongback as they would the central FH core. 

I'm thinking this could be a reasonable LRB replacement for the 5-seg SRB's after all of the casings have flown, but without needing the Block 2 core upgrades that the more powerful Advanced Boosters will need top handle the increased loads.  A pair of F9 v1.1 would be just about 2.8M lb (vac) thrust each with longer burn times than SRB's and better isp (although not as good of isp as RD-180).  So two should actually be pretty close to the 5-seg, where two Atlas V CCB's would probably be a little under powered, and Block 1B would loose capacity.

If we're going to do an Ajax SLS, you might as well do it in style with some of these: http://www.kbkha.ru/?p=8&cat=11&prod=59

Each one of those engines produces some 2,000 kN of thrust (449,617.88 lbf, 203.9 tf), which put another way, is equivalent to 3.05 Merlin 1D engines at full throttle.  I'd take four of them and put them on an elongated version of the Antares SI converted to methalox.  With each booster developing 1,798,471 lbf or 8000 kN of thrust, that would be a more adequate stand-in for the base version of the SLS than Falcon Heavy boosters.  It'd also cut the engine count from 22 to just 12.  You then add on however many of those boosters as you needed.  With just four such boosters, you'd have more than adequate thrust for almost any mission and only 20 engines.  I might add that given the RD-162's performance, it'd likely give any RD-180/170-equipped LRB a real run for the money, particularly since it'd have superior t/w and Isp to make up for its less dense propellant mix. 

RD-162RD-191Dif
SL Thrust (kN)20001920.84.12%
Dry Weight21002200-4.55%
T/W97899.08%
Chamber Pressure (kg/cm²)175262.6-33%
Chamber Pressure (psi)2,4893,735
SL isp (s)3213113.22%
Vac isp (s)3563385.33%
Title: Re: AJAX Launcher
Post by: Lobo on 07/03/2013 05:07 pm
Downix,

I was wondering if you could describe the buttressing system that AJAX would have used to support the bottom lifting thrust loads of the Atlas boosters?  I think you'd said the mass added for them would be about the same as the mass removed by removal of the upper thrust beam?

Because AJAX would mount payloads up to 130mt or more, would that mean it's ET-sized core would then need to be built out of AL2219 like the SLS core?  Or could it retain the ET's AL2195?

Would it need the thicker plates than AL2195 could be made into, which is what SLS ran in to, because it would have similar payload capability to SLS?
What sort of dry mass of the AJAX core are we looking at?

Title: Re: AJAX Launcher
Post by: Downix on 07/03/2013 10:51 pm
Downix,

I was wondering if you could describe the buttressing system that AJAX would have used to support the bottom lifting thrust loads of the Atlas boosters?  I think you'd said the mass added for them would be about the same as the mass removed by removal of the upper thrust beam?

Because AJAX would mount payloads up to 130mt or more, would that mean it's ET-sized core would then need to be built out of AL2219 like the SLS core?  Or could it retain the ET's AL2195?

Would it need the thicker plates than AL2195 could be made into, which is what SLS ran in to, because it would have similar payload capability to SLS?
What sort of dry mass of the AJAX core are we looking at?

Alright, to understand the buttressing system you need to first understand the ET tank design. The ET was designed for a heavy side-load, namely the Shuttle. This side-reinforcement can be made to go around the entire tank. Now, the buttresses connect to the ET-derived core, which still maintains the heavy side-strength, but were not given reinforcement for loads on top of the structure. The ET holds the buttressing in place, just as it did the Shuttle.

The buttress themselves were designed as an aluminum isometric-style truss system, 3 groups of 3 nested pairs each, 10" diameter. I cannot remember the alloy used, but it was an aluminum-zinc alloy which was stronger than typical aluminum but without as good of heat resistance. To protect them from the heat of friction and to improve airflow around them, they were to be wrapped in alumina sheathing. The truss design to be used was incredibly strong for linear compression. By pairing this with the ET's already present side-strength, this makes a very strong structure which can carry a very heavy weight on top. The designed failure point was ~600 tons at max-q, full burn of 4G. The trusses themselves are very lightweight, the primarily failure comes from bending, which is why they are paired up with the ET structure, to reinforce the structures.

In this, the tank structure itself would not have needed to be thickened, the heavy weight being carried by the buttresses. No change in the alloys used was planned for nor needed.

The total core weight came to ~58 metric tons. This was with a heavy margin (assuming the buttresses would come out 20% heavier, the boattail would be 20% heavier, etc).
Title: Re: AJAX Launcher
Post by: HappyMartian on 07/06/2013 07:01 am

Possible Japan and China could be partners too. Why compete with the HLV when they each can design their own HLV? When they could combine their effort and save money were it is needed on mission hardware for the missions each wants.


Japan and China are just about as likely to be partners as are Israel and Iran.


Or "about as likely" as we Americans would be to include the Russians in the group of nations that will build, supply, and crew a large LEO space station or bases on the Moon and Mars, right?

The Europeans and other folks are likely to partner with China on some human and robotic LEO and BLEO missions. Japan is a closer neighbor than Europe. Japan and China already work together to make many nifty products that are sold everywhere. Good neighbors should be able to work together both on Earth and in space.

I live in Asia and it would be a really smart and wise idea for Japan and China to partner on LEO and eventually BLEO human spaceflight capabilities and missions. They could even build a Lander. Yep, such a Lander would be really useful to put on an AJAX Launcher, wouldn't it?

The latest astronomical research suggests there are oodles and oodles of potentially habitable planets across our Milky Way Galaxy. Most of the Milky Way robots and other folks should be peaceful and friendly, but there could be one or more crazies with the advanced technology and desire to do a whole lot of damage to Earth's humans and other residents.

Maybe it would be a good idea for all nations to learn how to consistently work together in LEO and BLEO for the good of our species and all the other species on Earth. By working together we can become strong, or by bickering, not working together, and fighting some more ugly wars amongst ourselves we humans can become weak and easy to be eliminated if a predator from BLEO decides that push has come to shove.
   
Build trust, economic progress, strength, and peace one human LEO or BLEO mission at a time. Or opt for mistrust, fear, hate, ultra nationalism, and wars. Your choice. My choice. Our choice.

Good thinking RocketmanUS! 

And thank you Downix! I do like the AJAX Launcher!
Title: Re: AJAX Launcher
Post by: Lobo on 07/12/2013 09:45 pm
Downix,

I was wondering if you could describe the buttressing system that AJAX would have used to support the bottom lifting thrust loads of the Atlas boosters?  I think you'd said the mass added for them would be about the same as the mass removed by removal of the upper thrust beam?

Because AJAX would mount payloads up to 130mt or more, would that mean it's ET-sized core would then need to be built out of AL2219 like the SLS core?  Or could it retain the ET's AL2195?

Would it need the thicker plates than AL2195 could be made into, which is what SLS ran in to, because it would have similar payload capability to SLS?
What sort of dry mass of the AJAX core are we looking at?

Alright, to understand the buttressing system you need to first understand the ET tank design. The ET was designed for a heavy side-load, namely the Shuttle. This side-reinforcement can be made to go around the entire tank. Now, the buttresses connect to the ET-derived core, which still maintains the heavy side-strength, but were not given reinforcement for loads on top of the structure. The ET holds the buttressing in place, just as it did the Shuttle.

The buttress themselves were designed as an aluminum isometric-style truss system, 3 groups of 3 nested pairs each, 10" diameter. I cannot remember the alloy used, but it was an aluminum-zinc alloy which was stronger than typical aluminum but without as good of heat resistance. To protect them from the heat of friction and to improve airflow around them, they were to be wrapped in alumina sheathing. The truss design to be used was incredibly strong for linear compression. By pairing this with the ET's already present side-strength, this makes a very strong structure which can carry a very heavy weight on top. The designed failure point was ~600 tons at max-q, full burn of 4G. The trusses themselves are very lightweight, the primarily failure comes from bending, which is why they are paired up with the ET structure, to reinforce the structures.

In this, the tank structure itself would not have needed to be thickened, the heavy weight being carried by the buttresses. No change in the alloys used was planned for nor needed.

The total core weight came to ~58 metric tons. This was with a heavy margin (assuming the buttresses would come out 20% heavier, the boattail would be 20% heavier, etc).

Downix, very interesting.  Thank you.   In the whole ET/Jupiter/SLS/Ares V conversations, the side load reinforcements to supposed the Orbiter isn't usually talked about, as it's not necessary for an in-line configuration.  Just the retention of the Upper thrust beam, removal of the side load reinforcements, and strengthening the core if more than three RS-25's are on it.

Did that 58mt core weight include the RS-25 engines?
I think Jupiter was about 64mt core dry mass including engines for the J-130 and 67mt for the J246 (from the Direct baseball cards) , and I think the Block 1/1B SLS is looking at around 80mt? (I thought I remember reading that on the forum somewhere). 

If your 58mt for AJAX is less the engines, then that'd be about the same mass with engines as the Jupiters?

SLS goes with the heavier AL2219, and has a stretched core. 
Title: Re: AJAX Launcher
Post by: Downix on 07/13/2013 10:51 pm
Downix,

I was wondering if you could describe the buttressing system that AJAX would have used to support the bottom lifting thrust loads of the Atlas boosters?  I think you'd said the mass added for them would be about the same as the mass removed by removal of the upper thrust beam?

Because AJAX would mount payloads up to 130mt or more, would that mean it's ET-sized core would then need to be built out of AL2219 like the SLS core?  Or could it retain the ET's AL2195?

Would it need the thicker plates than AL2195 could be made into, which is what SLS ran in to, because it would have similar payload capability to SLS?
What sort of dry mass of the AJAX core are we looking at?

Alright, to understand the buttressing system you need to first understand the ET tank design. The ET was designed for a heavy side-load, namely the Shuttle. This side-reinforcement can be made to go around the entire tank. Now, the buttresses connect to the ET-derived core, which still maintains the heavy side-strength, but were not given reinforcement for loads on top of the structure. The ET holds the buttressing in place, just as it did the Shuttle.

The buttress themselves were designed as an aluminum isometric-style truss system, 3 groups of 3 nested pairs each, 10" diameter. I cannot remember the alloy used, but it was an aluminum-zinc alloy which was stronger than typical aluminum but without as good of heat resistance. To protect them from the heat of friction and to improve airflow around them, they were to be wrapped in alumina sheathing. The truss design to be used was incredibly strong for linear compression. By pairing this with the ET's already present side-strength, this makes a very strong structure which can carry a very heavy weight on top. The designed failure point was ~600 tons at max-q, full burn of 4G. The trusses themselves are very lightweight, the primarily failure comes from bending, which is why they are paired up with the ET structure, to reinforce the structures.

In this, the tank structure itself would not have needed to be thickened, the heavy weight being carried by the buttresses. No change in the alloys used was planned for nor needed.

The total core weight came to ~58 metric tons. This was with a heavy margin (assuming the buttresses would come out 20% heavier, the boattail would be 20% heavier, etc).

Downix, very interesting.  Thank you.   In the whole ET/Jupiter/SLS/Ares V conversations, the side load reinforcements to supposed the Orbiter isn't usually talked about, as it's not necessary for an in-line configuration.  Just the retention of the Upper thrust beam, removal of the side load reinforcements, and strengthening the core if more than three RS-25's are on it.

Did that 58mt core weight include the RS-25 engines?
I think Jupiter was about 64mt core dry mass including engines for the J-130 and 67mt for the J246 (from the Direct baseball cards) , and I think the Block 1/1B SLS is looking at around 80mt? (I thought I remember reading that on the forum somewhere). 

If your 58mt for AJAX is less the engines, then that'd be about the same mass with engines as the Jupiters?

SLS goes with the heavier AL2219, and has a stretched core. 
That is including three engines. Realize, the AJAX core is also slightly smaller than the Jupiter core as well. Eliminate the engines, and AJAX is still a few tons lighter than the Jupiter core. But it also holds ~20% less fuel as well.
Title: Re: AJAX Launcher
Post by: Lobo on 07/15/2013 04:17 pm
That is including three engines. Realize, the AJAX core is also slightly smaller than the Jupiter core as well. Eliminate the engines, and AJAX is still a few tons lighter than the Jupiter core. But it also holds ~20% less fuel as well.

Well, every kg shaved off the core is another kg to LEO right?  So I'd think if properly utilizing the sustainer-core-to-orbit parallel architecture of STS, Block 1/1B SLS, J-130, or AJAX, I think it'd be better to make the core as small as possible, rather than stretching it and making it longer (like SLS or streched Jupiter), I would think going with more booster power and performance would be the better way to go to get the perfomrance up?
(Although I understand that Jupiter was utilizing things as close to STS as possible, so they weren't messing with the boosters)

So, since you had as many engines as J-130, but 20% less fuel, I'm assuming that is possible becuase the Atlas V cores have higher impulse and burn for 250 seconds, vs. 120 seconds for the SRB's. Do the RS-25's throttle back and run throttled down for most of the boosted ascent?  Is that how there's then enough fuel to still get to orbit with 20% less fuel?

Could you have done an "AJAX" with a pair of Dynetics boosters for example?  (roughly the same thrust as eight Atlas V's) Or would the shorter burn time (approx 150 seconds) of those boosters mean the AJAX core would run out of fuel before orbit?

Title: Re: AJAX Launcher
Post by: Downix on 07/15/2013 04:45 pm
That is including three engines. Realize, the AJAX core is also slightly smaller than the Jupiter core as well. Eliminate the engines, and AJAX is still a few tons lighter than the Jupiter core. But it also holds ~20% less fuel as well.

Well, every kg shaved off the core is another kg to LEO right?  So I'd think if properly utilizing the sustainer-core-to-orbit parallel architecture of STS, Block 1/1B SLS, J-130, or AJAX, I think it'd be better to make the core as small as possible, rather than stretching it and making it longer (like SLS or streched Jupiter), I would think going with more booster power and performance would be the better way to go to get the perfomrance up?
(Although I understand that Jupiter was utilizing things as close to STS as possible, so they weren't messing with the boosters)
It depends on your target. For deep space missions, more core power will have an edge for a particular form of missions.
Quote
So, since you had as many engines as J-130, but 20% less fuel, I'm assuming that is possible becuase the Atlas V cores have higher impulse and burn for 250 seconds, vs. 120 seconds for the SRB's. Do the RS-25's throttle back and run throttled down for most of the boosted ascent?  Is that how there's then enough fuel to still get to orbit with 20% less fuel?
Correct, if you are keeping the g-loads at under 4G's. On the other hand, for a payload which can handle higher g-loads (say, a cryogenic fuel depot at L1) you can burn the core at a higher rating, for a higher payload. This was part of how I got AJAX to meet the congressional requirements for 130 metric ton
Quote
Could you have done an "AJAX" with a pair of Dynetics boosters for example?  (roughly the same thrust as eight Atlas V's) Or would the shorter burn time (approx 150 seconds) of those boosters mean the AJAX core would run out of fuel before orbit?


The latter. I optimized everything around the Atlas booster and its longer burn time. With the Dynetics boosters, instead AJAX would wind up in the ocean.
Title: Re: AJAX Launcher
Post by: clongton on 07/15/2013 08:23 pm
As avid a supporter (obviously [duh]) as I was for the Jupiter, I totally loved the AJAX. It was much more in line with what I would have done with Jupiter if we had not been restricted to the use of the SRB's. Much more flexible, more powerful, much more useful and had wonderful synergy by using the Atlas CCB. It would have cost less to field than Jupiter and FAR less than SLS, while being, not only AS capable as either Jupiter or SLS, but actually MORE capable than either.
Title: Re: AJAX Launcher
Post by: RocketmanUS on 07/15/2013 08:54 pm
As avid a supporter (obviously [duh]) as I was for the Jupiter, I totally loved the AJAX. It was much more in line with what I would have done with Jupiter if we had not been restricted to the use of the SRB's. Much more flexible, more powerful, much more useful and had wonderful synergy by using the Atlas CCB. It would have cost less to field than Jupiter and FAR less than SLS, while being, not only AS capable as either Jupiter or SLS, but actually MORE capable than either.
If not human rating the AJAX, could it have used RS-68A's instead of RS-25's, RS-68A' not over heated by the RD-180's compared to the SRB's?
( Less payload mass to orbit I know. )
Title: Re: AJAX Launcher
Post by: Lobo on 07/15/2013 10:42 pm
As avid a supporter (obviously [duh]) as I was for the Jupiter, I totally loved the AJAX. It was much more in line with what I would have done with Jupiter if we had not been restricted to the use of the SRB's. Much more flexible, more powerful, much more useful and had wonderful synergy by using the Atlas CCB. It would have cost less to field than Jupiter and FAR less than SLS, while being, not only AS capable as either Jupiter or SLS, but actually MORE capable than either.

X2

Yea, Direct was constrained to trying to make everything as directly Shuttle derived as possible, so you couldn't mess with the boosters to get greater booster performance like AJAX.  If USAF were to let ULA drop Delta IV, then that would be even more Atlas V CCB's made every year, in addition the the existing Atlas V flights, the ones used for AJAX, and [preferrably] the crews launching on Atlas V as the CLV.  (Atlas V-55/ACES)  That would be a -lot- of Atlas V CCB's built per year. 

Probably about as close to a common government launcher as we're likely to have ever gotten.  The usage of RD-180's might have been enough to warrant PWR building a US-version of it to drop into Atlas and make any Russian engine heart-burn go away.

How ESAS never came up with an LV that was similar to this is such a mystery.  I guess they didn't like that many boosters...but seems silly to toss out such an obviously flexible and synergetic concept on what's likely a fairly minor tecnical challenge.  Especially if you didn't fly crews on it.

Title: Re: AJAX Launcher
Post by: Downix on 07/15/2013 10:44 pm
As avid a supporter (obviously [duh]) as I was for the Jupiter, I totally loved the AJAX. It was much more in line with what I would have done with Jupiter if we had not been restricted to the use of the SRB's. Much more flexible, more powerful, much more useful and had wonderful synergy by using the Atlas CCB. It would have cost less to field than Jupiter and FAR less than SLS, while being, not only AS capable as either Jupiter or SLS, but actually MORE capable than either.
If not human rating the AJAX, could it have used RS-68A's instead of RS-25's, RS-68A' not over heated by the RD-180's compared to the SRB's?
( Less payload mass to orbit I know. )
No, it could not. Not for heating issues, but for isp issues. The RS-68A would lose performance due to the dramatic loss of ISP. You'd only need two engines for thrust, but the drop from ~450 to ~415 impulse would kill the performance, dropping its peak from ~138 metric tons to ~74 metric tons.

Incidentally, I did study an Atlas-like setup, using an SSME + 2 RS-68A drop-engines at one point. That produced the maximum performance of any AJAX setup, giving me a peak of 144 metric tons.
Title: Re: AJAX Launcher
Post by: Lobo on 07/16/2013 12:14 am
No, it could not. Not for heating issues, but for isp issues. The RS-68A would lose performance due to the dramatic loss of ISP. You'd only need two engines for thrust, but the drop from ~450 to ~415 impulse would kill the performance, dropping its peak from ~138 metric tons to ~74 metric tons.

Incidentally, I did study an Atlas-like setup, using an SSME + 2 RS-68A drop-engines at one point. That produced the maximum performance of any AJAX setup, giving me a peak of 144 metric tons.

What about a cluster of J2X engines?  Only suggesting that becuase J2X will be developed anyway, but RS-25E hasn't yet.  And AJAX is an alternative to SLS, so without SLS, there's not necessarily a need for RS-25E.  Especially with the much later booster staging of AJAX compared to SLS.  J2X has pretty good performance in vacuum...448s vs. 450s for RS-25.  Four of them would be about 350klbs less than three RS-25's, but should be pleanty of thrust by the time the Atlas cores separate at 250 seconds into flight.

What would be the likely per unit cost of J2X vs. RS-25E?  I'm guessing less because it's smaller and not staged combustion?

Interestingly, the RD-0120 would be a GREAT engine for AJAX, or SLS, or Direct, or any expendable sustainer-core-to-orbit LV.  455s ISP at vacuum.  And apparently much more simple/cheap than RS-25, even though it's staged combustion.
Maybe the RS-25E will be similar to the RD-0120 in those ways?
But wouldn't require a new development program.  Although as it's out of production, it'd probably need new tooling to make.   

Guess it might make for a much "too Russian" LV though...
Title: Re: AJAX Launcher
Post by: Lobo on 07/18/2013 05:38 pm
Downix,

You said AJAX could use an ACES-71 upper stage?

So my question is, would AJAX have done basically the same ascent profile as SLS Block 1?  With both cores taking the upper stage almost to LEO?
The DUUS they are talking about for Block 1B SLS only has four RL-10 engines on it, the same as ACES could mount.  Could SLS Block 1 mount a stretched ACES stage as it's DUUS, rather than a new purpose built stage with an 8.4m LH2 tank and 5, 5.5, or 6.3m LOX tank?  NASA would get their DUUS and ULA would get their common EELV upper stage.

I believe NASA is now looking at ACES as their new 5m CPS for their non-DUUS concepts.  Could they merge the concepts and have an ACES DUUS?

SLS will be a fair bit longer than the AJAX core would be, so maybe that would create a stack height issue that AJAX would not have had?
Title: Re: AJAX Launcher
Post by: Downix on 07/19/2013 02:45 am
Ok, combining these two to answer.
What about a cluster of J2X engines?  Only suggesting that becuase J2X will be developed anyway, but RS-25E hasn't yet.  And AJAX is an alternative to SLS, so without SLS, there's not necessarily a need for RS-25E.  Especially with the much later booster staging of AJAX compared to SLS.  J2X has pretty good performance in vacuum...448s vs. 450s for RS-25.  Four of them would be about 350klbs less than three RS-25's, but should be pleanty of thrust by the time the Atlas cores separate at 250 seconds into flight.

What would be the likely per unit cost of J2X vs. RS-25E?  I'm guessing less because it's smaller and not staged combustion?
The J-2X is bigger, not smaller, than the SSME. It is also likely to wind up more expensive than the SSME at the same production levels. In addition, you would need 6 of them to replace 3 RS-25's, which you'd lack the space for under the tank. NASA actually did study this option on the RAC studies.
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Interestingly, the RD-0120 would be a GREAT engine for AJAX, or SLS, or Direct, or any expendable sustainer-core-to-orbit LV.  455s ISP at vacuum.  And apparently much more simple/cheap than RS-25, even though it's staged combustion.
Maybe the RS-25E will be similar to the RD-0120 in those ways?
That is the idea.
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But wouldn't require a new development program.  Although as it's out of production, it'd probably need new tooling to make.   

Guess it might make for a much "too Russian" LV though...
long out of production, it would take more time to set up than to finish the RS-25E program begun in 2002.
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Downix,

You said AJAX could use an ACES-71 upper stage?

So my question is, would AJAX have done basically the same ascent profile as SLS Block 1?  With both cores taking the upper stage almost to LEO?
Similar, but not identical. Lighter core gives AJAX a higher curve, more eccentric parking orbit.
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The DUUS they are talking about for Block 1B SLS only has four RL-10 engines on it, the same as ACES could mount.  Could SLS Block 1 mount a stretched ACES stage as it's DUUS, rather than a new purpose built stage with an 8.4m LH2 tank and 5, 5.5, or 6.3m LOX tank?  NASA would get their DUUS and ULA would get their common EELV upper stage.

I believe NASA is now looking at ACES as their new 5m CPS for their non-DUUS concepts.  Could they merge the concepts and have an ACES DUUS?
I've not heard that. I've only heard of an enlarged DCUS, which is not a bad idea either.
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SLS will be a fair bit longer than the AJAX core would be, so maybe that would create a stack height issue that AJAX would not have had?

That could be an issue, yes.
Title: Re: AJAX Launcher
Post by: Lobo on 07/19/2013 06:40 am
I've not heard that. I've only heard of an enlarged DCUS, which is not a bad idea either.

I don't know that it's ACES, just that in NASA's Option 1 and Option 2 from Chris's recent article on the DUUS, they are looking now at a 5m CPS, instead of the previous 7.5m CPS.  I'm only guessing it might be ACES as I know ULA was selling ACES in their recent paper on using EELV's for commercial crew.

I was making an assumption there, but I could be wrong.  It could be a stretched DCUS too, like Boeing had in their lunar gateway plan as the "in-space stage".

But, it got me thinking about perhaps a DUUS with more direct commonality with the EELV common upper stage.
Title: Re: AJAX Launcher
Post by: Downix on 07/21/2013 10:22 pm
I've not heard that. I've only heard of an enlarged DCUS, which is not a bad idea either.

I don't know that it's ACES, just that in NASA's Option 1 and Option 2 from Chris's recent article on the DUUS, they are looking now at a 5m CPS, instead of the previous 7.5m CPS.  I'm only guessing it might be ACES as I know ULA was selling ACES in their recent paper on using EELV's for commercial crew.

I was making an assumption there, but I could be wrong.  It could be a stretched DCUS too, like Boeing had in their lunar gateway plan as the "in-space stage".

But, it got me thinking about perhaps a DUUS with more direct commonality with the EELV common upper stage.
It sounded like the enlarged DCUS to me, barrel stretch to the existing DCUS systems.
Title: Re: AJAX Launcher
Post by: HappyMartian on 07/22/2013 03:07 pm
Someone suggested that we put the current configuration in the first entry, so here goes:

AJAX is a means of achieving the goals of the Congressionally mandated Space Launch System while reducing overhead costs by sharing resources with other United States launch systems. By studying the various Shuttle components, it was determined the optimal configuration would be to replace the existing pair of segmented solid rocket boosters with 2 pairs of liquid rocket boosters.  For cost, political and performance purposes, AJAX chose the ULA Atlas Common Core Booster (CCB).
....

Atlas CCB w/ nosecap (hard numbers):
dry weight: 21,844 kg
Fuel weight: 284,453 kg
....



This probably was considered previously, however:

The CCB or first stage of the Atlas V with its 1 RD-180 has a thrust 860,568 lbf and an Isp of 311 seconds at sea level.

In a vacuum its thrust is 933,400 lbf with an Isp of 338.
with a Burn time of about 253 seconds.

The RD-180 has 50 - 100% continuous throttling capability.

AJAX wouldn't have used solids. However, if NASA goes with the Dark Knights SRB's for the SLS, might it still make sense to have the option to eventually add two pairs of liquid boosters based on the Atlas CCB?

Wouldn't this be a somewhat cheap way to significantly enhance the performance of the SLS?

The RD-180s on the Atlas CCBs could be throttled down to about 50% prior to the ignition of the Dark Knights and 4 RS-25s, and then throttled up after Max Q.

The empty four CCBs would only add less than 100,000 kg to the SLS when moving it to the launch pad. The core would need minimal modification because the Dark Knights SRBs would still structurally 'hold up or stabilize the core and payload' prior to launch.

The RD 180s would need propellant cross feeds for an engine out option and normally might burn for around 5 minutes.
 
Would this modified AJAX-SLS be cheaper than adding a large and specialized J-2X stage and yet offer similar or greater performance gains?

Title: Re: AJAX Launcher
Post by: Lobo on 07/22/2013 05:43 pm
It sounded like the enlarged DCUS to me, barrel stretch to the existing DCUS systems.

It certainly could be...but...

ULA wants ACES, correct?  They just need someone to pay for it.

An enlarged DCUS would leverage the existing DCUS, but in many ways, it'd be a new stage.  It would be supplied by ULA anyway.

If an enlarged DCUS is a new stage, and ULA wants money to make ACES and make it their new common upper stage, wouldn't it make sense to have ACES be the CPS?  ACES leverages existing systems too. 

Seems like ULA might want to make NASA a deal or bargin to develop their 5m CPS for them, and get ACES out of the deal, rather than an enlarged DCUS out of the deal, which probably won't be the common EELV upper stage. 
Title: Re: AJAX Launcher
Post by: Robotbeat on 07/29/2013 06:33 pm
BTW, Downix, do you have those CAD models of the AJAX launcher? I'm going to see how far I can get in doing a little computational fluid dynamics... it's been a couple years, and I don't have access to the tools I had back in school (we used FEMLab, which was built on top of MATLAB, but now they changed the name to "COMSOL Multiphysics"...), but there are some interesting new tools out there for free... I'm going to see if I can import your model into GMSH (a free mesh-generator and post-processor), and then we'll see if we can get a solver working on it... (I have one in mind)

1) I'd like to suggest that you keep things simple and model each of the bodies as axisymmetric shapes.  You can refine the model later.

2) you'll need a solver which can handle transonic and supersonic flow.  I believe the two you mentioned, FEMLab and COMSOL, are incompressible.  But I could be wrong.

3)  Which code did you have in mind?

OpenFOAM (http://www.openfoam.com/) incorporates turbulence models but last time I looked, (1 yr ago?) the equations for the pertinent solvers listed on their web page were solved uncoupled so the solvers can not solve (or at least get good answers) for steady state transonic (past supercritical) and supersonic flow.  They mention having solvers for transient compressible flow, but you'll need to validate the results for supercritical flows by comparing test cases to literature.  And, be careful with that since some WT tests can be questionable for supercritical flows.  I'd recommend comparing to axisymmetric shapes rather than 2D shapes (airfoils).  However, still be VERY careful.  There is a solver AeroFOAM (http://www.aero.polimi.it/freecase/?OpenFOAM_%2B_Code_Aster:Download) which has the elements required to solve transonic/supersonic steady state flow, but I believe it lacks turbulence models.  Also, I don't know how up to date it is.  If you have questions about OpenFOAM a good place to ask is Symscape (http://www.symscape.com/) in addition to online forums.

Another code is FreeCFD, (http://www.freecfd.com/).  I think it has the elements required, but I'm not sure.  I'm also not sure if it is being actively developed.

As for all the rest, the majority are incompressible  (Solving the coupled equations is a pain) or they don't have a turbulence model (laminar only) or they are 2D.

4)  Later, you mentioned that you don't have a powerful workstation...  Your machine may not be able to handle this...  (note:  for multicore machines, the bottle neck is not the floating point computations (cpu) but the memory bus)

5)  A suggestion, you can look in literature and get the forebody drag on blunted cones and ogives.  Then kluge in skin friction and base drag.  For example you can get blunted cone information from NASA TN D-3088 "Aerodynamic Characteristics of Spherically Blunted Cones at Mach Numbers from 0.5 to 5.0" and skin friction and base drag from Hoerner's Fluid-Dynamic Drag.  This will get you CD0.  Then spot check your results against CFD.  And, for the time, ignore CL and CM for the trajectory.

Edit:
As the CCBs move closer to one another the interference drag for transonic and supersonic flow will increase.  You May need to kluge something in or model that region up in a CFD code.  Euler results may be a good first crack at it since you are looking for the pressure rise.  Of course you'll be neglecting viscosity, but at this point the approximation is probably ok.  Of course caution must be used.  If viscosity creates a recircularization region ahead of the CCBs, the real drag may be appreciatively lower than Euler result.

Soo.... I've been doing some more OpenFOAM modeling with a completely unrelated project, but I'm interested if you know of any progress in OpenFOAM. Specifically, I want to model something descending (subsonically) through a supercritical gas. The equations of state are beyond me, but I do want to know if there are tools available in OpenFOAM to solve this. Are you aware of any?
Title: Re: AJAX Launcher
Post by: RocketmanUS on 12/20/2014 07:38 pm
RS-25's are not in production.
RD-180's are most likely not going to be used much longer in the U.S.
No advanced booster yet for SLS.

So how about having two boosters ( new Atlas V common core ) each with 2 or more BE-4's on them and a core powered by multiple BE-4's?

Core could be made with SLS vertical weld machine.

So I'm thinking three BE-4's on each booster and eight BE-4's on the core. Total of 7,700,000 lb at lift off.

US to use RL-10C's.

So could NASA have it's own HLV with commercial? Should have the potential to keep cost down.

The new Atlas V boosters could be the advanced boosters. The core and US could be the same ( manufacture and infrastructure ). Could have possible upgrades if needed like having four boosters ( infrastructure ).

Could be an AJAX like HLV.
Title: Re: AJAX Launcher
Post by: baldusi on 12/21/2014 04:13 am
That ship sailed a long time ago. I will predict that SLS will be the last NASA designed rocket. If there even a need for it to be replaced, commercial companies will do it. NASA will focus on what's on top.
Title: Re: AJAX Launcher
Post by: clongton on 12/21/2014 12:40 pm
Agree. NASA has been pushed out of the rocket design business as predicted 5 years ago. Ajax has sailed into the sunset. DIRECT has sailed into the sunset. SLS is the Senate's one last gasp of denial as a NASA design/build launch vehicle. As soon as commercial resupply of the ISS became an official project, NASA was done as a rocket designer because it destroyed the price structure. Commercial can do the same thing for far less money. NASA will now focus, as you said, on payloads. NASA will become a mission designer and administrator.
Title: Re: AJAX Launcher
Post by: A_M_Swallow on 12/22/2014 02:29 am
Agree. NASA has been pushed out of the rocket design business as predicted 5 years ago. Ajax has sailed into the sunset. DIRECT has sailed into the sunset. SLS is the Senate's one last gasp of denial as a NASA design/build launch vehicle. As soon as commercial resupply of the ISS became an official project, NASA was done as a rocket designer because it destroyed the price structure. Commercial can do the same thing for far less money. NASA will now focus, as you said, on payloads. NASA will become a mission designer and administrator.

It is considerably easier for a few politicians on a Senate committee to reallocate parts of NASA's budget that to get both Houses to agree to increase NASA's budget.  If the SLS is to be cancelled have major programs waiting to receive the money.  Possibilities include lunar landers, Mars transfer vehicles and gateway spacestations.  In FY2016 these programs do not lots of money, just sufficient for a way and means study, but they do need a place name in the budget.
Title: Re: AJAX Launcher
Post by: ArbitraryConstant on 12/26/2014 07:52 pm
So I'm thinking three BE-4's on each booster and eight BE-4's on the core. Total of 7,700,000 lb at lift off.
Now you've done it. Once the spell is broken and we can talk about a high thrust hydrocarbon core, do boosters even make sense?
Title: Re: AJAX Launcher
Post by: Lobo on 12/31/2014 06:07 pm
So I'm thinking three BE-4's on each booster and eight BE-4's on the core. Total of 7,700,000 lb at lift off.
Now you've done it. Once the spell is broken and we can talk about a high thrust hydrocarbon core, do boosters even make sense?

That's exactly the point.  Unless you are talking a modular platform like Falcon or Delta (or Atlas if A5H had ever been developed) A unique core that needs different and unique boosters to fly doesn't make a lot of sense.  Completely different structures for the core and boosters, different engines, etc.  At that point, much better to go with a monolithic hydrocarbon.  One core, one booster engine.

If you are building a modular platform, than common core type boosters make sense.
Title: Re: AJAX Launcher
Post by: clongton on 12/31/2014 07:53 pm
NONE of this has anything to do with AJAX.