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?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.
I'm not sure we reached a consensus vis-a-vis the full-length tank and the pre-burn.
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.Does it make sense to lengthen the tank, then?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.
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.
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.
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.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.
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.
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.
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?
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.
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.
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.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 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.
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 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.
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".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 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.
Sound suppression water volume?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 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.
Something which can be adjusted for, I would imagine.Sound suppression water volume?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 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.
-Alex
Build more water towers? There's a lot of water that gets dumped in a very short period of time.Something which can be adjusted for, I would imagine.Sound suppression water volume?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 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.
-Alex
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.
why not add some Atlas solids?
What are the open questions regarding the launcher that can begin to be addressed in this forum?
Can we calculate rough LOM figures based on past Atlas V performance?
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 ;)
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.
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.
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:
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?
now before anyone asks what would a 150+mt vehicle could carry
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?
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?Well, you know what I think about the whole issue. ;)
Using the new Senate bill, 75mT seems the target, is this agreeable with everyone?
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?
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.
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.
Short loading is not a viable method. No one in the real world would agree to it. Size the tanks for the application.
Why not just base-line 5 x CCB? What's so special about even numbers?
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.
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.
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
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.
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.
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.
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
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.)
Short loading is not a viable method. No one in the real world would agree to it. Size the tanks for the application.
1. Changing tank dimensions basically means redesign. Short-loading means adding some sensors.
2. Do you size your car's tank to every trip?
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.
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.
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.
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?
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.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.
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?
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.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.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.
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?
I think. ;)
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.
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.
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.
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)).
I think you math is slightly off.Hush, you realize I am actually giving extra margin by sacrificing those few extra percentage points, right? 8)
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.
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.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...
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.
No, more from done redesign. 1ET ring would be 20%.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?
Only for completeness, will share next a new Excel file containing a bit of formatted AJAX-440 (virtual) telemetry output relative to: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)
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
Only for completeness, will share next a new Excel file containing a bit of formatted AJAX-440 (virtual) telemetry output relative to: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)
a) STS ET Sized Core (71t + 728t prop)
b) Short Core possibility (60t + 565t prop)
( ... )
António
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.
This is rather interesting.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.
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.
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....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.
Actually, Downix, even the basic drawings/measurements would be helpful.Let me get them scanned in. ....
LOL! If you have a good digital camera, you can just take a picture.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?
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)
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.
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?
What's going on with this plan lately?
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.
Because Dr. Griffin, "The premiere rocket scientist of these times" chose it - put his name behind it, and defended it to Congress himself.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
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?
Because Dr. Griffin, "The premiere rocket scientist of these times" chose it - put his name behind it, and defended it to Congress himself.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
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.
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?
What's going on with this plan lately?
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.
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.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.
António
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:I am figuring on a skewed cone as well, the aerodynamics are right, plus, they look sexy. 8)
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
Look at the Atlas V SRB'sFrom here:
Very similar to the design I have.Look at the Atlas V SRB'sFrom here:
http://www.lockheedmartin.com/ssc/commercial_launch_services/launch_vehicles/AtlasV500Series.html
Look at the Atlas V SRB's
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?
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?
It is also not as if the CCB connection points would be all new either, they would be adapted from the shuttles connection system.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. :)
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. :)
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.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
Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.
Trying out a few. Right now messing with BlenderCAD.Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.
Which one?
And meanwhile, I've switched from freeCFD to FUN3D. Although FUN3D is harder to get a hold of, it should be much more powerful.Trying out a few. Right now messing with BlenderCAD.Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.
Which one?
And meanwhile, I've switched from freeCFD to FUN3D. Although FUN3D is harder to get a hold of, it should be much more powerful.Trying out a few. Right now messing with BlenderCAD.Due to the desire for CAD, I am trying to teach myself how to use a CAD program now.
Which one?
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
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. :)
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. :)
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.
"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.
...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).
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).
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
...
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....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).
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
...
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'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 meIn 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...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.
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...Keeping the 1.15 assumption, it matches the EELV's so fits in our needs
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?)...I was figuring on sticking closer to the DIRECT and NLS methodology here, despite Energia being a better assumption.
- 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.
- 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.
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...Understandable.
… 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
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.
You're putting ATK's words in my mouth - never said what you claim."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.
Didn't argue about solids, haven't since the 60's Minuteman I.QuoteCan 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.
Stop putting words I don't say into my posts.QuoteBack 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.
"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.
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.
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.
"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 PaytonWe'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.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.
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.
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....
There are three (3) main things to look for when deciding what cad software to use.What are you guys using?
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.
QuoteThere are three (3) main things to look for when deciding what cad software to use.What are you guys using?
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'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.
QuoteThere 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.
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.
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.
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.
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.
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
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.
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.
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.
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
Also thinking.. doesn't F9 or Taurus II tanking have better mass fraction than Atlas.. so much for the A part of AJAX
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.
Also thinking.. doesn't F9 or taurus II tanking have better mass fraction than Atlas.. so much for the A part of AJAX
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).
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)
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.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.
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.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?
This is getting, of course, a bit ahead until there is the SLS, but it does need to be kept in the back-mind.
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 think Downix's idea was to keep both the CCBs and the Core (as it is in J-130) almost entirely unchanged, if possible.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.No changes to CCB. Change the ET/core as much as you like. Economies of scale and flight proven history dominates here.
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)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.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.
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.
I would guess that a shorter core would have less stress... lower bending moment.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.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.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?
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.
Unless you added a 5th SSME, but then we get into Ares V issues.I would guess that a shorter core would have less stress... lower bending moment.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?
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
You're putting ATK's words in my mouth - never said what you claim."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.
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.Didn't argue about solids, haven't since the 60's Minuteman I.QuoteCan 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.
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.Stop putting words I don't say into my posts.QuoteBack 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.
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.
Not counting the SSME's, the reduced core is coming up at 44.4 m.
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 kgNot 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?
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.
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?
Thank you! I'll give it a try soon.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.
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.
<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?
... 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.
That's why they call it "Colorful Fluid Dynamics." ;) The important part is the pretty pictures! (Just kidding, of course...)
... 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.
The important part is the pretty pictures! (Just kidding, of course...)
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?
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.
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.
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
Hi all,
...
António
Not likely Ron. Sorry.
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.
(...)
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
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.
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.
I. LRB Details: nose cone, core integration, etc
...
II. 3D Models / Dimensions
...
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.
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.
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: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.
SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that
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
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.
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...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: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...
SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that
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...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: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...
SD-HLV (starting 2011)
~$3B from 2011-2017 for maybe 1 or 2 test flights, but mostly ATK welfare
$520M/flight after that
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.
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
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!
<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>
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.
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.<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).
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.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.
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
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?
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.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.
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
Thanks,
-Alex
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.
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
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.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.
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.
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?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.
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.My thoughts exactly. Are we still planning to use AV boosters?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.
Awesome :D A double win :D :DThe 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.My thoughts exactly. Are we still planning to use AV boosters?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.
Awesome :D A double win :D :D
( . . . )
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.
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.
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
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.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.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.
From all studies, the slightly shorter core is proving to be the best overall design, from both a T/W and performance standing.
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).Actually we settled on 4 SSME. The reasons were:
If its not on this thread you should check the previous All liquid SDHLV options thread. Should be somewhere in the heavy lift section.
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?No, those are with the Jupiter ET, not the adjusted core.
-Alex
Alright glad to hear it :) Sorry I forgot about that change. Been incredibly busy lately.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).Actually we settled on 4 SSME. The reasons were:
If its not on this thread you should check the previous All liquid SDHLV options thread. Should be somewhere in the heavy lift section.
1) we needed the thrust on liftoff
2) cut-out capability, can loose an engine after 12 seconds and still make it to orbit.
420: 47mT
440: 71mT
460: 92mT
480: 109mT
With a JUS (RL-10-B2 version) I got over 150mT. Ares V territory. The T/W on liftoff tho dropped however.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?
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.
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 :)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.
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.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 :)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.
BTW thanks Downix for the MT numbers from earlier :D
But here we go:BTW, thanks Downix for those numbers; added to the chart.
420: 47mT
440: 71mT
460: 92mT
480: 109mT
But here we go:BTW, thanks Downix for those numbers; added to the chart.
420: 47mT
440: 71mT
460: 92mT
480: 109mT
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
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:
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". ( . . . )
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
Launch T/W at liftoff >1.2 for controllability off the pad
IV. AJAX: v1.0 (AtlasV LRB + optimized SDLV core) vs v2.0 (boosters?, core?)
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 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
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.
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.
There's also Schilling's performance estimator, but it's not really as accurate as you'd probably like...
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?
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.
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.
simcosmos is the guy behind Orbiter (http://simcosmos.planetaclix.pt/), which means he has significant capability himself.
… 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!
- 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')...
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
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.
Hi Martin, sdsds, all
...
Thanks,
António
... and Chuck is claiming representation for people who I thought were volunteers.
... 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.
Not sure if I helped.
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."
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.
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.
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....
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.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.
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.
( . . . ) 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! ( . . . )
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 3:
Antonio, how did you account for varying thrust with altitude?
( . . . )
How well does the trajectory simulation run (i.e. payload into orbit) match the delta v calculations?
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...
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...
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
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!
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.
To answer I will need to make a short introduction about the performance implementation method (Orbiter Simulator + Multistage2.dll) that I'm using
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.
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.Well a DIV based model, using the standard Jupiter core, not our shrunk AJAX core:
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:Not to go too far down the rabbit hole, what about Delta-diameter RP-1 (fat Atlas) boosters?
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.
Worse T/W, you'd have more weight for the same thrust.Well a DIV based model, using the standard Jupiter core, not our shrunk AJAX core:Not to go too far down the rabbit hole, what about Delta-diameter RP-1 (fat Atlas) boosters?
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.
That's indeed what I intended, sorry for the oversight of not listing dual 180s.Worse T/W, you'd have more weight for the same thrust.Well a DIV based model, using the standard Jupiter core, not our shrunk AJAX core:Not to go too far down the rabbit hole, what about Delta-diameter RP-1 (fat Atlas) boosters?
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.
*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.
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.That's indeed what I intended, sorry for the oversight of not listing dual 180s.Worse T/W, you'd have more weight for the same thrust.Well a DIV based model, using the standard Jupiter core, not our shrunk AJAX core:Not to go too far down the rabbit hole, what about Delta-diameter RP-1 (fat Atlas) boosters?
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.
*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.
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?
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.Very true. We do have some targets, mainly STS and DIRECT based. But you are correct that we need to generate our own.
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?
Two questions:1. Yes believe it was sufficient.
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%?
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?
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).
eventually the SLS will be using disposable SSMEs [...] this modded engine [...] greater thrust at sea level
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.
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.
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.
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.
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.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.
From Downix:wider base, and cryo fuel. Proton is a unique beast, and if we were running non-cryo fuel, I'd look into it.QuoteThen 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.
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.
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.Somehow, I have a nasty feeling that the 4,6,8 LRB configs will be eliminated as unfeasible; can anyone offer a substantive reason?
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.
Ok, 624 first: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.Somehow, I have a nasty feeling that the 4,6,8 LRB configs will be eliminated as unfeasible; can anyone offer a substantive reason?
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.
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
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.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
Ok, 624 first:Check
ACES41 - 71mT
ACES71 - 84mT
ACES101 - 80mT
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.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.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
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.[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.
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 :)
I did one more test, I took my ACES 71, and swapped in a J-2X for the RL-10 cluster: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."
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?
Ok, so my estimates are heavier by a ton and a half. So performance will be better, good.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.
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.QuoteI, 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 :)QuoteI did one more test, I took my ACES 71, and swapped in a J-2X for the RL-10 cluster: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."
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?
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.
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.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.
Then if you attach it to the Ajax core, we can get a very heavy lifter if needed.
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.
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.
Probably the same way that Douglas fit 6x RL-10s on the 5.5 m diameter S-IV... :p
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.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...
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.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!
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.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.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...
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.
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.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!
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...
Wrote that while still half asleep, my goof. Fixed it above.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.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!
This must be the revision with one-and-a-half nozzles each.
cheers, Martin
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?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.
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.
...
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.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).
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.
There's that, but also this from November 18: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.
http://hatch.senate.gov/public/index.cfm?FuseAction=PressReleases.Detail&PressRelease_id=602f9c19-1b78-be3e-e07e-fb550421a64a&Month=11&Year=2010QuoteThe 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.
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).
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.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.
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.
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.
"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.
http://www.orlandosentinel.com/news/space/os-zombie-rocket-lives-20101227,0,4846338.storyThere are 12 design submissions being worked on. I would not be surprised if something like AJAX or Neptune is not included.QuoteBut 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.
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.
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 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.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.
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
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."
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.
... 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;
...
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.
Has there been a side-by-side presentation comparing AJAX-440 and AJAX-620?No, how about I do that then?
So payload loss of between 4-6mT.
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.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.....
So payload loss of between 4-6mT. Both of these used the same payload shroud as the J241 of 3957kg
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.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
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.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.....
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.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.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.....
We hit the sweet spot with that design.
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.
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.
RS-25 is capable of being pushed to 115%.
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.
109% has been certified, but the expectation is that the engine has three times greater chance of failure than 104.5%.Was not thinking of it as a baseline, only in terms of absolute emergency.
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.
109% has been certified, but the expectation is that the engine has three times greater chance of failure than 104.5%.Was not thinking of it as a baseline, only in terms of absolute emergency.
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.
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!"
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.
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.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....
Can someone please provide a brief description of AJAX.
Can someone please provide a brief description of AJAX. I looked at the beginning of this thread and didn't find one.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.
Thank You
Can someone please provide a brief description of AJAX. I looked at the beginning of this thread and didn't find one.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.
Thank You
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 billionCan someone please provide a brief description of AJAX. I looked at the beginning of this thread and didn't find one.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.
Thank You
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?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
- 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.
- 2 to 8 existing, single RD180 Atlas cores as strap ons. Is there a no strap on version?There are no plans for it.
- 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.
- 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.
Interesting idea. In an effort to further streamline the recurring cost you may want to consider:(editing to make things less muddled)
- 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)
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).
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.
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.
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?
The idea was to use the ACES horizontal lander. So, they would be about 90% identical.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.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.
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.The idea was to use the ACES horizontal lander. So, they would be about 90% identical.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.
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.
*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.
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.
guess that means the ruskies stole our idea ;) (joking ofc)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.
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?
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?
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.
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.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. The name should be Daedalus.
If you checked mass, this is 13% lighter as well, with less fuel.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.
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:
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.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
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'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 live up the street from where these are stored between ferrying operations.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
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:
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.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.
http://www.youtube.com/watch?v=quILBGryShUI'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!"
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.
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...
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%.
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!
If only they were flybacks!One thing at a time.
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.
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.
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.
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?
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.
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.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 coming.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 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?
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 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.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 :)
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.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?".
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
Damned sexy rocket.
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":
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.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.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?".
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.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).
I'm an economist. If you want me to look over some economics stuff, pm.Not yet, we're working on it right now. A lot of the renders are very old "sketches" don't forget.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).
Putting everything together is a challenge.
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.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.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.
Done. Any suggestions on what needs to be added?Not a bad idea.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.
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?Not a bad idea.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.
Aside from the description, it should probably also mention the AJAX paper that's in work, then link to it when it's released.
Damned sexy rocket.
I think there's a typo in this sentence:fixed
"Because the CCB's have less sea level thrust than the SRB's, the ET's fuel load, as it, was too heavy."
Damned sexy rocket.
Oh,yeah... Very, very sexy rocket...
Still a couple of stray apostrophes, but it's now a much better introduction to AJAX.Indeed.Damned sexy rocket.
Ok, updated. Keep em coming.
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.
QuoteBy 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 ofpairedliquid rocket boosters. For cost, political and performance purposes, AJAX chose the ULA Atlas Common Core Booster (CCB)."
EELV's
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?
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.
I have a suggested edit to the first sentence, which currently reads:QuoteAJAX 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.
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.I have a suggested edit to the first sentence, which currently reads:QuoteAJAX 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?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.
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.
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.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.
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.
There have been ET's built already with similar ring-swaps
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.There have been ET's built already with similar ring-swaps
This bit is news to me. To what tanks does this refer?
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.
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.
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.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.
Overall, from my ignorant point of view, it should be on the same ball park.
QuoteAlso, 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.
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.QuoteAlso, 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?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.
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.
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.
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.
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.
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.QuoteDIRECT 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).
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.
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.QuoteThe 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.QuoteDIRECT 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).
An Example picture of using ET-94 as a test vehicle.
http://www.nasaspaceflight.com/wp-content/uploads/2010/06/A171.jpg
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.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.
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.QuoteThe 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.QuoteDIRECT 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).
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.
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.
And I don't believe the DIRECT team has a structural analysis since they do not have aero loads (i.e. pressures).
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.
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.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.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?
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.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.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?
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.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.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?
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. "
I can, however, give the basics: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.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.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?
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. "
Yeah, that makes sense.
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.
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.
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
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?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.
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.
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.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.
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?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.
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?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)
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.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?
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)
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.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?
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.
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)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?
Agreed, which is why I want to expand it and make it more utilized than it is now.
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?You got it. Rollout would be the day before launch I would imagine, to give time to fuel it up.
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.
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.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.
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.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).
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.
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.
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.
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.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?
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.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.
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.
Downix,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.
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?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.
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.
Downix,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.
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?
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.
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.
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.
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.
"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.
Downix,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.
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?
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.
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.
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. :-)
That, my friend, is a secret. Shh! (it is who you know, not what you know)Downix,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.
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?
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)Downix,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.
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?
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 :-) )
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.
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.
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. :-)
That, my friend, is a secret. Shh! (it is who you know, not what you know)
The payload isn't the issue, it's the 280 metric ton difference in the core fuel load that is.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?
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.
Soon, very soon.That, my friend, is a secret. Shh! (it is who you know, not what you know)Downix,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.
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?
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 :-) )
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.
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!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?
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.
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].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.
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?
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!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?
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.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.
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?
Aero is a secondary consideration in LV. Once you get pass controllability it only has second order effects.
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?
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.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.
What about structures, heating, base heating, plume induced separation, staging, transonic buffet, or unsteady flow.
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.
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.
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).
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).
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.
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.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.
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.
I know all about margins. We estimate we only need 55mt for the core, so we list 63mt. Better to overestimate just in case.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.
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.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.
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.
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.
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.
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.
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.
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?
Downix,Off the shelf ACES-41 is the idea
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?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.
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.
Hmmmm...It's an alternate option, but I suspect it will be carried over to ACES if needed.
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?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.
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?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.
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?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.
[...] 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.
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 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.Soon, very soon.That, my friend, is a secret. Shh! (it is who you know, not what you know)Downix,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.
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?
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 :-) )
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.
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.
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.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.
Why would we want to invest several more billion into an engine without a role?
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)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?
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.
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.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?
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.
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?
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.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.
Ahem. Its Northrop-Grumman. Speaking as a former NG employee. :)Ah, my sincere apology.
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.
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.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.
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.
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.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.
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.
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.
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.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.So, with a theoretical RS-25T (with TAM) you'd only need two?
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.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?
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.
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 enginesFY2011 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.
Isn't RS-68 more of a DOD engine? Nasa's would have been the B version.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.
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.
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.
Isn't RS-68 more of a DOD engine? Nasa's would have been the B version.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.
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.
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?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.
(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.
Another question.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.
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.
Out of curiosity, what do the RS-25 engines run compared to the Atlas CCB's with RD-180 engines.
That's a good chart, mind if I use it? (it's not far off actually)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.
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)
A little something to give an idea for scale, it puts things in perspective. Saturn, Shuttle, Atlas V Heavy, and AJAX.
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.
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.
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.
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.
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.
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).
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.
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.Same, I don't see any outstanding issue with that.
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.
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.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
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.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.Same, I don't see any outstanding issue with that.
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.
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
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?
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?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.
Also, how much in terms of pad mods could Common Centaur have with a future large hydrolox EDS, especially if JUS-like (Centaur-derived)?
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?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.
Also, how much in terms of pad mods could Common Centaur have with a future large hydrolox EDS, especially if JUS-like (Centaur-derived)?
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?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.
Also, how much in terms of pad mods could Common Centaur have with a future large hydrolox EDS, especially if JUS-like (Centaur-derived)?
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.
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.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?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.
Also, how much in terms of pad mods could Common Centaur have with a future large hydrolox EDS, especially if JUS-like (Centaur-derived)?
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.
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.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.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?
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.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.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?
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?
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.
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.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.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?"
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.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.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?"
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?
Downix,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
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?
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:
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:Option 7, yes, I am familiar with it. Found it interesting how it gets mentioned, then vanishes from the details.
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
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:Option 7, yes, I am familiar with it. Found it interesting how it gets mentioned, then vanishes from the details.
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
If you have ESAS LV27 (5/5) upper stage (2x J-2S) on top of it, you'd hit about that by my estimates.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:Option 7, yes, I am familiar with it. Found it interesting how it gets mentioned, then vanishes from the details.
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
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?
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.
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.
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.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?
Downix,F-1A:
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.
Downix,F-1A:
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.
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.
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.
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.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....
So my thought is with AJAX plus EELV's, you can do away with the LEO depot ...
Ok Downix, I'm going to pick your ginormous brain for awhile.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.
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.It should be able to by my calcs, assuming that the SM is ACES derived.
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?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.
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?Quite a few. Moving out of LEO adds a new level of issues and uses more fuel.
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.
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.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....
And that is on the table, the upgrade path.
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.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.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....
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.
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.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.
Downix, do you have a hi res image of your AJAX logo?
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)
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.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.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.
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.
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.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.
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 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)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.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.
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.
Downix,peeve? Hardly, I like the AJ-26.
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?
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.
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.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
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.
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.Downix,peeve? Hardly, I like the AJ-26.
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?
In theory they could, the development would be more difficult than to just cluster 4 engines with separate turbopumps.
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.
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.
Downix,Now you're thinking like I have for almost a year now.
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.
Downix,Now you're thinking like I have for almost a year now.
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.
Downix,Now you're thinking like I have for almost a year now.
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.
That's 3 of us :)
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 :-[
Which is why my focus is on RL-10. Far better engine for our application.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.
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.
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.
Downix,Now you're thinking like I have for almost a year now.
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.
That's 3 of us :)
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.
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.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.
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.
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.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.
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.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.
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.
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.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.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.
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.
It happens. And hey, former competitor! (I worked for Dell)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 ....
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.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.
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.
...
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.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.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.
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.
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.
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.
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.
*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.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.
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.*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.
....
*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.
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.
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.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?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.
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.But we're not going to LEO, are we? We're going BEO, and that's where the F9H stops looking so good.
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.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.
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! :-)
Downix, Clogton,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.
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. :-)
The F9 and FH could be topped with the AV US as a high energy 3rd stage/EDS.Not really the thread for that, but both of you are quite right.
Jim pooh-pooh this idea by the way. Paraphrasing "SpaceX will not use the upper stage of another contractor."
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.
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.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.
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.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.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.
Downix,Now you're thinking like I have for almost a year now.
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.
That's 3 of us :)
I've seen the light...
Downix,Now you're thinking like I have for almost a year now.
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.
I'd even push like crazy for an ACES derived lunar lander.
Same here ACES is too good a concept to not do.
I'd even push like crazy for an ACES derived lunar lander.
Downix,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.
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.
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.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?Almost assuredly it will not meet the budget needs.
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.
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.
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.
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.
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.
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?
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?
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.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 $288 million per year for six years? Is this the cost to design the core; to create and install and/or refurbish the tooling; to produce one or more units; to conduct ground tests; flight tests? Etc.
How did USA propose to procure additional Shuttle ET units for CSTS?
Estimate to produce 7 units using http://cost.jsc.nasa.gov/AMCM.htmlVery gross use, but not a bad idea. I'll subtract the SSME's from the core weight (which you are off of):
(This is likely a gross misuse of the AMCM tool.)
qty: 7
weight: 85600 lb (includes 4x SSME)
mission type: launch vehicle
ioc: 2016
block: 4
difficulty: avg
2004$ 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.
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?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.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.
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.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?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.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.
Sounds rather low indeed. Was NLS assuming none of the SWLT development costs, ie using a LWT-derived structure only?
-Alex
I'm not sure of the actual sources where the above SLWT numbers are coming from, so maybe this helps?Very handy.
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
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'm not sure of the actual sources where the above SLWT numbers are coming from, so maybe this helps?Very handy.
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
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.
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.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.Could you provide an approximate breakdown of launch costs in percentage?
Sure:Cheaper.Could you provide an approximate breakdown of launch costs in percentage?
At which 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.
Which costs would be more affected by flight rate?
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.
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.
AJAX is *THE* answer to this whole mess.
AJAX is the *PERFECT* answer to this whole mess.
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.
any difficulties in getting the stock LRBs to support the weight of the ET+payload[?]
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.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.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...
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.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.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...
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?
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.
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.Solids have their limits, and we're hitting them. Ares I is a prime example of management overruling engineering.
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.Oh hey, love this site.
http://k26.com/buran/html/why_mars_.html Notice on the top left.
AJAX is *THE* answer to this whole mess.
AJAX is the *PERFECT* answer to this whole mess.
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.
why are we shooting for 75 tons vs say 100 tons as a starting point?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.
Sure Ajax can do it and maybe better thaN you think. With congress etc. involved wouldn't a 100 ton be a better choice?
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.
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.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.
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*
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)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?
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.
Any and every way we can.
The SpaceX website saysIn 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.
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.
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.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?
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).
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 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.
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.
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.
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...
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.
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. :-)
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.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.
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. :-)
Sorry to disagree with you but ULA will become an 80lb weakling this year. Austerity trumps them all in FY012
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.
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.
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: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?
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.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.
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. :-)
Sorry to disagree with you but ULA will become an 80lb weakling this year. Austerity trumps them all in FY012
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.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.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.
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. :-)
Sorry to disagree with you but ULA will become an 80lb weakling this year. Austerity trumps them all in FY012
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.
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
Atlas V has a much better upper stage. Falcon 9 has more T/W margin and a slightly better upper stage.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.
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
It is saying a lot, however, when while using cost figures from SpaceX that they remain the more expensive option, yes?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?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?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.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?
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 was referring to just the booster cost itself, the F9 Block III first stage is 10% more expensive than the Atlas V's CCB.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?
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.
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.
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?
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.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?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.
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.
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.
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.
I realise that you might not be able to answer all these in detail due to confidential information.Answered what I could.
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.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 was referring to just the booster cost itself, the F9 Block III first stage is 10% more expensive than the Atlas V's CCB.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?
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.
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?
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 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
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.
It's not a linear growth, the overhead needs for a single engine is different than for 6, so I understand.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 :(
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.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?
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.
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...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.QuoteSimple, 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?
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?
Or single RD-172, PWR has stated they could produce that also. Or a single AR-1000 as yet another option.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).
No, for it does not use them.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?
QuoteDo 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.
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.
AJAX/P2-260? Does this mean 2 RS-25 engine on core with 6 Phase II boosters?
Interesting. Then something does not add up with other, published costs.QuoteDo 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 71.6.2. 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.
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.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?
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.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.
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.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.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.
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.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.
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.
As I understand it NROL won't launch anything with a Russian built engine.
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 Soyuz-2-1v uses the NK-33A. I believe that is what is being referenced.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-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).The Soyuz-2-1v uses the NK-33A. I believe that is what is being referenced.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.
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.
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.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).The Soyuz-2-1v uses the NK-33A. I believe that is what is being referenced.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.
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.
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.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.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. ???
Whoever enforces ITAR could say that they are actually denying the capability by making further fabrication uneconomical :-\That would be an interesting argument to make.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. ???
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. ???
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 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.
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.
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 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.
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.
The main reason for using the Ares LAS as/is is three fold: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 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.
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.
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: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 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.
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.
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.
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.
Ah, got it. And yes, it's quite low-fidelity.The main reason for using the Ares LAS as/is is three fold: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 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.
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.
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.
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.
Any thoughts on using MLAS?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.
http://www.nasaspaceflight.com/2007/12/mlas-the-alternative-orion-launch-abort-system-gains-momentum/
I understand... they did flight test it. I'm sure you just don't recall it with all you are taking on.Any thoughts on using MLAS?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.
http://www.nasaspaceflight.com/2007/12/mlas-the-alternative-orion-launch-abort-system-gains-momentum/
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.I understand... they did flight test it. I'm sure you just don't recall it with all you are taking on.Any thoughts on using MLAS?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.
http://www.nasaspaceflight.com/2007/12/mlas-the-alternative-orion-launch-abort-system-gains-momentum/
Have a look at the video
Regards
Robert
http://www.nasa.gov/centers/wallops/missions/mlas.html
If it ain't broke then don't fix it! :)Precisely.
Are you familiar with the Uragan? I think you know where I am going with this....I'll assume you mean the "Energia II" or "Vulkan" or "Herkules", the 8-Zenit version of the Energia.
Regards
Robert
Very good, perhaps a glimpse of the future?;)Are you familiar with the Uragan? I think you know where I am going with this....I'll assume you mean the "Energia II" or "Vulkan" or "Herkules", the 8-Zenit version of the Energia.
Regards
Robert
Are you familiar with the Uragan? I think you know where I am going with this....I'll assume you mean the "Energia II" or "Vulkan" or "Herkules", the 8-Zenit version of the Energia.
Regards
Robert
Energia II for now... since you asked...:)Are you familiar with the Uragan? I think you know where I am going with this....I'll assume you mean the "Energia II" or "Vulkan" or "Herkules", the 8-Zenit version of the Energia.
Regards
Robert
No, 4-Zenit, but with flyback core and boosters.
I understand... they did flight test it. I'm sure you just don't recall it with all you are taking on.Any thoughts on using MLAS?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.
http://www.nasaspaceflight.com/2007/12/mlas-the-alternative-orion-launch-abort-system-gains-momentum/
Have a look at the video
Regards
Robert
http://www.nasa.gov/centers/wallops/missions/mlas.html
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.
Hmm... perhaps.
I was pondering doing a space blog, but it would be weird to discuss my own ideas.
Hmm... perhaps.
I was pondering doing a space blog, but it would be weird to discuss my own ideas.
You want to bet? I've had that for almost a year now.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?
Hmm... perhaps.Might I suggest you get in touch with Miles O'Brian. He knows the media, is an expert spokesperson and has contacts.
I was pondering doing a space blog, but it would be weird to discuss my own ideas.
I assume you mean the Journalist.Hmm... perhaps.Might I suggest you get in touch with Miles O'Brian. He knows the media, is an expert spokesperson and has contacts.
I was pondering doing a space blog, but it would be weird to discuss my own ideas.
Rergards
Robert
Yup, that's the guy...I assume you mean the Journalist.Hmm... perhaps.Might I suggest you get in touch with Miles O'Brian. He knows the media, is an expert spokesperson and has contacts.
I was pondering doing a space blog, but it would be weird to discuss my own ideas.
Rergards
Robert
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.
I love the AJAX picture! Keep up the great work! ;)Would look better with a real AJAX on it...
Cheers!
Edied.
THAT PICTURE IS SHOPPED I CAN TELL FROM SOME OF THE PIXELS AND FROM HAVING SEEN QUITE A FEW SHOPS IN MY LIFE
You want to bet? I've had that for almost a year now.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?
THAT PICTURE IS SHOPPED I CAN TELL FROM SOME OF THE PIXELS AND FROM HAVING SEEN QUITE A FEW SHOPS IN MY LIFE
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.
...
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!
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.I'd sooner have J-2X over SRB's.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.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.
...
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.
- Ed Kyle
such a waste, give me a good F-1 heheh
What we don't need: SRBS, ...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 actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
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.What we don't need: SRBS, ...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 actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
I think I'll be glad on leaving Utah in the next year or so... I think it's degrading my brain :)
Randy
::::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.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.What we don't need: SRBS, ...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 actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
I think I'll be glad on leaving Utah in the next year or so... I think it's degrading my brain :)
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.::::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.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.What we don't need: SRBS, ...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 actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
I think I'll be glad on leaving Utah in the next year or so... I think it's degrading my brain :)
Randy
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
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.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.
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
::::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.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.What we don't need: SRBS, ...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 actually would like to point out that I am fed up with SRBS at this point and I will tell you why:
I think I'll be glad on leaving Utah in the next year or so... I think it's degrading my brain :)
Randy
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
and most NASA will be forced to use them on whatever design they adopt.
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....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.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.
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
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.
The crux of the issue, need to get this to the right ears.
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
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.
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.
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.
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.
Ok. (if you only knew how many times I referenced your Shuttle Saturn model to folk)Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.
mkrobel is me of course!
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.
Ok. (if you only knew how many times I referenced your Shuttle Saturn model to folk)Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.
mkrobel is me of course!
I deleted your redundant account there Final.
I fixed your email address in it.Ok. (if you only knew how many times I referenced your Shuttle Saturn model to folk)Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.
mkrobel is me of course!
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
Not sure if you saw this or not ...but we might have another way to get and Ajax type built, maybe even cheaper.Those aren't RD-171's in there. Those are AJ-26's!!
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.
Ok, have Lobo, Baldusi and Final unblocked, do not know who mkrobel and seeyounavigator is however.Hi Downix,
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)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.
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.
Downix,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.
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.
If you look at the RAC studies, you'll find several block evolutions that looks pretty darn similar.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?
Downix,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.
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.
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.
Actually yes, the ascent engine for the Apollo LM was ablative, not just the nozzle but the combustion chamber as well.Downix,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.
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.
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?
Has any ablative nozzle been man rated yet? Would think at this time it might be viewed as adding risk?
http://spacenews.com/launch/110603-aerojet-teledyne-brown-form-propulsion-alliance.html*breaths a bit of a sigh* Ok, now I can put that doc on ajaxlauncher.com. I'll put it up in a bit.
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.”
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.”
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.
???
Hey,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.
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?
Hey,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.
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?
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.
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.Hey,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.
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?
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.
Depends on the nature of the configuration. There are avenues which limit this as an issue.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?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.
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.
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.
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.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.
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?
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...:)
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.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.
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.
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.
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?
One other question.Just the core. Simplifies the control system.
With AJAX, are all of the booster gimbaled? Or just the RS25's on the core?
One other question.Just the core. Simplifies the control system.
With AJAX, are all of the booster gimbaled? Or just the RS25's on the core?
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.One other question.Just the core. Simplifies the control system.
With AJAX, are all of the booster gimbaled? Or just the RS25's on the core?
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)
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.
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.
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.
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.
As a first stage engine, the RS-25's high isp is better optimised for BEO payloads though.
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.
Here's a question for both Downix and Chuck,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.
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?
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.
Downix,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.
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?
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.
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.
Downix,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.
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.
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Downix,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.
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.
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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.
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.Downix,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.
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.
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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?
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?
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.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).
Downix,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.
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?
Downix,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.
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?
From what I understand, it shares a majority of pieces with the Zenit, which has already been used as a booster.Downix,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.
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?
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.
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.From what I understand, it shares a majority of pieces with the Zenit, which has already been used as a booster.Downix,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.
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?
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.
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. ;-)
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.
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.
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.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.
Any benefits to reusing the boosters?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.
Also, what about reusing the core like was planned with the fully reusable Energia?
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).
Any benefits to reusing the boosters?
Also, what about reusing the core like was planned with the fully reusable Energia?
Yes I did, and was pleasantly surprised by it.QuoteCooke’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
Downix,Long term storage paired with instant use options. No need to fuel it first.
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?
Are there any technological advantages to SRB's over LRB's?
Long term storage paired with instant use options.
4-seg SRB has an extensive proven flight history of 220 back-to-back human-rated units since the fixes following the last failure.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.
5-seg does not have this.
Ross.
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 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).
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).
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.
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 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.
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.
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.
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.
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.
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.
Are there any technological advantages to SRB's over LRB's?
Long term storage paired with instant use options.
Extremely reliable ignition.
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.
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 ?
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.
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.
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.
Politically though it's a great idea satisfying everyone so expect it in a few years as the SLS Mark II ;).
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.
May be not segmented solids. But what about some refurbished ICBM? There must be a lot of Pacekeeper first stages available.
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.
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.
Watching the Committee today gave me hope, the discussions of liquid boosters especially.
Watching the Committee today gave me hope, the discussions of liquid boosters especially.
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.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.
Watching the Committee today gave me hope, the discussions of liquid boosters especially.
AJAX used the RD-180 for test flights
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.
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.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!
Watching the Committee today gave me hope, the discussions of liquid boosters especially.
Why, what was discussed?
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.
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.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 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.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.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?
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 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 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.
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.We already have that from Aerojet with their AJ-500, which is based on the AJ-26.
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
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. ;-)
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).
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).
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.
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.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).
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.
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.
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.
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.
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)
The stars are aligning.
http://www.nasaspaceflight.com/2011/07/nasa-ula-saa-complete-human-rating-atlas-v/
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.
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.
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.
It's the name for a US built form of the AJ-26.
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 :)
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.
So I understand it, no. They place large orders, then run from the warehouse for a period.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?
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.QuoteIt 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?
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
Yes -- 48%-108% for the AJ-26 as it is.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?
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.Yes -- 48%-108% for the AJ-26 as it is.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 -- Some samples have been reused far more than just 10.
Yes -- There is a restart/airstart system for them
No clue, but I would assume vacuum. Most companies focus on that numbers.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.Yes -- 48%-108% for the AJ-26 as it is.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 -- Some samples have been reused far more than just 10.
Yes -- There is a restart/airstart system for them
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.
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
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.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?
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.
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.
Also from the FBO posting (attached Q&As):Yes, they want existing engines which run on RP-1 and meet the performance profile.QuoteQuestion:
“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.
andQuoteQuestion:
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.
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.
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.
So with a 21 year wait to get SLS up and running, how many decades would it take for AJAX??Assuming all is go by Jan 1st, could be flying by end of 2015.
Got to believe it would be a LITTLE quicker...
(still can't believe what I've read over there...)
Later! OL JR :)
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?
I have the current working paper up for peer review under L2:
http://forum.nasaspaceflight.com/index.php?topic=25432.0
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 have a rough page on that made, but am working to clean it up, with diagrams to display how it works.
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!
No offense to Chris or Nasaspaceflight.com, but why on L2, shouldn't this be as freely accessible as possible?
Right now working on the appendices, the data charts and such. Need to still locate an artist for some pretty rendering... 8)
Do you have plans to write an AJAX article on Wikipedia?In theory I could I suppose. Would it be considered above trivial?
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.Do you have plans to write an AJAX article on Wikipedia?In theory I could I suppose. Would it be considered above trivial?
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.Yes -- 48%-108% for the AJ-26 as it is.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 -- Some samples have been reused far more than just 10.
Yes -- There is a restart/airstart system for them
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!
Nate,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.
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
Twin side by side tanks feeding single engine?Nate,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.
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
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.
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.
No, I am saying it would not inject significantly more than what the 3-engine core could.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.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.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?
Interesting, I always thought of AJAX without any Upper Stage as only delivering it's payload to LEO.
Incidentally, shouldn't the SLS Act have specified "a 70tn to LEO capability evolvable to 65tn to TLI/GSO or so?".
Downix,Some, right now waiting for the right documents. *twiddling thumbs*
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...
Downix,Some, right now waiting for the right documents. *twiddling thumbs*
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...
Checking my mailbox daily...Downix,Some, right now waiting for the right documents. *twiddling thumbs*
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...
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?
I'll be adding those numbers to the first page.No, I am saying it would not inject significantly more than what the 3-engine core could.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?
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…
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.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
Now this is interesting.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.
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.
Now this is interesting.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.
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.
That works.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.
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.
Hey Nate,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)
Do you have any updates that you could share with us at this time. :)
Robert
Thanks Nate,Hey Nate,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)
Do you have any updates that you could share with us at this time. :)
Robert
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.
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.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?
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.
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.
FYI everyone, I'll be in Florida next week, if anyone wants to meet up for coffee.
When will the paper be out?So did the Ajax Paper ever make it into the public realm?
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.
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.
RD-162 | RD-191 | Dif | |
SL Thrust (kN) | 2000 | 1920.8 | 4.12% |
Dry Weight | 2100 | 2200 | -4.55% |
T/W | 97 | 89 | 9.08% |
Chamber Pressure (kg/cm²) | 175 | 262.6 | -33% |
Chamber Pressure (psi) | 2,489 | 3,735 | |
SL isp (s) | 321 | 311 | 3.22% |
Vac isp (s) | 356 | 338 | 5.33% |
Downix,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.
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?
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.
Downix,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.
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?
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).
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.Downix,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.
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?
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.
It depends on your target. For deep space missions, more core power will have an edge for a particular form of missions.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?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
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.
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?
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.
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.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.
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.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.
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.That is the idea.
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.long out of production, it would take more time to set up than to finish the RS-25E program begun in 2002.
Guess it might make for a much "too Russian" LV though...
Downix,Similar, but not identical. Lighter core gives AJAX a higher curve, more eccentric parking orbit.
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've not heard that. I've only heard of an enlarged DCUS, which is not a bad idea either.
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?That could be an issue, yes.
I've not heard that. I've only heard of an enlarged DCUS, which is not a bad idea either.
It sounded like the enlarged DCUS to me, barrel stretch to the existing DCUS systems.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.
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
....
It sounded like the enlarged DCUS to me, barrel stretch to the existing DCUS systems.
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?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.
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.
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?
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?