NASASpaceFlight.com Forum

SLS / Orion / Beyond-LEO HSF - Constellation => Heavy Lift Launch Vehicle (HLV/SLS) => Topic started by: kraisee on 10/26/2006 04:43 PM

Title: "DIRECT" Goes Live
Post by: kraisee on 10/26/2006 04:43 PM
For Your Information:

Cape Canaveral, Florida
25th October 2006

A grass-roots effort, supported by many engineers and mid-level managers within the National Aeronautics and Space Administration (NASA), is announcing its proposal today, targeted to influence NASA to review again its plans for the new “Ares” family of launch vehicles.  If adopted, the new approach promises to save the agency $35 Billion over the next 20 years.

Called the “Direct Shuttle Derivative”, or “DIRECT”, the proposal calls for NASA to replace the separate “Ares-I” Crew Launch Vehicle (CLV) and the massive “Ares-V” Cargo Launch Vehicle (CaLV) currently being designed to replace the Space Shuttle, with a single “Universal Launcher” system capable of performing both roles.

This would immediately cut in half the expected $40 Billion development cost of the two planned launchers, and would also halve the recurring fixed costs of operating two divergent launcher systems concurrently.

The proposal, available on www.directlauncher.com, approaches the problem of Lunar and Mars missions from an integrated perspective, dealing with the most important issues facing NASA today, such as multi-billion-dollar development costs, extensive infrastructure replacement, low vehicle performance, lower safety performance than planned, and long-term program risks.

Coming hot on the heels of recent Congressional Budget Office and Government Accounting Office criticisms that NASA must reassess its spending plans for the new “Vision for Space Exploration”, and in the wake of much argument from inside NASA’s own Science Community regarding recent mission and budget cuts made to fund the development of the new launchers and the Orion CEV spacecraft, this proposal seems to offer a particularly viable alternative path for NASA to consider.

The DIRECT approach calls for a single launch vehicle, based on the very reliable and already man-rated 4-segment Solid Rocket Boosters (SRB) used on the Space Shuttle today, a Core Stage based very closely on the existing External Tank, but with two RS-68R engines, based on the engines used by the Delta-IV, mounted underneath.   This configuration initially offers more than 70 tons of lift capability to orbit, compared to just 22 tons for the Ares-I.   Add an Upper Stage, similar to the one Ares-V requires and this performance climbs to over 98 tons on every flight.   Two flights of DIRECT exceed the combined payload performance of the Ares-I and Ares-V together, which are both required under current plans for each Lunar mission.

By reusing existing launcher elements, support infrastructure and current manufacturing facilities to the maximum possible degree, DIRECT requires only a fraction of the expensive changes required by the two Ares vehicles.   This not only saves Billions, but would also reduce schedules considerably.

The idea itself is far from new, in fact it was originally proposed by NASA’s Marshall Space Flight Center in 1986, in the aftermath of the 1986 Challenger accident.   However, DIRECT has evolved the concept into a modern integrated approach, which fits with NASA’s mandate, workforce retention requirements , and performance needs, and neatly integrates into the current support structure which exists for Shuttle today.

The concept promises to allow NASA to spend an extra $35 Billion of its budget on making use of its new spacecraft, instead of using that money just building and operating the launch vehicles.

For more information, please visit: www.directlauncher.com

Ross B Tierney
[email protected]
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/26/2006 06:00 PM
Ross, very very similar approach was considered in ESAS. Do you really think that NASA will listen to amateurs doing just another powerpoint study? I can't believe that you can be so naive. The only result will be more people believing in funny conspiracy theories not supporting space exploration.
The clever man carefully considers all alternatives and makes a decisions. Once the decision is made its time to go and perform the plan. Changing the plan all the time takes you nowhere.
The only possibility how to get to the Moon sooner is to give NASA more money or kill STS sooner.
Title: RE: "DIRECT" Goes Live
Post by: on 10/26/2006 06:26 PM
I wonder what, if anything, will come of this.  There's nothing in here that NASA hasn't already considered.  And, since NASA came to a different conclusion, one must assume that either:
1) There are considerations not included in your proposal that resulted in the current  Ares concept, or
2) NASA is just doing whatever it wants regardless of the facts, or
3) Your information and/or conclusions are incorrect or incomplete.

In any of these cases, your presentation will have no effect on the decision to go ahead with Ares.

Will some member of congress read it and demand that NASA take a few more months to explain once again why Ares is the best approach?  Maybe, but not likely.

Will some member of congress enter it into the Congressional Record as proof of NASA's incompetence and fiscal irresponsibility, as he casts his vote against next year's NASA appropriation bill?  I wouldn't be surprised.


Is it a fun exercise in "What would I do if I was Mike Griffin?"  Surely.




Title: RE: "DIRECT" Goes Live
Post by: kraisee on 10/26/2006 07:15 PM
There are fundamentally TWO key differences from the ESAS LV 24/25 vehicle to this alternative:-


1) Switch from 3 x $90m Space Shuttle Main Engines to 2 x $25m RS-68 Regenerative Nozzle engines.

This: Decreases cost considerably, decreases schedule, improves safety, increases performance.


2) ESAS *NEVER* studied the LV-24/25 configuration with an EDS performing the last part of the ascent.   Only LV27 was studied with such an Upper Stage/EDS, making LV 27.3.

This: Improves performance massively and brings the 2-launch IMLEO up to well above the Stick/CaLV alternatives.   This option was NOT considered by ESAS.


With the Ares-I underperforming, and the budget shortfalls being prediced by Griffin, GAO and also CBO, I simply think a change like this makes a lot more sence than continuing down the path being followed right now.

And there is no reason other than PR, not to consider changing.   The vast majority of the work done so far easily benefits this concept too.

I'm under no illusion that NASA will magically decide to follow this as a "god-send".   But I do not believe the current plan will work any longer.   I believe the funding for Ares-V will be cut before it ever flies, and the total performance of Ares-I will cause endless complications, cost overruns and schedule slips for NASA over the next twenty years.

Further, from Griffin's own mouth, it seems that even if Ares-V is built and flies, NASA won't have any spare funding to do much of anything with it.

Changing direction after Ares-I is built will be too late, and the US risks being stuck in Low Earth Orbit for 30 more years while China and India slowly develop their 15-20 year programs and just sweep straight past.

I'm speaking out for what I believe in.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: on 10/26/2006 07:26 PM
Quote
kraisee - 26/10/2006  1:58 PM

I'm speaking out for what I believe in.

Ross.

Nothing wrong with that.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/26/2006 07:30 PM
Anything that get rid of the stick is good
Title: Re: "DIRECT" Goes Live
Post by: meiza on 10/26/2006 08:12 PM
Quote
JIS - 26/10/2006  6:43 PM
The clever man carefully considers all alternatives and makes a decisions. Once the decision is made its time to go and perform the plan. Changing the plan all the time takes you nowhere.
The only possibility how to get to the Moon sooner is to give NASA more money or kill STS sooner.

Now, changing the plan all the time surely, yes, takes you nowhere. But sometimes there really is a better way and it is so much better that even though you waste some time and effort by going back, you still gain so much that you come to the objectives better via that better way. It is a reasonable question.

The idea of Direct is that it is quite close to current shuttle hardware and could be brought online quickly and with little money. It also enables to make lunar flights with very much one type of launcher instead of two. That should reduce costs. It also has performance margin.

For a slightly humorous note, I can get some quote here...

"We all want progress, but if you're on the wrong road, progress means doing an about-turn and walking back to the right road;
in that case, the man who turns back soonest is the most progressive." -C. S. Lewis


I'm not in love with the Direct completely, since it is somewhat big for crewed flights and in a class that makes alternatives impossible, there's just no commercial uses for 70 ton rockets. Its flight rates won't be very high either because of that.
Maybe if NASA put enough money to COTS as lighter manned spaceflight / ISS service backup, I'd be closer to happier.

Perhaps the price of RS-68 engines will go down though, making Delta IV cheaper?
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 10/26/2006 08:27 PM
Quote
JIS - 26/10/2006  10:43 AM

Ross, very very similar approach was considered in ESAS. Do you really think that NASA will listen to amateurs doing just another powerpoint study? I can't believe that you can be so naive. The only result will be more people believing in funny conspiracy theories not supporting space exploration.

The ESAS’s team’s primary requirement was to justify an SRB based CLV.  Known lovingly as the stick or Scotty Rocket.  This is rule number one governing all past and current decisions making at NASA for the present.  ESAS is just the cover story for the original Planetary Society paper that kicked off this whole approach.

The stick itself was born of the conflicting love astronauts feel towards flying and their families.  The stick was seen by many astronauts as a way to reconcile this conflict.  Designing and producing a machine to add 7x the explosive power of dynamite to you and then remove that energy safely in order to return you back to earth will never be safe, simple or soon.  Going to the moon and Mars is yet another order of magnitude more dangerous.  

Quote
JIS - 26/10/2006  10:43 AM
The clever man carefully considers all alternatives and makes a decisions. Once the decision is made its time to go and perform the plan. Changing the plan all the time takes you nowhere.

Actually going no where would be an improvement over the current plan.   At present we are going backwards.  Less than 1% of the total long range budget of VSE has been spent to this point.  I think we can afford a few new ideas before we burn up the other 99% going down a rat hole.  Considering how gerrymandered ESAS was we really haven’t had an unbiased study on how we are going to spend over a ¼ Trillion dollars over the next 30 years.  Ross’s plan is one of the most detailed, cohesive and consolidated near term plans I have seen.

Quote
JIS - 26/10/2006  10:43 AM
The only possibility how to get to the Moon sooner is to give NASA more money or kill STS sooner.

“Kill STS” is what got the ELV crowd kicked out.  More money is what everyone wants.  We have to work with what we have more efficiently.

Ross has compiled a very comprehensive and cohesive plan that works within the limitations of the budget, infrastructure, time frame, and politics.  All these same issues are violated under the current plan and are solved by this one.

The bigger question is this, is there anyone at NASA willing to risk their career by promoting this better approach?

Who wants to be the John Hoboult of this generation’s effort to return to the moon?

If it was easy everyone would be doing it.

Title: Re: "DIRECT" Goes Live
Post by: psloss on 10/26/2006 08:49 PM
Very well done, Ross.  Thanks for sharing it here.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/26/2006 09:12 PM
Quote
meiza - 26/10/2006  3:55 PM

I'm not in love with the Direct completely, since it is somewhat big for crewed flights and in a class that makes alternatives impossible, there's just no commercial uses for 70 ton rockets. Its flight rates won't be very high either because of that.

I agree with you Meiza, this isn't primarily designed for sat. launches (although it is capable of lifting 5 replacement TRDS satellites to GEO in one shot), no.   DIRECT's primary purpose is to enable the manned program of exploration of our solar system.

The extra Crew launcher's performance could be utilized:   Bringing crew and cargo up on a single flight is not inherently dangerous - only doing it the way STS did in a delicate winged plane, flying on the side of a debris-making launcher is.

DIRECT can bring up two or even three full Shuttle-loads on each flight, along with a Crew - and that could be put to very good use by, for example, fixing Hubble in the future, or replacing big bits of the ISS when they fail in the future.    Ares-I does not offer that ability.   Always, it will require another module to be launched separately.

Oh, with $35Bn in savings, don't you think NASA could afford to man-rate an EELV for CEV-only flights to LEO as well?

Ross.
Title: Re: "DIRECT" Goes Live
Post by: ryan mccabe on 10/26/2006 09:31 PM
Quote
JIS - 26/10/2006  12:43 PM

The clever man carefully considers all alternatives and makes a decisions. Once the decision is made its time to go and perform the plan. Changing the plan all the time takes you nowhere.
The only possibility how to get to the Moon sooner is to give NASA more money or kill STS sooner.

JIS, that is ignorant.

The selection of the Ares vehicles was made using assumptions that are no longer valid, and it is foolish to reject alternatives simply because NASA has published CG drawings of the Stick. There is very little to "lose" by dropping Ares and adopting the DIRECT vehicle. We will use these launch vehicles for perhaps 20-30 years: we need to get them right.

The Ares I is the single greatest factor in why we will have a gap in manned capability. A more cost efficient launch vehicle (like DIRECT) and a vehicle with a shorter development phrase (like DIRECT) will get us LEO, the Moon, and beyond faster than Ares I.
Title: Re: "DIRECT" Goes Live
Post by: rumble on 10/26/2006 09:57 PM
Quote
meiza - 26/10/2006  3:55 PM

I'm not in love with the Direct completely, since it is somewhat big for crewed flights and in a class that makes alternatives impossible, there's just no commercial uses for 70 ton rockets. Its flight rates won't be very high either because of that.
Yes, it's overkill, but it's actually more economical than flying the right-sized (actually under-sized) Ares I, and certainly more economical than flying the combo of Ares I & V.  

There's a lot more to taking a ride into space than just the gas can & engines, and DIRECT takes advantage of money already spent in those areas (infrastructure & staffing) in addition to taking advantage of components and manufacturing that already exists.

I would have rather seen a rocket like the Saturn V again, but based on the constraints we have to work with, DIRECT is a slam-dunk.


Overkill...it would open up possibilities we haven't considered yet.  We don't launch 70mt at a time because we haven't had a vehicle that could get us there.  We have a good financial excuse for building an overkill vehicle:  It's dramatically cheaper without compromising anything else.
Title: Re: "DIRECT" Goes Live
Post by: Manel on 10/26/2006 10:36 PM

  Overkill to ISS ?

  Only loading less LH2 and O2 on the  ET  you can adjust the mass delivered to the ISS

  But,  where is the problem with delivering more tons to LEO at the same or lower price per launch ?
Title: Re: "DIRECT" Goes Live
Post by: AndyMc on 10/26/2006 11:14 PM
Quote
kraisee - 26/10/2006  3:55 PM

Oh, with $35Bn in savings, don't you think NASA could afford to man-rate an EELV for CEV-only flights to LEO as well?

Ross.


Exactly, and going a long way to achieving 'assured manned access to space' and much faster better and cheaper (to coin a phrase) than the ESAS.

In my opinion 'Direct' is an excellent proposal that addresses all current needs, with the possibility of future powerful upgrades, without throwing away everything that was built and paid for already, (like was done in the the transition from Apollo to Shuttle).  If NASA really values the tax payers money it receives then it will look seriously at the potential of this plan, while remembering the lessons of the past.

Title: RE: "DIRECT" Goes Live
Post by: gpaul on 10/27/2006 12:37 AM
Looks very interesting but brings to mind the risks involved with side by side propulsion systems. I presumed that the A1 was designed for the crew specifically to avoid placing solids next to the fuel tank. Understanding the in this case the crew cabin is above the explosion if an accident occured, it seems unlikely that we would be able to separate such a large vehicle fast enough to escape.

Gary
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 10/27/2006 02:25 AM
Gary,
   The key factor, for either design, comes from the reaction speed of the LAS.   It must attempt to escape the blast wave following-on behind.   That's pretty-much going to be the same environment for either vehicle in such a contingency scenario.   But on either vehicle, there is a lot of distance between the motors (the most likely point of critical failure) and the spacecraft.

   One thought I have had - with 48.9mT of spare lift capability in the SLA under the CEV, I wonder if flights going without cargo couldn't instead carry a large 48mT water tank just under the CEV itself?   That would provide one heckuva "bullet proof vest", located immediately under the CEV, in case of problems "back there".

   Another potential advantage is that the CEV is offset from the immediate trajectory of the SRB's too.   If there were an accident, the SRB may just sweep straight past a capsule...   A *Big Maybe*, but less likely to collide with the CEV than having it directly in-line ramming right up the chuff...

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/27/2006 02:30 AM
Quote
Manel - 26/10/2006  6:19 PM


  Overkill to ISS ?

  Only loading less LH2 and O2 on the  ET  you can adjust the mass delivered to the ISS

  But,  where is the problem with delivering more tons to LEO at the same or lower price per launch ?

Agreed.

Ares-I sure hasn't got the ability to lift any of the unflown parts of ISS after STS retires.   It won't be able to bring up replacement Gyro's for the ISS when they fail next time.   It can't ever be able to bring up any new camera modules to Hubble.

With Ares-I, the US will lose all of that capability for the next 30 years.


Some are even beginning to question if the performance falls much more, whether it may even be able to fly the CEV.

Not to mention, but even with Ares-I, we will be forced to wait until another $20 Billion is spent to make Ares-V before we can go to the moon, or launch anything the size of SkyLab again.

DIRECT's first vehicle can do it all - and much more besides, because there's about $2 Billion worth of spare money available to NASA every year...

Ross.
Title: Re: "DIRECT" Goes Live
Post by: aftercolumbia on 10/27/2006 02:41 AM
Quote
JIS - 26/10/2006  11:43 AM

Ross, very very similar approach was considered in ESAS. Do you really think that NASA will listen to amateurs doing just another powerpoint study? I can't believe that you can be so naive. The only result will be more people believing in funny conspiracy theories not supporting space exploration.
The clever man carefully considers all alternatives and makes a decisions. Once the decision is made its time to go and perform the plan. Changing the plan all the time takes you nowhere.
The only possibility how to get to the Moon sooner is to give NASA more money or kill STS sooner.

I would say go for it.  I am certain that efforts like this have an impact on NASA (even "big" NASA) especially remembering that it was an original "grass-roots" study that began Constellation (read Seitzen and Cowing's 2004 book "New Moon Rising" for the details.)

After Columbia Project (http://aftercolumbia.tripod.com) began in such a way on 2 February 2003 (i.e.: the question popped into my head, "what if the CAIB recommends never to fly the Shuttle again?")
Title: Re: "DIRECT" Goes Live
Post by: Jymp on 10/27/2006 03:38 AM
It will never happen, NASA will go with the Ares 1 & Ares V period, you guys with all these "Better" ideas might as well drop it and get on with having a life.
Title: Re: "DIRECT" Goes Live
Post by: ryan mccabe on 10/27/2006 03:49 AM
Quote
Jymp - 26/10/2006  10:21 PM

It will never happen, NASA will go with the Ares 1 & Ares V period, you guys with all these "Better" ideas might as well drop it and get on with having a life.

Stranger things have happened....

A member of the Doobie Brothers devised the scheme now being used by the US Navy to implement the AEGIS Ballistic Missile Defense System.

Title: RE: "DIRECT" Goes Live
Post by: kraisee on 10/27/2006 03:59 AM
Here's a novel concept which DIRECT could offer as a performance upgrade.

Our very own Chuck Longton from this forum, suggested this idea to me earlier this evening.   A quick bit of tinkering with the artwork, and I can show it to you all now...

It is basically a "cargo bay" squeezed in between the Crew Module and Service Module of the CEV.


Even the basic variant of DIRECT certainly has more than enough performance to lift such an item as this to the ISS.

It does not change the aerodynamic profile for the CLV, although there is no reason it could not be lengthened if required.

A transmission tunnel running up the spine of the new module connects the CM and SM together largely as normal.

This would immediatly offer the ability to deliver the remianing ISS elements which are no longer planned to fly, and are simply gathering dust, and any other valuable hardware which will be relegated to the scrapheap with Ares-I.


Consider this simply a 'concept' of what might be possible if the Crew Launch Vehicle has 70mT lift capacity instead of just 22mT.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: ryan mccabe on 10/27/2006 04:09 AM
Quote
kraisee - 26/10/2006  9:08 PM

   One thought I have had - with 48.9mT of spare lift capability in the SLA under the CEV, I wonder if flights going without cargo couldn't instead carry a large 48mT water tank just under the CEV itself?   That would provide one heckuva "bullet proof vest", located immediately under the CEV, in case of problems "back there".


Ross, you've created a very interesting  scenario with so much extra lift available on a standard ISS or LEO flight. Certainly with the funds liberated from Ares development, more ISS flights than the two currently alloted in the initial manifest are possible. I really believe that when you create a capability, someone will find something to do with it.

In the commercial sector, perhaps NASA could offer to place several Bigalow modules in orbit for little to no cost. That gives Bigalow somewhere to send his Atlas-launched crew vehicle, and makes the whole venture considerably more plausible. In return, NASA greatly increases the probability of private space access.

So, perhaps if you want your DIRECT vehicle to work, see if Bigalow will endorse it.

Also, I suggest a "get involved" link on your website. If nothing else, I can prepare a form letter that you can place online so people can write their congressmen, senator, etc. I would love to help!

Ryan
Title: RE: "DIRECT" Goes Live
Post by: Zachstar on 10/27/2006 04:10 AM
After the extreme spending that has been going on in our .gov I think the taxpayers deserve to ask "Isnt there a better, cheaper idea?"

Thats why I can't thank you enough for you and SimC's efforts! If anything it will perhaps help the .gov be on their toes.

With the Democrats in a good position to take back congress and the sure deadlock that will happen. They mise well be talking about the real issues.

"Why 2 different rockets to get back to the moon?" Instead of "Why ought that dude get to marry that other dude?"

"Why is America paying for things like the Ares I-1 test flight uselessly?" Instead of " We need a new law to ban this video game!!!"

I suggest we start to email this idea to congress. It's time we stop handing blank checks to bad ideas. America deserves better.
Title: Re: "DIRECT" Goes Live
Post by: Far Reach on 10/27/2006 05:24 AM
Given the latest performance figures released on L2 show the CLV can't lift 20mT to -30X100 now, even after the massive re-design of the 'stick' to help the crisis they are in, NASA can stay this course as much as they want, but they'll not have a VSE.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 10/27/2006 11:39 AM
Quote
ryan mccabe - 26/10/2006  11:52 PM

In the commercial sector, perhaps NASA could offer to place several Bigalow modules in orbit for little to no cost. That gives Bigalow somewhere to send his Atlas-launched crew vehicle, and makes the whole venture considerably more plausible. In return, NASA greatly increases the probability of private space access.

So, perhaps if you want your DIRECT vehicle to work, see if Bigalow will endorse it.

NASA can't use it for commercial sector.  Not allowed by law.
Title: Re: "DIRECT" Goes Live
Post by: Wolverine on 10/27/2006 11:46 AM
My hat is off to you guys.  You've obviously put a lot of work and passion into this project and it shows.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 10/27/2006 11:51 AM
Quote
kraisee - 26/10/2006  11:42 PM

Here's a novel concept which DIRECT could offer as a performance upgrade.

It is basically a "cargo bay" squeezed in between the Crew Module and Service Module of the CEV.

Consider this simply a 'concept' of what might be possible if the Crew Launch Vehicle has 70mT lift capacity instead of just 22mT.

Ross.

I don't think that is a viable method.  Messes up the CEV and the LV to "cargo bay" interface is iffy.  It causes most of the load to be "hung" vs axial compression.  Anyways, there won't any ISS modules left on the ground.  If you are talking CAM (or any other module), it can be redesigned/modified by the time it would be flown on a Direct Vehicle*.  It would be best to do it like the Apollo LM or ASTP docking module and have the "ISS" module behind the CEV in a "CLA" and have it extracted like the LM.  The CEV could deliver it (since it has lunar mission fuel capacity) near the ISS like the HTV, and the station arm grabs the module.  The CEV undocks from the module, the arm moves it out of the way and the CEV docks with the station.


*  You need a name of the vehicle.  Direct is the concept but.......
Title: Re: "DIRECT" Goes Live
Post by: rumble on 10/27/2006 01:17 PM
Jim, I thought about docking to extract the payload, but is there enough time after MECO and before the 1st circularization burn to turn around & pull it out?  Or should we allow the core to become orbital (60X160 or something), then put retros on it to make it suborbital again after the CEV extracts the payload?

The other idea I had is having a small kick stage just behind the payload module so it could perform the 1st post-MECO burn, buying more time before the CEV had to dock with it.

Name:  Should DIRECT be the Ares II?
Title: RE: "DIRECT" Goes Live
Post by: ryan mccabe on 10/27/2006 01:41 PM
Quote
Jim - 27/10/2006  6:22 AM

NASA can't use it for commercial sector.  Not allowed by law.

What prevents that law from being changed? I doubt the law was written with any consideration of a vehicle like the DIRECT concept where so much extra mass could be made available. The possible scenarios (limited ones, at that) where commercial payloads could be flown would be very different than any situation NASA carried commercial payloads on the Shuttle.

I don't see the point in having a Wright Amendment for space...
Title: Re: "DIRECT" Goes Live
Post by: meiza on 10/27/2006 01:48 PM
That'd be cool, have a NASA subsidized vehicle offering free rides to space. I bet the other launch providers would be overjoyed.
Title: RE: "DIRECT" Goes Live
Post by: ryan mccabe on 10/27/2006 01:50 PM
Quote
Jim - 27/10/2006  6:22 AM

NASA can't use it for commercial sector.  Not allowed by law.

What prevents that law from being changed?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/27/2006 02:24 PM
Because the law says NASA can't compete against the commercial sector.   Who would change such a law?  There is no way to spin it positively.

Why bother with Bigelow then.  NASA can build and put up the hotel space station and then fly the vistors there.

Bigelow or anyone else can find and pay for their own way.   NASA does not provide commercial launch services.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 10/27/2006 02:32 PM
Quote
ryan mccabe - 27/10/2006  9:24 AM

Quote
Jim - 27/10/2006  6:22 AM

NASA can't use it for commercial sector.  Not allowed by law.

What prevents that law from being changed? I doubt the law was written with any consideration of a vehicle like the DIRECT concept where so much extra mass could be made available. The possible scenarios (limited ones, at that) where commercial payloads could be flown would be very different than any situation NASA carried commercial payloads on the Shuttle.

I don't see the point in having a Wright Amendment for space...

It is no different than the shuttle

Title: Re: "DIRECT" Goes Live
Post by: charlieb on 10/27/2006 02:33 PM
Just sent an email with the DIRECT link to Jeff Hanley and Mark Geyer.  I wonder if I even get a reply...
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/27/2006 02:43 PM
Quote
rumble - 27/10/2006  8:00 AM

Name:  Should DIRECT be the Ares II?

Exactly. This is my opinion as well. I'm writing down my view about Ares family (Ares 1, Ares II and Ares V) and I'll publish it here next week. If I wouldn't have other obligations it would have been here already.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/27/2006 02:51 PM
I wouldn't call it Ares, to keep it away from being associated with the stick
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/27/2006 02:59 PM
Stick belongs to Ares family but it doesn't have the core.
Title: Re: \
Post by: Crispy on 10/27/2006 03:29 PM
Front Page story, Chris?
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/27/2006 04:36 PM
I'm actually proposing that this should just simply replace the Ares-I directly (okay, pun intended).

The basic DIRECT CLV should be the NEW ARES-I.

ARES-II would be with the Upper/Earth Departure Stage.

ARES-III would be the Growth Option CLV.

ARES-IV would be the Growth Option with EDS.

That's my personal preference, but I'll settle for whatever is most popular.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: aftercolumbia on 10/27/2006 05:09 PM
I don't mean to be rude or arrogant, but I think the commercial sector (especially once I get into it) could come up with a vehicle even Direct Launcher would have a very difficult time in competition with.  The thing is that Direct Launcher is a 70,000kg class booster; the biggest in the commercial market are 25,000kg class.  The private market at 70,000kg is currently nil, and in the next 20 years, probably 2, 3 if you're lucky, launches.  These launches would be space hotels or GEO commercial waystations and use smaller boosters for primary operations.  Also, if a GEO commercial waystation can be built from Ariane (or other CSG launcher) launches, that's one fewer.

I wouldn't say the law can't be changed, but I might say it doesn't need to be.  Given how NASA has traditionally absorbed and ostensibly endorsed commercial and commercializable Air Force programs like DC-X, only to spongefest and porkbarrel them into oblivion, it might not be such a good idea to get that law changed.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/27/2006 05:44 PM
After,
   I agree.   I think *ultimately* a commercial vendor could come up with something cheaper, more powerful etc.   But that in and of itself, does not solve all of NASA's problems.   NASA has other things which it must also balance:   Such as keeping its political master happy - it is after all a government agency.

   One of NASA's biggest, yet least-publicised, concerns in retiring Shuttle and moving into the VSE has been "Workforce Retention".

   Each of the major space states (TX, CA, AL, MS, FL, DC, UT etc) has many Senators, House Reps and Governors who sit on NASA's various budget appropriations committees.   If NASA were to kills 10,000 jobs in someone's state, there's no way that state's representatives will vote to increase NASA's budget the next year - they'll probably be after blood instead.

   So NASA has to balance pure cost and technical requirements against this situation aswell.   They must have a solution which guarantees the workforce remains largely intact, and one which can prove it.

   The best way to retain the current workforce is to continue utilizing most, if not all, of the current facilities and launch hardware and just replace the stuff which we have found to be problematic (read, the "Orbiter" element).

   Ares offers such a transition, albeit a very expensive one.   DIRECT also offers such a solution to all these factors, at half the cost of Ares.   The Delta, Atlas or even Falcon derived solutions do NOT address the political aspect of NASA's problem.   Sure they would cost less than Ares or even DIRECT, but that cost saving comes PURELY from reduced staffing levels.   The figures I have seen is they would result in 10,000 job losses in Florida, 80,000 job losses in Texas, 70,000 job losses in Alabama, and many, many more in the other states affected.   250,000+ new unemployed people becomes a national economy problem - which is far bigger problem to the government.

   NASA must juggle this important issue, in amongst all the others, when making far-reaching decisions like this.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: koraldon on 10/27/2006 05:49 PM
Good luck, seems like a solid proposal.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/27/2006 10:30 PM
Quote
kraisee - 26/10/2006  4:55 PM
I agree with you Meiza, this isn't primarily designed for sat. launches (although it is capable of lifting 5 replacement TRDS satellites to GEO in one shot), no.   DIRECT's primary purpose is to enable the manned program of exploration of our solar system
The agreement with DoD in the first place mandates that all government sat launches of 20 mT or less be done with EELV.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/27/2006 10:44 PM
Quote
JIS - 26/10/2006  1:43 PM
Ross, very very similar approach was considered in ESAS.
Actually, a very similar approach was NOT considered in ESAS. Direct's approach is an ET-derived core stage WITH SRB's. Page 383 of the ESAS report SPECIFICALLY states that the ET-derived core WITHOUT SRB's was considered and rejected. But the ET-derived core WITH SRB's (Direct concept) was not considered at all.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/27/2006 11:06 PM
Quote
rumble - 27/10/2006  9:00 AM
Jim, I thought about docking to extract the payload, but is there enough time after MECO and before the 1st circularization burn to turn around & pull it out?  Or should we allow the core to become orbital (60X160 or something), then put retros on it to make it suborbital again after the CEV extracts the payload?

The other idea I had is having a small kick stage just behind the payload module so it could perform the 1st post-MECO burn, buying more time before the CEV had to dock with it.
I considered both these options. In the case of #1, I don't think there's enough time to cover any anomolies. In the case of #2, why carry fuel to orbit and just use it to dump the ET? Why not just don't let the ET get into orbit? My thought with the cargo cage between the CM & SM is that MECO would be just shy of orbital velocity, allowing the ET to dump itself into the atmosphere, because at MECO, the velocity would still be suborbital. The SM engine behind the cargo cage (or even the basic Orion configuration without cargo) would provide the final kick for LEO insertion. Just like Shuttle does now with the OMS. Problem solved.
Title: RE: "DIRECT" Goes Live
Post by: clongton on 10/27/2006 11:50 PM
Quote
kraisee - 26/10/2006  11:42 PM
Consider this simply a 'concept' of what might be possible if the Crew Launch Vehicle has 70mT lift capacity instead of just 22mT.
Ross.
Ross, Shuttle has carried lots of military and DoD payloads to orbit. Do you think the DoD and/or the USAF would be interested in a "Destiny Science Module" sized orbital "object"? Perhaps this concept needs to find it's way to these agencies, showing this "possibility", manned or unmanned.
Chuck
Title: RE: "DIRECT" Goes Live
Post by: clongton on 10/27/2006 11:55 PM
Quote
Jim - 27/10/2006  7:34 AM
It causes most of the load to be "hung" vs axial compression.
How is that different from Shuttle?
Title: RE: "DIRECT" Goes Live
Post by: clongton on 10/28/2006 12:39 AM
Quote
clongton - 27/10/2006  7:38 PM

Quote
Jim - 27/10/2006  7:34 AM
It causes most of the load to be "hung" vs axial compression.
How is that different from Shuttle?
Further on this. I should have mentioned that the payload would be secured in the cargo module in exactly the same manner as Shuttle; it would be secured in axial compression at the bottom end of the canister, and stabilized axialy along the spline. Any excess length to the cargo module would be compensated for by having different length modules available for use, in 5 meter length increments, to help keep the overall distance, nose to tail, at a minimum. That improves RCS functioning by keeping the CG within specific ranges. Jim is right; to secure the payload in the axial direction only would not be a good thing. Mounting different length Orion-C's (Orion-Cargo) in the SLA would be by having matching sets of Cargo Cannisters and SLA mounting platforms, maintaining a constant overall length and solid mounting at all times.
BTW, the cargo module does not necessarily need to be an enclosed container. It could also just be a "cage" configuration, provided that it was properly strengthened. Less costly, since it will be disposed of anyway, along with the SM.
Title: RE: "DIRECT" Goes Live
Post by: clongton on 10/28/2006 01:57 AM
Quote
kraisee - 26/10/2006  11:42 PM
Consider this simply a 'concept' of what might be possible if the Crew Launch Vehicle has 70mT lift capacity instead of just 22mT.
Ross.
Pure practicality also requires that we consider the possibility of another loss of a Shuttle, with or without loss of crew.
Nobody wants to even think about it, but it COULD happen.

IF it does, the Shuttle program will be dead, right then and there, period. It will never fly again.
Unless the ISS is already finished, there will be no way to finish it, or to service Hubble, unless NASA decides soon to replace Ares I/V with Direct.

Direct could finish construction of the ISS. The development of both Direct and Orion would be speeded up by the transfer of funding from the cancelled Shuttle program to the ongoing Direct, and would be online in (relatively) short order.

Once online, Direct could do the Hubble servicing mission.
Direct could maintain the health of the station by flying the very heavy replacement parts, like the gyros, for example.
With Ares I, the station is doomed to die as soon as it starts to wear down, because there will be no other LV capable of flying them.

If NASA stays with the Ares, and the unthinkable happens again, the station will be unfinished and all but useless, and Hubble will die an unnecessary death. The American manned space program will be crippled for 25 to 30 years.

Ares I/V is simply the WRONG thing to do.
Even without another Shuttle accident, it cripples the American manned space program.

Direct prevents that.
Direct is the RIGHT thing to do, for all the right reasons, and also for reasons nobody wants to talk about or think about.
Title: Re: "DIRECT" Goes Live
Post by: MKremer on 10/28/2006 02:17 AM
OK, I can envision something like - an ISS module cargo 'cage' with a bare, passive CBM at one end, and an Orion dock at the other. That 'cage' would also need enough power by itself to supply launch-to-ISS-docking heating and health data transmission via some kind of relay to MCC.

So in summary, the integrated vehicle launches, the Orion CM/SM docks with the ISS cargo 'cage', then goes through ISS rendezvous and station-keeping for CBM docking via SSRM, Orion undocking from the 'cage' and doing its own ISS docking, then removing the ISS module (via SSRM) from the 'cage' for its own mating. At the end of the mission, Orion re-docks with the 'cage', the CBM is released, then Orion follows a re-entry procedure that releases the 'cage' for it's own re-entry disposal before it re-enters itself.

Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/28/2006 03:16 AM
Quote
MKremer - 27/10/2006  10:00 PM
OK, I can envision something like - an ISS module cargo 'cage' with a bare, passive CBM at one end, and an Orion dock at the other. That 'cage' would also need enough power by itself to supply launch-to-ISS-docking heating and health data transmission via some kind of relay to MCC.

So in summary, the integrated vehicle launches, the Orion CM/SM docks with the ISS cargo 'cage', then goes through ISS rendezvous and station-keeping for CBM docking via SSRM, Orion undocking from the 'cage' and doing its own ISS docking, then removing the ISS module (via SSRM) from the 'cage' for its own mating. At the end of the mission, Orion re-docks with the 'cage', the CBM is released, then Orion follows a re-entry procedure that releases the 'cage' for it's own re-entry disposal before it re-enters itself.
What I envision is similar, but without the separate Orion/Cargo Cage docking maneuver.

1. Power to the cage would be supplied by the SM.
2. The integrated vehicle launches, and Orion-C rendezvous with ISS to a station-keeping position, without demating; CEV in front, cargo cage behind it, SM at the end.
3. The cargo cage (CC) opens its sides, and the station captures and removes the payload with the station arm.
4. The cargo cage closes its sides and Orion proceeds to dock with the station.
5. At end of mission, the intigrated Orion-C undocks, does the de-orbit burn, jetisons the SM/cage combination and re-enters the atmosphere. SM & cage burn up.

The Orion-C configuration never reconfigures itself until the de-orbit burn. It stays in the launch configuration; CM/CC/SM. It's less complicated that way. Otherwise Orion has to uncouple itself after MECO, rotate 180 degrees, dock with the CC/SM, and then prepare for the circularization burn. It only has 1/2 orbit to do this. If ANYTHING doesnt go perfect, the entire mission is jepordized. This is unnecessary. Just leave everything configured as it is at launch, do the final orbit insertion & circularization burn, and rendezvous with ISS. Consider the Orion-C as a single spacecraft consisting of a recoverable front (CM) and disposable rear (CC/SM). Think of the CC as an extension of the SM.
Title: Re: "DIRECT" Goes Live
Post by: MKremer on 10/28/2006 04:14 AM
Quote
clongton - 27/10/2006  9:59 PM

Quote
MKremer - 27/10/2006  10:00 PM
So in summary, the integrated vehicle launches, the Orion CM/SM docks with the ISS cargo 'cage', then goes through ISS rendezvous and station-keeping for CBM docking via SSRM, Orion undocking from the 'cage' and doing its own ISS docking, then removing the ISS module (via SSRM) from the 'cage' for its own mating. At the end of the mission, Orion re-docks with the 'cage', the CBM is released, then Orion follows a re-entry procedure that releases the 'cage' for it's own re-entry disposal before it re-enters itself.
What I envision is similar, but without the separate Orion/Cargo Cage docking maneuver.
Um, regardless of whether the ISS module goes up on its own or rides with the CEV booster, you *will* need a docking maneuver between the CEV and the ISS module 'cage' once everything gets to orbit. How else would it get from the launch orbit to the ISS orbit and into SSRMS capture station-keeping?

Quote
1. Power to the cage would be supplied by the SM.
2. The integrated vehicle launches, and Orion-C rendezvous with ISS to a station-keeping position, without demating; CEV in front, cargo cage behind it, SM at the end.
3. The cargo cage (CC) opens its sides, and the station captures and removes the payload with the station arm.
4. The cargo cage closes its sides and Orion proceeds to dock with the station.
5. At end of mission, the intigrated Orion-C undocks, does the de-orbit burn, jetisons the SM/cage combination and re-enters the atmosphere. SM & cage burn up.

Sure, but -
1) Won't allow any temp or health data from pre-launch to docking (quite important) without its own power source (likely batteries) and transmitter.
2) Agreed - Orion stays docked until CBM/ISS connection is complete.
3) Don't see a need for "sides" - the cargo 'cage'/cargo carrier should be completely open once the LV outer fairing is gone. No need for any additional enclosure.
4) Again, no need for "sides" - there's just the cargo 'cage' with Orion docked to one end.
5) Agreed. Once the 'cage' is empty it serves no other useful purpose, so Orion re-docks to the 'cage', the 'cage' is released from the CBM port, then Orion moves it into a disposal orbit on the way to its own re-entry.
Title: RE: "DIRECT" Goes Live
Post by: AndyMc on 10/28/2006 09:41 AM
Quote
kraisee - 26/10/2006  10:42 PM

Here's a novel concept which DIRECT could offer as a performance upgrade.

Our very own Chuck Longton from this forum, suggested this idea to me earlier this evening.   A quick bit of tinkering with the artwork, and I can show it to you all now...

It is basically a "cargo bay" squeezed in between the Crew Module and Service Module of the CEV.


Even the basic variant of DIRECT certainly has more than enough performance to lift such an item as this to the ISS.

It does not change the aerodynamic profile for the CLV, although there is no reason it could not be lengthened if required.

A transmission tunnel running up the spine of the new module connects the CM and SM together largely as normal.

This would immediatly offer the ability to deliver the remianing ISS elements which are no longer planned to fly, and are simply gathering dust, and any other valuable hardware which will be relegated to the scrapheap with Ares-I.


Consider this simply a 'concept' of what might be possible if the Crew Launch Vehicle has 70mT lift capacity instead of just 22mT.

Ross.

From your diagram Ross, it looks to me as though an airlock module could fit behind the CM, which fitted with a hatch in the heatshield, would enable EVAs for fixing Hubble and the like without de-pressurizing the CM.
Title: RE: "DIRECT" Goes Live
Post by: RedSky on 10/28/2006 12:32 PM
Quote
AndyMc - 28/10/2006  4:24 AM
From your diagram Ross, it looks to me as though an airlock module could fit behind the CM, which fitted with a hatch in the heatshield, would enable EVAs for fixing Hubble and the like without de-pressurizing the CM.

Why would you need such a complication like a tunnel through the heatshield?  All you'd need to do is carry it up cradled behind, then perform a transposition and docking to pick it up.  Something like this was done... but wasn't used as an airlock... the ASTP docking adapter/tunnel.   A CEV version would probably look alot like this... but could be beefed up to carry MMUs the EVAers could don before egress so  they wouldn't have to be restricted by umbilicals.

Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/28/2006 02:17 PM
Quote
MKremer - 27/10/2006  11:57 PM

Quote
Um, regardless of whether the ISS module goes up on its own or rides with the CEV booster, you *will* need a docking maneuver between the CEV and the ISS module 'cage' once everything gets to orbit. How else would it get from the launch orbit to the ISS orbit and into SSRMS capture station-keeping?
No docking maneuver is required because the CC is already physically attached between the CM and the SM. It is a “cargo bay” of sorts, like in Shuttle. Together these 3 items CM (Command Module), CC (Cargo Cage) and SM (Service Module) form 1 single ship, just like Shuttle. Likewise, the Orion-C (Orion-Cargo) is one single spacecraft, consisting of 3, solidly connected modules.

Orion is a 2-module spacecraft (ignoring the abort tower), consisting of CM & SM. Think of the CC as a "cage", an extension on the fwd side of the SM, PERMANENTLY attached to the SM. For Orion-C, a 3-module spacecraft, the CM attaches to the fwd end of the CC in the same manner as it does to the SM in the 2-module version. The basic Orion delivers crew to some destination. Orion-C is optimised to deliver crew AND cargo to some destination. That cargo can be in a pressurized OR unpressurized module, mounted in the CC "cage", and secured at the CC aft end and along the axial spline/tunnel.

Together this integrated spacecraft does the circularization burn using the SM engine, arrives at ISS to a station-keeping position, where the SSRMS extracts the payload. The Orion-C spacecraft then moves to a docking port and docks, all 3 modules together, with the "cage" now empty.

Quote
Quote
1. Power to the cage would be supplied by the SM.
2. The integrated vehicle launches, and Orion-C rendezvous with ISS to a station keeping position, without de-mating; CEV in front, cargo cage behind it, SM at the end.
3. The cargo cage (CC) opens its sides, and the station captures and removes the payload with the station arm.
4. The cargo cage closes its sides and Orion proceeds to dock with the station.
5. At end of mission, the integrated Orion-C undocks, does the de-orbit burn, jettisons the SM/cage combination and re-enters the atmosphere. SM & cage burn up.

Quote
1) Won't allow any temp or health data from pre-launch to docking (quite important) without its own power source (likely batteries) and transmitter.
I think you’re assuming that the SM has no batteries, only solar cells. I’m not clear on that. If true, then you are correct. But if batteries are onboard the SM, like I think they are, then power can come from them, which would be the preferred method. It keeps the CC as simple as possible. All the required data monitoring devices can be built into the CC and connected to the power/data tunnel going the length of the CC from SM to CM. These should be standard "off-the-shelf" instrumention which can be mounted in the CC, connected to the payload, and plugged into the tunnel.

Can someone else on this thread speak to this? Does the SM have batteries onboard as part of it’s power system?

Quote
3) Don't see a need for "sides" - the cargo 'cage'/cargo carrier should be completely open once the LV outer fairing is gone. No need for any additional enclosure.
4) Again, no need for "sides" - there's just the cargo 'cage' with Orion docked to one end.
The “sides” form the physical structure and connection from the CM to the SM. My personal preference would be for some type of "cage" structure, not solid sides. Something like the cage that goes around a ladder attached to the side of an industrial building. Just enough "structure" to provide connection and strength. The “space” in between IS the CC, where the cargo/payload is secured. Together, this is a single spacecraft consisting of crew, cargo and propulsion/power modules.

Quote
5) Agreed. Once the 'cage' is empty it serves no other useful purpose, so Orion re-docks to the 'cage', the 'cage' is released from the CBM port, then Orion moves it into a disposal orbit on the way to its own re-entry.
No "re-dock" is required, because it never "docks" in the 1st place. The entire 3-module integrated spacecraft docks at the ISS, stays for the duration, undocks from ISS, does the de-orbit burn, then Orion CM sheds the SM/CC combination and re-enters the atmosphere.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 10/28/2006 02:44 PM
Quote
clongton - 27/10/2006  7:33 PM

Quote
kraisee - 26/10/2006  11:42 PM
Consider this simply a 'concept' of what might be possible if the Crew Launch Vehicle has 70mT lift capacity instead of just 22mT.
Ross.
Ross, Shuttle has carried lots of military and DoD payloads to orbit. Do you think the DoD and/or the USAF would be interested in a "Destiny Science Module" sized orbital "object"? Perhaps this concept needs to find it's way to these agencies, showing this "possibility", manned or unmanned.
Chuck

The DOD doesn't want deal with a manned spacecraft, again.    

The EELV's can carry a "Destiny Science Module" or bigger.

NASA can build the CaLV because the DOD has no need for it. (part of the agreement)

The big  DOD ones are on the west coast and the east coast are HEO missions.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 10/28/2006 02:47 PM
Quote
clongton - 27/10/2006  7:38 PM

Quote
Jim - 27/10/2006  7:34 AM
It causes most of the load to be "hung" vs axial compression.
How is that different from Shuttle?

You have the "SLA" attaching near the base of the CM and the rest of the cargo and SM (the load) are behind this attach point and "hung"

You misunderstood me.   Axial is the way to go, like all other LVs'
Other than modules, the shuttle attach design mucked up spacecraft design  and they had to use ASE which added weight
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/28/2006 03:02 PM
You are making unnecessarily complicated.
1.  You are mixing cargo and crew - a lesson learned no-no from shuttle
2.  The CEV can't abort to orbit easily with the  cargo (too heavy)
3.  The cage is a kluge.  Let the payload sit on its aft like all payloads
4.   Orion-C mucks up the CEV design, increasing its costs
5.  Do the Apollo T&D and have the CEV pull it out and take it along
Edit:  

Biggest problem
6.  The RCS on the SM is too far away from the CG of the vehicle for docking.  You would need a fwd RCS system.

Take everything to orbit just like Apollo"
1.  The CEV stays the same and it can abort to orbit easily
2.  LIDS provides crew access to the cargo
3.  The LIDS can provide the data interface to the cargo after docking
4.  The CEV and cargo doesn't have to dock with the ISS.  The SSRMS can berth the two or the cargo.

There is maybe only one ISS module on the ground, the CAM, otherwise everything else is a new build, so shuttle legacy attachment is not needed.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/28/2006 03:07 PM
"All the required data monitoring devices can be built into the CC and connected to the power/data tunnel going the length of the CC from SM to CM. These should be standard "off-the-shelf" instrumention which can be mounted in the CC, connected to the payload, and plugged into the tunnel."

No such a thing.

The CEV is going to have a data link with the LSAM thru the LIDS, use this
Title: Re: "DIRECT" Goes Live
Post by: Jon_Jones on 10/28/2006 03:23 PM
I don't think I saw anyone mention this yet, but since the DIRECT idea seems to offer a large payload, and pressumably capable of launching a larger and heavier CEV, could one make room to attach a robotic arm on said larger CEV? perhaps have it folded up and tucked into the SM somewhere like the Apollo experiments bay?
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 10/28/2006 03:31 PM
2 questions about DIRECT:
- How do you propose to achieve lunar surface cargo missions (flying one EDS and one LSAM together)
- What is the reason for having the LSAM dock base first with the EDS? Would it not be simpler to dock the CEV nose-first to the EDS?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/28/2006 03:32 PM
Quote
Jon_Jones - 28/10/2006  11:06 AM

I don't think I saw anyone mention this yet, but since the DIRECT idea seems to offer a large payload, and pressumably capable of launching a larger and heavier CEV, could one make room to attach a robotic arm on said larger CEV? perhaps have it folded up and tucked into the SM somewhere like the Apollo experiments bay?

Why?
1.  What is its use?
2.  It would not be reusable.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 10/28/2006 05:13 PM
As I just explained on another thread, my prefered approach would be to fly a "Mission Module" (MM) in the SLA, and transition the CEV to it when it reaches orbit, docking with the LIDS.

[EDIT: See the picture below]

The MM can have a (cheap and probably disposable) Remote Manipulator System (RMS) mounted to it whenever required, but for ISS missions I would just install a second RMS at the Station permanently.

For ISS delivery missions, either the CEV can dock the MM to the station and then disconnect itself and dock separately.   The RMS would grab the MM in close proximity first, CEV then disconnects and docks elsewhere, while the RMS docks the MM to the station.

This would offer a lot of capacity to deliver many science racks, gyros etc without the need for any more launch costs other than the Crew Rotation which must be done anyhow.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/28/2006 05:32 PM
Quote
Kaputnik - 28/10/2006  11:14 AM

2 questions about DIRECT:
- How do you propose to achieve lunar surface cargo missions (flying one EDS and one LSAM together)

DIRECT+EDS can launch 38mT to TLI.   While not as much as Ares-V (54mT), it is the COST factor which makes DIRECT far better value...



Ares-I CLV costs $850m per year to operate, before flights are accounted for.   Ares-V CaLV costs another $1,272m per year just to operate.

DIRECT costs $900m per year to operate both CLV and CaLVs.

This means that DIRECT can use the $1222 difference to actually fly missions.   Before any Ares flights are paid for (CLV or CaLV), DIRECT can actually launch 8 missions!   That's 304mT on the way to the moon before the first flight of an Ares-I or Ares-V is even paid for.


Quote
- What is the reason for having the LSAM dock base first with the EDS? Would it not be simpler to dock the CEV nose-first to the EDS?

There are a variety of approaches possible.   I chose that particular one, for demonstration purposes only, because the LSAM will already have ground facing cameras, radar systems and attachment points.   It can perform a docking maneuver fairly easily in that direction, and requires no additional systems (minimal mass penalty).

By replacing the pyro disconnect system with a mechanical one, the LSAM can disconnect from its launcher, and then re-connect, using the same connection hardware, to the EDS.   It's certainly one extra step, but it sure isn't brain surgery for talented astronaut pilots.


Ultimately, I'm just making *suggestions* as to some of the possible solutions.   I would hope someone can come up with an even better way to dock the CEV, LSAM and EDS together prior to the TLI burn.   I'm okay with whatever works best :)


The limits are DIRECT's standard configuration can launch 70.9mT, and with the EDS; can launch 98.2mT.

You need to account for a 20mT CEV, a 45mT LSAM and 88mT of propellant needed inside the 15mT EDS.


Discuss. :)


Ross.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/28/2006 05:54 PM
Quote
Jim - 28/10/2006  10:45 AM
You are making it unnecessarily complicated.
1. You are mixing cargo and crew - a lesson learned no-no from shuttle
Yes and no. The problem with Shuttle was that there was no choice. Shuttle was designed as a truck, and was, by nature, a cargo hauler. Orion is, by nature, a taxi, a people hauler. This configuration, Orion-C, is just a way to put extra capacity to use when appropriate. It fills the lift vacuum left by retirement of Shuttle, but would only be flown when there was a need for it, like replacing gyros on ISS, or large items on Hubble. Things like that and whatever else folks come up with that needs lifting with astronauts aboard. Experience is that when capacity exists, people will find a way to use it. But most of the time, Orion-C would not be flying; it would be hauling people only.

Incidentally, I’m not implying that cargo and satellite launches need to be manned. That’s just not so. Orion-C would only be appropriate if manned intervention and/or installation of the payload were required once at the orbital destination. That situation would usually be the exception, not the norm. Think Progress, and ESA ATV. There needs to be an automated EELV cargo canister flying as well (VSE would probably find very good use for it). Most normal cargo would go that route, unmanned.

Unmanned launchers are very good and much less expensive than manned vehicles. We need to keep the cost down at every turn when we can, and use the unmanned launch capability as much as possible. But when a manned launch with cargo is really desirable, there just is no good substitute. Orion-C fills that void.

Quote
2. The CEV can't abort to orbit easily with the cargo (too heavy)
Depends entirely on how much fuel capacity there is in the SM. If that becomes an issue, this could be addressed by a stretch version of the SM with larger tanks.
Can someone on the forum run those numbers? Could Orion-C abort to orbit with the current SM capacity, with a Destiny-size module, or ISS gyros, in toe?

Quote
3. The cage is a kluge. Let the payload sit on its aft like all payloads
5. Do the Apollo T&D and have the CEV pull it out and take it along
The cage is lightweight structure to connect the CM & SM. This lets Orion-C abort to orbit with payload. Apollo style docking and extraction results in a loss of mission if abort to orbit is required, whereas in that situation Orion-C saves the mission.

Quote
4. Orion-C mucks up the CEV design, increasing its costs
It’s just a concept, one of many perhaps, on how Orion could serve multiple needs in the VSE beyond just being a taxi.

Quote
Biggest problem
6. The RCS on the SM is too far away from the CG of the vehicle for docking. You would need a fwd RCS system.
True statement. Orion would need countering RCS jets up front as well. It’s not a bad idea to put some there anyway. Something like Shuttle does now. As long as there is this capability to sub as a cargo hauler when needed, CM RCS jets are required. So why not put them in? Its better to have something you don’t need all the time, than to be prevented from a desirable mission just because the capability wasn’t included in the design. Better to have something you don’t need, than to need something you don’t have. The capacity is there, and RCS are not that complicated, or expensive. So why not put them in? Caveat: I’d put this whole question in the category of future growth options. The last thing I’m suggestion is to change the Orion baseline at this point. Orion is fine, just change the launcher to Direct.

Quote
There is maybe only one ISS module on the ground, the CAM, otherwise everything else is a new build, so shuttle legacy attachment is not needed.
I can’t imagine that a shuttle-like capability would not be desirable sometimes in the next 30 years. For example, I don’t think ISS will go away in 2016. It’s still designated a national lab, and the station will need heavy lift servicing which doesn’t justify an Ares V class launch. I’m sure the international partners will occasionally contract for a launch to ISS of such items. But I was also thinking of providing the capability to actually complete the ISS in the event that Shuttle stands down before 2010 because of another accident.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 10/28/2006 06:00 PM
I understand the tremendous cost benefits of DIRECT and I am firmly in support of the idea. However, I am concerned about the inability of the system to deliver an LSAM (and/or LSAM derived lunar surface hardware) to the lunar surface in a single launch. With either a smaller surface cargo (and the LSAM making up some of the delta-v) or with the 5-segment growth options it becomes possible, but both of these are compromises. I see this as perhaps the only advantage of Ares V. The ability to deliver a fully functional LSAM in a single launch could allow Ares-V to perform a surface rescue mission with minimal delays or complication.
On my second point, I would have thought that the forward end of the CEV would contain all the necessary docking apparatus required- it just seems intuitively a better approach. Of course, as you have said in the proposal, lunar-orbit rendezvous could become a better mission plan with the use of DIRECT, but at the moment I think the key in selling the plan is to show its ability to neatly dovetail into the existing project Constellation.

Finally, I have taken the liberty of adding DIRECT to Wikipedia, linked from SDLV and Ares.

Good luck!
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/28/2006 06:12 PM
Quote
Jon_Jones - 28/10/2006  11:06 AM
I don't think I saw anyone mention this yet, but since the DIRECT idea seems to offer a large payload, and pressumably capable of launching a larger and heavier CEV, could one make room to attach a robotic arm on said larger CEV? perhaps have it folded up and tucked into the SM somewhere like the Apollo experiments bay?
Anything is possible in the future, if Direct becomes the launcher. But I have to go with Jim on this one. The SM is jetisoned at re-entry, and if the arm is part of it, that's a waste, a huge waste. Remember, just because capacity increases doesn't mean we can afford to throw stuff away. It would need to be part of the CEV design. But a larger CEV with that kind of capability is a thought for the far future. Remember, this isn't Shuttle, and isn't designed as a 1 to 1 replacement. For the forseeable future ... aint happening. Good thinking though. Keep it coming.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/28/2006 06:22 PM
Kaputnik,
If there *is* a real issue with that, then develop the Growth Options.

They will still cost a ***LOT*** less than developing the Ares-V from scratch (EDIT: $4Bn for SRBs, $2-3Bn for barrel stretch Core and EDS = 1/3rd cost of developing Ares-V), continue using the same manufacturing and processing infrastructure and increase performance to a higher level than Ares-V.

The "Ares-IV" DIRECT + EDS Growth Option can launch 137mT to 100x160nm.

If NASA doesn't have the money though (quite possible 10 years from now), then 38mT will still allow the Lunar and Mars program to continue.

With Ares, if NASA doesn't have the money, Ares-V is cancelled, and without that, Ares-I isn't going anywhere near the moon on its own.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/28/2006 07:09 PM
Quote
Jim - 28/10/2006  10:45 AM

2.  The CEV can't abort to orbit easily with the  cargo (too heavy)
5.  Do the Apollo T&D and have the CEV pull it out and take it along
Edit:  

Take everything to orbit just like Apollo"
1.  The CEV stays the same and it can abort to orbit easily
More on this.
Jim, I was thinking that the abort-to-orbit mode could be the configuration decider. I would suggest:
1. If the payload is suppose to stay in orbit, (ISS component/replacement part, Hubble service, etc), then fly the Orion-C configuration which would allow an abort-to-orbit option with payload, to get the payload into orbit. A future flight could always retrieve the payload and complete the mission.
2. If the payload is to be discarded at end of mission, like a mission module or something along that line, then configure like the Apollo/LM. Fly a normal Orion and do the T, D & extract manuever. Then, if an abort-to-orbit situation arises, just leave the MM behind and climb to orbit.

Just some options. What do you think?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/28/2006 08:05 PM
Quote
clongton - 28/10/2006  2:52 PM

More on this.
Jim, I was thinking that the abort-to-orbit mode could be the configuration decider. I would suggest:
1. If the payload is suppose to stay in orbit, (ISS component/replacement part, Hubble service, etc), then fly the Orion-C configuration which would allow an abort-to-orbit option with payload, to get the payload into orbit. A future flight could always retrieve the payload and complete the mission.
2. If the payload is to be discarded at end of mission, like a mission module or something along that line, then configure like the Apollo/LM. Fly a normal Orion and do the T, D & extract manuever. Then, if an abort-to-orbit situation arises, just leave the MM behind and climb to orbit.

Just some options. What do you think?[/QUOTE]

For Apollo, abort to orbit meant the mission was over, the LM or DM would be trashed.  The current CEV engine is only 10k, not much power drag the payload with.  Anyways, saving the crew is the reason.
Title: RE: "DIRECT" Goes Live
Post by: wingod on 10/28/2006 09:37 PM
Quote
ryan mccabe - 27/10/2006  8:24 AM

Quote
Jim - 27/10/2006  6:22 AM

NASA can't use it for commercial sector.  Not allowed by law.

What prevents that law from being changed? I doubt the law was written with any consideration of a vehicle like the DIRECT concept where so much extra mass could be made available. The possible scenarios (limited ones, at that) where commercial payloads could be flown would be very different than any situation NASA carried commercial payloads on the Shuttle.

I don't see the point in having a Wright Amendment for space...

Actually the Space Act of 1998 "requires" NASA to use commercial sources unless it can validate that there are no commercial providers for the particular service.  Now NASA has pretty much ignored it but a company could bring a lawsuit based upon the law and win.
Title: Re: "DIRECT" Goes Live
Post by: ryan mccabe on 10/28/2006 09:43 PM
Quote
Jim - 28/10/2006  9:45 AM

You are making unnecessarily complicated.
1.  You are mixing cargo and crew - a lesson learned no-no from shuttle[
2.  The CEV can't abort to orbit easily with the  cargo (too heavy)

1). What in principle is wrong with launching cargo and crew together?

The lesson I gathered from STS was don't build a fragile vehicle with few contingency options. How do the DIRECT cargo modules shown compromise the ability of the CEV to perform an abort?

2). Does the Ares I have any abort-to-orbit capability with a single J2-X on the second stage? I would think any propulsion failure at any point but the last moment before MECO would leave a CEV stranded in a useless orbit (or no orbit at all). It's erroneous to say that the DIRECT can't perform ATO with cargo when the Ares I can't perform one at all...

Regards,
Ryan
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/28/2006 09:57 PM
Quote
ryan mccabe - 28/10/2006  5:26 PM

Quote
Jim - 28/10/2006  9:45 AM

You are making unnecessarily complicated.
1.  You are mixing cargo and crew - a lesson learned no-no from shuttle[
2.  The CEV can't abort to orbit easily with the  cargo (too heavy)

1). What in principle is wrong with launching cargo and crew together?

The lesson I gathered from STS was don't build a fragile vehicle with few contingency options. How do the DIRECT cargo modules shown compromise the ability of the CEV to perform an abort?

2). Does the Ares I have any abort-to-orbit capability with a single J2-X on the second stage? I would think any propulsion failure at any point but the last moment before MECO would leave a CEV stranded in a useless orbit (or no orbit at all). It's erroneous to say that the DIRECT can't perform ATO with cargo when the Ares I can't perform one at all...

1a.  It compromises the design of both vehicles. The cargo will have manrating requirements.   The Challenger crew died for a comsat mission.  Station resupply would be similar.  Don't risk crew for Tang, t-shirt and toilet paper.  There are few shuttle missions that actually required crew and "cargo".   Just some of the lab missions and not every one, some could have been on ELV missions.  The Russians haven't use a shuttle to build a station.   HST missions?  For the cost of the shuttle flights, on or two replacement HST's could have flown.

1B.  That is why the CEV is a capsule and nothing bigger.  Crew transport, nothing more.

1c.  The extra weight makes less viable abort options.  The CEV engine is only 10K thrust

2 . Yes and more than a few seconds before MECO.  Also some early aborts options involve retro or posi burns to put the CEV in a better abort landing area.
Title: Re: "DIRECT" Goes Live
Post by: bad_astra on 10/29/2006 12:19 AM
Quote
Jim - 26/10/2006  2:13 PM

Anything that get rid of the stick is good

Agreed. I don't think Direct has a chance of being looked at seriously by NASA, but I appreciate what Kraisee has done.
Title: RE: "DIRECT" Goes Live
Post by: bad_astra on 10/29/2006 12:24 AM
Quote
but a company could bring a lawsuit based upon the law and win.

and be Northropped out of contracts forever.
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 10/29/2006 01:03 AM
Quote
bad_astra - 28/10/2006  7:02 PM

Quote
Jim - 26/10/2006  2:13 PM

Anything that get rid of the stick is good

Agreed. I don't think Direct has a chance of being looked at seriously by NASA, but I appreciate what Kraisee has done.

No, anything that can get the job done (technically and politically) is good. Launch vehicles are a means, not an end.

Simon ;)
Title: Re: "DIRECT" Goes Live
Post by: rumble on 10/29/2006 03:51 AM
What gives DIRECT a chance is that the stick is between a rock & a hard place, AND that DIRECT is a far better price performer while still meeting ALL requirements.
Title: RE: "DIRECT" Goes Live
Post by: simcosmos on 10/29/2006 09:49 AM
Note to readers: looong text
(made a large copy+paste from some of my archived DIRECT related documents
+ also used html tags in some format because of that)


Ok, going back a little in the discussion...
       
    I. DIRECT CLV + payloads
   
    a) Assuming a CEV (SM+CM) in a similar configuration to what we
      know it looks like today (plans) plus some kind of separated Mission
      Module (MM) or cargo, etc, below it.
   
    b) Assuming also no hardware integration / single vessel
      configuration (SM+MM+CM)
   
    c) Assuming that CEV makes a procedure similar to Apollo in
      order to extract the mission module from the ET core and then carry such
      module to its destination.
   
      I probably missed something in the past posts but, in the continuation
      of what Rumble wrote behind, I believe that haven't yet seen comments
      about ET core's attitude stabilization after MECO and, again, the
      available time to make such error-free extraction if in a sub-orbital trajectory.
   
      As also noted in past posts, if ET makes MECO and we have a sub-orbital
      trajectory, the most viable options (forgetting for a moment some
      constraints) would be either an integrated configuration (service module
      attatched to some sort of cargo container by its turn attatched to the
      command module) or that the "payload" had its own orbital
      insertion capability (but that would require some flight coordination
      between payload and CEV or that both were linked).
   
      I mean: a sub-orbital injection of the ET means about 30 minutes (or so)
      to separate the CEV, rotate, approach, dock with mission module / cargo
      carrier, extract, build safe distance from ET, rotate prograde, fire for
      stable orbit, no software / hardware / human faults allowed. At the same
      time, and I might be wrong, the ET would perhaps need to have some kind of
      attitude stabilization method, no?
   
      Again, assuming an Apollo like procedure to extract cargo, the time
      problem could be solved with a temporary ET insertion into orbit but,
      unless there were plans to make something with the ET (orbital
      utilisation), that would probably cause more problems... The ET would then
      have to be deorbited and, again, perhaps some kind of RCS would be needed.
   
      So, trying to sum up all: would I be less correct when writing that
      unless attitude stabilisation of an ET in sub-orbital trajectory (after
      MECO) is not a problem, and also if time to perigee is more than enough
      for the extraction procedure, with the CEV acting as a TUG (I doubt there
      is time if problems happen), it seems that the most viable options are
      really to give some kind of propulsion to the payload element and / or go
      for some kind of integrated configuration between CEV and *payload*.

 
      Any extra input regarding this subject?

   

   
    II. Regarding LSAM design and DIRECT
   
      For obvious reasons, DIRECT's proposal gives, as example in the pdf, a
      lunar mission using CEV, LSAM and overall mission design similar to the
      ESAS reference approach (after TLI).
   
      By other hand, and this is just my personal opinion, given the different
      nature of the first phase of the mission (LSAM+CEV launched together,
      DIRECT's launch capability, etc) I think that a different LSAM design
      would be much better, in particular, something similar to Lockheed
      Martin's LSAM (but not exactly equal to the conceptual images) would
      probably be better suited for DIRECT's use:
   
   

   
    III. DIRECT and Lunar Missions
   
      Note: what I will write next is, in part, the result of past tests in
      Orbiter simulator: still have to update performance numbers + tweak +
      clean a number of other configuration files as well better research about
      the technical feasibility of some aspects. However, it should give, at
      least, a first indication of some DIRECT's possibilities (a good number not
      possible with Ares I).
   
    III.A) EDS + CEV Missions
   
      DIRECT CLV + EDS could be used to send a CEV into a lunar fly-by or even
      into lunar insertion (depending of technical constraints / other)
      just with a single *direct* launch.
   
      III.a.1) CEV - Lunar Fly-By:
      (very few constraints)
   
      EDS has only to make 2 burns in a short - hours max. - time.
   
      BURN#1 starts while at sub-orbital trajectory and serves to make
      EDS+CEV achieve parking orbit. Such parking orbit does not need to be very
      high because the TLI (BURN#2) should happen in the next orbit,
      once all confirmed to be OK.
   
      No rendezvous operations, no dockings, no long orbital periods: it is
      launch and go. The EDS should have more than enough resources for a proper
      TLI. (after that, EDS is discarded - Moon impact?, solar orbit? - and CEV
      continues the fly-by mission).


   
      One constraint can be the test and opening of CEV solar panels before
      TLI but I guess that can be achieved with proper EDS-to-CEV interface
      design.
   
 
   
      III.a.2) CEV Full Lunar (Orbital) Mission:
      (some constraints added, in particular relative to number of engine
      restarts (how much extra helium needed?) and to propellants conservation
      (and then… going to the Moon takes ~3 days = 72 hours, which is way
      much less than ESAS requirements regarding propellants conservation for
      EDS in a LSAM+CEV mission)
   
      In this case, the EDS has to make a few extra burns than in the Fly-By
      mission:
   
      BURN#1: sub-orbital trajectory burn to make EDS + CEV achieve
      stable parking orbit (again, does not need to be a very high orbit)
   
      BURN#2: TLI, as described earlier. Major constraint / concern is
      to check that the CEV solar panels are ok.
   
      BURN#3: MCC: this can be done with EDS main engine (J-2S had a
      low thrust mode, hummm, not sure if J-2X will also have such feature) or,
      perhaps better, with its RCS (nice if RCS was LH2/LO2, BURN#3 can actually
      be more than one burn to fine tune trajectory).
   
      BURN#4: LOI: EDS should be able to, at least, make the EDS+CEV
      achieve an elliptical lunar orbit of 100Km x 6000Km or so (I managed to do
      that in Orbiter by using a far from optimised launch profile - but a good
      launch window - and still had a little of juice inside the EDS after lunar
      insertion)…
   
      BURN#5: After lunar insertion: EDS separates from CEV and then
      either is commanded to crash into Moon's surface or stays in orbit and can
      act as comm. Relay or for orbital fuel depot (see comments about
      propellants handling, transfer and conservation >> Centaur tech?).
   
      The two previous scenarios (crash vs orbital utilisation) depend of
      available propellants after LOI (design and flight procedures still need
      to be tweaked) As for the CEV, it can use the high elliptical orbit to
      have some nice views of the Moon and also to effectively (read cheaply)
      change its orbital inclination at the apoapsis (the higher the apoapsis,
      the cheaper the inc. change is). It can also circularise the orbit.
   
      Still have to check but as far as I remember, the CEV is planned for a
      dV of 1700m/s. With this mission design, it might arrive at lunar orbit
      with full propellants onboard (again, need to check math, improve
      implementation with updated data, etc) :)
   

   
     Notes about possible EDS upgrades / future
      mission paths!

   

         
  1. This kind of EDS utilization
            might also serve to build a lunar station (replace the CEV by a ~20mt
            module).

  2.      
  3. With increased EDS confidence and upgrades, the CEV's service module
            could even become the EDS itself, whenever more demanding performance is
            required. That would open new exciting possibilities for CEV operations!

  4.    

   
    Examples of EDS upgrades path:
   
   
      The two points above are not hard to imagine in a later exploration
      phase, where the LSAM could also become a reusable design and with in-situ
      production and/or even propellants brought from Earth (which would be
      stored in previous EDS left in certain lunar orbits)…Other (empty)
      EDS could even be conceived to be brought to lunar surface (by an
      evolution of the first LSAM design) and somehow used to support lunar
      bases operations.
   

   
    III.B) EDS + CEV + LSAM Missions
   
      Despite what is written above, in particular about the EDS / LSAM / CEV
      upgrade paths, a first lunar return / exploration moment will probably
      require (or end up in) something more like CEV fly-by and ESAS mission
      reference with LSAM to lunar surface / CEV in orbit.
   
      Again, perhaps a more optimised LSAM design would be better(?):
      that would perhaps put a split mission and LOR as a stronger mission profile (math needed).

     Also: I might be wrong, but it might not be necessary to build a new ET core
     if using 5 segment SRB with DIRECT's default core, at least there are some studies
     around about how would be possible to make such upgrade for the shuttle.
   

   
      As last note, there is Mars and beyond: like in ESAS, all very
      fuzzy and surely needing a lot extra discussion but DIRECT would be able
      to support such goals as well, either using basic variants or the upgrade
      paths (and perhaps also having the assistance of EELV as a good
      complement).
   
      However, one step at a time...
   
      The big question is: despite all constraints, do we really want to make a
      more intensive space exploration effort?
   
      And note that I use "we" without being a North-American
      myself, such is the power of the "Exploration Dream" and even
      knowing that isn't all kisses and roses in real world :)
   
      António
   
      PS: work with DIRECT Orbiter addon (and related 'toys') continues...
      slowly but continues ;)
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/29/2006 12:48 PM
Its very unclear for me. If there are two launches of Ares II (DIRECT) to LEO. One with LSAM+CEV other with EDS, then its clear that docking will be more complex and more difficult with potentially more delays than according to ESAS. There will be need for some new docking adapter as well. How do you want to dock and stack LSAM + CEV + EDS?
It's clear that you can't fly the similar robotic mission to the Moon as with Ares V + EDS + LSAM because the AresII + EDS can't lift anything else.
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 10/29/2006 01:01 PM
Could the core stage instead do a direct insertion, allow the CEV to do what needs to get the cargo out, and then have a ring of small solids on core to do a retro burn?

Simon ;)
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 10/29/2006 02:21 PM
I think at this stage it is important to keep DIRECT as simple as possible, to show how it can directly (no pun intended!) replace the Ares vehicles whilst giving huge cost savings in both development and operation, and significant schedule improvements. This means keeping all others aspects of the lunar missions as close to the ESAS plan as possible.
All this talk of mission modules, cargo containers, self-deorbiting Core stages etc, is not going to sell DIRECT to anybody, interesting though they may be.

I would have thought that the simplest solution would be to have the CEV atop the LSAM and the LSAM perform the apogee burn, leaving the Core to safely re-enter as per STS. Then, if the CEV and LSAM want to translate and re-dock, they can do it in their own good time. Personally I would have thought it best just to leave the CEV/LSAM in the launch configuration for a CEV-EDS docking, with the translation/re-docking coming after EDS jettison.
Alternatively it could be better to have the CEV and LSAM launched separately and not dock at all until they are both in lunar orbit- but this is a bigger change from the ESAS plan.

ISS flights with Orion and DIRECT are so hypothetical that it doesn't seem worth complicating the basic design for such a mission.

KISS...
Title: Re: "DIRECT" Goes Live
Post by: PaulL on 10/29/2006 03:27 PM
Kraisee, your proposal is interesting and well detailed. However, I have the following two questions:

1- You specify the EDS development cost at $6.1B for both the ESAS and DIRECT plans. Should't the ESAS EDS development cost be lower as the cost for the J-2X would hace been covered under the ARES-I development cost?

2- The DIRECT launcher is over powered for ISS missions requiring only the CEV. Would it make sence to only use one RS-68 engine with partially filled ET for such missions? I expect that this would produce a launcher which could still easily put the 25 tons CEV in LEO but costing $20M less that the standard two RS-68 engines launcher. Using only one engine should also improve the launcher's LOC (mean).

PaulL
Title: Re: "DIRECT" Goes Live
Post by: rumble on 10/29/2006 03:55 PM
Kaputnik:  Agreed.  The DIRECT concept is simple, and should be kept that way.  Its selling point is: price/performance/safety/reduced timeline/workforce retention/fewest changes to current shuttle infrastructure possible.

At the same time, I don't think us running "what-if" scenarios hurts...it simply outlines some possibilities that aren't there in the Ares I/V world.  From a "selling DIRECT" perspective, they speak to "and it can do all these extra things, too."


SimC:  Fantastic writing/thoughts there.  A few comments:
1)  Attitude control of core stage after MECO:  my guesses:  Unless both RS-68s shut down identically, there will be at least a slight thrust differential between them for some number of moments.  I think we can count on it having at least a minor bit of end-over-end tumble.  However, I also think it WILL be minor.  Some tiny RCS thrusters could be added to counteract any tumble from MECO.  How was this handled on Apollo?  (granted, it was a single engine, so no chance for differing shutdown speeds)  Did S-IVB have RCS?

2)  The LM lander (especially dual axis thrust, concept 1) has always caught my fancy.  Having well-stored Lox/LH2 instead of hypergols would mean we have more delta-v capability for the same propellant mass.  I like your comments there.

I really have little to add...that was well said.
Title: Re: "DIRECT" Goes Live
Post by: simcosmos on 10/29/2006 04:10 PM
Quick and probably not 100% correct answers:

1) Yes, Apollo SIVB had RCS (but not sure if they fired to momentarily kill any residual rotation (or something like that) at the start of docking procedure). Also to remember that the target should be in +/- free drift. However, the problem with an ET core is a little different from Apollo, not only because of its size but also because of it being in a sub-orbital trajectory, ence my preference to not complicate too much the ET design unless the objective would be to use it for some orbital purpose (which would not be the case for an ISS mission in the near term, I guess)

2) ESAS LSAM was also LH2/LO2 for LOI and descent: one of the differences in LM's landers is that all those propellants use something like a derivative of a Centaur upper stage thus having the potential to be lighter (the tanks) and to allow for easier control of things like eventual future propellant transfer needs and reduction of boil-off rates. In an ideal world, with more investment in Centaur tech, even CEV's service module and  LSAM's ascent stage could be based in LH2/LO2 although methane / oxygen (or something similar) would also be nice to have for those cases.

To end: I agree with the kaputnik's comments: in my loooong post above I always tried to use a most common *ESAish* scenario before extrapolating into other DIRECT ideas but I also agree with Rumble, we are discussing these ideas because the concept design potentially opens space for such discussion (at least when directly comparing with AresI concept and all what surrounds it)

António
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 10/29/2006 05:48 PM
I hope my post above didn't seem too sceptical/pessimistic; the additional payload capacity of DIRECT/Orion over Ares I/Orion does open up a lot of possibilities. For what its worth, perhaps the best option to exploit these capabilities would be to be fit a propulsion system to the core, perhaps mounted at the top of the LOX tank, which would both allow for controlled docking and also provide de-orbit capability. The unit would be a separate module flown only when a secondary payload was to be launched that required the translation and docking manoeuvre.
Antonio- your "loooong" posts are very much appreciated!

On the RCS issue: can't the Orion itself null the MECO-induced motion before separation? Obviously separation of Orion will cause some sort of motion in itself but this could presumably be minimal. It might also be worth mentioning that the Soviets succesfully docked a Soyuz with Salyut 7 despite it's RCS being inactive and the station being completely inert and slowly rotating in space- so docking with an inert object is possible, just not perhaps ideal.

My main concern remains that, as currently planned, DIRECT cannot deliver an LSAM to the moon in a single shot. This *should* not be a big problem because so many options are opened up if DIRECT is chosen, but it does remain something of a stick (again, no pun intended...) with which detractors could beat the DIRECT proposal. Essentially, it is unable to do one of the tasks that the Ares plan can do. I can't help but feel that this is a more pressing issue than the problem of how to extract cargo from a sub-orbital Core stage.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 10/29/2006 05:53 PM
Can you launch a partially fueled EDS and a partially fueled LSAM descent stage on a single Direct launcher to put robotic cargo on the moon? You could even have more LH2 but less LOX and have longer flight times if that saves mass...
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/29/2006 06:13 PM
EDS for Ares II (Direct) wouldn't be accomodated and designed for LSAM being started atop of it. So the infrastructure.
As the variable cost of Ares V and Ares II will be very similar (only difference is the cost of 3 more RS-68 and slightly bigger SRB) it will be always cheaper to use exactly the same configuration of LSAM and EDS launched on Ares V reference mission.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/29/2006 06:20 PM
Quote
PaulL - 29/10/2006  10:10 AM

Kraisee, your proposal is interesting and well detailed. However, I have the following two questions:

1- You specify the EDS development cost at $6.1B for both the ESAS and DIRECT plans. Should't the ESAS EDS development cost be lower as the cost for the J-2X would hace been covered under the ARES-I development cost?

2- The DIRECT launcher is over powered for ISS missions requiring only the CEV. Would it make sence to only use one RS-68 engine with partially filled ET for such missions? I expect that this would produce a launcher which could still easily put the 25 tons CEV in LEO but costing $20M less that the standard two RS-68 engines launcher. Using only one engine should also improve the launcher's LOC (mean).

PaulL

1 - Yes and the development cost of core for Ares II and Ares V will be exactly the same. The difference is nearly two times more massive payload for slight increase of variable cost.

2 - There is no ET at Ares II (Direct). There is a core which is of very little commonality with ET. Changing number of engines means long and expensive recertification.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 06:32 PM
Ares II?  One (e.g. a mission's planner) can't think of a "payload" in the abstract sense.  "The bigger the better" is not a specification.  What is the payload?  What instruments?  What is it for?  How much $$$?  Who pays for it?
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 06:38 PM
One of the threats to the Direct concept is the problem of the perceived overkill of launching the ~20mT CEV with a launcher capable of lifting ~70mT. Everyone wants to use that extra lift for something useful but as Ross has pointed out the safest (and cheapest) use is to carry a mass simulator that could provide extra shielding in the event of catastrophe.  

Jim has pointed out any other use of the extra lift runs contrary to the CAIB report’s recommendation to not mix cargo and crew. While clongton was correct in pointing out that the recommendation was based on the fragile shuttle, with it’s integrated payload bay, Jim pointed out that cargo would have to be “man rated”. Given Dr. Gifford’s comments about man rating this may be something of a red herring but it is something that is taken very seriously by both congress and NASA. Ross’s suggestion of carrying an ATV may offer a way to diffuse this criticism since the two craft would operate independently. The CM/CC/SM suggestion as well as mission modules are interesting but, given their conflicts with the no cargo/crew combinations, should be something for long-term consideration.

A better utilization of the extra lift might be a return to a larger, more capable CEV within the constraints of the lunar mission capabilities.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 06:51 PM
If one needs to loft an X amount of pounds to reach and dock with the ISS, that's how much one needs to loft (at a lowest possible cost).  Granted, the CEV's primary mission is not the ISS.  Still, we need to tailor the craft to the mission(s), not the other way around.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 10/29/2006 06:54 PM
Quote
JIS - 29/10/2006  7:03 PM

Quote
PaulL - 29/10/2006  10:10 AM

Kraisee, your proposal is interesting and well detailed. However, I have the following two questions:

1- You specify the EDS development cost at $6.1B for both the ESAS and DIRECT plans. Should't the ESAS EDS development cost be lower as the cost for the J-2X would hace been covered under the ARES-I development cost?

2- The DIRECT launcher is over powered for ISS missions requiring only the CEV. Would it make sence to only use one RS-68 engine with partially filled ET for such missions? I expect that this would produce a launcher which could still easily put the 25 tons CEV in LEO but costing $20M less that the standard two RS-68 engines launcher. Using only one engine should also improve the launcher's LOC (mean).

PaulL

1 - Yes and the development cost of core for Ares II and Ares V will be exactly the same. The difference is nearly two times more massive payload for slight increase of variable cost.

2 - There is no ET at Ares II (Direct). There is a core which is of very little commonality with ET. Changing number of engines means long and expensive recertification.

Ares V has a 10 m diameter tank though, and that requires different tooling and pad infrastructure AFAIK.

But I think it's a question of short-term vs long-term focus. Maybe eventually NASA could ditch Ares I and just use Ares V for Lunar exploration. Do light missions with single launches for just crew perhaps. A lot of the missions would be robotic cargo missions with no CEV. Or there are those depots or ISRU which change the game a lot.
But now NASA is facing quite a lot of immediate costs and also needs to wait long for Ares V. Direct is a solution for those things right here in the nearer future.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 07:17 PM
EELVs fly and can deliver ISS cargo/crew (provided rendezvous capable spacecraft).  What "NASA thinks" is neither here nor there.  The Ares is a waste of money.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 07:18 PM
Kaputnik your point about the inability for Direct to deliver a LSAM to the moon is well taken but the Aries program would not be able to achieve this until fairly late in the program. Direct could have flown several missions by that time.

A work around might be for there to be two launches; CEV plus LSAM and an EDS to a ISS inclination orbit. The CEV/LSAM would separate, the CEV continuing to the ISS while the LSAM docks autonomously with the EDS. Given the lower mass the EDS may be able to over come the poor orbital position to achieve TLI. An alternative might be to make the two launches to the lunar inclination orbit and practice various docking procedures. The CEV could return to earth while the LSAM stack proceeds to TLI.

Both offer an opportunity to verify docking, separation, and other procedures in LEO while delivering the unmanned LSAM to the moon.

Alternatively the program could wait to deliver unmanned LSAMs until the later phases of Direct are developed.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 07:28 PM
(just a note) It looks like we are "slipping" into multi-launch/orbital assembly anyway, kind of funny how the laws take their hold....
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 07:43 PM
The Constellation/ Ares program has always been a multi-launch/ orbital assembly solution. The CEV has to dock with the LSAM/EDS stack, that’s orbital assembly in my book.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 07:45 PM
Quote
Norm Hartnett - 29/10/2006  12:26 PM

The Constellation/ Ares program has always been a multi-launch/ orbital assembly solution. The CEV has to dock with the LSAM/EDS stack, that’s orbital assembly in my book.

Precisely!  And it's been noted before.  But some arguments presented this (multi-launch/ orbital assembly)  as a thing to be afraid of...
Title: Re: "DIRECT" Goes Live
Post by: rumble on 10/29/2006 08:22 PM
Please don't get stuck on the fact that DIRECT has too much capacity for a crew launcher.  If this was a clean-sheet rocket, we wouldn't have all the cost benefits of it.  It is the path of least resistance because it changes so little from current shuttle "everything."

The core stage IS an ET, with the top of the LOX tank & nose modified, and with an aft thrust structure added (and with the fuel/lox lines run a bit further south).  Shuttle mount brackets removed.  Other than that, same diameter, same tank capacities, and 3 of the 4 bulkheads will be unchanged.  The SRB mount points will be in the same location as on the shuttle's ET.  JIS, your "little commonality" comment just doesn't hold water.  That's commonality if I've ever seen it!

The commonality with the shuttle is what enables us to keep so much of the current shuttle infrastructure intact.  Crawlers, VAB, MLP ("minor" modifications), flame trenches, SRB processing facilities.  

The EDS is practically the same EDS as proposed in ESAS for Ares V, or at least for the current Ares V.  (same engine & physical dimensions)

But please don't get stuck on DIRECT's over capability...  It wasn't designed to be 2x to 3x too big...  it just happens to be what we've already got, and it'll work beautifully.

No brainer.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 08:31 PM
We could loft ISS bound payloads on the EELVs faster than waiting for the "Direct"  The mission is served by *a* launcher.  If a launcher is over specified it's not useful for the *mission*.  

[edit] I'm not "against" the Direct.  In fact, some of the features do appeal to me.  But we must look at what we are trying to acomplish
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/29/2006 08:33 PM
Quote
lmike - 29/10/2006  3:28 PM

Quote
Norm Hartnett - 29/10/2006  12:26 PM

The Constellation/ Ares program has always been a multi-launch/ orbital assembly solution. The CEV has to dock with the LSAM/EDS stack, that’s orbital assembly in my book.

Precisely!  And it's been noted before.  But some arguments presented this (multi-launch/ orbital assembly)  as a thing to be afraid of...

LMike,
   The problem is that every vehicle you launch has a risk factor, and every assembly in orbit has a risk factor.

   For pure simplicity, and just to demonstrate the basic philosophy, lets assign 1% failure factor to each of thos risk factors.

   With Ares/DIRECT you're talking two launches to launch the 180mT needed to fly the size mission you want, plus one or two assemblies = 4% risk.

   With even a Delta-IV Heavy launchiong 28mT to LEO, that's 7 flights and 6 assemblies = 13% risk.

   While the pure numbers aren't accurate, the PROPORTION of 325% more risk applies to whtever the real numbers actually are.



For a 500mT Mars missions:

   Ares/DIRECT both need about 6 flights, and 5 assemblies = 11% risk.

   Delta-IV Heavy requires 18 flights and 17 assemblies = 35% risk.

   A comparison of about 3 times more risky.


That and the fact that every docking adaptor requires extra weight to each basic element.   Adding that many more adaptors will require even MORE flights, which increases the risk even further.


It just isn't a practical or safe approach.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 08:39 PM
Kraisee, thank you for the lucid explanation.  If you are not "afraid" to do a 2 flight assembly (Direct) why be squeamish with the n*2 flight assembly?  You'd still lose the mission if you loose a docking?
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 08:39 PM
It is fairly clear that the Ares I is already in political trouble as well as having the engineering problems Ross described in the Direct presentation. Both the GAO report and the CBO report did not come out of nowhere, congressman requested these reports and both reports call the Ares I into question, the GAO from a procurement procedure standpoint and the CBO from the EELV alternative standpoint. The CBO is fairly clear in stating that the Delta IV is capable of performing Ares I’s mission with man rating and the Atlas could do the same with a little more improvement. This means that NASA is in violation of the Commercial Space Act already. There is probably not sufficient muscle in congress to kill the Ares I in favor of the EELV solution given the job retention issue and the link to the Ares V.

Direct, however, does not face this kind of challenge. Since it’s lift is so superior to any EELV now in inventory and given that it addresses the job retention issue it avoids the possibility. Direct should appeal to and receive the backing of the EELV crowd precisely because of the lift overkill. It is obviously a waste to use this launcher for ISS support and re-supply when both COTS and the EELV may provide a more cost effective solution. At the same time Direct frees up budget for development/procurement of these solutions, a win/win opportunity for the commercial community. The only piece of the pie the EELV folks don’t get is the moon missions.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 10/29/2006 08:39 PM
What if you fire the Direct EDS to empty (or so-so that you can still safely dispose of it) and just make up the rest of the velocity with the LSAM descent stage? It's going to be a very precisely navigating, throttlable and multiple-fire craft anyway. But what would the payload at lunar surface be, or would there be any?
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 08:46 PM
meiza remember that Direct is not capable of lofting the EDS and LSAM together.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 10/29/2006 08:49 PM
With partial fueling all the time of course... or do you mean aero loads because of length?
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 08:51 PM
Quote
Norm Hartnett - 29/10/2006  1:22 PM
... Since it’s lift is so superior to any EELV now in inventory ...

It must be noted that the EELV lift now in the inventory is a given.  It lofts sats and the NASA/NRO payloads.  The 'Direct's lift is a proposal.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 08:56 PM
Quote
lmike - 29/10/2006  1:34 PM

Quote
Norm Hartnett - 29/10/2006  1:22 PM
... Since it’s lift is so superior to any EELV now in inventory ...

It must be noted that the EELV lift now in the inventory is a given.  It lofts sats and the NASA/NRO payloads.  The 'Direct's lift is a proposal.

According to the CBO report the cost of developing the super heavy versions of both the Delta and Atlas are about equivalent to the Ares V, Mike. Direct is much much cheaper.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 08:59 PM
I was talking about an ISS mission.  See, the "super heavy" or the "super dooper ultra heavy" does not enter untill we agree we are talking about the same mission.  We still must put the mission in front.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 09:05 PM
Quote
Norm Hartnett - 29/10/2006  1:39 PM
... Direct is much much cheaper.

Still a proposal.  Not something we can argue against or for...  The EELVs do have hard numbers behind them.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 09:06 PM
Quote
lmike - 29/10/2006  1:42 PM

I was talking about an ISS mission.  See, the "super heavy" or the "super dooper ultra heavy" does not enter untill we agree we are talking about the same mission.  We still must put the mission in front.

Somewhere I said

Quote
It is obviously a waste to use this launcher for ISS support and re-supply when both COTS and the EELV may provide a more cost effective solution. At the same time Direct frees up budget for development/procurement of these solutions, a win/win opportunity for the commercial community.

I agree with you see my post on the last page. (The one you quoted)
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/29/2006 09:06 PM
Quote
rumble - 29/10/2006  3:05 PM

The core stage IS an ET, with the top of the LOX tank & nose modified, and with an aft thrust structure added (and with the fuel/lox lines run a bit further south).  Shuttle mount brackets removed.  Other than that, same diameter, same tank capacities, and 3 of the 4 bulkheads will be unchanged.  The SRB mount points will be in the same location as on the shuttle's ET.  JIS, your "little commonality" comment just doesn't hold water.  That's commonality if I've ever seen it!

The commonality with the shuttle is what enables us to keep so much of the current shuttle infrastructure intact.  Crawlers, VAB, MLP ("minor" modifications), flame trenches, SRB processing facilities.  


ET is substantially different to Ares core because there are different loads, different engines, different pipework and instrumentation. This means complete redesign. The struture of the tank might look similar but will be different.
However, it is possible that some tooling from ET could be used. But the main cost will be redesign, development, testing and certification of the core and engines.
   
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/29/2006 09:11 PM
Quote
JIS - 29/10/2006  8:31 AM

Its very unclear for me. If there are two launches of Ares II (DIRECT) to LEO. One with LSAM+CEV other with EDS, then its clear that docking will be more complex and more difficult with potentially more delays than according to ESAS. There will be need for some new docking adapter as well. How do you want to dock and stack LSAM + CEV + EDS?

Actually JIS, have a look at Appendix 3 of the Proposal available on the directlauncher.com website.

It demonstrates two of the possible methods.

There are plenty of other methods available, but those two approaches have the advantages of both testing the LSAM's descent engines in LEO, and also not requiring any additional docking hardware on any of the Lunar-bound hardware.



Quote
It's clear that you can't fly the similar robotic mission to the Moon as with Ares V + EDS + LSAM because the AresII + EDS can't lift anything else.

Actually, DIRECT can.

DIRECT + EDS can launch 38mT of useful payload on top to a Lunar-compatible trajectory.

But Ares-V costs $1.3 Billion more every year, just to operate, before you pay for flights.   That cost is one DIRECT does not have.   That $1.3 Billion would pay for 8 extra DIRECT launches (304mT to Lunar Trajectory) before you've paid for the very first Ares-V - every year.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/29/2006 09:14 PM
Quote
lmike - 29/10/2006  4:48 PM

Still a proposal.  Not something we can argue against or for...  The EELVs do have hard numbers behind them.

The man rated EELV's and super-EELV's are just as far away from current boosters as DIRECT is from Shuttle.   They are all based on reconfigured existing hardware and best-guess costings based on what is flying currently.

Ross.

Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 09:17 PM
The "man rated" EELV's do fly and deliver payloads.  As we speak.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 09:18 PM
Mike there is simply no political support for a purely EELV solution. Nor is it politically acceptable to replace the Stick with an EELV while developing the Ares V, too many people are out of work for too long. The beauty of the Direct solution is that it addresses the political issues while solving the "Stick" issue and solves many of NASA'a future budget short falls in the process.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 09:23 PM
Quote
Norm Hartnett - 29/10/2006  2:01 PM

Mike there is simply no political support for a purely EELV solution. Nor is it politically acceptable to replace the Stick with an EELV while developing the Ares V, too many people are out of work for too long. The beauty of the Direct solution is that it addresses the political issues while solving the "Stick" issue and solves many of NASA'a future budget short falls in the process.

I can understand this angle.  Thank you.  But perhaps we can convince/replace our representatives?
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 09:37 PM
As Ross pointed out in the proposal; with the savings NASA realizes from implementing Direct the costs of manrating the Delta IV are trivial and that provides assured access to space. And without any of the political overhead now in effect.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 10/29/2006 09:52 PM
"man rating" is not a problem as far as I can see.  We could loft a CEV on a Soyuz-U if it (the CEV) fit the mass bill.   The Direct doesn't seem to address the immediate needs (ISS crew launch/recovery)
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 09:58 PM
If NASA meets Ross's proposed development timeline the basic Direct (RL-68) would be flying by 2011. Close enough to meet those needs until the COTS/EELV community gets up to speed. Might have to buy a couple of rides from the Russians.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 10:30 PM
The thing is, Mike, if NASA goes ahead with the Ares program there would not be money to develop a man rated EELV. There is no political support for developing a man rated EELV instead of Ares I. Only if NASA adopts the Direct will there be sufficent cash to allow the development of a man rated EELV. That is why the EELV community should be supporting the Direct proposal.
Title: RE: "DIRECT" Goes Live
Post by: clongton on 10/29/2006 10:47 PM
Quote
Jim - 28/10/2006  10:30 AM
You have the "SLA" attaching near the base of the CM and the rest of the cargo and SM (the load) are behind this attach point and "hung"
Got you. Answer: the picture is misleading. The load isn't "hung" from the SLA/Orion mating point. It is secured at the aft end of SM on a payload platform at the fwd end of the LV. All the axial loading drives right down the center of the LV. The SLA is just there as a shroud, and is jetisoned once out of the atmosphere.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 10:59 PM
Quote
Jim - 28/10/2006  7:45 AM

There is maybe only one ISS module on the ground, the CAM, otherwise everything else is a new build, so shuttle legacy attachment is not needed.

What happened to the US Habitat module? Last I heard it was at least partially completed and then mothballed. I am not sure what the status on the Russian power module is, that might also be a potential cargo to the ISS.

The one I like best is Ross's proposed 70mT replacement for the ageing FGB. I wonder how many of the IP's would be willing to contribute to a module that extended the lifetime of the station 10 years plus?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/29/2006 11:03 PM
The Hab shell is being used as a ground testbed.  The SM is just as old.  It would be hard to R&R the FGB.  The ops associated with splitting the station in  two may not be possible
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/29/2006 11:18 PM
Quote
JIS - 29/10/2006  4:49 PM
ET is substantially different to Ares core because there are different loads, different engines, different pipework and instrumentation. This means complete redesign. The struture of the tank might look similar but will be different.
However, it is possible that some tooling from ET could be used. But the main cost will be redesign, development, testing and certification of the core and engines.
Ares core does not yet exist, so the redesign you speak of doesn't exist. Direct reuses the existing Shuttle ET, almost completely "as is". Only major (actually minor) modifications are to remove Shuttle attachment structure and add thrust structure on fdw & aft ends. Plus some minor additional tweeking.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 11:19 PM
I didn't communicate well when I said replace the FGB. I meant replace much of it's functionality, presumeably it retains it's spaceworthyness and would just become living space while its capabilites would transfer to the new module.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/29/2006 11:26 PM
Quote
rumble - 29/10/2006  4:05 PM
But please don't get stuck on DIRECT's over capability...  It wasn't designed to be 2x to 3x too big...  it just happens to be what we've already got, and it'll work beautifully. No brainer.
By reusing what we've got, we get what's already there.
It would cost a lot more money to deliberately remove the excess capacity than to leave it alone.
Just leave it as it is. NASA's got some pretty smart people who would love to be asked: "hey you guys, what do you think we could do with 48 mT extra capacity and $35 billion to play with"?
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/29/2006 11:30 PM
Quote
Norm Hartnett - 29/10/2006  3:26 PM
The Constellation/ Ares program has always been a multi-launch/ orbital assembly solution. The CEV has to dock with the LSAM/EDS stack, that’s orbital assembly in my book.
In the same manner as Apollo; The CM had to dock with the LM. I guess that's orbital assembly as well. Whether it is 1, 2 or 3 LV is irrelevant.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/29/2006 11:33 PM
Quote
Norm Hartnett - 29/10/2006  7:02 PM

I didn't communicate well when I said replace the FGB. I meant replace much of it's functionality, presumeably it retains it's spaceworthyness and would just become living space while its capabilites would transfer to the new module.

It is basically inert now, it doesn't really provide any functionally to the ISS anymore.  Power and attitude control are done by the USOS, propulsion done by the RS.  It might just be providing propellant storage.  Anyways, the spaceworthiness issue is the basic structure and materials.  Some of the ECS systems, fans and ducts may have limited life.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/29/2006 11:38 PM
Quote
Norm Hartnett - 29/10/2006  2:21 PM
A better utilization of the extra lift might be a return to a larger, more capable CEV within the constraints of the lunar mission capabilities.
One could always hope for a larger, more capable CEV. The 25mT version currently envisioned (and contracted) was the product of the limited lift capacity of Ares I. When I was stock car racing, my pit crew learned quickly to only change 1 thing at a time; that's how you maintain control of the situation. First thing to change: the LV from Ares to Direct. Get Direct flying CEV "as is". Then consider other, more efficient options.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/29/2006 11:52 PM
Quote
clongton - 29/10/2006  4:21 PM

Quote
Norm Hartnett - 29/10/2006  2:21 PM
A better utilization of the extra lift might be a return to a larger, more capable CEV within the constraints of the lunar mission capabilities.
One could always hope for a larger, more capable CEV. The 25mT version currently envisioned (and contracted) was the product of the limited lift capacity of Ares I. When I was stock car racing, my pit crew learned quickly to only change 1 thing at a time; that's how you maintain control of the situation. First thing to change: the LV from Ares to Direct. Get Direct flying CEV "as is". Then consider other, more efficient options.

True, but given that the CEV is still in early development and that the changes would be a return to original designs it might not be so big a change. If not you are quite right, better to have Direct flying and develop things to use the extra lift later.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/29/2006 11:54 PM
the "original" design is the current CEV.  There isn't going back to 5.5m.  Since the 5m is being designed for the lunar mission, there are no "lost" capabilities.  There is no need for more capabilities than that.  Any additional capabilities are part of the "mission module", whether it is the LSAM, MTV, etc
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/30/2006 01:10 AM
Quote
kraisee - 29/10/2006  3:54 PM

Quote
It's clear that you can't fly the similar robotic mission to the Moon as with Ares V + EDS + LSAM because the AresII + EDS can't lift anything else.

Actually, DIRECT can.

DIRECT + EDS can launch 38mT of useful payload on top to a Lunar-compatible trajectory.

Ross.

What a magic rocket. Where would you put your payload? What about liftoff thrust, assembly, fairing?
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/30/2006 01:26 AM
Quote
clongton - 29/10/2006  6:01 PM

Quote
JIS - 29/10/2006  4:49 PM
ET is substantially different to Ares core because there are different loads, different engines, different pipework and instrumentation. This means complete redesign. The struture of the tank might look similar but will be different.
However, it is possible that some tooling from ET could be used. But the main cost will be redesign, development, testing and certification of the core and engines.
Ares core does not yet exist, so the redesign you speak of doesn't exist. Direct reuses the existing Shuttle ET, almost completely "as is". Only major (actually minor) modifications are to remove Shuttle attachment structure and add thrust structure on fdw & aft ends. Plus some minor additional tweeking.

Ares II core is what Ross' DIRECT must use.

Using Musk's lesson learned file I would be afraid of buckling the damn tank because Ross is going to put 80t of payload on the top of ET and fire all engines he has.
Hopefully, everything will collapse by its own weight long before the actual explosive launch.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/30/2006 01:54 AM
Quote
JIS - 29/10/2006  9:09 PM

Quote
clongton - 29/10/2006  6:01 PM

Quote
JIS - 29/10/2006  4:49 PM
ET is substantially different to Ares core because there are different loads, different engines, different pipework and instrumentation. This means complete redesign. The struture of the tank might look similar but will be different.
However, it is possible that some tooling from ET could be used. But the main cost will be redesign, development, testing and certification of the core and engines.
Ares core does not yet exist, so the redesign you speak of doesn't exist. Direct reuses the existing Shuttle ET, almost completely "as is". Only major (actually minor) modifications are to remove Shuttle attachment structure and add thrust structure on fdw & aft ends. Plus some minor additional tweeking.

Ares II core is what Ross' DIRECT must use.

Using Musk's lesson learned file I would be afraid of buckling the damn tank because Ross is going to put 80t of payload on the top of ET and fire all engines he has.
Hopefully, everything will collapse by its own weight long before the actual explosive launch.

You are way off base.

It is a minor redesign to take the payload, just some thicker tank gauges
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 10/30/2006 02:45 AM
Quote
Jim - 29/10/2006  6:37 PM

the "original" design is the current CEV.  There isn't going back to 5.5m.  Since the 5m is being designed for the lunar mission, there are no "lost" capabilities.  There is no need for more capabilities than that.  Any additional capabilities are part of the "mission module", whether it is the LSAM, MTV, etc

I agree; keep the CEV as small and simple as practical, and leave the fancyness to the LSAM, MTV, or whatever. :)

Probably the best that Direct can achieve at the moment is to become a semi-official back-up option, and then if Ares I falls flat at a design review in the near future, the management can quietly start an official study of the concept...

Simon ;)
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 02:46 AM
Quote
JIS - 29/10/2006  8:53 PM

What a magic rocket. Where would you put your payload? What about liftoff thrust, assembly, fairing?

No magic here.   Just a modular design :)

The DIRECT can have a large fairing on top of the EDS, just like Ares-V.   In fact the *exact* same fairing should fit without change.

The current design of the MLP and Pad are also planned for 20m of extra height extensions if additional height is required in the future.   The number of variants shown in the proposal is limited deliberately to prevent complicating the paper too much - it is already a pretty extensive piece without this!

But here, have a look at the theoretical range of DIRECT launcher configurations which seem easily possible.

The most useful and plausible ones to me, are highlighted in red, blue and green.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 03:26 AM
Quote
JIS - 29/10/2006  9:09 PM

Using Musk's lesson learned file I would be afraid of buckling the damn tank because Ross is going to put 80t of payload on the top of ET and fire all engines he has.
Hopefully, everything will collapse by its own weight long before the actual explosive launch.

I don't see why, because DIRECT is not very different to STS in either GLOW or Liftoff Thrust.

The tank has proven very reliable for that amount of thrust, and it can also handle the VERY difficult loads involved in hanging the Orbiter on the side - which DIRECT completely avoids.


Wouldn't that argument actually affect the Ares-V FAR more?   It is, after all, considerably more "agressive" when it comes to thrust.


Don't get me wrong:   Whatever happens, throughout DIRECT's development figures, we have been assuming a *full and complete* development program for the new core as if it were completely unrelated to anything existing currently.   It is costed and scheduled for that.

But DIRECT *will* share the form factor of ET.   There are many parts which in practice have manufacturing ready to go right now.

Tank Dome gores will be exactly the same.

The current manufacturing process for the walls for the tanking are in place to handle DIRECT immediately.   Tanking would be virtually identical to ET, just perhaps with slightly thicker walls being milled.

The Aft LOX tank plumbing, where it drops out of the aft dome, and goes outside down the LH2 tank - all that can remain exactly as it is today - no changes are needed at all.

The layout of Interstage is deliberately identical in order to support the current SRB's.   ET engineers who have contributed are convinced that what is built today should qualify as strong enough for DIRECT's loads 'as-is'.   If so, then production need not change at all.

But DIRECT's costs & schedule still assume a full development non-the-less.   That was the conservative approach we used throughout.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 03:31 AM
Quote
Norm Hartnett - 29/10/2006  7:35 PM

True, but given that the CEV is still in early development and that the changes would be a return to original designs it might not be so big a change. If not you are quite right, better to have Direct flying and develop things to use the extra lift later.

Norm, the 5.0m CEV will be able to perform all the same functions as the 5.5m one, but does so while massing a few tons less.

There's just no reason to go through the hassle of changing it all over again, now.   It wouldn't offer any advantages.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/30/2006 08:57 AM
OOOps. So ET engineers say that it doesn't matter whether the load from 3 SSME goes through orbiter as with STS or from 2 RS-68 through the tank as with DIRECT?
When STS is sitting on the ramp the orbiter weight goes trough the inner rings to SRBs.
When DIRECT is sitting on the ramp the weight of payload goes through the LOX tank at least. And when RS-68 ar running their thrust goes through tank not through the orbiter.
I think that either ET is seriously oversized for STS or you consult wrong people.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 10/30/2006 10:22 AM
Kraisee-
out of curiosity, if you launched a DIRECT+Orion 'underweight', i.e. with no ballast (and no EDS), what sort of orbit could be achieved? If a suitable launch window were used (since the RS68s would not be restarted in space and it would have to be a 'one-burn' scenario) could TLI be achieved? If not, what sort of eliptical orbit would result?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/30/2006 11:50 AM
Quote
JIS - 30/10/2006  4:40 AM

OOOps. So ET engineers say that it doesn't matter whether the load from 3 SSME goes through orbiter as with STS or from 2 RS-68 through the tank as with DIRECT?
When STS is sitting on the ramp the orbiter weight goes trough the inner rings to SRBs.
When DIRECT is sitting on the ramp the weight of payload goes through the LOX tank at least. And when RS-68 ar running their thrust goes through tank not through the orbiter.
I think that either ET is seriously oversized for STS or you consult wrong people.

Yes, It is only a minor difference in the "tank", nly some skin thickness has to be change and STS support hardware removed.  But as Ross says, the fwd and Aft have have propulsions systems and payload sections added .   Mods similar to these have been studied for the shuttle over the years.  There were studies for placing a payload section on the front or aft of the tank, other studies added engines to the aft.  Direct has nothing new on the ET  that hasn't been looked at by NASA for STS improvement.

ARES V needs a complete new tank.  Nothing in common with the existing ET except the material type.  

You have yet to qualify yourself.  What makes you think it can't be done easily?

Edit:  
I forgot, it must be the early hours.   NASA.  Yes, I said, NASA has looked at the similar vehicles over the years, going back as far as late 70's with shuttle derived vehicles.   The only difference between "Direct" and those studies is the use of SSME's and RS-68's.  So, there!   NASA said in those studies it was easy to adapted the ET.

the "Direct" configuration isn't new or unique.  It is an old concept that is better than the "stick"

Edit2:

I must be getting old.  In 1985, Boeing proposed the same thing (abet with 1 SSME) to compete against what became the Titan-IV.  It was also propose by Hughes for the Jarvis vehicle (mark II, first Jarvis used F-1's and J-2's)


Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/30/2006 12:12 PM
OK, you apparently know that better. Only different thickness, different shape of LOX tank, fwd and aft sections, thrust structure. OK I believe you that's old concept and easily done.
My point was that in the slightly more complicated way its possible to design Ares V core as well. The only difference is manufacturing. I'm sure you would say that the design of Atlas phase 2 core compared to Atlas V core is quite strightforward as well. Or not?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/30/2006 12:15 PM
yes
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/30/2006 12:50 PM
Quote
Norm Hartnett - 29/10/2006 4:22 PM
It is fairly clear that the Ares I is already in political trouble as well as having the engineering problems Ross described in the Direct presentation. Both the GAO report and the CBO report did not come out of nowhere, congressman requested these reports and both reports call the Ares I into question, the GAO from a procurement procedure standpoint and the CBO from the EELV alternative standpoint.
Ross - did you send a copy of the paper to these congressmen?
Title: Re: "DIRECT" Goes Live
Post by: clongton on 10/30/2006 01:00 PM
Quote
Norm Hartnett - 29/10/2006  3:01 PM
 The CEV/LSAM would separate, the CEV continuing to the ISS while the LSAM docks autonomously with the EDS.
Technical note: ISS orbital inclination is not optimal for lunar missions. Complicates things.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/30/2006 01:39 PM
Quote
clongton - 30/10/2006  5:43 AM

Quote
Norm Hartnett - 29/10/2006  3:01 PM
 The CEV/LSAM would separate, the CEV continuing to the ISS while the LSAM docks autonomously with the EDS.
Technical note: ISS orbital inclination is not optimal for lunar missions. Complicates things.

Yes, I was just throwing out some ideas on how to get an unmanned LSAM to the moon using Direct.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/30/2006 03:16 PM
Quote
kraisee - 29/10/2006  3:54 PM

Quote
JIS - 29/10/2006  8:31 AM

Its very unclear for me. If there are two launches of Ares II (DIRECT) to LEO. One with LSAM+CEV other with EDS, then its clear that docking will be more complex and more difficult with potentially more delays than according to ESAS. There will be need for some new docking adapter as well. How do you want to dock and stack LSAM + CEV + EDS?

Actually JIS, have a look at Appendix 3 of the Proposal available on the directlauncher.com website.

It demonstrates two of the possible methods.

There are plenty of other methods available, but those two approaches have the advantages of both testing the LSAM's descent engines in LEO, and also not requiring any additional docking hardware on any of the Lunar-bound hardware.

Ross.

Thank you for answer. I've read that Appendix.

However, I was concerned about docking of CEV+LSAM to EDS. There must be some kind of navigation and some way how to connect LSAM to EDS. As LSAM is the most weight critical part of the system I'm afraid that this is not too effective.
Maybe the same instrument used for lunar landing could be used but still some special docking adaptor is required.
 

Title: Re: "DIRECT" Goes Live
Post by: Chris Bergin on 10/30/2006 03:18 PM
Quote
clongton - 30/10/2006  1:33 PM

Ross - did you send a copy of the paper to these congressmen?

That sort of thing is automatic. You should see where people come from to this site (via the backend server stats). Proper exposure is not an issue.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/30/2006 03:52 PM
Quote
kraisee - 29/10/2006  9:29 PM

Quote
JIS - 29/10/2006  8:53 PM

What a magic rocket. Where would you put your payload? What about liftoff thrust, assembly, fairing?

No magic here.   Just a modular design :)

The DIRECT can have a large fairing on top of the EDS, just like Ares-V.   In fact the *exact* same fairing should fit without change.

The current design of the MLP and Pad are also planned for 20m of extra height extensions if additional height is required in the future.   The number of variants shown in the proposal is limited deliberately to prevent complicating the paper too much - it is already a pretty extensive piece without this!

But here, have a look at the theoretical range of DIRECT launcher configurations which seem easily possible.

The most useful and plausible ones to me, are highlighted in red, blue and green.

Ross.

The biggest advantage of Ares1 / AresV combination is that Ares V itself can easily switch from manned lunar missions to robotic missions with LSAM descent stage serving as robotic platform or lunar base supply mission.

It is very simple switch.

Any modification of base line DIRECT costs something and its advantage is disappearing.

And what about safety? Do you have any idea why approach similar to DIRECT is considered (by ESAS) safer than AresV?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/30/2006 03:58 PM
Quote
JIS - 30/10/2006  11:35 AM

The biggest advantage of Ares1 / AresV combination is that Ares V itself can easily switch from manned lunar missions to robotic missions with LSAM descent stage serving as robotic platform or lunar base supply mission.


Direct can do the same
Title: Re: "DIRECT" Goes Live
Post by: Zachstar on 10/30/2006 04:39 PM
Quote
JIS - 30/10/2006  10:35 AM

The biggest advantage of Ares1 / AresV combination is that Ares V itself can easily switch from manned lunar missions to robotic missions with LSAM descent stage serving as robotic platform or lunar base supply mission.


It is very simple switch.

As Jim said Direct can easily do the same.

Quote
JIS - 30/10/2006  10:35 AM
Any modification of base line DIRECT costs something and its advantage is disappearing.

Extra costs for mods were built into the cost unless ross suddenly removed them.

Quote
JIS - 30/10/2006  10:35 AM
And what about safety? Do you have any idea why approach similar to DIRECT is considered (by ESAS) safer than AresV?

I consider sitting on a barely tested 5 seg SRB compared to well tested 4 segs and RS-68s very unsafe. And as for safety for the unmanned Direct shares alot more with STS than AresV so it is even more tested and proven safe.

JIS can I ask what is your real problem with Direct?
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 10/30/2006 04:58 PM
Quote
JIS - 29/10/2006  6:09 PM

Quote
clongton - 29/10/2006  6:01 PM

Quote
JIS - 29/10/2006  4:49 PM
ET is substantially different to Ares core because there are different loads, different engines, different pipework and instrumentation. This means complete redesign. The struture of the tank might look similar but will be different.
However, it is possible that some tooling from ET could be used. But the main cost will be redesign, development, testing and certification of the core and engines.
Ares core does not yet exist, so the redesign you speak of doesn't exist. Direct reuses the existing Shuttle ET, almost completely "as is". Only major (actually minor) modifications are to remove Shuttle attachment structure and add thrust structure on fdw & aft ends. Plus some minor additional tweeking.

Ares II core is what Ross' DIRECT must use.

Using Musk's lesson learned file I would be afraid of buckling the damn tank because Ross is going to put 80t of payload on the top of ET and fire all engines he has.
Hopefully, everything will collapse by its own weight long before the actual explosive launch.

Not an issue.  First over 80% of the current ET mass is above the LOX/LH2 intertank join at lift off.  The Thrust of the SRB’s takes out about 87% of this load assuming a 100,000 kg mass above the LOX tank.  That leaves about 13% of the load to be transmitted down the LH2 tank to the 2 RS-68 engines.  In a four engine configuration the upper stage mass must grow in order to not over accelerate the vehicle and optimize the lift capacity. In this scenario the compressive loads do get much higher than the current LH2 tank sees.  Couple options, make a stronger tank.  Two have the engine thrust beam pass off some load to the SRB’s via a new aft thrust load attachment which then transmits the load up to the existing thrust beam in the intertank region.  

Either way this load path is far easier to deal with than the one between the SRB and Upper stage on the Stick.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 06:02 PM
Quote
Kaputnik - 30/10/2006  6:05 AM

Kraisee-
out of curiosity, if you launched a DIRECT+Orion 'underweight', i.e. with no ballast (and no EDS), what sort of orbit could be achieved? If a suitable launch window were used (since the RS68s would not be restarted in space and it would have to be a 'one-burn' scenario) could TLI be achieved? If not, what sort of eliptical orbit would result?

Kaputnik,
   A very quick and dirty check shows that a basic DIRECT (no EDS) should easily be able to launch an Orion CEV to 22,000nm GEO.

   Some form of TLI might be possible by launching straight into TLI and burning some of the CEV's own propellant.   But without the EDS, I'm unsure if the CEV would have sufficient propellant left for a full Lunar Orbit Insertion and TEI burn later.    A simple figure-of-8 Lunar flyby may be possible.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 06:10 PM
Quote
JIS - 30/10/2006  7:55 AM

OK, you apparently know that better. Only different thickness, different shape of LOX tank, fwd and aft sections, thrust structure. OK I believe you that's old concept and easily done.
My point was that in the slightly more complicated way its possible to design Ares V core as well. The only difference is manufacturing.

Actually Ares-V changes aren't limited to manufacturing.   As the Proposal demonstrates, it does requires completely new tooling to handle a 33ft wide core, but also requires many changes within the VAB, needs three completely rebuilt MLPs, each with a massive new LUT on board.   New Crawlers are then needed to move the much heavier stack around, and extensive Pad changes are necessary too.

And that's in addition to the long list of mods required by Ares-I including two completely new MLP's with their own LUT's.

DIRECT removes nearly all of those additional costs and schedule-sensitive items from the development program.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 06:11 PM
Quote
clongton - 30/10/2006  8:33 AM

Quote
Norm Hartnett - 29/10/2006 4:22 PM
It is fairly clear that the Ares I is already in political trouble as well as having the engineering problems Ross described in the Direct presentation. Both the GAO report and the CBO report did not come out of nowhere, congressman requested these reports and both reports call the Ares I into question, the GAO from a procurement procedure standpoint and the CBO from the EELV alternative standpoint.
Ross - did you send a copy of the paper to these congressmen?

Not yet.   Good thinking.   Thank-you.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 06:20 PM
Quote
JIS - 30/10/2006  10:59 AM

However, I was concerned about docking of CEV+LSAM to EDS. There must be some kind of navigation and some way how to connect LSAM to EDS. As LSAM is the most weight critical part of the system I'm afraid that this is not too effective.
Maybe the same instrument used for lunar landing could be used but still some special docking adaptor is required.

My personal approach (probably not the one NASA would come come up with themselves), is this:

1) The Core Stage of the Crew LV has a bracket, with a 'female' mechanical connection.

2) The LSAM has a 'male' connection which is locked to the Core Stage during launch.

3) After Orbital insertion, these are mechanically disconnected and the LSAM/CEV make the circ. burn (different approaches to this are possible, so I will deliberately glance over the specifics of the circ. burn).

4) The EDS is waiting in orbit already with another 'female' mechanical connection.

5) The LSAM carefully docks with the EDS and the male & female connectors are locked together, amking a solid connection for the TLI.

6) After the TLI, *both* parts of the heavy docking mechanisms are discarded using pyro disconnects - so the docking mechanisms mass does *not* need to be taken to the Lunar surface.


That's the *sort* of approach I would offer as a suggestion.   I would hope that some bright spark within NASA could actually come up with something even better though :)

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 06:29 PM
Quote
JIS - 30/10/2006  11:35 AM

The biggest advantage of Ares1 / AresV combination is that Ares V itself can easily switch from manned lunar missions to robotic missions with LSAM descent stage serving as robotic platform or lunar base supply mission.

It is very simple switch.

Any modification of base line DIRECT costs something and its advantage is disappearing.

Jim is correct - DIRECT is precisely the same as Ares-V from this point of view.

Try to think of DIRECT as a "mini-Ares-V", with about 70% of the payload performance and fewer engines to go wrong.

Everything Ares-V is planned to do, DIRECT can also accomplish.   If not through sheer capacity, then by being able to fly 8 extra flights for the same cost of the Ares-V.

Oh, and DIRECT is also the initial CLV booster design too.


Quote
And what about safety? Do you have any idea why approach similar to DIRECT is considered (by ESAS) safer than AresV?

The two key differences regarding Ares-V and DIRECT safety figures are:-

1) Ares-V has two SRB's which are flying in a configuration previously untested and unflown before.   DIRECT uses the exact same ones which have flown 182 manned missions successfully already.

2) Ares-V also have five core main engines.    DIRECT, only two.


And while it doesn't affect the numbers at all, the Ares-V is physically a much larger booster than we've been used to launching for the last 30 years.   DIRECT is considerably smaller and is very close to hardware flying today - it is considerably more of a "known quantity".

Ross.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 10/30/2006 06:37 PM
So a single Direct with EDS and a fairing can launch an LSAM descent stage that can very roughly carry about 14 metric tons of payload to lunar surface? (Compared to 20 tons with Ares V?)
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/30/2006 07:43 PM
Quote
meiza - 30/10/2006  11:20 AM

So a single Direct with EDS and a fairing can launch an LSAM descent stage that can very roughly carry about 14 metric tons of payload to lunar surface? (Compared to 20 tons with Ares V?)

Wow, is that right? That is much better than I had thought.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 08:42 PM
A single DIRECT + EDS can launch 38mT payload (LSAM) to TLI.

Ares-V can do 54mT to TLI, but costs at least $1.3Bn more - every year.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: SileasResearch on 10/30/2006 09:27 PM
Ross - check your info _at_ directlauncher.com mail for some comments I sent you regarding the paper (non-technical - typos, formating, etc.) and for information about the IEEE Aerospace Conference to which I think you should submit this paper.
Thanks,
David
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/30/2006 09:35 PM
Ok Ross we know it is cheaper.

Can a single Direct + EDS deliver LSAM to lunar surface with sufficient fuel on board to make Lunar Orbit Rendezvous and how much payload above that can it deliver?

Or to perform that sort of mission does it require two launches one with EDS and one with LSAM? (Yes we know it will still be cheaper in the overall picture)
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/30/2006 09:50 PM
DOH. Doing the math 54-38=16, 20-16=4 it would appear that a single Direct+EDS can deliver 4mT of cargo to the lunar surface with an LSAM.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 10/30/2006 10:02 PM
Ok, more clarification. For Ares V robotic missions, the LSAM is actually larger than for crewed missions, since the EDS doesn't have to TLI and the LSAM doesn't have to LOI insert the CEV. (LSAM mass 54 vs 33 tons in astronautix, but it talks about methane propellants. And btw yes, I'm speaking metric all the time.)
But with Direct, the robotic LSAM actually is close to the same size as manned... You fly with a partially fueled EDS and inject 38 tons to TLI. The partially fueled EDS can do it since the injection mass doesn't have CEV. And that kind of LSAM could land more than the crewed since it doesn't have to TLI the CEV.
But is the LSAM the same size, or is it bigger or smaller? And if it's smaller, what happens if you use a normal LSAM with partial refueling? That gives some payload penalty in the form of empty tanks. Or could the EDS be tanked even less and the LSAM to full and staging to LSAM be performed earlier so you don't have to lug around the empty EDS? Or does it have better ISP? Maybe these questions don't have much effect on payload and are also very far in the future to merit investigation.

Can we get cheap robotic missions with same-size LSAM descent stage as human missions? That eliminates one configuration too and saves money.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 10/30/2006 10:17 PM
My understanding was that one reason you do robotic LSAMs was to have a backup LSAM for crew return.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 10/30/2006 10:23 PM
Quote
Norm Hartnett - 30/10/2006  5:18 PM

Ok Ross we know it is cheaper.

Can a single Direct + EDS deliver LSAM to lunar surface with sufficient fuel on board to make Lunar Orbit Rendezvous and how much payload above that can it deliver?

Or to perform that sort of mission does it require two launches one with EDS and one with LSAM? (Yes we know it will still be cheaper in the overall picture)

A single DIRECT + EDS can place over 36mT into a stable Lunar Orbit.

The mass of what can be landed is entirely down to the mass & design of the descent stage at that point, and we have not got trades for that yet.   As a rule of thumb, expect about 70% of whatever Ares-V can do.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: George CA on 10/31/2006 12:40 AM
Ross, why do you think this system wasn't adopted by NASA/ESAS? What do you see as the underlying reasons for their decision to go with the 1.5 system?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/31/2006 01:11 AM
Quote
George CA - 30/10/2006  8:23 PM

Ross, why do you think this system wasn't adopted by NASA/ESAS? What do you see as the underlying reasons for their decision to go with the 1.5 system?

The ESAS is the 1.5 launches.     Direct doesn't meet all the requirements in the ESAS (mass to lunar orbit)
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 09:58 AM
Quote
kraisee - 30/10/2006  1:03 PM

Quote
JIS - 30/10/2006  10:59 AM

However, I was concerned about docking of CEV+LSAM to EDS. There must be some kind of navigation and some way how to connect LSAM to EDS. As LSAM is the most weight critical part of the system I'm afraid that this is not too effective.
Maybe the same instrument used for lunar landing could be used but still some special docking adaptor is required.


5) The LSAM carefully docks with the EDS and the male & female connectors are locked together, amking a solid connection for the TLI.


This is a part I was concerned about. It is docking operation which could easily fail. Much more easily than CEV-LSAM docking.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 10/31/2006 10:40 AM
Quote
JIS - 31/10/2006  10:41 AM
This is a part I was concerned about. It is docking operation which could easily fail. Much more easily than CEV-LSAM docking.

As Ross has stated on a number of occasions now there are many options here. My own feeling is that it would be best to leave the CEV/LSAM coupled in their launch configuration until docking with the EDS. Thus the CEV would dock nose-first with the EDS and the operation would in effect be no different to a CEV/LSAM docking. Following EDS jettisont the two craft separate, CEV translates, and docks with the LSAM. Whatever structure was used to couple the two craft could then be jettisoned.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 10:55 AM
Quote
SMetch - 30/10/2006  11:41 AM

Quote
JIS - 29/10/2006  6:09 PM

Using Musk's lesson learned file I would be afraid of buckling the damn tank because Ross is going to put 80t of payload on the top of ET and fire all engines he has.
Hopefully, everything will collapse by its own weight long before the actual explosive launch.

Not an issue.  First over 80% of the current ET mass is above the LOX/LH2 intertank join at lift off.  The Thrust of the SRB’s takes out about 87% of this load assuming a 100,000 kg mass above the LOX tank.  That leaves about 13% of the load to be transmitted down the LH2 tank to the 2 RS-68 engines.  In a four engine configuration the upper stage mass must grow in order to not over accelerate the vehicle and optimize the lift capacity. In this scenario the compressive loads do get much higher than the current LH2 tank sees.  Couple options, make a stronger tank.  Two have the engine thrust beam pass off some load to the SRB’s via a new aft thrust load attachment which then transmits the load up to the existing thrust beam in the intertank region.  

Either way this load path is far easier to deal with than the one between the SRB and Upper stage on the Stick.

Wrong. The worst case is at higher acceleration when LOX tank in ET supports hydrostatic pressure only and its own mass. With Direct it must stand the hydrostastic load plus weight of the payload (EDS+payload=70t or more). The maximum acceleration of Direct is about 4g or more (Ross would know exact number) which is much higher than STS (3g). This is after SRB separation.
LHX tank must stand higher loads too because of payload at the top and higher acceleration. This loads are simply not there with STS.
I think that redesign of the tanks will take little less time and certification than Ares V core. Jim says that the result will be only higher thickness and weight of the tank compared to ET.
If the diferent thickness and shape is not a concern in Michoud than its not going to be a problem.
They say the different diameter is a problem because of new tooling.
Unfortunatelly I know little about manufacture processes of the rocket tanks so I can't say how difficult would be to produce 10m Ares core, 8m EDS and 5.5m US (for Ares1/V) compared to 8m core and EDS for Direct.
But I doubt the difference will be in many billions.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 11:07 AM
Quote
Kaputnik - 31/10/2006  5:23 AM

Quote
JIS - 31/10/2006  10:41 AM
This is a part I was concerned about. It is docking operation which could easily fail. Much more easily than CEV-LSAM docking.

As Ross has stated on a number of occasions now there are many options here. My own feeling is that it would be best to leave the CEV/LSAM coupled in their launch configuration until docking with the EDS. Thus the CEV would dock nose-first with the EDS and the operation would in effect be no different to a CEV/LSAM docking. Following EDS jettisont the two craft separate, CEV translates, and docks with the LSAM. Whatever structure was used to couple the two craft could then be jettisoned.

This means docking port, docking support systems and some type of communication for EDS. The CEV+LSAM fairing will cut directly to CEV+LSAM mass (few mT). The docking operation would have to be done by LSAM engines and CEV' RCS complicating control. As the LSAM is the most weight critical component this will directly cut to the Moon landed mass.
Carying CEV+LSAM fairing across the TLI cuts again to LSAM mass as CEV is already of minimum weight.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/31/2006 11:18 AM
Quote
JIS - 31/10/2006  6:38 AM
Unfortunatelly I know little about manufacture processes of the rocket tanks so I can't say how difficult would be to produce 10m Ares core, 8m EDS and 5.5m US (for Ares1/V) compared to 8m core and EDS for Direct.
But I doubt the difference will be in many billions.

The bulk of savings are not in the manufacture.  They are from not having to modify the launch base.   The VAB, MLP's, crawlers, etc can be use with minor mods since the ET and SRB's are in the same positions.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 11:23 AM
Quote
kraisee - 30/10/2006  5:06 PM

A single DIRECT + EDS can place over 36mT into a stable Lunar Orbit.

Ross.

Ross could you break it down to more uderstandable numbers? As I uderstand DIRECT it launches about 70t or so to 80x160nm. With EDS fired suborbitally you claim it can lift about 90t to this orbit. In this mass is apparently EDS and propellants. So I suppose that instead of some propellants you take some tons of payload and perform TLI. Then you perform LOI with EDS+payload to lunar orbit.
My question is what is the payload and what are the dry&gross weight for EDS.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 10/31/2006 11:29 AM
Jis wrote:
"This means docking port, docking support systems and some type of communication for EDS. The CEV+LSAM fairing will cut directly to CEV+LSAM mass (few mT). The docking operation would have to be done by LSAM engines and CEV' RCS complicating control. As the LSAM is the most weight critical component this will directly cut to the Moon landed mass.
Carying CEV+LSAM fairing across the TLI cuts again to LSAM mass as CEV is already of minimum weight."



Firstly, 2xDIRECT delivers a substantially larger payload to LEO than the 1.5xAres plan. This given a certain room (c.15mT) for margin.


You don't need the whole aerodynamic fairing/SLA to be carried past LEO, just some basic structure to link the Orion and LSAM. Not significant given the greater capacity of 2xDIRECT
Orion/LSAM need to be able to operate as a single spacecraft because they do the LOI burn together. LSAM engines would also be used for the 'OMS1' burn.
Yes, EDS will need docking apparatus. But this is in common with all DIRECT plans. Again, the weight would be negligible given the overcapacity.
Finally, it is worth mentioning that if the LSAM is so weight critical, why have NASA elected to use the LSAM to do LOI instead of Orion?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/31/2006 11:33 AM
"Finally, it is worth mentioning that if the LSAM is so weight critical, why have NASA elected to use the LSAM to do LOI instead of Orion?"

So it can do an unmanned lunar sortie
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 11:34 AM
Quote
Jim - 31/10/2006  6:01 AM

The bulk of savings are not in the manufacture.  They are from not having to modify the launch base.   The VAB, MLP's, crawlers, etc can be use with minor mods since the ET and SRB's are in the same positions.

Yeah, it seems to be right. So most of these many billions savings goes from these modifications?
My only concern with this is how old this infrastructure really is. I think that MLP's and crawlers basic structures are about 40 years old. Is it possible to operate them for another 20 years? Isn't possible to canibalise usefull parts for new infrastructure?
Mybe I'm worng because I know very little about this. But generally its sometimes better to build new structure than repair and modificate the old one (several decades old).
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 11:48 AM
Quote
Kaputnik - 31/10/2006  6:12 AM

Firstly, 2xDIRECT delivers a substantially larger payload to LEO than the 1.5xAres plan. This given a certain room (c.15mT) for margin."


This margin could quickly disappear with changes to EDS and LSAM.
However, my biggest concern is with safety and responsibility of manned DIRECT (launching LSAM+CEV with EDS waiting at LEO could cause more delays), more complicated mission design and less performance (or incompatibility) with LSAM derived robotic exploration & lunar base support.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 10/31/2006 12:08 PM
Quote
JIS - 31/10/2006  12:31 PM
...my biggest concern is with safety and responsibility of manned DIRECT (launching LSAM+CEV with EDS waiting at LEO could cause more delays), more complicated mission design and less performance (or incompatibility) with LSAM derived robotic exploration & lunar base support.

I presume you are comparing DIRECT to Ares?
DIRECT offers no disadvantage in terms of LEO rendezvous- there are still two launches, one of them manned. Could you explain what the difference is in terms of safety and delays?

With DIRECT the LSAM will be smaller. But LSAM design is not set in stone. Even with the Ares plan there are comlications, for example:
- Option One: LSAM optimised for a c.76t LOI burn and delivery of crew to the surface. When used unmanned the LOI mass would be only 54t allowing a substantial mass saving, but the hardware would be unable to deliver any more mass to the surface so this is 'wasted' capacity.
- Option Two: LSAM optimised for a c.54t LOI burn and delivery of maximum cargo to the surface. When used in manned missions the LSAM is over-engineered to carry heavier cargo and thus wastes mass.
- Option Three: Two LSAM derivatives, one for cargo and one for crew. Expensive.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 01:02 PM
Quote
Kaputnik - 31/10/2006  6:51 AM

Quote
JIS - 31/10/2006  12:31 PM
...my biggest concern is with safety and responsibility of manned DIRECT (launching LSAM+CEV with EDS waiting at LEO could cause more delays), more complicated mission design and less performance (or incompatibility) with LSAM derived robotic exploration & lunar base support.

I presume you are comparing DIRECT to Ares?
DIRECT offers no disadvantage in terms of LEO rendezvous- there are still two launches, one of them manned. Could you explain what the difference is in terms of safety and delays?

ESAS needs two docking events and one docking port: CEV with LSAM+EDS at LEO and LSAM with CEV at LLO. Direct needs three docking events and two docking ports: CEV+LSAM with EDS at LEO, redocking of CEV with LSAM+EDS, docking of LSAM with CEV at LLO.

Delays could be caused when EDS is launched first and then manned DIRECT with LSAM and CEV is to be launched. With Ares 1 this is no problem as Ares 1 is inherently safer and simpler and flight configuration will be extensively tested during flights to ISS. DIRECT however, will not undergo such testing with CEV+LSAM config. It is likely that LSAM itself will cause scrubs and delays.      

Quote
With DIRECT the LSAM will be smaller.
???

Quote
But LSAM design is not set in stone. Even with the Ares plan there are comlications, for example:
-Option One: LSAM optimised for a c.76t LOI burn and delivery of crew to the surface. When used unmanned the LOI mass would be only 54t allowing a substantial mass saving, but the hardware would be unable to deliver any more mass to the surface so this is 'wasted' capacity.
- Option Two: LSAM optimised for a c.54t LOI burn and delivery of maximum cargo to the surface. When used in manned missions the LSAM is over-engineered to carry heavier cargo and thus wastes mass.
- Option Three: Two LSAM derivatives, one for cargo and one for crew.

Unmanned LSAM could be heavier because  
1.   EDS+LSAM doesn’t need to wait at LEO
2.   EDS doesn’t need to carry CEV at TLI
3.   LSAM doesn’t need to carry CEV at LOI
4.   LSAM doesn’t need to go to Moon through the LLO but it can land directly
5.   LSAM has spare thrust for landing.

The problem with DIRECT is that it is not optimised for this option. The only thing which has to be changed with ESAS design is to replace the ascend stage and crew support of LSAM with cargo and upgrade landing legs.
Title: Re: "DIRECT" Goes Live
Post by: Heg on 10/31/2006 01:13 PM
Wow, if there's going to be "some basic structure to link the Orion and LSAM" I think it would be better to jettison the fairing just after MECO and prior to circularizing burn - saving some LSAM's fuel.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 10/31/2006 01:20 PM
Quote
JIS - 31/10/2006  1:45 PM
Unmanned LSAM could be heavier because  
1.   EDS+LSAM doesn’t need to wait at LEO
2.   EDS doesn’t need to carry CEV at TLI
3.   LSAM doesn’t need to carry CEV at LOI
4.   LSAM doesn’t need to go to Moon through the LLO but it can land directly
5.   LSAM has spare thrust for landing.

The problem with DIRECT is that it is not optimised for this option. The only thing which has to be changed with ESAS design is to replace the ascend stage and crew support of LSAM with cargo and upgrade landing legs.

Yes, the Ares V allows a heavier cargo LSAM. I am aware of this and the factors you posted above were considered when I made my previous post. But to actually produce any benefit this will require modifications from the manned version. The descent stage may need more propellant, higher thrust engines, upgraded RCS, strengthened landing legs and a strengthened 'chassis'; so to optimise it for the cargo role means almost a new spacecraft- it is certainly more of a departure from baseline than modifying an ET to make a DIRECT Core, which you seem to take exception to. My post above was an attempt to explain the options which are available. Two different LSAMs is one option but an expensive one.

On the other points- a DIRECT-launched LSAM will have to be around 70% smaller than an Ares V launched LSAM, if the unmanned single-launch option is retained (which is should be, for potential surface resuce missions, in my opinion). As I see it this is the single main drawback of DIRECT but not an insurmountable one. There's no such thing as a free lunch though. You don't save $35bn without some sort of knock-on effect.

If DIRECT were chosen now and Ares were dropped, it could be flying by 2011. That gives several years to build up flight experience, certainly more than will be accumulated with Ares I before the start of lunar operations. Saying Ares 1 is inherently safer and simpler is an opinion and not a fact.
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 10/31/2006 01:36 PM
Now, here's the $64 billion dollar question: would the lower cost and faster schedule of Direct allow for a sooner landing on the Moon, within the current budgets?

Simon ;)
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 02:31 PM
Quote
Yes, the Ares V allows a heavier cargo LSAM. I am aware of this and the factors you posted above were considered when I made my previous post. But to actually produce any benefit this will require modifications from the manned version. The descent stage may need more propellant, higher thrust engines, upgraded RCS, strengthened landing legs and a strengthened 'chassis'; so to optimise it for the cargo role means almost a new spacecraft- it is certainly more of a departure from baseline than modifying an ET to make a DIRECT Core, which you seem to take exception to. My post above was an attempt to explain the options which are available. Two different LSAMs is one option but an expensive one.
As I’ve explained the unmanned LSAM could be launched in exactly the same configuration as manned one or if allowances are acceptable the payload (stress) can be heavier for unmanned flight. No need to redesign anything. DIRECT LSAM is not this case.  

Quote
On the other points- a DIRECT-launched LSAM will have to be around 70% smaller than an Ares V launched LSAM, if the unmanned single-launch option is retained (which is should be, for potential surface resuce missions, in my opinion). As I see it this is the single main drawback of DIRECT but not an insurmountable one. There's no such thing as a free lunch though.


This would mean design of more configurations of LSAM which is not for free.

Quote
You don't save $35bn without some sort of knock-on effect.

This is very rough estimate. And I think it’s incorrect.

Quote
If DIRECT were chosen now and Ares were dropped, it could be flying by 2011.

Maybe DIRECT test flight with dummy core ;-))
Just kidding.
I agree that it should be possible to develop a rocket stage (core or US or EDS in 4-5 years). The first test flight of Ares 1 is in similar time frame as DIRECT although it will cost more in short term.    

Quote
That gives several years to build up flight experience, certainly more than will be accumulated with Ares I before the start of lunar operations. Saying Ares 1 is inherently safer and simpler is an opinion and not a fact.

There is something like 16 flights of exactly the same configuration of ARES 1 + CEV before lunar mission.
Ares 1 is inherently safer over DIRECT because there is one staging with two engines compared to two staging with four engines.
Ares 1 has roll control but it can be back up-ed unlike staging or engines.

Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/31/2006 02:43 PM
Quote
JIS - 31/10/2006  10:14 AM

1.  As I’ve explained the unmanned LSAM could be launched in exactly the same configuration as manned one or if allowances are acceptable the payload (stress) can be heavier for unmanned flight. No need to redesign anything. DIRECT LSAM is not this case.  

2. This would mean design of more configurations of LSAM which is not for free.

3. This is very rough estimate. And I think it’s incorrect.

4. I agree that it should be possible to develop a rocket stage (core or US or EDS in 4-5 years). The first test flight of Ares 1 is in similar time frame as DIRECT although it will cost more in short term.    


5.  There is something like 16 flights of exactly the same configuration of ARES 1 + CEV before lunar mission.
6.  Ares 1 is inherently safer over DIRECT because there is one staging with two engines compared to two staging with four engines.7.  
7.  Ares 1 has roll control but it can be back up-ed unlike staging or engines.


1. There is no difference between the weight of a manned and unmanned LSAM in any concept (Direct or ESAS)

2.   there isn't a Direct LSAM or ESAS LSAM, there is only one configuration of the LSAM.  It would be determined early if Direct is used.

3.  What is your qualifications to say it is incorrect.  35, 20 or 5 billion is still savings
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/31/2006 02:50 PM
Quote
JIS - 31/10/2006  10:14 AM

1.  As I’ve explained the unmanned LSAM could be launched in exactly the same configuration as manned one or if allowances are acceptable the payload (stress) can be heavier for unmanned flight. No need to redesign anything. DIRECT LSAM is not this case.  

2. This would mean design of more configurations of LSAM which is not for free.

3. This is very rough estimate. And I think it’s incorrect.

4. I agree that it should be possible to develop a rocket stage (core or US or EDS in 4-5 years). The first test flight of Ares 1 is in similar time frame as DIRECT although it will cost more in short term.    


5.  There is something like 16 flights of exactly the same configuration of ARES 1 + CEV before lunar mission.
6.  Ares 1 is inherently safer over DIRECT because there is one staging with two engines compared to two staging with four engines.
7.  Ares 1 has roll control but it can be back up-ed unlike staging or engines.


1. There is no difference between the weight of a manned and unmanned LSAM in any concept (Direct or ESAS)

2.   there isn't a Direct LSAM or ESAS LSAM, there is only one configuration of the LSAM.  It would be determined early if Direct is used.

3.  What is your qualifications to say it is incorrect.  35, 20 or 5 billion is still savings

4.  The core of direct could be completed earlier since it used ET heritage

5.  No, 12 missions

6.  The Direct engines are started on the ground and are safer than the airstart of the Stick

7.  Not a valid comparision.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 03:39 PM
Quote
Jim - 31/10/2006  9:33 AM

1. There is no difference between the weight of a manned and unmanned LSAM in any concept (Direct or ESAS)

2.   there isn't a Direct LSAM or ESAS LSAM, there is only one configuration of the LSAM.  It would be determined early if Direct is used.

I was reffering to single DIRECT launch of EDS + robotic payload.

Quote
3.  What is your qualifications to say it is incorrect.  35, 20 or 5 billion is still savings

Same as anybody else here.

Quote
4.  The core of direct could be completed earlier since it used ET heritage

The question was if it could be launched by 2011.

Quote
6.  The Direct engines are started on the ground and are safer than the airstart of the Stick
7.  Not a valid comparision.

Sorry it was meant to be together.
OK so if DIRECT can't be more responsible than Ares1 is it safer?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/31/2006 03:55 PM
Quote
JIS - 31/10/2006  11:22 AM

3.  What is your qualifications to say it is incorrect.  35, 20 or 5 billion is still savings

Same as anybody else here.


Not quite.  I work for NASA
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 04:09 PM
So you are qualified to say that DIRECT would save $35bn. Correct?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/31/2006 04:16 PM
COULD save $35B, but I qualified my answer stating that any savings in the billions is better.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 10/31/2006 04:33 PM
Well, I've said that I don't believe that it will be $35B. My second and last comment about the price of DIRECT was that I don't believe that savings during design&manufacture of 8m cores + 8m EDS instead of 10m core + 8m EDS + 5.5 US will be in many billions.
I haven't made any other comments at this issue.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 10/31/2006 05:27 PM
Quote
JIS - 31/10/2006  12:16 PM

Well, I've said that I don't believe that it will be $35B. My second and last comment about the price of DIRECT was that I don't believe that savings during design&manufacture of 8m cores + 8m EDS instead of 10m core + 8m EDS + 5.5 US will be in many billions.
I haven't made any other comments at this issue.

Yes, there will.   All the tooling at MAF is set up for 8m.  Now you need new tooling for 10, 7, and 5.5m tanks.  That means there are 3 completely separates designs, not variants of a existing design.  Also, it is not just in the design of the core, it is the elimination of the  X billion dollar 5 segment SRB development.

Read the document, Ross lists all the savings
Title: Re: "DIRECT" Goes Live
Post by: meiza on 10/31/2006 07:36 PM
Regarding the LSAM mass for the umpteenth time, I actually think (not having run any analysis myself) that the Direct single-launch robotic LSAM is closer to the dual-launch crewed one (both about 33 tons?) than as with Ares V, where the robotic lander is much heavier (54 tons)...

There's so many posts about it in this thread and stuff in between that it's hard to get it. Not having to lug the 25 ton CEV in TLI helps that much.

But that can be seen to be actually hindering the complete utilization of Ares V making it not that much more capable than Direct in robotic missions. Or only that capable with extra cost of designing a much bigger LSAM descent stage.

Note that, as a separate issue, both robotic LSAMs are heavy after LOI since they didn't insert the CEV, so there is more margin from there... but if the manned LSAM is not overdesigned for the robotic one to land that much more mass (legs), the extra mass at LLO is wasted. Perhaps it can be used as fuel margin.
Title: Re: "DIRECT" Goes Live
Post by: Zond on 10/31/2006 10:08 PM
I like the direct proposal. And the arguments make a lot of sense. I am mostly concerned the Ares V will never get build because it will be a very easy victim in congress when cuts have to be made. Direct removes this concern.
I have one question: why are you choosing to launch the CEV and the LSAM together and then the EDS?  Wouldn't it be easier to give the LSAM and the CEV each their own EDS and then docking the CEV and LSAM in lunar orbit (or in L1 or L2)? This would avoid the akward LSAM/CEV to EDS docking and you have to make less changes to carry out cargo missions to the moon. I do see one big disadvantage: the LSAM would probably have to be smaller and your mass budget for the CEV would be too big.
Title: Re: "DIRECT" Goes Live
Post by: kfsorensen on 10/31/2006 11:11 PM
Quote
Zond - 31/10/2006  4:51 PM

Wouldn't it be easier to give the LSAM and the CEV each their own EDS and then docking the CEV and LSAM in lunar orbit (or in L1 or L2)? This would avoid the akward LSAM/CEV to EDS docking and you have to make less changes to carry out cargo missions to the moon. I do see one big disadvantage: the LSAM would probably have to be smaller and your mass budget for the CEV would be too big.
I've thought this would be a good idea too--wait until the LSAM has reached the "lunar vicinity" rendezvous point (be it LLO, L1, or L2) before launching the CEV.  That way you know that that part of the mission has made it that far.  Maybe the mass imbalance could be addressed by having the CEV carry the LSAM "cab" along as a "mission module", much like the orbital module in the Soyuz.  When it reached the LSAM, the mission module would attach to the LSAM, detach from the CEV, and fly down to and up from the lunar surface.

Later on, when we get to reusable LSAMs and lunar propellants, the CEV part of the system is already in the right configuration to drop down to a "single-launch" mission profile.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 10/31/2006 11:43 PM
Quote
Zond - 31/10/2006  11:51 PM
I like the direct proposal. And the arguments make a lot of sense. I am mostly concerned the Ares V will never get build because it will be a very easy victim in congress when cuts have to be made. Direct removes this concern.
I have one question: why are you choosing to launch the CEV and the LSAM together and then the EDS?  Wouldn't it be easier to give the LSAM and the CEV each their own EDS and then docking the CEV and LSAM in lunar orbit (or in L1 or L2)? This would avoid the akward LSAM/CEV to EDS docking and you have to make less changes to carry out cargo missions to the moon. I do see one big disadvantage: the LSAM would probably have to be smaller and your mass budget for the CEV would be too big.

I absolutely agree that Direct is a very good proposal.

Regarding the two EDS idea, how much would it help to launch the LSAM ascent stage togeather with the CEV?

Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/01/2006 05:11 AM
Quote
meiza - 31/10/2006  3:19 PM

Regarding the LSAM mass for the umpteenth time, I actually think (not having run any analysis myself) that the Direct single-launch robotic LSAM is closer to the dual-launch crewed one (both about 33 tons?) than as with Ares V, where the robotic lander is much heavier (54 tons)...

There's so many posts about it in this thread and stuff in between that it's hard to get it. Not having to lug the 25 ton CEV in TLI helps that much.

But that can be seen to be actually hindering the complete utilization of Ares V making it not that much more capable than Direct in robotic missions. Or only that capable with extra cost of designing a much bigger LSAM descent stage.

Note that, as a separate issue, both robotic LSAMs are heavy after LOI since they didn't insert the CEV, so there is more margin from there... but if the manned LSAM is not overdesigned for the robotic one to land that much more mass (legs), the extra mass at LLO is wasted. Perhaps it can be used as fuel margin.

Meiza,
   The single-launch robotic lander (and the 2-launch LOR only lander) must mass only 38mT.   The 2-launch EOR-LOR one can mass about 48mT.

   I wonder if the Descent Stage could not be designed to have a standard set of main tanks making the 38mT configuration, but have a set of optional tanks adding the extra 10mT for extra performance?

   That way the same basic lander design could be utilized for all missions.

   The ESAS design "looks" modular enough to do this fairly easily already...


   Of course, a 2nd, 3rd and even 8th launch still costs less than the first Ares-V, so you can still make massive gains by simply launching more flights...

Ross.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/01/2006 10:02 AM
Quote
Zond - 31/10/2006  4:51 PM
I have one question: why are you choosing to launch the CEV and the LSAM together and then the EDS?  Wouldn't it be easier to give the LSAM and the CEV each their own EDS and then docking the CEV and LSAM in lunar orbit (or in L1 or L2)? This would avoid the akward LSAM/CEV to EDS docking and you have to make less changes to carry out cargo missions to the moon. I do see one big disadvantage: the LSAM would probably have to be smaller and your mass budget for the CEV would be too big.

This would mean different design of CEV compared to what is being designed.
Other subsystems would be diferrent too but they are not in design yet (not Ares 1 case).
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/01/2006 02:24 PM
I wonder if this is a sign that NASA is beginning to reevaluate the Ares I-1 test flight and perhaps the entire Ares I concept. (From the “STS-125/Hubble may switch to Atlantis” article)

"While Constellation will suffer around a one year hit to their Pad 39B modification plans for the Ares I-1 test flight, the dual pad approach also allayed fears that the single pad (l-t-l) possibility was simply too ambitious."

It certainly slows spending on the Ares I infrastructure and may lengthen the window for evaluating Direct.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/01/2006 02:39 PM
Maybe they will cancel Ares I-1 completelly as some are calling for. But I doubt it.
Title: Re: "DIRECT" Goes Live
Post by: HD209458 on 11/01/2006 03:22 PM
Speaking of the cost, kraisee, do you have a more detailed break-down than the images you posted up here earlier (i.e. - the sand charts)? I would be interested to see how you arrived at the numbers you are using.
Title: Re: "DIRECT" Goes Live
Post by: imcub on 11/01/2006 05:55 PM
From my perspective, the biggest downside to building Direct is that Congress/the President would think NASA already has a 'big" booster and might not want to fund Ares V.  

So has any one considered this ... build Direct for most flights and then build Ares 5 if Congress and the President are still willing to fund it in 6 or 7 years.  The Ares I development cost could be saved, the moon would still reachable if Ares-V wasn't funded using an extra Direct flight or two.  CEV/ISS would happen sooner.   To make up for the lack of 5 segment boosters from Ares I, the Ares V could be designed using 3 SRBs (or 4) to make up for the lack of 2 segments.  

Any thoughts?



Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/01/2006 06:05 PM
Quote
HD209458 - 1/11/2006  11:05 AM

Speaking of the cost, kraisee, do you have a more detailed break-down than the images you posted up here earlier (i.e. - the sand charts)? I would be interested to see how you arrived at the numbers you are using.

HD, those numbers are based on the ones used in the November 2005 ESAS Report.   The ACI version of the report, which was accidentally released on NASAWatch for about 24 hours back at the start of the year, contained many of the numbers (see the sand chart attached below).   That led me to the original trade studies where those figures came from.   I have been given access to those, although I do not have a copy myself.

The figures were tailored further, after the changes in the CLV design from 4-seg/SSME config to 5-seg/J-2X and the CaLV conversion from 8.4m, 5xSSME, 2xJ-2X to 10m, 5xRS-68B, 1xJ-2X (development cost for J-2X and 5-seg is now absorbed by CLV) - again all of the numbers are based on the ESAS trades figures.

For any items which previously did not exist at all in the ESAS, I have gone to the horses mouth and sought my own quotes - for example the $25m figure for the Regen variant of the RS-68.   That is a ballpark number sourced unofficially, but directly, from PWR and is immediately comparative to the man-rated ablative variant at $20m each.


I recognise that the ESAS numbers are already out of date, but I do not have access to the more up-to-date numbers.   One source has offered up a lot of the current numbers, but I still have some gaps.   I am reluctant to change only part of the comparison without changing the rest.   ESAS is the only complete data-set I have.

The important thing is that the "proportion" of the costs will remain broadly the same no matter what has happened since.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/01/2006 06:15 PM
Quote
imcub - 1/11/2006  1:38 PM

From my perspective, the biggest downside to building Direct is that Congress/the President would think NASA already has a 'big" booster and might not want to fund Ares V.  

So has any one considered this ... build Direct for most flights and then build Ares 5 if Congress and the President are still willing to fund it in 6 or 7 years.  The Ares I development cost could be saved, the moon would still reachable if Ares-V wasn't funded using an extra Direct flight or two.  CEV/ISS would happen sooner.   To make up for the lack of 5 segment boosters from Ares I, the Ares V could be designed using 3 SRBs (or 4) to make up for the lack of 2 segments.  

Any thoughts?


Personally I think it all depends on NASA's success.

If NASA continues to drive Ares-I into what many are predicting will be a failure program, Congress simply won't trust them with the money for any second vehicle.

If NASA can however achieve the new moon missions successfully, there will be offers of cash to upgrade existing systems.

Either way, DIRECT doesn't *need* a second vehicle.   If there *IS* extra cash available to upgrade the systems, then the Growth Options can be built - but if no extra cash is made available, NASA can still continue to Mars with the standard 70mT & 98mT DIRECT configurations.

The second vehicle becomes 'a nice upgrade' rather than 'an essential element we must have'.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/01/2006 07:07 PM
Quote
imcub - 1/11/2006  7:38 PM

From my perspective, the biggest downside to building Direct is that Congress/the President would think NASA already has a 'big" booster and might not want to fund Ares V.  

So has any one considered this ... build Direct for most flights and then build Ares 5 if Congress and the President are still willing to fund it in 6 or 7 years.  The Ares I development cost could be saved, the moon would still reachable if Ares-V wasn't funded using an extra Direct flight or two.  CEV/ISS would happen sooner.   To make up for the lack of 5 segment boosters from Ares I, the Ares V could be designed using 3 SRBs (or 4) to make up for the lack of 2 segments.  

Direct is a big booster, what would be gained by developing Ares V after Direct? If you want to lauch more mass to the moon or go to mars divide your mission into approriate sized chunks and fax an order for more Directs. It must be far faster and cheaper then too develop a new launcher.

And Direct can be stretched with a five segment SRB:s, more fuel and third RS-68 if making it larger makes sense. It might make sense if the mission is to employ the development staff etc.

The only need I can think of for an even larger launcher would be for undividable missions such as launching complete spools with orbital elevator thread if such can be developed. If such a need is found it would probably be easiest to build a new pad and stack a laucher made out of bundled Direct parts on it.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/01/2006 07:15 PM
Quote
imcub - 1/11/2006  1:38 PM

From my perspective, the biggest downside to building Direct is that Congress/the President would think NASA already has a 'big" booster and might not want to fund Ares V.  

Any thoughts?
Assuming that Direct is actually selected to build, I don't see why NASA would WANT to build Ares V. The Direct heavy lift version with the growth option is a better vehicle in every way, and NASA would already have it.
See Appendix 9 in the paper.
Ares V......131.6 mT to ~30 x 100 nm orbit @ 28.5 degrees
Direct HL...137.5 mT to   60 x 160 nm orbit @ 28.5 degrees
That's 6 mT more payload to a better orbit. No contest
To build Ares V once Direct is built is a waste of funding and effort.
Direct replaces BOTH Ares I & Ares V
Title: Re: "DIRECT" Goes Live
Post by: kfsorensen on 11/01/2006 07:24 PM
Quote
Magnus_Redin - 1/11/2006  1:50 PM

The only need I can think of for an even larger launcher would be for undividable missions such as launching complete spools with orbital elevator thread if such can be developed. If such a need is found it would probably be easiest to build a new pad and stack a laucher made out of bundled Direct parts on it.
How about a momentum-exchange tether that could then "throw" CEVs propellantlessly from LEO to trans-lunar injection?
Title: Re: "DIRECT" Goes Live
Post by: josh_simonson on 11/01/2006 07:28 PM

That comparison is a little wierd.  The heavy 'direct' launcher outpaces the stock Aries V because it has a much better engine.  With the same engines, the bigger, wider, better fueled and higher fuel fraction Aries V aught to win.

 Kraisee: what would Aries V's performance be with 5x RS-68 'regen'?  That's a natural and straightforward growth option for the Aries V, and it's unfair to compare Direct with a slew of growth options to a static Aries V.

Title: Re: "DIRECT" Goes Live
Post by: imcub on 11/01/2006 07:32 PM
Quote
kraisee - 1/11/2006  12:58 PM

If NASA continues to drive Ares-I into what many are predicting will be a failure program ...



So how much of the failure predictions are coming from inside NASA?   I have been reading Jim's posts with great interest.  I know he is fully set against the first 4 segment PR launch, and he has shown a fair amount of interest, critical thought, and review of your Direct proposal, but I can not quite determine which he would choose if it were up to him.

Putting the technical issue's with the Stick aside, the Billions of $ that are going to be required for the infrastructure changes is huge in my mind.  It could be that the Stick might be the perfect size to launch a CEV, but between the development cost, infrastrure changes, a development time for the Stick, I have to believe that something like Direct is a better, faster, cheaper way.

By the way ... Nice proposal Ross.


Title: Re: "DIRECT" Goes Live
Post by: imcub on 11/01/2006 07:37 PM
Quote
clongton - 1/11/2006  1:58 PM

Quote
imcub - 1/11/2006  1:38 PM

From my perspective, the biggest downside to building Direct is that Congress/the President would think NASA already has a 'big" booster and might not want to fund Ares V.  

Any thoughts?
Assuming that Direct is actually selected to build, I don't see why NASA would WANT to build Ares V. The Direct heavy lift version with the growth option is a better vehicle in every way, and NASA would already have it.
See Appendix 9 in the paper.
Ares V......131.6 mT to ~30 x 100 nm orbit @ 28.5 degrees
Direct HL...137.5 mT to   60 x 160 nm orbit @ 28.5 degrees
That's 6 mT more payload to a better orbit. No contest
To build Ares V once Direct is built is a waste of funding and effort.
Direct replaces BOTH Ares I & Ares V

Opps ....  I've had it in my head that Direct was ~70% of the Ares V capacity.   I guess I missed the Direct HL option.

Thanks for the correction and sorry for the 2 booster suggestion  (... as imcub puts tail between his legs and slinks away ... )
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/01/2006 07:43 PM
Quote
josh_simonson - 1/11/2006  3:11 PM

That comparison is a little wierd.  The heavy 'direct' launcher outpaces the stock Aries V because it has a much better engine.  With the same engines, the bigger, wider, better fueled and higher fuel fraction Aries V aught to win.

 Kraisee: what would Aries V's performance be with 5x RS-68 'regen'?  That's a natural and straightforward growth option for the Aries V, and it's unfair to compare Direct with a slew of growth options to a static Aries V.

Yes the regen engine is a better engine, but I'm not sure that is the MAIN contributor to the better performance of Direct heavy. It definetely makes a difference, about 5% IIRC, however there is an underlining design difference at work here as well. 5 engines simply burn the fuel up way too quickly. Direct's 3 engines burn longer, getting better overall performance from the vehicle as a whole. I don't have the numbers in front of me but someone else on this thread has also addressed this design difference and wondered why the Ares V engineers overlooked this performance advantage. Upgrading Ares's engines would make a difference, but not enough to justify the cost. It's a case of diminishing returns.
Can someone speak to this difference?
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 11/01/2006 09:30 PM
Ross, would you mind posting the models you used to get the mass-to-LEO numbers? It'd be pretty interesting to see a line-by-line comparison with Ares V...

Simon ;)
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/01/2006 09:55 PM
Quote
clongton - 1/11/2006  2:26 PM

I don't have the numbers in front of me but someone else on this thread has also addressed this design difference and wondered why the Ares V engineers overlooked this performance advantage.

That would be me.  Here's where I asked the question:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=5086&start=1&posts=9

Still no definitive answer, though.
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/02/2006 12:13 AM
Quote
JIS - 31/10/2006  3:38 AM

Quote
SMetch - 30/10/2006  11:41 AM

Quote
JIS - 29/10/2006  6:09 PM

Using Musk's lesson learned file I would be afraid of buckling the damn tank because Ross is going to put 80t of payload on the top of ET and fire all engines he has.
Hopefully, everything will collapse by its own weight long before the actual explosive launch.

Not an issue.  First over 80% of the current ET mass is above the LOX/LH2 intertank join at lift off.  The Thrust of the SRB’s takes out about 87% of this load assuming a 100,000 kg mass above the LOX tank.  That leaves about 13% of the load to be transmitted down the LH2 tank to the 2 RS-68 engines.  In a four engine configuration the upper stage mass must grow in order to not over accelerate the vehicle and optimize the lift capacity. In this scenario the compressive loads do get much higher than the current LH2 tank sees.  Couple options, make a stronger tank.  Two have the engine thrust beam pass off some load to the SRB’s via a new aft thrust load attachment which then transmits the load up to the existing thrust beam in the intertank region.  

Either way this load path is far easier to deal with than the one between the SRB and Upper stage on the Stick.

Wrong. The worst case is at higher acceleration when LOX tank in ET supports hydrostatic pressure only and its own mass. With Direct it must stand the hydrostastic load plus weight of the payload (EDS+payload=70t or more). The maximum acceleration of Direct is about 4g or more (Ross would know exact number) which is much higher than STS (3g). This is after SRB separation.
LHX tank must stand higher loads too because of payload at the top and higher acceleration. This loads are simply not there with STS.

I'll be more specific,

We have actually optimized around this issue among others.  With the right main engine flow rate you can drain the Lox fast enough to compensate for the load increase once the SRB's taper off.  We used the current Shuttle external to internal load curve as a baseline to compare too. We also have a full 2nd stage to take advantage of the optimal lift capability of the base SSTS system with RS-68’s.  Bottomline this issue can be dealt with the above approach and/or by increasing the tank strength (weight) for two 2 RS-68 variants.  When you look at the MTOW to TLI efficiency ratio curve there will be a saw tooth of high and low points as you shoot for different TLI values utilize variations in the base SSTS system.  Either way these types of issues are well within experience limits something the stick doesn’t have.
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/02/2006 12:40 AM
Quote
clongton - 1/11/2006  12:26 PM

Quote
josh_simonson - 1/11/2006  3:11 PM

That comparison is a little wierd.  The heavy 'direct' launcher outpaces the stock Aries V because it has a much better engine.  With the same engines, the bigger, wider, better fueled and higher fuel fraction Aries V aught to win.

 Kraisee: what would Aries V's performance be with 5x RS-68 'regen'?  That's a natural and straightforward growth option for the Aries V, and it's unfair to compare Direct with a slew of growth options to a static Aries V.

Yes the regen engine is a better engine, but I'm not sure that is the MAIN contributor to the better performance of Direct heavy. It definetely makes a difference, about 5% IIRC, however there is an underlining design difference at work here as well. 5 engines simply burn the fuel up way too quickly. Direct's 3 engines burn longer, getting better overall performance from the vehicle as a whole. I don't have the numbers in front of me but someone else on this thread has also addressed this design difference and wondered why the Ares V engineers overlooked this performance advantage. Upgrading Ares's engines would make a difference, but not enough to justify the cost. It's a case of diminishing returns.
Can someone speak to this difference?

In a meeting we had at NASA HQ in Nov 2005 we suggested that using RS-68 with a true second stage would optimize the design.  They said the ISP was to low and SSME were the way to go.  When I showed them the performance curves ($/mT and mT to LEO) for this option, an option they never ran in ESAS, only the contractor from Aerospace Corp was taking any notes everyone else was taking another sip of the kool-aid.  I’m not sure but I think the Wal-Mart Lander was a product of that same meeting.  If true  they only got about 25% of what we were saying concern the system wide advantages of that approach and FUBAR'd the other 75%.  Chock up another one for hey Kool-aid.  Gee that guy is a lot tougher than he looks.

The "ESAS" knows all how dare you challenge the all wise "ESAS".  I think the next 30 years and 1/4 Trillion dollar program deserves more than 90 days.
Title: Re: "DIRECT" Goes Live
Post by: NASA_LaRC_SP on 11/02/2006 12:58 AM
Quote
rumble - 1/11/2006  4:38 PM

Quote
clongton - 1/11/2006  2:26 PM

I don't have the numbers in front of me but someone else on this thread has also addressed this design difference and wondered why the Ares V engineers overlooked this performance advantage.

That would be me.  Here's where I asked the question:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=5086&start=1&posts=9

Still no definitive answer, though.

I'm one of the number of NASA engineers who will only post on L2, but I will PM you an answer.

In regards to DIRECT. It has gained attention, especially with the Ares crisis.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/02/2006 03:51 AM
Quote
NASA_Langley_spammer - 1/11/2006  8:41 PM
In regards to DIRECT. It has gained attention, especially with the Ares crisis.

I wish there were some way to talk at a bit more length to people on the inside.   There are still quite a few ideas and concepts which were related to the concept, but had to be left out of the proposal because, at 33 pages, it was already getting too long to keep people's attention!

If there were only some way to share this info with people on the inside who are interested in the concept.   Ideally in some sort of Q & A environment.

I would really like a chance to answer people's questions more fully.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/02/2006 04:00 AM
Hmmm, just a thought...

NASA probably can't actually approach me for such info directly.   I'm betting they're concerned about what I want in return.   Nothing's free, right?   So I will make a request; just for the official record:-


If DIRECT were utilised, I would appreciate a private tour for myself, some friends and the group of contributors to the concept thus far, of the first DIRECT LV while it is being prepared for flight at KSC.   Also I would like VIP tickets to watch the launch from the Saturn-V Center.

That's what I want.   Nothing more.   I think that price is fairly cheap.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/02/2006 04:11 AM
Quote
simonbp - 1/11/2006  5:13 PM

Ross, would you mind posting the models you used to get the mass-to-LEO numbers? It'd be pretty interesting to see a line-by-line comparison with Ares V...

What exactly are you referring to Simon?

I have been utilizing a tool sourced from a chap in the European Space Agency which is used for "quick'n'dirty" rocket calculations there.   It is not as advanced as POST, but it has proven to be surprisingly accurate to within +/- 2%.

Once I had a configuration I was very happy with, I had a chap from MSFC volunteer to run up a simulation in POST for me.   He validated my findings and actually said my payload figures were quite conservative - about 3% lower than his (72,836kg to 60x160nm, 28.5d).


Using this tool I can easily create graphs of most things calculated through the flight profile using it.   Would that be of use to you?   I usually produce graphs of velocity, altitude, acceleration, dynamic pressure, pitch angle and AOA, and the DIRECT CLV data is included in Appendix 1 of the proposal.   I can graph any other criteria in the model too.

Ross.

Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/02/2006 04:23 AM
Quote
imcub - 1/11/2006  3:15 PM

So how much of the failure predictions are coming from inside NASA?

Nothing is coming through official channels - that would be bad PR for NASA and that could screw the whole program up - which NONE none of us want.

But many people on here either work within the Ares development program, or know people who are doing so.   Word is filtering, from most levels, about the problems Ares-I is suffering from.


I have now heard this from three different sources, but the performance is so poor, that the leading option for saving Ares-I right now is to add two Castor SRB's, with directional engines, to the base of the first stage.

This would offer a minor boost in performance, but would only bring payload mass back just up above 20mT to LEO, although the directional nozzles it would offer an alternative method for roll-control capability.

BUT, this is *NOT* a good solution because you have suddenly tripled the number of engines needed at launch - which COMPLETELY RUINS the safety factors of the concept.   Loss of Crew numbers fall below 1 in 1000 at that point.

That puts DIRECT about 400 points ahead of Ares-I on safety margins.   If that solution were chosen, the Ares-I concept should become utterly pointless to even the most casual observer.   It would be less safe, less powerful, far more expensive and longer to develop.   It loses to DIRECT in every single area at that point.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: ryan mccabe on 11/02/2006 05:54 AM
Ross, I've tried emailing you directly but for some reason my G-mail is acting finicky. I've drafted a form letter that people can send to their congressmen or senator if they are interested in getting the word out. Perhaps a "Get Involved" link on the DirectLauncher.com page with a list of the legislators on the Space/Science subcommittees and a download of the document?

Attach an executive summary to the back, and you can help get those appropriating the money to consider alternatives...
Title: Re: "DIRECT" Goes Live
Post by: Chris Bergin on 11/02/2006 11:20 AM
We've gone live with our take of DIRECT, in part one of two articles - the next covering the other four alternatives.

http://www.nasaspaceflight.com/content/?cid=4886
Title: Re: "DIRECT" Goes Live
Post by: RedSky on 11/02/2006 12:48 PM
Hey Ross,  I see the Directlauncher.com hit counter is nearing 11,000.  Not bad for being up only a week or so.  Someone's looking in.  Any count on the pdf downloads?   Let's see if there's a bump after the DIRECT article on NSF.  
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/02/2006 12:59 PM
Quote
kraisee - 1/11/2006  10:54 PM

Quote
simonbp - 1/11/2006  5:13 PM

Ross, would you mind posting the models you used to get the mass-to-LEO numbers? It'd be pretty interesting to see a line-by-line comparison with Ares V...

Once I had a configuration I was very happy with, I had a chap from MSFC volunteer to run up a simulation in POST for me.   He validated my findings and actually said my payload figures were quite conservative - about 3% lower than his (72,836kg to 60x160nm, 28.5d).


Could you make public dry and gross weight of stages plus engines estimated weight and isp?
It could be interresting.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/02/2006 03:06 PM
Quick reply to three messages:

Ryan, I have received your letter.   We are working out a way to utilise it, but we have to be very careful not to make NASA dig its heels in against the proposal.

RedSky, the site has been hosted on my own server and elsewhere on a faster server (thanks Chris) when the traffic was heavy.   I don't have details for the busy period, but my own system shows about 75% of people coming to the site are taking the time to grab the pdf too.

And JIS, I have been attempting to do so for a while now, but have been too busy to finish it.   As there is a request, I shall try to expedite that.   One complication though:   My contact at PWR asked me not to publicly reveal the performance of the RS-68 Regen.   I may have to put that info in L2 only.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: ryan mccabe on 11/02/2006 06:10 PM

Feel free to use it any way you like, or not at all. I got mail delivery errors both times I sent it, so I wasn't sure it was going out.

Best of luck!
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/02/2006 07:35 PM
Um, I'm not trying to sound obnoxious or anything honestly, but do you really think NASA is going to scrap a plan they have been working on for the past couple of years in favor a design that a model rocket hobbyist came up with? I also don't really see anything here that hasn't been looked at by NASA over and over since the early days of STS. If reducing development costs were really the driving factor NASA could have gone with a Shuttle C variant. NASA can get the money now so they want to use it to build something that can get us back to the moon--that is the goal and their mandate. If we try to do it on the cheap we will end up like STS. NASA traded development costs for long term usability. We ended up with something that in the long run cost us a lot more money. I fear that "Direct" would share the same fate--not quite up to a comprehensive lunar and mars program, but too expensive as a LEO ferry.  Its the stingy man who spends the most!

Also, I'm getting rather fed up with the rumors and whispering about dire things going on in the Ares I project. If you work on the project, are an aerospace engineer, or have any kind of real world experience building real launch vehicles (models and computer programs don't count!) then I would love to hear about what's going on--good or bad. If you just have "unnamed sources" or "gut feelings" leave them home.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/02/2006 07:47 PM
This is not the product of a model rocketry enthusiast. It is the product of some of the brightest minds at NASA, NASA field centers, and NASA's major contractors. Ross was the focal point of preparing the presentation, and he did one hell of a job. But the genesis of the paper comes from real space scientists and engineers in a position to propose something that will actually work, and work a lot better than the current design. These are professional people on the inside, not hobbyists looking for a name for themselves.  :o
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/02/2006 07:48 PM
"I'm not trying to sound obnoxious or anything honestly, but do you really think NASA is going to scrap a plan they have been working on for the past couple of years"

Yes, it has been called X-33, X-34, X-37, Shuttle-C, OMV, ASRM, FWC SRB, Shuttle Centaur, Triana, etc

"Also, I'm getting rather fed up with the rumors and whispering about dire things going on in the Ares I project."

Too bad, get ready for more
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/02/2006 07:59 PM
X-33, X-34, X-37, Shuttle-C, OMV, ASRM, FWC SRB, Shuttle Centaur, Triana, etc were not presidential mandates. They were at best vague demonstrations of technology looking for a raison d'etre. Shuttle Centaur was cancelled as being too dangerous after Challenger wasn't it?

Do you have anything intelligent to offer regarding Ares I? Actual information? I would love to here it--but save the sarcasm for your comedy routine please!
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/02/2006 08:00 PM
Quote
clongton - 2/11/2006  2:30 PM

This is not the product of a model rocketry enthusiast. It is the product of some of the brightest minds at NASA, NASA field centers, and NASA's major contractors.

Who apparently won't sign their names to it?
Title: Re: "DIRECT" Goes Live
Post by: RedSky on 11/02/2006 08:07 PM
Quote
Jim - 2/11/2006  2:31 PM

...   X-33, X-34, X-37, Shuttle-C, OMV, ASRM, FWC SRB, Shuttle Centaur, Triana, etc

And don't forget the OSP and CRV...
both which were stopped, if I recall,  because something better and more capable was needed instead.
Title: Re: "DIRECT" Goes Live
Post by: Chris Bergin on 11/02/2006 08:15 PM
Quote
tom nackid - 2/11/2006  8:18 PM

Also, I'm getting rather fed up with the rumors and whispering about dire things going on in the Ares I project. If you work on the project, are an aerospace engineer, or have any kind of real world experience building real launch vehicles (models and computer programs don't count!) then I would love to hear about what's going on--good or bad. If you just have "unnamed sources" or "gut feelings" leave them home.

Sources are always unnamed, unless you want to see people sacked. This site reports good and bad, but doesn't choose an angle, it simply reports what is actually going on. We have no control over if it's good or bad.

Where you got "gut feelings" from, I'm not at all sure.

Yeah, we'd all love nothing but good news, but actual news determines it, as it's called being objective, as opposed to head in the sand.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/02/2006 08:16 PM
Quote
tom nackid - 2/11/2006  2:43 PM

Quote
clongton - 2/11/2006  2:30 PM

This is not the product of a model rocketry enthusiast. It is the product of some of the brightest minds at NASA, NASA field centers, and NASA's major contractors.

Who apparently won't sign their names to it?

From the PDF of the proposal:

"Many highly qualified persons at NASA HQ and Field Centers and NASA's major contractors,
were among the contributors and critiques of the technical and financial merits of this approach.
Ultimately, after intense discussions and the resulting revisions, the general consensus is that this
approach, the “DIRECT” approach, is the one that will best serve the VSE and the national interests.
In order to not complicate their lives as they continue to focus on the tasks before them of trying to
implement the VSE as currently envisioned, I am providing them with the confidentiality they deserve.
They are all free, of course, to discuss this paper, and their role in its formation, if desired, with their
co-workers and managers as they see fit."

I'm not doubting Mr. Tierney's honesty, I would just feel more comfortable if I knew exactly who all these experts were and what their role currently is in the space program.
Title: Re: "DIRECT" Goes Live
Post by: Chris Bergin on 11/02/2006 08:19 PM
Quote
tom nackid - 2/11/2006  8:59 PM


I'm not doubting Mr. Tierney's honesty, I would just feel more comfortable if I knew exactly who all these experts were and what their role currently is in the space program.

I understand where you're coming from, but for them to be named would mean they'd likey get the sack for not towing the company line. It's not going to happen.

I know at least three of them, so you can trust me or not ;)
Title: Re: "DIRECT" Goes Live
Post by: ronatu on 11/02/2006 08:22 PM
I did not read all thread but still would like to suggest to make 3 version of rocket:
central core w/o SRBs for 25-30 mt to LEO;
CC+SRBs for upto 62.5 to LEO
and CC+SRBs upto 98 to LEO.
To cut expences.
Title: Re: "DIRECT" Goes Live
Post by: RedSky on 11/02/2006 08:29 PM
Gee, Tom.  From your Ares-I defensive posts, I would have thought you to be a NASA insider on the front lines of the program.  From your website, as a graphic artist and illustrator, I would think that even a model rocketeer would have a more informed take on the matter, let alone the highly professional and erudite group that is responsible for the DIRECT presentation.

Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/02/2006 08:33 PM
Quote
Chris Bergin - 2/11/2006  3:02 PM

Quote
tom nackid - 2/11/2006  8:59 PM


I'm not doubting Mr. Tierney's honesty, I would just feel more comfortable if I knew exactly who all these experts were and what their role currently is in the space program.

I understand where you're coming from, but for them to be named would mean they'd likey get the sack for not towing the company line. It's not going to happen.

I know at least three of them, so you can trust me or not ;)

Can you at least say what roles they play at NASA or a contractors and what credentials they have? Are they aerodynamicists, propulsion experts? Just saying "NASA employee" could me anything from the director of a center to a PR flack who like rockets.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/02/2006 08:39 PM
Quote
RedSky - 2/11/2006  3:12 PM

Gee, Tom.  From your Ares-I defensive posts, I would have thought you to be a NASA insider on the front lines of the program.  From your website, as a graphic artist and illustrator, I would think that even a model rocketeer would have a more informed take on the matter, let alone the highly professional and erudite group that is responsible for the DIRECT presentation.


Actually I'm not defending or attacking the Ares I project. As I said I don't have enough info to do either. If someone would like to give me some concrete info. -- good or bad--I would be happy to listen.

As for "highly professional and erudite group" again I have nothing that shows if this is true or not. I'm not accusing anyone of lying, but as I said all I am hearing is rumor, unnamed sources and NASA conspiracies.

PS: I am also a model rocketeer and have lost many a bird to rocket eating trees and rooftops.
Title: Re: "DIRECT" Goes Live
Post by: RedSky on 11/02/2006 08:53 PM
Quote
tom nackid - 2/11/2006  3:22 PM

Actually I'm not defending or attacking the Ares I project. As I said I don't have enough info to do either. If someone would like to give me some concrete info. -- good or bad--I would be happy to listen.

Are you a NSF L2 subscriber?  If you've been reading what's been going on over the past 6 months or so with Ares-I... you'd be looking for alternatives, too.
Title: Re: "DIRECT" Goes Live
Post by: imcub on 11/02/2006 09:45 PM
Quote
kraisee - 1/11/2006  11:06 PM

I have now heard this from three different sources, but the performance is so poor, that the leading option for saving Ares-I right now is to add two Castor SRB's, with directional engines, to the base of the first stage.

...

BUT, this is *NOT* a good solution because you have suddenly tripled the number of engines needed at launch - which COMPLETELY RUINS the safety factors of the concept.   Loss of Crew numbers fall below 1 in 1000 at that point.

That puts DIRECT about 400 points ahead of Ares-I on safety margins.   ...

Ross.

Speaking of safety ... if Ares V were to non-catestrophicly loose an engine ... I assume it could continue on to orbit.     (Of course that might depend on its altitude when it lost it)

What happens if Direct looses one of its two liquid fueled rockets?  

At what altitude could the mission continue with a CEV or fully loaded?

Since you have only 2 liquid fuel rockets, are the odds of an engine failure so much lower with 2 vs 5 that its actually safer?


Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/02/2006 09:49 PM
Quote
tom nackid - 2/11/2006  3:42 PM

X-33, X-34, X-37, Shuttle-C, OMV, ASRM, FWC SRB, Shuttle Centaur, Triana, etc were not presidential mandates.

Neither is the Stick.  The President didn't say go build the stick
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/02/2006 09:54 PM
Quote
ronatu - 2/11/2006  4:05 PM

I did not read all thread but still would like to suggest to make 3 version of rocket:
central core w/o SRBs for 25-30 mt to LEO;
CC+SRBs for upto 62.5 to LEO
and CC+SRBs upto 98 to LEO.
To cut expences.

Core alone can't make it to orbit.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/02/2006 09:54 PM
Quote
tom nackid - 2/11/2006  3:59 PM

I'm not doubting Mr. Tierney's honesty, I would just feel more comfortable if I knew exactly who all these experts were and what their role currently is in the space program.

They are scared for their jobs.

Anyone who doesn't tow the line, even in the face of impending disaster, is usually sacked.   You'd be amazed at the witch hunts I've seen in the past.   It's really brutal in that business.   They don't want to be the target of a witch hunt, and neither would I.   But my pay check isn't sourced from NASA at all, so I can stand up and present a face.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/02/2006 10:13 PM
Quote
tom nackid - 2/11/2006  4:16 PM

Can you at least say what roles they play at NASA or a contractors and what credentials they have? Are they aerodynamicists, propulsion experts? Just saying "NASA employee" could me anything from the director of a center to a PR flack who like rockets.

Of the people I have had contact me and contribute to the proposal, there has been a real mix!

From NASA, Lockheed, Boeing, USA, PWR, ATK, and a variety of other companies, there are managers and engineers from all levels (high, mid and low levels), there are indeed both aerodynamicists and propulsion engineers, also experts in the fields of payloads, life support, TPS, Ground Support Systems, manufacturing, architecture, quality control - to list but a few.   It has been an amazing amalgam.   What started just as a fun mental exercise on my part, grew into something far beyond my own capabilities - that's for sure!

Most people involved have simply offered their own expertise in order to assist the concept along - to help "put it on the correct rails" in that particular field.   None have actually been "anti Ares".   But they simply think the CLV is flawed and DIRECT just offers a better solution.

I won't be any more specific about the contributors than that.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/02/2006 10:36 PM
Quote
imcub - 2/11/2006  5:28 PM
Speaking of safety ... if Ares V were to non-catestrophicly loose an engine ... I assume it could continue on to orbit.     (Of course that might depend on its altitude when it lost it)

What happens if Direct looses one of its two liquid fueled rockets?  

At what altitude could the mission continue with a CEV or fully loaded?

Since you have only 2 liquid fuel rockets, are the odds of an engine failure so much lower with 2 vs 5 that its actually safer?

DIRECT has a considerable engine-out capability for CLV flights taking just an Orion to LEO.   Comparatively, the Ares-I doesn't have any engine-out capability.

And actually the Ares-V does not have engine out capability for Lunar 131mT payloads being planned - that is its maximum payload and assumes a 100% successful launch every time.   It can *probably* lose one engine very late in the flight (last 30 secs or so before MECO) and still make a suitable stable orbit, but that's all the engine-out capability built in to it currently.

The original ESAS CaLV did have engine-out capability when in 5xSSME form.

DIRECT is in precisely the same boat as Ares-V.   For full payload mass missions, it needs all of its engines, although again, it does have a bit of tollerance towards the end of the trajectory.   Specific numbers still need to be worked out in more detail in something like POST to be precise, but the last 30 seconds seems to be about the same story as Ares-V.

One option which was considered for DIRECT would be to always fly a third, completely spare, engine on the main core.   Run all engines at 66% thrust normally, and if you lose one, just throttle the remianing two up to 100%.   You lose about 9mT payload to LEO, but gain 100% single-engine-out capability.   I decided to leave it out given that an engine-out event with RS-68 is not expected to occur even as often as 1 in 200 flights.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: josh_simonson on 11/03/2006 12:27 AM
Aries 1 is not a presidential mandate.  As many folks like to say VSE != ESAS.  George W doesn't care how we get to the moon as long as a disporportionate part of the funding is spent in Texas and Florida.

>I did not read all thread but still would like to suggest to make 3 version of rocket:
>central core w/o SRBs for 25-30 mt to LEO;
>CC+SRBs for upto 62.5 to LEO
>and CC+SRBs upto 98 to LEO.
>To cut expences.

I liked the CC quasi SSTO too (using the SM for the last bump to ISS).  I don't think 2 RS-68s would lift it though, the version I simmed only had a 1.2 T/W ratio at liftoff with 5 RS-68 and a 30t payload, though it did have the huge 10M tank to lift since the idea was to use the Aries V core for CLV instead of a seperate rocket.  I'm pretty sure that a near-SSTO like that would have higher safety number than Aries 1 since it doesn't air-start any engines except the CEV-SM OMS.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/03/2006 11:23 AM
Or you could have partial propellant load in the first stage (but lots of engines) and the EDS as second stage and light it earlier than you do when you fly with SRB:s. Ed Kyle proposed launchers something like it in the summer in this forum, I suggest searching.
That gets rid of the solids, if you dislike them. Of course that makes ATK unhappy.
It'd be something if solids were used only for the lunar missions but ISS support and other LEO stuff could be done without. Maybe that's too many configurations to be economical.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/03/2006 11:45 AM
Quote
meiza - 3/11/2006  7:06 AM
 Maybe that's too many configurations to be economical.
Multiple configuration options of the same vehicle family is what will drive economies of scale, should Direct be adopted. Much better, by far, than developing completely different vehicles for different flight requirements.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/03/2006 12:16 PM
But if the tank needs to be designed for three configurations instead of two, it will be more expensive to design and manufacture and will be heavier...
Title: Re: "DIRECT" Goes Live
Post by: Drapper23 on 11/03/2006 01:13 PM
Ross, Your proposal is excellent & in my opinion is the key to a successful VSE. One thing you ought to do is go on the CoastToCoastAM radio program & discuss your very interesting proposal.  Sincerely Yours, Rick L. Sterling-WV State Political Coordinator For The Mars Society & Contributor To The Stafford Commission Report(Nuclear Propulsion Section) On The SEI Manned Lunar Mars Program.  P. S. Coast To Coast AM has had many notable guests such as Col Buzz Aldrin, Seth Shostak & Dr. Robert Zubrin. It has 20 million strong worldwide listening audience. If your interested contact George Noory at [email protected]
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/03/2006 01:18 PM
ESAS says that vehicle no. 25 (inline STS derivative with two 4seg SRBs and 3 SSME core) and orbit 28.5deg 30x160 nm has lift capability of 86.5mT with net payload 73.5mT.
DIRECT study says that vehicle ETA 2013 (inline STS derivative with two 4seg SRBs and 2 RS-68 regen core) and orbit 28.5deg 60x160 nm orbit has net payload of 70.9mT.
It seems to me that 3xSSME and mysterious 2xRS-68 regenerative are equivalent in thrust, weight and ISP. Or is there any hidden difference?
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/03/2006 02:51 PM
Quote
SMetch - 1/11/2006  6:56 PM

We used the current Shuttle external to internal load curve as a baseline to compare too. We also have a full 2nd stage to take advantage of the optimal lift capability of the base SSTS system with RS-68’s.  Bottomline this issue can be dealt with the above approach and/or by increasing the tank strength (weight) for two 2 RS-68 variants.

So what is the dry/wet weight of the DIRECT core?
It's simple question easy to answer for anybody involved with DIRECT.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/03/2006 03:01 PM
Quote
kraisee - 2/11/2006  4:37 PM

They are scared for their jobs.


Something is wrong there. I work in industry where employer is scared to loose their engineers so much that they don't mind if you take few months of holidays if you want some rest.
But it's true that I'm not messing up with my boss' decisions. He actually comes for advice.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/03/2006 03:56 PM
Quote
JIS - 3/11/2006  10:34 AM

Quote
SMetch - 1/11/2006  6:56 PM

We used the current Shuttle external to internal load curve as a baseline to compare too. We also have a full 2nd stage to take advantage of the optimal lift capability of the base SSTS system with RS-68’s.  Bottomline this issue can be dealt with the above approach and/or by increasing the tank strength (weight) for two 2 RS-68 variants.

So what is the dry/wet weight of the DIRECT core?
It's simple question easy to answer for anybody involved with DIRECT.

Direct is Ross.  It is his baby
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/03/2006 04:10 PM
Quote
meiza - 3/11/2006  7:59 AM
But if the tank needs to be designed for three configurations instead of two, it will be more expensive to design and manufacture and will be heavier...
meiza;
Understand that I’m not advocating ANY configuration change at this time. The present effort should be to get Direct flying essentially as configured in the published paper. All of this other discussion falls under the category of “potential” future growth options.

Basically, the Direct concept has the capacity, by virtue of its “over capacity” and Shuttle Derived design base, to entertain multiple launch configurations, which can be tailored to the payload and orbit requirements. The key feature is to NOT entertain ANY change in tank diameter; it must remain as it is, the same as STS/Direct. What “can” be adapted at a future time is the attachment points of the current length tank to support either 3 or 4 segment SRB’s, with the 31% stretch option for 5 segment SRB’s. In addition, the aft thrust structure could be made universally adaptable to 1, 2, 3 or even 4 RS-68s engines. I don’t think it would be wise to consider more than 4 engines, because then you are getting into the same problem as Ares V (5 engines consume the fuel load too quickly). These options can be coupled with or without an US, fully or partially fueled. These combinations (3, 4 or 5 segment SRB’s, 1 to 4 RS-68’s, with or without US fully or partially fueled) provide an almost limitless variation in flight profiles, letting you tailor the LV to the required payload and orbit. In addition to this launch capacity variation, there could also be a variety of SLA’s tailored to standard sizes. It’s what we call in the design world a “family of parts”.

I don’t have numbers for any of these, they’re just the type of configurations I see as worthy of investigation. Investigation could end up eliminating some of these combinations as useless, but it’s what I see as being possible, pending verification.

Again, all this falls under the category of potential future growth options, NOT for implementation at this time. But in terms of the expense of design/build, this kind of flexability in one LV could be worth its weight in gold. :)

Ares could never provide this kind of potential. Ares I can't seem to get out of its own way, and Ares V is just too inefficient in its base design to do anything else.

Before the USSR collapsed, the Energya launch vehicle was starting to come on line, and that is the same approach they were taking. There was a core booster, which was configurable with a variety of strap on's with or without US's. That gave it a boost to LEO of between 35mT to 175mT, with the one family of LV. In fact, it was being referred to as a Universal Launch System. When the USSR collapsed, funding died along with this design base. But one of the strap on's is still being used today as the LV for Boeing's Sea Launch, the Zenit. An interesting, if old read on this is at http://www.k26.com/buran/
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/03/2006 04:46 PM
Good post, clongton. I just meant that a study should be made: Should the tank be given that extra margin that it can fly without the solids and with a partially fueled second stage plus some payload. Should an Universal Tank be designed?
Does it need any extra capacity for no-solids? Doesn't it, since the solids normally support the full lox tank and above stuff on liftoff, or at least most of it?

I just mean that it could be useful to design the capability in in the original design if it doesn't cost much in design money or manufacturing complications or mass. Then it's easy to start flying the actual no-solids configuration later.
But if the no-solids requirement kills the performance with solids, for example that the hydrogen tank becomes super-heavy, then it's not wise to include the capability in the basic design. Or that the universal tank's top is overdesigned for the no-solid version that's just lifting a light EDS and tiny payload, tempting to do point design optimizations.
Or that the Universal Tank design constraints are very complex with three different configurations and it's very costly and time-consuming to optimize a design.

I don't have the faintest idea.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/03/2006 05:18 PM
Core only necessitates pad mods for support and hold mechanisms and tank mods to interface with these.  That would mess up the whole basic design
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/03/2006 05:30 PM
That's why I made the point that it must not be considered for now, at all. These changes are not just cosmetic, even though they maintain the identical footprint. While a great deal of flexability would be gained from following a path somewhat like I suggested, the changes on the pad and mlp would be extensive and expensive.
Thoughts for a later time, maybe, but not for now.
Get Direct flying as-is. That opens the door to all kinds of possibilities later.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/03/2006 06:23 PM
Couldn't you just have two "mock SRB:s". Like Saturn I had the milk stool. There are many options how to construct the support.
Title: Re: "DIRECT" Goes Live
Post by: HailColumbia on 11/03/2006 06:31 PM
Quote
meiza - 3/11/2006  2:06 PM

Couldn't you just have two "mock SRB:s". Like Saturn I had the milk stool. There are many options how to construct the support.

but whats the point of making a lesser rocket with a new upperstage? why not just use the SRBs?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/03/2006 06:38 PM
Quote
meiza - 3/11/2006  2:06 PM

Couldn't you just have two "mock SRB:s". Like Saturn I had the milk stool. There are many options how to construct the support.


??? Milkstool is one thing but .....   The SRB's separate away from the vehicle.   That would be too big of a kludge like Soyuz.  Not to talk bad about Soyuz
Title: Re: "DIRECT" Goes Live
Post by: MarkWhittington on 11/03/2006 06:41 PM
Alright, accepting for the point of discussion that Direct is a far better option than the current Ares 1 and Ares 5, how do the proponents of the plan believe that Direct will become the means by which NASA returns to the Moon? This question is asked with due consideration of NASA's tendency to be mulish when it comes to pursuing dysfunctional plans and the tendency, already mentioned in this thread, to punish dissenters.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/03/2006 06:46 PM
See www.directlauncher.com
Download the paper
It's explained in detail
Title: Re: "DIRECT" Goes Live
Post by: HailColumbia on 11/03/2006 07:04 PM
Quote
MarkWhittington - 3/11/2006  2:24 PM

Alright, accepting for the point of discussion that Direct is a far better option than the current Ares 1 and Ares 5, how do the proponents of the plan believe that Direct will become the means by which NASA returns to the Moon? This question is asked with due consideration of NASA's tendency to be mulish when it comes to pursuing dysfunctional plans and the tendency, already mentioned in this thread, to punish dissenters.

I dont think that many of us really belive that direct will be adopted, we all hope it will. Its brilliant.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/03/2006 07:10 PM
At last, I've had a few hours this afternoon to extract the data from the simulations and put it into a presentable form.   They are about to go on the DIRECT thread in L2.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/03/2006 07:15 PM
Quote
Jim - 3/11/2006  7:21 PM

Quote
meiza - 3/11/2006  2:06 PM

Couldn't you just have two "mock SRB:s". Like Saturn I had the milk stool. There are many options how to construct the support.


??? Milkstool is one thing but .....   The SRB's separate away from the vehicle.   That would be too big of a kludge like Soyuz.  Not to talk bad about Soyuz

I'm very unfamiliar with the launch pad designs of STS or Direct, I admit.
But perhaps you could have a steel "bridge" that transfers the support load from the SRB pad attachment points to the core base. It of course has to have it's own release mechanism at launch, but that would be simple like with SRB:s. Nothing like the Soyuz "clamp" from where the rocket is hung and that must release and swing away. The core would thus stay at the same position as when it used the SRB:s. I don't know about wind/moving loads and if they'd require some more supports, but couldn't those be removed well before launch?
Title: Re: "DIRECT" Goes Live
Post by: MarkWhittington on 11/03/2006 07:15 PM
Quote
clongton - 3/11/2006  1:29 PM

See www.directlauncher.com
Download the paper
It's explained in detail

Perhaps I didn't express my question clearly. Let me rephrase. Who, with the power to make the decision, has to be perusaded that Direct Launcher is the way to go back to the Moon? How is that person to be persuaded, given everything we know about how NASA and the aerospace business works?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/03/2006 07:20 PM
Quote
meiza - 3/11/2006  2:58 PM

Quote
Jim - 3/11/2006  7:21 PM

Quote
meiza - 3/11/2006  2:06 PM

Couldn't you just have two "mock SRB:s". Like Saturn I had the milk stool. There are many options how to construct the support.


??? Milkstool is one thing but .....   The SRB's separate away from the vehicle.   That would be too big of a kludge like Soyuz.  Not to talk bad about Soyuz

I'm very unfamiliar with the launch pad designs of STS or Direct, I admit.
But perhaps you could have a steel "bridge" that transfers the support load from the SRB pad attachment points to the core base. It of course has to have it's own release mechanism at launch, but that would be simple like with SRB:s. Nothing like the Soyuz "clamp" from where the rocket is hung and that must release and swing away. The core would thus stay at the same position as when it used the SRB:s. I don't know about wind/moving loads and if they'd require some more supports, but couldn't those be removed well before launch?

Those are only lateral supports.  Main load path is in the fwd attachment.  The SRB's push the ET through these points.
Title: Re: "DIRECT" Goes Live
Post by: ryan mccabe on 11/03/2006 07:21 PM

It would likely be necessary that Mike Griffin himself would have to admit that the issues plaguing Ares would be best solved by selecting an alternate launch vehicle. How can that be accomplished? Persuade mid/high-level NASA managers, Congressional committee members, Senate committee members, and varying levels of the media that DIRECT is a superior launch vehicle.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/03/2006 07:22 PM
Quote
MarkWhittington - 3/11/2006  2:58 PM

Quote
clongton - 3/11/2006  1:29 PM

See www.directlauncher.com
Download the paper
It's explained in detail

Perhaps I didn't express my question clearly. Let me rephrase. Who, with the power to make the decision, has to be perusaded that Direct Launcher is the way to go back to the Moon? How is that person to be persuaded, given everything we know about how NASA and the aerospace business works?

the Associate Administration for Exploration, Scott Horiwitz.    

Congress or a failure in Ares I design.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/03/2006 07:31 PM
Quote
Jim - 3/11/2006  3:05 PM

the Associate Administration for Exploration, Scott Horiwitz.
Are you aware if he was given hard copy or not?
Title: Re: "DIRECT" Goes Live
Post by: MarkWhittington on 11/03/2006 07:41 PM
Does anyone know if Scott or any other higher up at NASA has reacted to the Direct Launcher plan. If so, what has it been?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/03/2006 07:46 PM
Doubt he even knows about it.   Not many people at KSC even know about it
Title: Re: "DIRECT" Goes Live
Post by: MarkWhittington on 11/03/2006 07:55 PM
Has there been any attempt to get the media's attention on Direct Launcher? I don't mean just the aerospace media, but the broader media. I imagine that "NASA Insurgents Push for Alternative Return to the Moon" might make a compelling headline.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/03/2006 07:59 PM
Direct is just one alternative.  There are others and some may be better.   For one, I prefer EELV for the CLV.  But anything is better than the current Stick.

Basically, the real story is the stick is not cutting it
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/03/2006 08:04 PM
Quote
Jim - 3/11/2006  8:03 PM

Quote
meiza - 3/11/2006  2:58 PM

Quote
Jim - 3/11/2006  7:21 PM

Quote
meiza - 3/11/2006  2:06 PM

Couldn't you just have two "mock SRB:s". Like Saturn I had the milk stool. There are many options how to construct the support.


??? Milkstool is one thing but .....   The SRB's separate away from the vehicle.   That would be too big of a kludge like Soyuz.  Not to talk bad about Soyuz

I'm very unfamiliar with the launch pad designs of STS or Direct, I admit.
But perhaps you could have a steel "bridge" that transfers the support load from the SRB pad attachment points to the core base. It of course has to have it's own release mechanism at launch, but that would be simple like with SRB:s. Nothing like the Soyuz "clamp" from where the rocket is hung and that must release and swing away. The core would thus stay at the same position as when it used the SRB:s. I don't know about wind/moving loads and if they'd require some more supports, but couldn't those be removed well before launch?

Those are only lateral supports.  Main load path is in the fwd attachment.  The SRB's push the ET through these points.

Yeah but the core (without solids) has to have enough strength to stand on its own anyway since that's how it works when launched alone?
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/03/2006 10:03 PM
Quote
clongton - 3/11/2006  5:53 PM

Basically, the Direct concept has the capacity, by virtue of its “over capacity” and Shuttle Derived design base, to entertain multiple launch configurations, which can be tailored to the payload and orbit requirements. The key feature is to NOT entertain ANY change in tank diameter; it must remain as it is, the same as STS/Direct. What “can” be adapted at a future time is the attachment points of the current length tank to support either 3 or 4 segment SRB’s, with the 31% stretch option for 5 segment SRB’s. In addition, the aft thrust structure could be made universally adaptable to 1, 2, 3 or even 4 RS-68s engines. I don’t think it would be wise to consider more than 4 engines, because then you are getting into the same problem as Ares V (5 engines consume the fuel load too quickly). These options can be coupled with or without an US, fully or partially fueled. These combinations (3, 4 or 5 segment SRB’s, 1 to 4 RS-68’s, with or without US fully or partially fueled) provide an almost limitless variation in flight profiles, letting you tailor the LV to the required payload and orbit. In addition to this launch capacity variation, there could also be a variety of SLA’s tailored to standard sizes. It’s what we call in the design world a “family of parts”.

Growth or shrinkage is not attractive unless there is a large number of lauches per year that can pay for the work. If the number is small it is cheaper to make the payload larger or lauch water ballast and if you need a larger launcher subdivide the payload on more launchers.

But this removes the need for some fun some technical discussions.
I would guess that four RS-68:s wont work with the proposed easy changes of the Mobile Launcher Platforms.
That leaves the options of three or two RS-68:s or one if some means off roll control is added.

Stretching to five segment SRB:s and three RS-68:s is discussed in the original paper and it makes sense
to make room for it in the support infrastructure if the cost is small.

The easiest shortening to a 3 segment SRB:s would probably be to add an empty "load transmission" segment and load less fuel in the core. The next step would be to shrink the liquid hydrogen section of the core and remove the empty barrel segment. But this only removes cheap metal and even cheaper solid and liquid fuel unless you shrink untill one RS68 is enough but then you need a large roll controll system.

If the volume of small missions becomes large enough to merit shrinking the Direct I would recommend the development of a smaller and slimmer SRB that is made small enough that two RS-68:s can handle all the roll and directional control needed and then is the core shortened to fit the fuel load that can be lifted with the smaller SRB:s. I have no intuition for the capacity that would give.

But if volumes get that large it might make sense to develop a liquid flyback booster instead of the SRB:s.
Title: Re: "DIRECT" Goes Live
Post by: Chris Bergin on 11/03/2006 11:41 PM
Quote
MarkWhittington - 3/11/2006  8:38 PM

Has there been any attempt to get the media's attention on Direct Launcher? I don't mean just the aerospace media, but the broader media. I imagine that "NASA Insurgents Push for Alternative Return to the Moon" might make a compelling headline.

Good question Mark. Welcome to the site (and the others that have turned up via this thread).

It has been seen by some areas of Constellation (through support or interest - ironically, most of the dislike of the stick comes from Constellation, rather than EELV folks, which is a common misconception).

Whether Doc has seen it or not is irrelevant, I would claim. There are a lot of people that have signed off on the Stick and will do until the day its cancelled. Stumpy is a good example. A NASA study (Constellation KSC) that was roadblocked before it even did anything at Constellation MSFC, because it wasn't the Stick, period.

As far as mainstream media outside space flight/aerospace specific, I doubt there's any chance. Most of them don't even give a crap about the Shuttle unless there's a tragedy. The mainstream (sorry, need to stop here for a second and just say that I have to use stupid words to get my point across. I know that means I must have a weak argument, but that's why I use bad words). only care about what‘s spoon-fed to them by the wire services....I know, I've worked in it.

Remember, any way you cut it, this concept has been drawn up by someone outside of NASA and thus unless NASA commision it for study, it'll never be nothing more than the aforementioned.

Also a note on this site. We are objective, we're in favour of allowing all levels of debate and open to news good and bad, so long as it's accurate. I personally don't mind what gets us to the moon, be it the Stick, EELV or a bloody Caravan, so long as it works.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/03/2006 11:51 PM
Quote
Magnus_Redin - 3/11/2006  5:46 PM
If the volume of small missions becomes large enough to merit shrinking the Direct I would recommend the development of a smaller and slimmer SRB that is made small enough that two RS-68:s can handle all the roll and directional control needed and then is the core shortened to fit the fuel load that can be lifted with the smaller SRB:s. I have no intuition for the capacity that would give.

The volume of missions are small, it is only to launch the CEV

smaller and slimmer SRB?????????

The whole point is to use the existing SRB design and infrastructure.  A new development program, and redesign of all the facilities would cost 10's of Billions.  Not to mention, it negates the #1 reason (supposed) the STS SRB's are being used: It is a "safe, proven" design

Anyways, there are better ways of doing things before even considering smaller SRB's

Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/03/2006 11:54 PM
Quote
meiza - 3/11/2006  3:47 PM

Yeah but the core (without solids) has to have enough strength to stand on its own anyway since that's how it works when launched alone?

Then it has nothing in common with Direct, both in the flight and ground systems
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/04/2006 04:32 AM
Quote
clongton - 3/11/2006  3:14 PM

Quote
Jim - 3/11/2006  3:05 PM

the Associate Administration for Exploration, Scott Horiwitz.
Are you aware if he was given hard copy or not?

Dr. Horowitz is probably the number one person against a change from Ares-I.

But a copy of the proposal was e-mailed me to his boss; Dr. Michael Griffin, and a separate copy was also sent to his subordinate in charge of the LV development program; Steve Cook.

I know they both arrived, but I am unaware of any reaction at this time.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/04/2006 04:41 AM
BTW, the Core of DIRECT can not fly withour SRB assistance.

It just does not have sufficient thrust:weight and contains many tons of hardware internally specifically designed to support the SRB's.

If a Core were to be made to fly alone, it would have to be custom-designed for that flight circumstance and would likely have a LOT of changes to the current configuration (stage and infrastructure) to get anything like good performance from it - and that would require another $20 billion dollar development program!

That is what DIRECT is specifically trying to remove, so it defeats the purpose entirely.

For that $20 billion, NASA could instead pay to launch 142 of the regular configuration DIRECT's, each placing 70.9mT into LEO, totalling a little over 10,000mT going to orbit!

That's actually what DIRECT does anyway, by deleting the Ares-V from the equation.

Ross.

Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/04/2006 07:28 AM
Quote
Jim - 4/11/2006  1:34 AM
The volume of missions are small, it is only to launch the CEV

smaller and slimmer SRB?????????

The whole point is to use the existing SRB design and infrastructure.  A new development program, and redesign of all the facilities would cost 10's of Billions.  Not to mention, it negates the #1 reason (supposed) the STS SRB's are being used: It is a "safe, proven" design


I absolutely agree.

My point is that downsizing only makes sense if the volume of missions is very large and it makes the launcher simpler and thus cheaper to produce. Removing major engines or controllable SRB nozzels saves a lot of work hours and machine shop time, removing tankage and fuel dont matter much.

But volume alone will bring down the cost due to more efficient processing, the same number of employes, buildings and machines can probably make more launchers if you start series production.

If you need an order of magnitude more lauches then the currently planned CEV missions it might make sense to make a smaller version of the Direct.  And then might a smaller and simpler SRB make more sense then a stacking a three segment SRB. But I dont have the knowledge or data to run the numbers.

But with an order of magnitude more missions it might be reasonable to build a pair of new launch pads, MLP:s, a new processing building and a series of flyback liquid fueled boosters.

Another point is that Direct kind of already has a small version, the Delta IV heavy. It uses the same RS-68 engine and that is a large part of the Direct production line allowing the two launchers to share economy of scale in engine manufacturing.
 
Quote
Anyways, there are better ways of doing things before even considering smaller SRB's

What kind of improvements are you suggesting?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/04/2006 11:35 AM
Quote
Magnus_Redin - 4/11/2006  3:11 AM

What kind of improvements are you suggesting?

It doesn't have to use shuttle components.  It does have to look anything like "direct".  There are many cheaper EELV derivatives that could do the mission.  These are on other threads.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/04/2006 03:00 PM
(Apologies if this has been discussed before)
Whilst I am wholeheartedly in favour of keeping DIRECT simple and as close as possible to being a 'plug in' replacement for ARES in the ESAS, there have been numerous digressions now on future developments so my own thoughts are as follows:
- The LSAM should always been flown on its own, with LOR only for manned missions and unmanned landings being possible with ostensibly no change in descent stage hardware whatsoever.
- The CEV should always been flown alone and be capable of performing its own LOI and LEI burns; it would dock with the LSAM already in LLO. This means that if/when ISRU reusable LSAMs become available the original launch architecture can still be used as is.

The main disadvantage I can see is that there is no LSAM 'lifeboat' but I would like to think that we can design safer, more robust, more reliable vehicles today than in the 60s.
DIRECT is much better able to perform this mission than Ares; Ares-1 will NEVER get an Orion to the moon in one shot. For DIRECT, it would appear that an augmented SM would be needed to ensure sufficient propellant for LOI and TEI, but that is a relatively minor change.
Just another variation on the launch strategy which favours DIRECT over less flexible approaches.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/04/2006 05:46 PM
Quote
Jim - 3/11/2006  2:42 PM

Direct is just one alternative.  There are others and some may be better.   For one, I prefer EELV for the CLV.  But anything is better than the current Stick.

Basically, the real story is the stick is not cutting it

Care to elaborate in a meaningful way? What are the problems. How did you come to find out about them?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/04/2006 05:55 PM
performance is continuously being reduced.

Before:
22.9 mT payload into a 30 x 160 nmi orbit inclined inclined 51.6 deg.

Later:

19.3 mT payload into a -30 x 100 nmi orbit inclined inclined 51.6 deg.

Now:

 mT payload into a -30 x 100 nmi orbit inclined inclined 51.6 deg.

Need to find this


Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/04/2006 07:02 PM
Quote
Jim - 3/11/2006  3:42 PM

Direct is just one alternative.  There are others and some may be better.   For one, I prefer EELV for the CLV.  But anything is better than the current Stick.
Basically, the real story is the stick is not cutting it
Jim;
I know you prefer the EELV for a CLV, and Direct for cargo and heavy lift. How would you propose NASA use its funding to establish an EELV CLV in such a way that would MAKE SURE that Direct is developed? My biggest fear from using EELV CLV is that we'll get stuck with a taxi-only space program and Direct will not get funded. To my way of thinking, that would be a sin.
Chuck
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/04/2006 07:40 PM
Quote
clongton - 4/11/2006  1:45 PM

Quote
Jim - 3/11/2006  3:42 PM

Direct is just one alternative.  There are others and some may be better.   For one, I prefer EELV for the CLV.  But anything is better than the current Stick.
Basically, the real story is the stick is not cutting it
Jim;
I know you prefer the EELV for a CLV, and Direct for cargo and heavy lift. How would you propose NASA use its funding to establish an EELV CLV in such a way that would MAKE SURE that Direct is developed? My biggest fear from using EELV CLV is that we'll get stuck with a taxi-only space program and Direct will not get funded. To my way of thinking, that would be a sin.
Chuck

I'm confused. If you already have an EELV for  launching Orion why would you need Direct? Why not just  go ahead and develop the Ares V and have a real HLLV? Isn't the whole point of Direct to save development costs by only building one vehicle to do both cargo and crew launches?
Title: Re: "DIRECT" Goes Live
Post by: Heg on 11/04/2006 08:08 PM
Direct - especially w/ EDS - is more efficient launcher. Growth option with 3 RS-68R and 5-segment SRB's actually lifts more to LEO than Ares V.

But after all I'd prefer using man-rated Delta IV Heavy as a CLV for Orion test flights and ISS missions.
Title: Re: "DIRECT" Goes Live
Post by: HailColumbia on 11/04/2006 08:45 PM
Quote
tom nackid - 4/11/2006  3:23 PM


I'm confused. If you already have an EELV for  launching Orion why would you need Direct? Why not just  go ahead and develop the Ares V and have a real HLLV? Isn't the whole point of Direct to save development costs by only building one vehicle to do both cargo and crew launches?

well, that is an option, but direct is still better

1. you cant just slap orion an an EELV like its a normal payload, these things will have to be man rated, there is a debate about how much work that would really entail, but it will still have to be done.

2. ARES V will have a very low flight rate, which will make it pretty expensive. DIRECT, by only using one type of booster will increase the flight rate and costs go down due to volume. (obviously not super high flight rate, but still better)

3. even if you did get a cheap EELV manned launcher, thats still two seperate rockets you have to deal with.

as NASA has commited to a solution requireing two launches anyway, Direct is obviously the way to go as it puts more into orbit with two rockets then 1 ARES V and 1 ARES 1 would anyway.
Title: Re: "DIRECT" Goes Live
Post by: hop on 11/04/2006 10:05 PM
Quote
tom nackid - 4/11/2006  10:29 AM
Care to elaborate in a meaningful way? What are the problems. How did you come to find out about them?
The  Ares I/V plan was sold on the premise that it was a straightforward re-use of shuttle components (remember "safe simple soon" ?), but it has clearly turned into the development of two new vehicles. The Direct plan does a far better job of meeting the original goal.

Given the extremely low flight rates of all these vehicles, cutting the number of vehicles to be developed in half is likely to be a big savings, even if the per flight cost are a lot higher. Direct does even better, in that the one new vehicle being developed is much closer to an existing vehicle. It doesn't need 5 seg SRBs or a different ET diameter. It also does a much better job of re-using existing infrastructure.

Like Jim, I'm not convinced Direct is the perfect answer, but it certainly looks better than developing a completely new launcher just for the CEV, which is what the stick has turned into.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/05/2006 02:02 AM
Quote
kraisee - 3/11/2006  11:15 PM

Quote
clongton - 3/11/2006  3:14 PM

Quote
Jim - 3/11/2006  3:05 PM

the Associate Administration for Exploration, Scott Horiwitz.
Are you aware if he was given hard copy or not?

Dr. Horowitz is probably the number one person against a change from Ares-I.

But a copy of the proposal was e-mailed me to his boss; Dr. Michael Griffin, and a separate copy was also sent to his subordinate in charge of the LV development program; Steve Cook.

I know they both arrived, but I am unaware of any reaction at this time.

Ross.

I'm sure that Griffin's secretary will be very polite with his/her answer.
Griffin certainly doesn't want to hurt anybody.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/05/2006 02:06 AM
Quote
Jim - 4/11/2006  6:18 AM

Quote
Magnus_Redin - 4/11/2006  3:11 AM

What kind of improvements are you suggesting?

It doesn't have to use shuttle components.  It does have to look anything like "direct".  There are many cheaper EELV derivatives that could do the mission.  These are on other threads.

I agree with Jim that there are cheaper alternatives how to get people to ISS than whatever STS derivative.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/05/2006 02:25 AM
If NASA will look for something different that the cheapest way to ISS they could actually find one interesting point with Ares II (Direct).
Imagine what performace Ares V would have with RS-68 upgraded magic engine. It could be even possible to use ET diameter core with less engines (Ares IV or even Ares III) and get the same performance as with "old" Ares V. This deletes some of infrastructure changes and 5seg SRB could be still developed for Ares 1.
The only unknown is with that "magic" RS-68. But there is still plenty of time for development.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/05/2006 08:02 AM
The politicians forced NASA to choose an SDLV solution.

Unless you can guarantee their states don't lose any jobs, it is going to be an SDLV and there's no way to change that.   EELV's would only require about 1/10th of the current workforce.   Can you show me any politicians who will vote for a solution which results in thousands of job losses in their own states?   I sure can't think of any.

Nobody has come up with any sort of comprehensive plan for an EELV (or other) solution which preserves the existing workforce in all the space staes.

Until they do, they will remain out in the cold.   Sorry, but simply ignoring that basic fact is just as bad as the proverbial Ostrich sticking its head in the sand and just praying that the big bad predator doesn't eat it.   It might make you feel a bit better, but it sure doesn't help at all!

Solve the political problem here, and the EELV's might have become possible.   Until then, or until all politicians change their basic nature (yeah, right!), it will be SDLV all the way - I guarantee it.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/05/2006 08:11 AM
Quote
tom nackid - 4/11/2006  3:23 PM

Isn't the whole point of Direct to save development costs by only building one vehicle to do both cargo and crew launches?

Bingo Tom, that's precisely it in a nut shell.

The savings by doing DIRECT are supposed to enable OTHER things, like *more* lunar missions, or *more* science and exploration probes being afforded, or *new* propulsion technologies...

Griffin himself says it is essential that other nations 'chip in' for the US to be able to afford to do anything at all once we return to the moon.   The $35Bn of savings by choosing DIRECT would allow NASA to make sure it all gets done without having to *rely* on anyone else.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/05/2006 02:57 PM
"The only unknown is with that "magic" RS-68."

It is not magic.   The NRO is paying for some upgrades
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/05/2006 04:27 PM
Then I must repeat my previous question:

"ESAS says that vehicle no. 25 (inline STS derivative with two 4seg SRBs and 3 SSME core) to orbit 28.5deg 30x160 nm has lift capability of 86.5mT with net payload 73.5mT.
DIRECT study says that vehicle ETA 2013 (inline STS derivative with two 4seg SRBs and 2 RS-68 regen core) to orbit 28.5deg 60x160 nm has net payload of 70.9mT."
 
It seems to me that 3xSSME and mysterious 2xRS-68 regenerative are equivalent in thrust, weight and ISP.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/05/2006 04:33 PM
the RS-68 will have less ISP, note the drop in payload capability.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/05/2006 04:40 PM
There is difference in orbits.

ESAS say lift capability of 86.5mT with net payload 73.5mT.
DIRECT says net payload of 70.9mT

What is the difference between lift capability and net payload?
Because ESAS considers lower orbit than DIRECT I think that net payloads 73.5mT and 70.9mT are NEARLY equivalent.
Title: Re: "DIRECT" Goes Live
Post by: mong' on 11/05/2006 09:31 PM
what I really doubt in this plan is the RS68 upgrade.
I know an upgrade to regeneratively cooled nozzle was always kept in mind during developement of the engine but could it be done for $1Bn ? and what about the individual price of the engines after such an upgrade ?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/05/2006 09:41 PM
I doubt it is  $1b, more likely less
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/06/2006 12:39 PM
Quote
JIS - 5/11/2006  5:23 PM
What is the difference between lift capability and net payload?

In the absence of any response to this question I would assume that 'lift capability' is the total mass placed into orbit including the upper stage of the LV, whilst 'net payload' is the useful paylaod excluding the rocket stage, fairing, residual propellants, etc.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/06/2006 04:47 PM
Quote
mong' - 5/11/2006  5:14 PM

what I really doubt in this plan is the RS68 upgrade.
I know an upgrade to regeneratively cooled nozzle was always kept in mind during developement of the engine but could it be done for $1Bn ? and what about the individual price of the engines after such an upgrade ?

I don't have a final cost.

I have severely over-estimated the cost at $1Bn.

Understand that the work required to upgrade RS-68 to "Regen" spec is considerably less than the work to make the J-2X - and that contract has been issued to PWR already totalling just $50 million for complete DDT&E, 7 test units, 2 engines for certification and one full-spec flight engine.   And remember that J-2X is going to have an all-new nozzle.   This means it is going through it's own "Regen" development program as just one *part* of that contract.


Even though RS-68 is larger than J-2X, the Regen development will cost a lot less than the entire development program of the J-2X.   I have still assumed a far higher number to cover ANY eventualities, including major element re-design if, somehow, it should be necessary.

If it does prove unnecessary (probably), then NASA would simply have a lot of spare cash left over :)    And that's a bad thing, how?


The RS-68's major components (pumps, combustion chamber, valves, injector etc) were designed from the start to be used with a Regenerative Nozzle upgrade at some point in the future.   They have actually been tested for that performance already.   They are howevere FLOWN considerably under the performance limits because they are using an ablative nozzle to keep costs down to just $12m per engine for Delta-IV.

PWR indicated, completely unofficially, that $5m per unit would be the additional cost for a Regen nozzle, assuming numbers around 10-20 per year.

Add in the $8m NASA has indicated will be the extra cost for the man-rated version and you get $25m per final RS-68R man-rated unit.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/06/2006 05:08 PM
Quote
Kaputnik - 6/11/2006  8:22 AM

In the absence of any response to this question I would assume that 'lift capability' is the total mass placed into orbit including the upper stage of the LV, whilst 'net payload' is the useful paylaod excluding the rocket stage, fairing, residual propellants, etc.

JIS and Kaputnik,
The difference is the mass of the other items brought up, but which have little to do with the payload itself.   Things such as payload fairings, payload mounting structures attaching the payload to the final stage, any additional push-stages (if required for circularization for example) are all factored in to the total 'lift capability', but not included in the net payload numbers.

DIRECT's Lift Capacity is also considerably higher - a little over 83mT.

DIRECT+EDS' Lift Capacity is over 110mT plus the 14.4mT EDS itself.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/06/2006 07:15 PM
The latest version of the DIRECT proposal has just been released.

v1.1.0 improves the readability of a lot of the images, and expands on the Development Phase section.

It is available on www.directlaucher.com.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: ryan mccabe on 11/06/2006 07:38 PM
Just an aesthetic note, but I like the improved banner on the directlauncher.com page. The first banner suffered from some crummy resolution. Looks much sharper.

A performance question: what is the status of the RL-60? How would performance and development/flight costs vary if a cluster of 3-4 RL-60 were used, rather than a single J2-X? The preliminary specifications for the RL-60 show much better ISP and mass efficiency than the first generation J-2. From an amature's standpoint, the RL-60 would also have some hope of application outside of the VSE.

Also, from the FAQ section of your webpage, you note the performance to LEO as the following:

DIRECT to 100x160nm 28.5deg:          
70,916kg    
or 156,343lb

DIRECT to 100x160nm 51.6deg:       
70,907kg    
or 156,323lb

Is it really just a 9 kg hit to reach a higher inclination ISS orbit? Seems very disproportionate to what the STS suffers on ISS flights

Regards
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/06/2006 08:26 PM
I've been looking at this again and the only reason I can come up with is the insertion point ithe initial orbit.


For Lunar CLV missions, 60x160nm 28.5deg orbit, the insertion point is at an altitude of 123nm (227km).

For ISS CLV missions, 60x220nm 51.6deg orbit, the insertion point is at only 92nm (171km).

That would seem to go a long way to explaining the difference.


Ares have both been further tweaked to force a lower insertion point and trade that for improved performance, but my tools don't allow me to do that manually to DIRECT, so I think there is a potential for additional DIRECT performance here...

Ross.
Title: RE: "DIRECT" Goes Live
Post by: HIP2BSQRE on 11/07/2006 05:58 AM
Good Evening,

In TeamVisions "Space Exploration Optimization (http://www.teamvisioninc.com/downloads/AIAA-2006-7517-146.pdf)  they mention a vicheal called the Jupiter I.  Is your vicheal divered off their vicheal?  Do you see some ways that the "Direct" vicheal can benifit from some of the analysis that TeamVision have done?  One of biggest differance is they postpone development of the JS2-X but would put approx 80mt into LEO (p.14).  It is pretty funny, two organizations coming up with the same type of vicheal at approx. the same time.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/07/2006 08:51 AM
I haven't really looked into any of their proposals before.

I saw the photo of the massive Jupiter 3 uber-booster over on another thread and thought it was seriously wild.   But honestly, I thought it was just for fun...   I didn't know until just now that it was supposed to be serious.   I also didn't know they had smaller booster concepts too, especially not one which is indeed quite similar to DIRECT.

Although neither of our groups were the first on this concept :)

The idea actually dates back to Challenger.   It was a logical alternative (with 3 SSME's), along with Shuttle-C, for launching cargo missions, and was even considered for use with a re-started Apollo line of Crew capsules too.   But there was simply no cash available to develop any new launcher at the time, so NASA just fixed Shuttle and carried on using that.

In 1991 it resurfaced as the National Launch System (NLS), proposed by NASA and the DoD with 4 less powerful, cheap main engines, as an alternative platform for launching Titan-IV class (and heavier) payloads.

And it also appeared in the ESAS Report with the SSME's again (LV 24/25).


It's not the slightest surprise to me that two separate groups have come up with this particular variant, using two RS-68's though.   It's such a simple concept to create from what we fly today, that its really a no-brainer.   The RS-68's simply remove the three very expensive SSME's ($90m each!), and replaces them with two, far cheaper, engines.   That's what NASA did already with Ares-V anyhow, so it's a completely NASA-validated approach.


The only difference between the Jupiter-I concept and DIRECT is the Regen version of the RS-68 which DIRECT uses to boost performance.   This is not an expensive upgarde, certainly only a tiny fraction as expensive as the Ares-I's $4Bn program just to make and qualify the 5-seg SRB!


Jupiter-II is kinda similar to the DIRECT Growth Options which I showed in my proposal, but Jupiter-II has a third stage, so would be more complex.   Thus Jupiter-II would also cost more to make & operate than DIRECT+EDS.


I should perhaps, at this point, also mention that there actually is no current requirement for any program to go much above 100mT to LEO per launch - unless of course your CLV is a truly puny little performer like Ares-I is.   In that single case, your Cargo lifter is forced to make up the difference if you're trying to keep launch numbers down.


As for Jupiter-III - that behemoth will *never* be commissioned.   It's got way too many engines to go wrong, too many elements which must all work together reliably, too many separation events, too many different propellant types, too much mass to use any existing facilities, too much thrust to launch from *ANY* existing site, and a list of development nightmares spottable from orbit!   The cost for developing that beast would be truly obscene (100 billion or more, bare minimum), and with so many things to go wrong - it would simply *never* be considered safe.


Of course, if you want to launch 500mT - you could just spend $980m for 7 DIRECT launches, and save yourself a whole bunch o' cash.


If you really must have a new 500mT to LEO booster, it would be a LOT cheaper and easier to just build a really big dumb booster in the Nova class.   There are quite a few Nova concepts which would be far simpler to make, some of which offer far higher performance than the Jupiter-III.

But man, what an incredible looking rocket concept!!!    It's like Saturn-V, Shuttle and Nova bits all got 'Frankensteined' together!!!

It will never be considered, because of cost and safety, but I sure would love to see it 'brough to life' on some TV show or Film.   I can see it now, lifting a daring crew off to rescue the Earth in "Armagedon-II"! :)

Ross.
Title: Re: "DIRECT" Goes Live
Post by: Zond on 11/07/2006 07:29 PM
Quote
kraisee - 6/11/2006  6:30 PM
I have severely over-estimated the cost at $1Bn.

Understand that the work required to upgrade RS-68 to "Regen" spec is considerably less than the work to make the J-2X - and that contract has been issued to PWR already totalling just $50 million for complete DDT&E, 7 test units, 2 engines for certification and one full-spec flight engine.   And remember that J-2X is going to have an all-new nozzle.   This means it is going through it's own "Regen" development program as just one *part* of that contract.

Where do you get your number for a total development cost of $50 million for the J-2X? According to this press release, NASA Announces J-2X Rocket Engine Development Contract  (http://www.spaceref.com/news/viewpr.html?pid=20017) Pratt & Whitney Rocketdyne get $50 million just to initiate development.
I expect that J2-X development will cost over $1 billion. And if the rumors are true and Ares-I is seriously underperforming they will try to optimise the J-2X to the limit which will make the development costs soar.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/07/2006 08:50 PM
Yeah, that's true.

If the J-2X spec stays around 275k/450s I think it will stay below $1Bn.   If they have to squeeze every last scrap of performance to compensate for all the other shortcomings in Ares-I, then yes, the cost may well exceed that figure.

But RS-68 doesn't have to do that.   The powerplant was designed to be operated roughly 5% higher than it is being operated today on Delta-IV.   5% extra performance is what you get by upgrading to the Regen.   It is not a coincidence - it is part of the intended design.   The pumps, injectors, combustion chambers have ALL been qualified to those limits already.   All PWR expect to need is the right nozzle, and a test/re-qualification program.

I was actually told "under $300m" by my PWR contacts.   While they said that was for a man-rated unit, I still assumed doubling that for NASA's "man-rating" requirements, and rounded THAT up to give plenty of room for unexpected growth.   $1Bn is a *gross* over-estimate IMHO.   If the final figure turns out to be $800m, or even $400m, then NASA can afford to launch an extra probe or two to somewhere interesting.   If it does grow to $1Bn, it still stays "on-budget", and everyone's happy because it still costs $3Bn less than developing the 5-seg SRB's...

And it wil lnot cost anywhere near as much as J-2X.   That engine is technically a much more complicated unit than RS-68, with a considerably wider range of requirements.   It must be air-startable, must be re-startable and will be required to have an extensive on-orbit lifespan too.

No such complicated requirements apply to RS-68 - it is a ground lit, used-once, disposable engine, albeit a fairly big one - and the 'big cost' items are already designed to produce the power we want - so there is no program at all to improve performance beyond current design limits - like J-2X is having to go through.   So NONE of those costs will apply.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/07/2006 10:16 PM
Part of the RS-68 mods will be to eliminate the huge fireball at ignition (or so I hear).  What causes that, and how can it be eliminated?  The fireball blackened most of the insulation on the Delta IV Heavy flight!  That seems a bit dangerous to me.

And besides...the SSME doesn't do it...   ;-)

Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/07/2006 11:37 PM
Quote
rumble - 7/11/2006  5:59 PM

Part of the RS-68 mods will be to eliminate the huge fireball at ignition (or so I hear).  What causes that, and how can it be eliminated?  The fireball blackened most of the insulation on the Delta IV Heavy flight!  That seems a bit dangerous to me.

And besides...the SSME doesn't do it...   ;-)


It is a artifact of the fuel lead to condition the engine for ignition.   It isn't dangerous and doesn't really need to be eliminated.  The Delta IV design takes it into account.
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/08/2006 03:43 AM
Oh...  I had always assumed that was part of what needed to happen to man-rate that engine.

How does the SSME avoid that?  Would the down-draft of the sound suppression water tend to pull the H2 downward?

If it's really not an issue, then I guess these questions are just academic.  It's just un-settling for ignition to scorch the paint & insulation 1/2 way or more up the rocket.
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 11/08/2006 03:58 AM
Quote
Jim - 7/11/2006  6:20 PM
It isn't dangerous and doesn't really need to be eliminated.  The Delta IV design takes it into account.

A massive, Hydrogen-powered fireball encasing your launch vehicle isn't dangerous?!?

It might be within engineering tolerances, but that doesn't make it inherently safe. I really doubt that it would not be a roadblock to man-rating....

Simon ;)
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/08/2006 11:11 AM
The "ball of flame" at RS-68 ignition is NOT a hinderance to man-rating. Recall that the Saturn-V had a similar event at ignition too, but it was a far larger vehicle, so while the ball of flame was a similar size, it *appeared* to be a much smaller event.

The TPS on the stage itself can easily handle this short-term effect.   And in fact it will have to handle far worse heating later on the ascent as the plume starts to ride up the sides of the stage.


None-the-less, NASA has requested PWR to mitigate it in the man-rated variant.   I understand this is primarily for PR concerns though, not technical ones.   It simply doesn't look good on TV to the tax=paying public and the politico's who are unaware of what's really going on.

IIRC, the plan is to re-route the excess propellant back through the engine somehow, but I don't have any specifics to hand.   Ultimately though, it's just a plumbing job ;)

Ross.
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/08/2006 12:59 PM
Well, could we take ADVANTAGE of the fireball, then?  Could we leave either an un-scorchable or an easily blackened bit of lettering on the core stage?  Maybe a clear paint with different thermal characteristics...  So that after the fireball, it reveals "NASA" or "USA" or something...  whatever.

The fireball would then be seen as an expected and designed-for event, reporters would be talking about it & looking forward to it, and it would then be perceived as the non-event it is.

Thermally-reactive paint may be cheaper than a re-plumbing job.  :)
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/08/2006 01:31 PM
Quote
rumble - 8/11/2006  8:42 AM
Thermally-reactive paint may be cheaper than a re-plumbing job.  :)
That is actually not a bad idea.
Chuck
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/08/2006 02:03 PM
If you had a sucking device in the flame conduit and also spark igniters, the flame would be happening to the below and side of the vehicle... although that increases pad costs. And you have to make sure it doesn't happen in an enclosed volume or else, kaboom. :)
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/08/2006 02:04 PM
What kind of flames would the five RS-68 on Ares V generate  btw?
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/08/2006 02:11 PM
Quote
meiza - 8/11/2006  9:47 AM

What kind of flames would the five RS-68 on Ares V generate  btw?

1.667 times a Delta IV Heavy or 5 x a D-IV Medium
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/08/2006 02:19 PM
Assuming no re-plumbing changes for RS-68 on the Ares-V, then I think the flame would be big.   Stretch about half way up the Core and probably char the SRB's paintwork too.

But NASA is paying to have the ball of flame deleted, so its a non-issue.

On the other hand, DIRECT assumes using a change to Regenerative Nozzles, and it would be a relatively simple job to design the plumbing alterations during the design phase of that change.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/08/2006 02:23 PM
Quote
meiza - 8/11/2006  9:46 AM

If you had a sucking device in the flame conduit and also spark igniters, the flame would be happening to the below and side of the vehicle... although that increases pad costs. And you have to make sure it doesn't happen in an enclosed volume or else, kaboom. :)

I wonder if something would be possible like that.   Or perhaps a very thorough helium or nitrogen purge immediately surrounding ignition...

Another approach might be to ignite one engine ahead of the others.   That would create a strong venturi effect sucking air (and flame from any other engine ignitions) down into the flame trench.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/08/2006 02:49 PM
Quote
meiza - 8/11/2006  8:46 AM

If you had a sucking device in the flame conduit ...
The sound suppression water ends up doing this.  Watch the vapor clouds beneath the SSME's during the last 20(?) seconds before ignition.  Before the water starts flowing, the vapor just hangs around, but after the water starts, it creates a slight vacuum, pulling the vapors into the flame trenches.  ...or so it appears, anyway.

I still like the idea of keeping the plume and using it to reveal a "hidden" message on the core stage.  :)
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/08/2006 02:52 PM
Quote

1.  If you had a sucking device in the flame conduit and also spark igniters, the flame would be happening to the below and side of the vehicle... although that increases pad costs. And you have to make sure it doesn't happen in an enclosed volume or else, kaboom.

2.I wonder if something would be possible like that.   Or perhaps a very thorough helium or nitrogen purge immediately surrounding ignition...

3. Another approach might be to ignite one engine ahead of the others.   That would create a strong venturi effect sucking air (and flame from any other engine ignitions) down into the flame trench.


1.  There are already ROFI's.  Sucking won't work, due to H2 density and the size of the sucking device.

2.  Purge won't work is H2 is flammable in 4% to 96% air mixtures

3.   there would be a staggered start like the Saturn but H2 is too light

The D-IV flame trench is open to prevent "kaboom"
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/08/2006 03:08 PM
Where, precisely on the RS-68, does the H2 come from?   I've been assuming it is from either of the outboard exhausts, or a vent line on the engine bell.

Assuming it is isolated to such very specific points, could not a disposable vacuum line be placed in the immediate proximity of whichever of these locations to draw the excess propellant away?

Sure it would get scorched by the launch, but if it were specifically designed to be a simple pipe replaced after every launch, it would possibly solve the problem very cheaply with no extra mass required on the engine itself.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/08/2006 03:30 PM
It is coming out the bell and the two turbopump exhausts.  One turbopump exhaust is the roll control nozzle.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/08/2006 03:40 PM
So theoretcially something lika a 4" diameter pipe could be aimed at these locations to suck the vented propellant away from that area.   As long as it doesn't get close to the engine during liftoff (it may require retracting at around ~T-20s), and as long as it is designed to be easy to service after a launch, I would think it could do the job quite effectively.   Even if it only got 95% of the excess propellant, that would reduce the flame burst massively.

It could probably be prototyped on the Delta-IV Pad first too.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: tom nackid on 11/08/2006 03:51 PM
Quote
kraisee - 8/11/2006  5:54 AM

None-the-less, NASA has requested PWR to mitigate it in the man-rated variant.   I understand this is primarily for PR concerns though, not technical ones.   It simply doesn't look good on TV to the tax=paying public and the politico's who are unaware of what's really going on.Ross.

Give me a break! Do you have any sources that it is "...mainly a PR concern..."? So sick of people play acting at being a rocket scientist on this board. I'm outta here.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/08/2006 03:56 PM
Adding regenerative nozzle might be possible but what about massive ISP upgrade? As Direct has nearly the same payload capability as STS inline derivative with 3 SSMEs the ISP must be nearly the same. I know that you want to use the higher thrust and higher "g" approach but ISP of RS-68 "magic upgrade" must still be significantly higher than the common RS-68. You want apparently increase pressure in the main chamber. This could be quite significant change.
Another issue might be with ET insulation which is not designed for this ball of fire. RS-68 will be redesigned not to release this fireball anyway so it shouldn't pose big risk.
My biggest concern with RS-68 for Direct is still with it's major ISP improvement.
If it really is possible to improve it significantly the costs asociated with AresV development could be greatly reduced. Core diameter could stay 8.4m and number of engines could be reduced to four (or three?) RS-68 "magic".
I'm sure that NASA is closely watching this issue. The fact that they haven't come with this means that the ISP upgrade is not so stright forward.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/08/2006 04:09 PM
Quote
JIS - 8/11/2006  11:39 AM
Another issue might be with ET insulation which is not designed for this ball of fire..

It is the same foam that is used on the Delta-IV.  The thickness of the foam has to be changed anyways, so adding a little more at the aft shouldn't matter
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/08/2006 04:12 PM
Quote
kraisee - 8/11/2006  11:23 AM

So theoretcially something lika a 4" diameter pipe could be aimed at these locations to suck the vented propellant away from that area.   As long as it doesn't get close to the engine during liftoff (it may require retracting at around ~T-20s), and as long as it is designed to be easy to service after a launch, I would think it could do the job quite effectively.   Even if it only got 95% of the excess propellant, that would reduce the flame burst massively.

Ross.

Most of the H2 comes from the bell and is released at the beginning of engine start, not before.  Regen nozzle would be worse, since the bell now has to be conditioned too.
Title: RE: "DIRECT" Goes Live
Post by: RedSky on 11/08/2006 04:56 PM
Seems like discussion of DIRECT is really starting to show up in other places...

http://selenianboondocks.blogspot.com/2006/11/direct-and-other-esas-alternatives.html
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/08/2006 05:29 PM
Quote
Jim - 8/11/2006  10:52 AM

Quote
JIS - 8/11/2006  11:39 AM
Another issue might be with ET insulation which is not designed for this ball of fire..

It is the same foam that is used on the Delta-IV.  The thickness of the foam has to be changed anyways, so adding a little more at the aft shouldn't matter

Isn't it somehow patented or anybody could use it?
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/08/2006 05:33 PM
JIS, I do wish you would read up on the Regen.   It truly isn't "magic" as you keep saying, and that term isn't doing you any favours.

Regenrative Cooling is actually nothing special in rocketry.   It's the thing Space-X are doing on to turn their Merlin engine into the Merlin-II - to increase performance.   The SSME is a very example of a regeneratively cooled engine, "Regen" was used on the F-1, the original J-2 and will be used on the new J-2X also.   All it does is run the cryogenic fuel through the nozzle to actively help cool its inner surface.   In the simplest terms, this allows the engine to be operated at higher performance levels without melting the nozzle.   There's a wonderful section in this Interspace News article about the SSME which demonstrates it very clearly.   See figure 2 for a great cutaway of a Regenerative Nozzle's structure.


Anyway, the "Regen" nozzle, optimized for vacuum operation instead of the Sea Level/Low Atmosphere optimization used at present for Delta-IV, increases both vacuum thrust and vacuum Isp by a little over 5% above the basic RS-68.

As I have said at least three times in various threads already, the major components (including the main combustion chamber) have ALREADY BEEN DESIGNED AND TESTED to this higher operating limit than are being operated on Delta-IV currently.   The powerplant is *already* able to run in this higher performance range, but with the cheaper ablative nozzle it is artificially limited to about 95% of it's maximum rated spec. for Delta-IV.   With the Regen, it can use it's full envelope.


RS-68 "Regen" is 820,000lbf vac Thrust with 435.4s Isp.

SSME is 512,000lbf vac Thrust, with 452.1s vac Isp.


Three SSME's on Shuttle produce 1,536,000lb vac Thrust in total.

The two RS-68-R's on DIRECT produce 1,640,000 vac Thrust, so this configuration produces only a very small amount of additional thrust (especially considering the max thrust of the two SRB's is 6,662,000lb f), so your "higher g" comment is untrue.   Maximum g forces are limited to 4g - as was stipulated in the ESAS Ground Rules and Assumptions, all of which DIRECT complies with.


So, the thrust is virtually the same, but the efficiency (Isp) is lower than SSME by about 4%.   This means these engines needs about 4% additional propellant to do the same job, and a bit more to cover the losses for that extra mass too.   In short, when optimized correctly, the DIRECT's tanks requires approximately 9% additional capacity over the standard ET.   This is well within the margins for the current manufaturing tooling to handle already, so is not a major headache from that perspective.

The important thing to do though, is to ensure that the Intertank structure is configured to stay at precisely the same height above the Pad, in order to support the Fwd SRB attachments without any changes.

So to accomodate the stretched tanks, the LH2 tank is stretched downwards into the space below the current tank dome used for Shuttle.   The engines must be mounted with their nozzles virtually in line with the SRGB exhausts anyway, so the gap between the tank dome and engine plumbing can be utilized with little to no aerodynamic or mass losses incurred at all.

In point of fact, there is a LOT of spare room in that region, and even with a larger than necessary thrust structure we are assuming (we've actually been using the structure from the 5-SSME powered ESAS CaLV in order to severely over-estimate the mass allowance), and bigger nozzles on the RS-68's this proves not to be of any concern at all.   The LOX tank is also stretched, but upwards from the Intertank.   Overall, this makes the stage at the Pad only ~70cm taller than if it were designed to precisely the same capacity as the ET.


Swapping the basic RS-68 for the Regen version certainly improves payload performance on the Ares-V also, but the 4% extra efficiency would NOT allow for any of the engines to be deleted.   If you delete an engine, you lose 20% of your power.   That's far more than the 4% you gain from the Regen - so there are no cost savings.   The "Regen" would have the extra costs associated with its development so that increases the already $20Bn development cost for Ares-V by another $1Bn.

The only saving would be that the Core stage tanks could be made a little shorter (96% capacity of current Ares-V), but that's not going to affect the price at all.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/08/2006 05:46 PM
Take a look at this image:




It is from STS-1, and the white paint shows up the natural scorching which the ET suffers on every flight.

The low pressure causes the exhaust plume to "climb up" and scorch the bottom of the tank already.   The effect which causes this is precisely the same as shown on this famous Apollo 11's flight picture...




It does NOT do any damage, because the foam TPS is designed to protect it.


Ares-V will be protected from this effect, which lasts minutes.   The few seconds of flame during the initial seconds of the launch is minor heating compared to the normal flight conditions it will have to face.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/08/2006 06:00 PM
Quote
JIS - 8/11/2006  1:12 PM

Quote
Jim - 8/11/2006  10:52 AM

Quote
JIS - 8/11/2006  11:39 AM
Another issue might be with ET insulation which is not designed for this ball of fire..

It is the same foam that is used on the Delta-IV.  The thickness of the foam has to be changed anyways, so adding a little more at the aft shouldn't matter

Isn't it somehow patented or anybody could use it?

Anyone can use it, both Delta-IV and Atlas use it.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/08/2006 10:58 PM
Quote
kraisee - 8/11/2006  7:16 PM

In point of fact, there is a LOT of spare room in that region, and even with a larger than necessary thrust structure we are assuming (we've actually been using the structure from the 5-SSME powered ESAS CaLV in order to severely over-estimate the mass allowance), and bigger nozzles on the RS-68's this proves not to be of any concern at all.   The LOX tank is also stretched, but upwards from the Intertank.   Overall, this makes the stage at the Pad only ~70cm taller than if it were designed to precisely the same capacity as the ET.

Ross.

Its intresting that there is a lot of spare room.  How would an even larger fuel load affect the performance? Is the lift of thrust to weight ratio the limiting factor?
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/08/2006 11:37 PM
Magnus,
There is a maximum point where extra propellant & tanking mass eventually exceeds the performance gains.   But it's not specifically liftoff thrust:weight though.   It's a variety of different factors incuding aerodynamics, trajectory, launch site latitude, target orbit perigee, apogee and inclination etc.   It is a pretty difficult problem to solve, and that's where program such as POST and the ESA tools I have here can make things a good bit simpler.

Even with those, a time-consuming analysis over a few weeks, of different sized tanks were tested exhaustively.   The best observed payload performance was narrowed down to between 8-10% higher than Shuttle's ET.   Using the ESA tools here, I eventually settled on 9%.   When run by a chap working (in his spare time) at MSFC, a figure of 8.2% capacity growth was indicated as optimal after a similar array of testing in POST.   That's pretty damn close in my book.

The optimal balance was calculated specifically for the DIRECT + EDS configuration booster - in order to provide the maximum possible propellant payload for the important TLI burns.

The standard DIRCET configuration, without EDS, will use precisely the same Core structure, deliberately unchanged even though it may be sub-optimal for those missions, in order to keep costs down enormously.

I did a series of tests that showed that the same Core is actually only about 2% larger than its absolute optimal configuration.   That's certainly close enough for me not to worry about it.   No propellant offload of the Core has been analysed yet for DIRECT to see if it can enhance performance further in the basic configuration.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/09/2006 09:59 AM
Quote
kraisee - 9/11/2006  1:20 AM

Magnus,
There is a maximum point where extra propellant & tanking mass eventually exceeds the performance gains.   But it's not specifically liftoff thrust:weight though.   It's a variety of different factors incuding aerodynamics, trajectory, launch site latitude, target orbit perigee, apogee and inclination etc.   It is a pretty difficult problem to solve, and that's where program such as POST and the ESA tools I have here can make things a good bit simpler.

Ross.

Thank you, I were only thinking in a simplistic economical way, I have no eduction in the field but a technology nerd must like rockets.  ;)

Why must all the engine bells exit at the same level?
Is it due to plume interactions affecting the lower engines?
If that is correct would it help to restrict the swiveling of the RS-68:s while the SRB:s burn since the SRB:s anyway provides most of the control authority? It would be nice if a control system change could save a meter of engine support structure.

Another question that must be basic is: If an extended hydrogen tank cost roughly the same in mass as the support structure for mounting the engines further down could it then make sense to extend the hydrogen tank and running the engines with a more hydrogen rich mixture? I guess it ends up with a no since it would require a lot of engine adjustments and recertification.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/09/2006 01:03 PM
Quote
kraisee - 8/11/2006  12:16 PM

Anyway, the "Regen" nozzle, optimized for vacuum operation instead of the Sea Level/Low Atmosphere optimization used at present for Delta-IV, increases both vacuum thrust and vacuum Isp by a little over 5% above the basic RS-68.

.....


The powerplant is *already* able to run in this higher performance range, but with the cheaper ablative nozzle it is artificially limited to about 95% of it's maximum rated spec. for Delta-IV.   With the Regen, it can use it's full envelope.


RS-68 "Regen" is 820,000lbf vac Thrust with 435.4s Isp.

Thank you for numbers. That's what I was looking for.

I think that current RS-68 vac performance is 745,000lbf  Thrust @ 410s ISP. So it is only 90% performance of your RS-68 "Regen". RS-68 R has also more than 6% increase in ISP.

I think that regenerative nozzle is not directly related to ISP so how it will be increased. I suppose that by higher chamber pressure and bigger expansion ratio of nozzle.

Quote
The two RS-68-R's on DIRECT produce 1,640,000 vac Thrust, so this configuration produces only a very small amount of additional thrust (especially considering the max thrust of the two SRB's is 6,662,000lb f), so your "higher g" comment is untrue.   Maximum g forces are limited to 4g - as was stipulated in the ESAS Ground Rules and Assumptions, all of which DIRECT complies with.

CEV is actually being designed already to launch on Ares1 and max g is apparently much less than 4g. This is could be serious showstopper for DIRECT.
Maybe I look at wrong place but what is the DIRECT max g for CEV+LSAM payload?
 

Quote
Swapping the basic RS-68 for the Regen version certainly improves payload performance on the Ares-V also, but the 4% extra efficiency would NOT allow for any of the engines to be deleted.   If you delete an engine, you lose 20% of your power.   That's far more than the 4% you gain from the Regen - so there are no cost savings.   The "Regen" would have the extra costs associated with its development so that increases the already $20Bn development cost for Ares-V by another $1Bn.

The only saving would be that the Core stage tanks could be made a little shorter (96% capacity of current Ares-V), but that's not going to affect the price at all.

Ross.

RS-68 Regen has actually 6% higher ISP and 10% higher thrust than common RS-68. It means that liftoff thrust of Ares IV with RS-68 regen would be only about 6% less than Ares V with common RS-68 while it could save maybe 15% of propelants or more because it could be possible to decrease 10m core back to 8.4m and spare lot of cash.
1B for RS-68 regen is nothing compared with cost of core diameter change.

The only problem with this is if such engine is feasible.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/09/2006 09:23 PM
Quote
JIS - 9/11/2006  8:46 AM

I think that regenerative nozzle is not directly related to ISP so how it will be increased. I suppose that by higher chamber pressure and bigger expansion ratio of nozzle.

That is my understanding.


Quote
CEV is actually being designed already to launch on Ares1 and max g is apparently much less than 4g.

The Orion is designed to handle 4g.   Don't forget that it is being designed to also be launched on the Ares-V and that hits 4g easily, even throttling down the main engines.

The place where DIRECT kills the Ares-I though is the maximum dynamic pressure.   Ares-I goes through a HUGE Max-q of over 800lb /sq ft.   Even the EELV's stay under about 720lb /sq ft.   DIRECT stays below 600lb /sq ft.


Quote
The only problem with this is if such engine is feasible.

The engine itself has already been tested to that level.   Making a new nozzle for it is not all that difficult.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: josh_simonson on 11/09/2006 10:43 PM
Was it tested at that level and still within the margins needed to be 'man rated'?
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/09/2006 11:48 PM
Quote
josh_simonson - 10/11/2006  12:26 AM

Was it tested at that level and still within the margins needed to be 'man rated'?

If RS-68 regen wont work for some unforseen reason it would still seem better to either downsize the moon missions to fit Direct stage one with an earth departure stage or start with Direct stage one and then stretch it with five segment SRB:s and a third RS-68. It still ought to be far cheaper to develop and use then Ares I plus Ares V.

Low budget work on a 5-segment SRB and provisions for a core stretch in the production and handling infrastructure and pad modification could perhaps be a reasonable parallell fallback development for the RS-68 regen development and certification?

A risk with the fallback plan is that Nasa would become performance greedy and prefer two stretched Directs with an EDS each for the moon missions.

Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/10/2006 01:55 AM
My contact at PWR was 100% confident that the engine spec I'm using was easily achieveble.   He believed another 3-5% was possible, but not guaranteeable.   He told me in the same conversation that I should treat it like the J-2X, where 274,000lbf thrust was easily achievable, but 293,500lbf was not guaranteeable.


None-the-less, just because you got me curious Magnus, I just ran some 'quick' numbers for the non-Regen DIRECT flying with the same EDS (really should optimize the EDS to suit the spec, but it's going to be pretty close, so I didn't bother this time).

Payload to 60x160nm, 28.5deg LEO is 87,889kg including the ESAS 5% GRA margin.   I just posted numbers in L2 for the Ares-I and Ares-V, to compare this number directly, the comparative maximum payload figure is 94,403kg.


Using NASA's math, this config with a standard CLV flight, and EDS on the CaLV create an IMLEO figure of about 146.5mT.    Ares-I and Ares-V can do 150.3mT, so the difference is only 4mT - and remember that is without optimizing the size of the EDS.

But if *both* the DIRECT CLV and CaLV flight use an EDS, the IMLEO figure climbs to 171.4mT, so even without the "Regen" upgrade, DIRECT could still out-perform the Ares solution by about 14%.

So, that actually means that Lunar missions on DIRECT would not be reliant on the Regen RS-68 at all.   They are quite possible without it, but it is a nice upgrade to have available whenever it is ready.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/10/2006 02:19 AM
Quote
josh_simonson - 9/11/2006  6:26 PM

Was it tested at that level and still within the margins needed to be 'man rated'?

Josh, my understanding is that the engine itself was tested at both the component and integrated level to the higher specification.

PWR believe that NASA could man-rate the engine with only minor modifications at the high performance rating, but just can't use the extra performance with an ablative nozzle.   They also believe it can be qualified at 106% mission power leve of *that* upgraded spec.   That results in the 820,000lbf thrust figure with the Regen upgrade.

The higher basic performance, combined with the Regen nozzle optimized for vacuum operations instead of Delta-IV's atmospheric optimization, can increases the efficiency of the unit to 435s.

Additional performance may be possible, but that's what they're totally confident of.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: HIP2BSQRE on 11/10/2006 04:14 AM
Are you going to communicate with the guy who does the Space Show and get to talk about "Direct"?  Have you thought about sending your proposal to congress or the people on space committees.  I think that you have a great proposal and NASA could do well to think about implementing it.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/10/2006 10:35 AM
I've been thinking about it, maybe possibly Ares V makes sense in the long run, if it ever gets there.
You can ditch the Stick and fly LEO missions with COTS or CEV w/ EELV or whatever. That'd save NASA money.

Then you can put the CEV on Ares V and do modest lunar crew missions in a single launch, and lunar robotic missions in a single launch too. You can launch fairly often, since that doesn't affect cost so much, just like with the space shuttle.

The problems with that are inflexibility in case of launcher problems / delays and it's also politically vulnerable. (I don't know if it'd be prudent to have a lunar base serviceable by only one type of launcher.)

But as a whole it makes some sense.

It's sad though that this can't be communicated upfront but is behind some political safesimplesoon Stick smoke veil.

Btw on some forum I saw the Ares V nicknamed as "Stack". :P
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/10/2006 10:35 AM
Quote
kraisee - 9/11/2006  4:06 PM

The Orion is designed to handle 4g.   Don't forget that it is being designed to also be launched on the Ares-V and that hits 4g easily, even throttling down the main engines.

The place where DIRECT kills the Ares-I though is the maximum dynamic pressure.   Ares-I goes through a HUGE Max-q of over 800lb /sq ft.   Even the EELV's stay under about 720lb /sq ft.   DIRECT stays below 600lb /sq ft.


Actually with original ESAS vehicles the Ares V with SSME's had maximum less than 3g's and Ares 1 with SSME had 4g's.
Now Ares V with RS-68 have apparently more g's and Ares 1 with J-2 less than 4 g's.
But it seems to be reasonable to design all components for 4 g's from the beginning.
My point is that if RS-68 is easily ugradeable it would be nonsense not to use it in Ares nad decrease core diameter. The real development won't begin before 2010 so it is still enough time to make this decision.
I think that DIRECT study can't revert decision to build Ares 1 but could have minor effect in promotion of further development of RS-68.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/10/2006 01:38 PM
Quote
JIS - 10/11/2006  12:18 PM
I think that DIRECT study can't revert decision to build Ares 1 but could have minor effect in promotion of further development of RS-68.

Why not?
If I add apparent technical merit with a naive impression of political needs for keeping the same work force and companies employed it seems like very good decision to scrap Ares I and Ares V and build Direct.

Politically it might be smarter to prioritize a downsized Ares V as the Ares I replacement after the Ares I development problems. An Ares V with the the same tankage diameter and basic infrastructure as the space shuttle and four segment SRB:s to keep the Ares I schedule and two slightly modified RS-68:s since it is the cheapes and fastest to develop engine. The Ares I second stage work can be reused as the Ares V EDS built with the extrenal tank tooling to keep the cost down and sized for landing a singe launch supply mission on the moon wich happens to maximize the usefull payload of a two launch mission with moon orbit docking.

If this does not spend enough money to keep everybody happy you can develop the five segment SRB and stretch the Ares V with three RS-68:s.

Ok, scrapping Ares I and Ares V is a realy bad idea, the good idea is to directly build a fast track Ares V with the most unexpensive engines available...
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/10/2006 02:31 PM
We are going in circles.
In fact building Ares II, Direct, Ares III, Ares IV or Ares V will cost about the same money as long as they stay with same diameter core.
Nasa told us that it's even cheaper to to spend more money on 10m core infrastructure than spending money on paying for SSMEs. OK I took that argument.
But Ross says that there is actually engine RS-68 regenerative which has nearly capability of SSME (+- few tons of payload) and is much cheaper. If this is really true (I'm not convinced) then NASA could still use the original 8.4m core and spare some money and everybody will be happy.

The problem is with another Ross statement that Ares 1 has serious development problems and two launches strategy would be better approach. This collides directly with NASA plan.
Ares 1 is simply better rocket better fitted for Orion. I have no problem to believe NASA and american industry that they will be able to manage the design of such rocket. Ross haven't convinced me to believe that DIRECT is better concept. It's difficult to say if he can pursue more competent people than me.
Time will show us.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/10/2006 03:49 PM
Quote
JIS - 10/11/2006  10:14 AM

Ares 1 is simply better rocket better fitted for Orion. I have no problem to believe NASA and american industry that they will be able to manage the design of such rocket. .

Keep drinking the koolade.  The design is flawed in the first place.
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/10/2006 03:57 PM
Note: This answer is just from my understanding of things, so if I'm wrong on some of this, someone please jump in and help me out.

Think back several months...  When Ares I was forced to change from an air-startable SSME for the 2nd stage to a substantially smaller engine (j-2x), they were forced to get more impulse from the 1st stage (thus the switch to the 5-seg).  Developing an air-startable SSME simply wasn't practical.

But even the 5-seg SRB doesn't make up the deficit, so now, by the time the 1st stage burns out, the 2nd stage can't make it to orbit.  ...at least, not with the CEV on it.  It is NOT a better rocket.  The constraint that it must use a single SRB for its first stage is a problem.

DIRECT is only a good idea because it is the path of least resistance most areas.  If DIRECT required the same number of infrastructure and tooling changes as Ares, it wouldn't be as attractive.  If DIRECT was more of a clean-sheet rocket like the ARES I & V are, it wouldn't be as attractive.

I agree.  DIRECT isn't a perfect fit to the CEV...there's wasted power there.  But even with wasting that extra capacity (for ISS launches, assuming we don't somehow take advantage of the extra), DIRECT ends up costing less money and taking less development time than than the pair of ARES I & V.  DIRECT wasn't designed with overkill in mind...its performance is simply what you end up with when you optimize "what we got" for the sweet spot.

DIRECT is a "sweet spot" because it's takes what we already have, and by making only minor changes, it becomes a very cost-effective option.  Certainly more cost- and time-effective than ARES.  It uses a large amount of existing shuttle infrastructure with very few modifications--a claim ARES I & V can't make.  DIRECT is also good because it's a single launch vehicle, compared to the two ARES.

On the technical, cost, and timeline merits, DIRECT is a better answer, hands-down!  However, a ship the size of NASA doesn't exactly turn on a dime.  My hope is that DIRECT will be given an honest evaluation.  If it can get that, and it's chosen for our VSE launcher, I believe it will only help our ultimate goal here, which is to get out of low earth orbit and start EXPLORING!
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/10/2006 04:26 PM
Quote
JIS - 10/11/2006  4:14 PM
The problem is with another Ross statement that Ares 1 has serious development problems and two launches strategy would be better approach. This collides directly with NASA plan.

I have no stake in any solution, especially since i live in Sweden. My only wish about this is that you guys get a new moon program running and preferably a large Hubble II before we get a period of weak economy. The lasting value of all this is the science gatherd and the technology development helping ordinary industry, the Ares I and Ares V combination is not especially exciting from this point of view.

Using several years developing a small almost ELV class launcher and then developing a very large very expensive one gives one fairly meaningless project since an equivalent capability alreday excisted followed by one that probably will be too expensive and thus cancelled.

As I see it NASA already have a two launch strategy for its moon missions. Having a Direct that has overcapacity for the Orion is like driving a gas gussling SUV to town instead of buying an additional small car. But it does not make sense to have two cars with different capacity if you only drive to town a dozen times per year. Its not worth the capital cost and staffing to have two launchers when one can do the job and as a bonus NASA gets more capacity to the moon.
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/10/2006 05:48 PM
And in the SUV analogy, the small car will cost a great deal of money to acquire, and the SUV can be had for a MUCH lower price.  Even though you're paying more in gas, your overall expense is substantially lower.  (close to 1/2 in the case of DIRECT.)

And in ARES, you STILL have to buy a NEW gas-guzzling SUV (Ares-V), even if you buy the small car, so you haven't saved anything.

Of course, the analogy breaks down, because cars aren't typically one-trip disposables.  ;-)
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/10/2006 07:23 PM
Quote
JIS - 10/11/2006  10:14 AM

We are going in circles.
In fact building Ares II, Direct, Ares III, Ares IV or Ares V will cost about the same money as long as they stay with same diameter core.
Nasa told us that it's even cheaper to to spend more money on 10m core infrastructure than spending money on paying for SSMEs. OK I took that argument.
But Ross says that there is actually engine RS-68 regenerative which has nearly capability of SSME (+- few tons of payload) and is much cheaper. If this is really true (I'm not convinced) then NASA could still use the original 8.4m core and spare some money and everybody will be happy.

No. That is not what I'm saying at all.   I am saying that the much higher thrust of the RS-68, combined with a higher Isp variant, already announced as an available upgrade by Rocketdyne themselves, means that two of them, with an appropriately sized tank, can, IN THIS VERY SPECIFIC DESIGN, perform a very similar role as the 3 SSME's used today.

It is a *very* careful balance of different factors, not just a straigh swap.

Ares-V could be made as DIRECT Growth Option II.   2x5seg and 3xRS-68R and get slightly higher performance than 131.6mT.

But four engines on the core will require 1/3 extra propellant, and a fifth engine will require about the same again.   Both of those options would make an 8.41m diameter tank too tall to be moved around inside the VAB, so the only choice at that point is to widen the tank.   10.06m is something they've had previous experience with, so that's naturally the next size up which they'll look at.


Quote
The problem is with another Ross statement that Ares 1 has serious development problems and two launches strategy would be better approach. This collides directly with NASA plan.

You have completely missed the point with that assumption.

Count how many launches are required by Ares for Lunar missions:

1xAres-I Crew   plus   1xAres-V Cargo.   How many launches is that?   My math makes it TWO launches.   Yes?   No?

So to accomplish that, you must develop TWO new vehicles, at $20Bn each.   You must run two programs, at roughly $1Bn per year, and the flights cost about $130m & $270m respectively.   So to get just the first Lunar mission going, you've spent at least $41Bn.


Instead, DIRECT proposes using the same basic vehicle for both of these flights:

1xDIRECT Crew   plus   1xDIRECT Cargo.   That is still TWO launches.

That means just one $20Bn development cost, one yearly $1Bn program cost and flight costs roughly the same as before.


Quote
Ares 1 is simply better rocket better fitted for Orion.

No it isn't.

It is noticably less powerful than the Atlas-V 552 or Delta-IV Heavy.   It is three times less powerful than DIRECT.

It will force NASA to spend twice as much money on new launch vehicles as necessary.

With extra solids, it will be less safe than Atlas 552 and Delta-IV Heavy, and much less safe than DIRECT.

And DIRECT would also completely remove the political risks of the second vehicle being cancelled.


So where, precisely, are the advantages with the Ares plan?   It isn't in cost.   It isn't in safety.   It isn't in schedule.   It isn't in program risk.   So I ask, where is it?


Oh yeah...   It lines the pockets of ATK and anyone who has pension plans/stock options/political connections with them.   That would seem to be the only 'advantage' it has now.


Quote
I have no problem to believe NASA and american industry that they will be able to manage the design of such rocket. Ross haven't convinced me to believe that DIRECT is better concept. It's difficult to say if he can pursue more competent people than me.

LOL.


Quote
Time will show us.

Yes it will.   Ares-I's limitations will force compromises to the design of *every* other element in the 30-year Constellation plans.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/10/2006 07:29 PM
Quote
rumble - 10/11/2006  11:40 AM
DIRECT isn't a perfect fit to the CEV...there's wasted power there.

Just curious, but why does it have to be 'wasted'?

Even for the small number of ISS missions we're planning, why can't it be utilised?   For no extra launch cost NASA could:

* Launch Node 3.
* Attach MPLM's with racks and racks of extra stuff on board to offer plenty more science.   Leave them there.
* Re-task the cancelled Habitation module to provide *extra* crew facilities.   Fly it on a DIRECT Crew rotation flight, along with the Science Power Platform in an effort to increase the crew size to 9 or 12?

All this can fly for free on the Phase 1 DIRECT crew rotation flights, which cost $140m each, compared to Ares-I's $130m.

Why not plan to USE the extra performance instead of wasting it?

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/10/2006 07:37 PM
Actually the analogy does work still.

But you just use the car very little:
* You're planning to only drive across the county four times per year (to drop off and pick up the kids at college).   Trip cost is only $15 per trip.
* You also need to drive across the country twice per year, but you need to tow your big boat, and that means you need a big SUV/Truck.   Trip Cost is about $100.


So what are you going to buy?

A $20,000 small car for the short trips and another $20,000 big one just for long-distance towing?   But you also don't have enough cash right now to buy the big one anyway, and no guarantees at all that your finances will even allow you to buy that second vehicle in a few years time when you really need it.

Wouldn't a single $20,000 vehicle able to do it all, be better value and guarantee you can afford it?

Ross.
Title: RE: "DIRECT" Goes Live
Post by: JWag on 11/10/2006 07:40 PM
I've only skimmed the DIRECT report and this thread, but it's made me more excited about manned spaceflight than I've been for a while.

Of course, having just completed Stephen Baxter's Voyage, I'm on kind of a high anyway.  :)

Good luck, and I will keep watching to see how someone like me (Joe Taxpayer) can help to get something better than Stick and Stack the Budget Busters.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/10/2006 07:44 PM
Quote
kraisee - 10/11/2006  2:12 PM

Quote
rumble - 10/11/2006  11:40 AM
DIRECT isn't a perfect fit to the CEV...there's wasted power there.

Just curious, but why does it have to be 'wasted'?

Even for the small number of ISS missions we're planning, why can't it be utilised?

Launch Node 3.

Attach MPLM's with racks and racks of extra stuff on board to offer plenty more science.   Leave them there.

Re-task the cancelled Habitation module to provide *extra* crew facilities.   Fly it on a DIRECT Crew rotation flight, along with the Science Power Platform in an effort to increase the crew size to 9 or 12?

And all this flies for free on regular crew rotation flights.

Lets plan to USE the extra performance.

Ross.

That all starts adding complexity and development costs. You are getting dangerously close to the "do it all spacecraft" concept that became STS. What kind of payload interfaces are you talking about here? Will these extras require EVAs? A robotic arm? How will you maneuver these components once you get them into orbit? Extra crew on ISS? That means extra crew return vehicles. Suddenly we are bogged down in repurposing and adapting ISS components and loose our focus on Lunar and Mars exploration. I say NASA should build a "going to the moon" system. If it can do some useful stuff with ISS then great--it will be some extra shakedown time if nothing else. But going to the moon and doing as much as we possibly can (meaning no scaled back lunar landers or reduction of potential landing sites) should be the focus.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/10/2006 08:05 PM
Tom,
   I would agree, but DIRECT saves NASA a *LOT* of money.   10% of it's entire 20 year budget.   That money can be used for any different purposes.   Out of the $35Bn saved, why not put something like $5Bn into ISS to expand it's facilities?   And that would be entirely for new facilities because launch costs are basically free.   That doesn't detract from the VSE at all.   The rest, $30Bn, can be invested to improve the VSE too.

   The CEV does not have to be changed at all.   The Core vehicle stays exactly the same for all flights, whether they are for LEO, Lunar or Mars missions, Crew or Cargo flights.   The EDS isn't required for these missions so is irrelevant for this.

   A new, very simple, payload carrier inside the SLA is the only new parts needed.   A relatively simple "chassis" could simulate the Shuttle's cargo bay mountings and offer a LIDS adaptor for the CEV to attach to to bring it to the ISS.   Total mass would be less than 25mT including the payload.

   CEV is *already* being designed to be able to maneuver the heavy (45mT) LSAM in any situations where the LSAM's RCS fails, so flying with the CofG offset like that is *already* going to be something the CEV *can do*.   At that point, only training and procedures are required to allow it to safely maneuver these payloads into close proximity to ISS (*NOT* docking).   At that point station can grapple the payloads, CEV can disconnect and dock elsewhere, and station places the module in its final place.   No new RMS arms are required, because the ISS has one capable of doing all the necessary work - although a second arm might not be a bad extra to consider too.

   ISS Crews perform EVA's all the time.   Of the 6-person crew rotation, two of the new crew can be trained to fit the module they bring up with them.   Probably the two non-scientists.

   Nothing seems to require any extra changes to the CEV or DIRECT LV from current plans.   This simply makes additional use of the new equipment which Ares can't ever offer.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: RedSky on 11/10/2006 08:17 PM
Quote
JIS - 10/11/2006  9:14 AM

Ares 1 is simply better rocket better fitted for Orion.

Err... no.  Actually, Orion is being fitted to Ares-I.  What happened to the 5.5m ship?  It became 5m because of Ares-I deficiency. Apollo on steroids became Apollo on vitamins.  And it may shrink down to just plain old Apollo 18 if it's cut back any more.   The Service Module has shrunk down to a mere envelope for the tanks, with absolutely no extra volume for the potential of scientific instruments.  Even Apollo had SimBays for photographic and scientific equipment, and carried small satellites to release in lunar orbit.  And Apollo was only in lunar orbit for several days.  Orion is expected to be in orbit for weeks.  Think of what could be done with a significant extra-volume in the SM.  It's a crime the CEV has reverted to being just a Taxi, rather than an "exploration and research ship".  All because of Ares-I.  If anyone think's we'll have learned all we can from LRO in lunar orbit before the return... then why even return?  Footprints in the dust?  Done that.

Orion should have been overbuilt for future opportunities, and the LV designed (whatever it takes) to launch it.  Not the other way around.   When Direct is used for lunar missions, there is no wasted excess capacity.  So the "excess" capability mentioned is only on ISS missions... and there's only what,  3 or 4 of those at most?  




Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/10/2006 08:28 PM
Quote
RedSky - 10/11/2006  3:00 PM

Quote
JIS - 10/11/2006  9:14 AM

Ares 1 is simply better rocket better fitted for Orion.

Err... no.  Actually, Orion is being fitted to Ares-I.  What happened to the 5.5m ship?  It became 5m because of Ares-I deficiency. Apollo on steroids became Apollo on vitamins.  And it may shrink down to just plain old Apollo 18 if it's cut back any more.   The Service Module has shrunk down to a mere envelope for the tanks, with absolutely no extra volume for the potential of scientific instruments.  Even Apollo had SimBays for photographic and scientific equipment, and carried small satellites to release in lunar orbit.  And Apollo was only in lunar orbit for several days.  Orion is expected to be in orbit for weeks.  Think of what could be done with a significant extra-volume in the SM.  It's a crime the CEV has reverted to being just a Taxi, rather than an "exploration and research ship".  All because of Ares-I.  If anyone think's we'll have learned all we can from LRO in lunar orbit before the return... then why even return?  Footprints in the dust?  Done that.

Orion should have been overbuilt for future opportunities, and the LV designed (whatever it takes) to launch it.  Not the other way around.   When Direct is used for lunar missions, there is no wasted excess capacity.  So the "excess" capability mentioned is only on ISS missions... and there's only what,  3 or 4 of those at most?  





But the single Apollo launch HAD to do everything. The whole point of the present architecture (I think) is to efficiently divide the "taxi" and the "exploration and research ship" roles. The Orion only has to keep 4 to 6 people alive, safe, relatively comfortable, act as a command and control center and safely reenter the earth's atmosphere from a lunar return trajectory. The Ares V will launch the real "exploration and research ship". The growth potential will be built into the Ares V not the Ares I. I think people are focusing too much on the crew launcher because that is perceived as the "sexy" part.

Seems like half the people on this forum complain that the CEV is too big and the other half complain that it is too small. Maybe that means that in reality it is just right!
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/10/2006 08:28 PM
Excellent point RedSky.

The Apollo SM was designed with six "bays" around the propellant tanks in the core.   Each bay could contain different hardware specific to that mission.

Orion doesn't include any of that capability :(

All because of the Ares-I's awful performance.

DIRECT could easily offer single-launch Lunar Flyby missions for CEV-only research in LLO, as early as 2014 if required.   It would be great to at least have the *option* to have a science package on the CEV.   If it doesn't fly with a science pack, the CEV's mass is lower anyway.   But it has to be included in the early *design* to become an option at all.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: MATTBLAK on 11/10/2006 08:43 PM
Quote
MondoMor - 11/11/2006  6:23 AM

I've only skimmed the DIRECT report and this thread, but it's made me more excited about manned spaceflight than I've been for a while.

Of course, having just completed Stephen Baxter's Voyage, I'm on kind of a high anyway.  :)

Good luck, and I will keep watching to see how someone like me (Joe Taxpayer) can help to get something better than Stick and Stack the Budget Busters.

Coincidentally, I'm just reading that again for the third time!! I just love the book. Its a bit prescient and a little sad, too. Somewhat like his next novel after that: Titan -- more prescient, more sad. But spectacular, nonetheless.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/10/2006 09:05 PM
Ross,

With all due respect I think that including the RS-68R and proposing additional payloads with the CEV in the main body of the proposal was a mistake. Comments here and on other sites focus on the possible additional payloads and on the developmental costs of the Regen engine to the detriment of the overall DIRECT proposal.

While I know you have rewritten the proposal a zillion times I think that the main body of the proposal should focus on the Phase I DIRECT with the "stock" RS-68 and using the mass simulator as shielding for initial test flights as well as ISS flights (and possible moon missions). By having the performance figures based on the Regen. Engine rather than the baseline engine some people seem to believe that the DIRECT is dependant on that engine. Since DIRECT will be flying with the baseline engine for at least the first three years it would be better to emphasize it’s capabilities. All of the other concepts should be relegated to Appendix 8 and 9 including proposed alternative payloads. A detailed discussion of the RS-68 - RS68R upgrade should be located there also.

This would bring the immediate benefits of the DIRECT proposal into sharp focus allowing a clearer discussion of the short-term cost/benefits of Direct vs. Ares as well as co-locating all the development/growth options.

Norm
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/10/2006 09:36 PM
Quote
kraisee - 10/11/2006  2:12 PM

Quote
rumble - 10/11/2006  11:40 AM
DIRECT isn't a perfect fit to the CEV...there's wasted power there.

Just curious, but why does it have to be 'wasted'?

Bad choice of words.  How about "surplus."  If ALL you want to put in orbit is a CEV + SM for ISS crew rotation, there's plenty of surplus.

But even if that's ALL some of the launches will be, you've saved enough in infrastructure and vehicle development & staffing that it's not painful to use an over-capable launcher to orbit the CEV ... for the very few times that's all it'll be.
Title: Re: "DIRECT" Goes Live
Post by: HIP2BSQRE on 11/10/2006 09:48 PM
I agree...good point
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/10/2006 09:50 PM
Good point, Norm.

And to the talk of "what else can we do with it"...  your point is well taken.  It started as people already familiar with DIRECT and on-board with the concept feeling like kids in a candy store, looking at unused capacity and dreaming of what extra to do with it.

Absolutely...  we need to focus on the fact that right-out-of-the-gate, DIRECT is a strong candidate.  

[email protected]
Title: Re: "DIRECT" Goes Live
Post by: RedSky on 11/10/2006 09:51 PM
Quote
kraisee - 10/11/2006  3:11 PM

Excellent point RedSky.

The Apollo SM was designed with six "bays" around the propellant tanks in the core.   Each bay could contain different hardware specific to that mission.

Orion doesn't include any of that capability :(

All because of the Ares-I's awful performance.

Ross.

Actually, I think there were only 2 free bays in the Apollo SM... the others had H2 and O2 tanks and fuel cells, and half of the hypergolic  tanks.  (I built the 1/32 Monogram "see through" Apollo CSM as a kid in the late 60's)  But, having any free volume for a "Scientific Instrument Module" Bay (SimBay) would really have been nice on the CEV SM.  Especially considering its supposed to be an "autonomous" craft in lunar orbit for weeks.  If nothing else, each mission with a "beefed up" CEV SM  might have been planned to enter a high lunar orbit (that is stable against the forces of the lunar Mascons), in order to release a CommSat (stored in a SimBay),  then descend to LLO for the continuation of the landing mission.   But of course, that requires a more capable SM.  As it is, any Lunar CommSat constellation will have to be directly launched separately.  If we plan on any farside landings, we will need this eventually.  What a waste, and what a lack of forward thinking.  We should have planned by building upon Apollo, not just remaking it (actually, without a SimBay, not even remaking it).
Title: Re: "DIRECT" Goes Live
Post by: DaveS on 11/10/2006 10:22 PM
Quote
RedSky - 10/11/2006  11:34 PM
Actually, I think there were only 2 free bays in the Apollo SM... the others had H2 and O2 tanks and fuel cells, and half of the hypergolic  tanks.  (I built the 1/32 Monogram "see through" Apollo CSM as a kid in the late 60's)  But, having any free volume for a "Scientific Instrument Module" Bay (SimBay) would really have been nice on the CEV SM.  Especially considering its supposed to be an "autonomous" craft in lunar orbit for weeks.  If nothing else, each mission with a "beefed up" CEV SM  might have been planned to enter a high lunar orbit (that is stable against the forces of the lunar Mascons), in order to release a CommSat (stored in a SimBay),  then descend to LLO for the continuation of the landing mission.   But of course, that requires a more capable SM.  As it is, any Lunar CommSat constellation will have to be directly launched separately.  If we plan on any farside landings, we will need this eventually.  What a waste, and what a lack of forward thinking.  We should have planned by building upon Apollo, not just remaking it (actually, without a SimBay, not even remaking it).
RedSky, you do know that the SIM bays were only available on the "J missions" SMs right? The SM bay first flew on A15. So it's not impossible that sometime in the future that Orion's SM could be expanded to have one.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/10/2006 10:50 PM
Quote
DaveS - 10/11/2006  6:05 PM

RedSky, you do know that the SIM bays were only available on the "J missions" SMs right? The SM bay first flew on A15. So it's not impossible that sometime in the future that Orion's SM could be expanded to have one.

But *only* if the launch vehicle is capable of lifting the extra mass.

Ares-I looks doubtful whether it can launch the full CEV as it is.   There's word on L2 now that the CEV may be cut down below 22mT...

I hope people here are understanding this is *all* happening because of the Ares-I.   And even more similar BS "solutions" are yet to come, I guarantee it.   Watch for them.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: MATTBLAK on 11/10/2006 11:09 PM
B.S. is right! At this rate, they'll kill Orion and just buy Soyuz off Russia with an American made upgraded Service Module. Sheesh! They've cut the CEV to the bone as it is. Soon, it'll be so cut-down it'll be useless for Lunar missions and there'll be no money left to expand it as a "Block II" Lunar ship. It'll become an ISS, LEO-only transport, of the 'falsely-cheap' variety, which a lot of Democrats will love.

I know this is a worst-case scenario, but it's scary nonetheless.   :(
Title: Re: "DIRECT" Goes Live
Post by: Lunar Dreamer on 11/11/2006 01:23 AM
Anything that works. Don't care what it is, so long as it works.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/11/2006 02:23 AM
"as long as it works".

Profound words indeed.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/11/2006 05:07 AM
Ross, JIS,

Quote
Quote
I think that regenerative nozzle is not directly related to ISP so how it will be increased. I suppose that by higher chamber pressure and bigger expansion ratio of nozzle.

That is my understanding.

As I understand it, regenerative cooling impacts Isp in a few ways:
1-You can typically run higher pressures
2-You typically don't need as much film cooling as you do with an ablative.  I'm not sure that this is a very big effect with LOX/LH2, but it can be a big deal with LOX/Kero or LOX/Alcohol engines.
3-You're preheating the propellant a bit, and that extra thermal energy goes back into the engine.  This is usually a fairly small effect, but could be as much as 5-10s IIRC.

I used to be a huge fan of ablatives before I actually got involved with building rocket engines.  Now I'm definitely firmly in the Regen-Cooled camp as far as liquids go.  Ablatives have their place, but regen cooling has some real performance, reusability, and reliability benefits.  It's really nice being able to know that a piece of hardware you're flying on has been qualification tested and shown to work.  With ablatives, you're effectively testing a whole new engine each time.  Also I think failure modes with regen engines are a little less severe.  The engine will still have to be shut down in the event of a serious burnthrough, but the odds of punting a nozzle section like SpaceX managed (a year or so ago during some torture testing) are a lot lower.

Quote
The engine itself has already been tested to that level.   Making a new nozzle for it is not all that difficult.

I'd really be surprised if they ran into too many problems with it.  They've got to already know the thermal environment of that engine very well if they've got a working ablative design, so designing and implementing a regen nozzle should really not be that hard.  I'd be really amazed if it took them more than $50-100M to make the changes, and then qualify them with a bunch of firings on the test stand.

~Jonathan Goff
  Masten Space Systems
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/11/2006 05:35 AM
Welcome to the site Jon.   Good piece you wrote on DIRECT.   Thanks.

I heard $300m from PWR for a final flight version of the man-rated, NASA-spec version of the Regen '68.   I'm quoting $1Bn to cover all eventualities though.   I've taken that same overly cautious approach throughout the rest of the proposal too.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: Naraht on 11/11/2006 08:53 AM
Quote
MATTBLAK - 10/11/2006  4:26 PM

Quote
MondoMor - 11/11/2006  6:23 AM

Of course, having just completed Stephen Baxter's Voyage, I'm on kind of a high anyway.  :)

Coincidentally, I'm just reading that again for the third time!! I just love the book. Its a bit prescient and a little sad, too.
It also borrows to a very disturbing extent from Murray and Cox's "Apollo: the Race to the Moon". I really wanted to enjoy it, but I couldn't quite manage to when I kept coming across whole phrases and sentences that I'd read before.
Title: Re: "DIRECT" Goes Live
Post by: mike robel on 11/11/2006 10:56 AM
Quote
MATTBLAK - 10/11/2006  6:52 PM

B.S. is right! At this rate, they'll kill Orion and just buy Soyuz off Russia with an American made upgraded Service Module. Sheesh! They've cut the CEV to the bone as it is. Soon, it'll be so cut-down it'll be useless for Lunar missions and there'll be no money left to expand it as a "Block II" Lunar ship. It'll become an ISS, LEO-only transport, of the 'falsely-cheap' variety, which a lot of Democrats will love.

I know this is a worst-case scenario, but it's scary nonetheless.   :(

FWIW,  I had the opportunity to talk to Fred Haise about the Constellation Program about 6 months ago.  He worked with Northrop on its CEV proposal and I asked him what he thought was going to happen.  His answer was, he thought we would get the CEV and Stick to go to the ISS, but the moon was very iffy and Mars was out of the question.

With the developments we are hearing about, I am giving more and more credance to his point of view.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/11/2006 12:41 PM
Quote
DaveS - 10/11/2006  6:05 PM

Quote
RedSky - 10/11/2006  11:34 PM
Actually, I think there were only 2 free bays in the Apollo SM... the others had H2 and O2 tanks and fuel cells, and half of the hypergolic  tanks.  (I built the 1/32 Monogram "see through" Apollo CSM as a kid in the late 60's)  But, having any free volume for a "Scientific Instrument Module" Bay (SimBay) would really have been nice on the CEV SM.  Especially considering its supposed to be an "autonomous" craft in lunar orbit for weeks.  If nothing else, each mission with a "beefed up" CEV SM  might have been planned to enter a high lunar orbit (that is stable against the forces of the lunar Mascons), in order to release a CommSat (stored in a SimBay),  then descend to LLO for the continuation of the landing mission.   But of course, that requires a more capable SM.  As it is, any Lunar CommSat constellation will have to be directly launched separately.  If we plan on any farside landings, we will need this eventually.  What a waste, and what a lack of forward thinking.  We should have planned by building upon Apollo, not just remaking it (actually, without a SimBay, not even remaking it).
RedSky, you do know that the SIM bays were only available on the "J missions" SMs right? The SM bay first flew on A15. So it's not impossible that sometime in the future that Orion's SM could be expanded to have one.

The bay flew empty for all other missions.  All is not loss, the current CEV still has a designated area/volumes similar to the SIM bay.  It is not on the side but the aft.  The CEV being wider than Apollo and the SM engine smaller, there is room on the aft of the SM.  Picture this:  the SM will have solar arrays stowed on the port and starboard sides and a HGA on the "top" of the aft.  Payloads can be attached to the "bottom" of the aft
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/11/2006 01:01 PM
Quote
MATTBLAK - 10/11/2006  6:52 PM
It'll become an ISS, LEO-only transport, of the 'falsely-cheap' variety, which a lot of Democrats will love.
Political labels don't work and shouldn't be part of this discussion. For example, I'm a Democrat and I *LOVE* Direct. I firmly believe that any other approach to the VSE, given the political necessity to use Shuttle Derived, is unwise and will do harm to the VSE. But that's just my opinion, and, like I've said before, others have honest disagreement. So lets keep the discussion to the numbers and to what's best for the VSE and our country, and leave politics out of it.
Chuck
Title: Re: "DIRECT" Goes Live
Post by: MATTBLAK on 11/11/2006 09:46 PM
Quote
clongton - 11/11/2006  11:44 PM

Quote
MATTBLAK - 10/11/2006  6:52 PM
It'll become an ISS, LEO-only transport, of the 'falsely-cheap' variety, which a lot of Democrats will love.
Political labels don't work and shouldn't be part of this discussion. For example, I'm a Democrat and I *LOVE* Direct. I firmly believe that any other approach to the VSE, given the political necessity to use Shuttle Derived, is unwise and will do harm to the VSE. But that's just my opinion, and, like I've said before, others have honest disagreement. So lets keep the discussion to the numbers and to what's best for the VSE and our country, and leave politics out of it.
Chuck

From your mouth to Gods ears!! ;)  However, forgive me, but I wouldn't have said it if I didn't believe it was true. Sorry for any offence. And I too think Direct would be a good way to go. Or at least, Delta IV for Orion and Direct upgraded for the HLV.
Title: Re: "DIRECT" Goes Live
Post by: wannamoonbase on 11/12/2006 11:52 AM
Quote
kraisee - 10/11/2006  6:33 PM

Quote
DaveS - 10/11/2006  6:05 PM

RedSky, you do know that the SIM bays were only available on the "J missions" SMs right? The SM bay first flew on A15. So it's not impossible that sometime in the future that Orion's SM could be expanded to have one.

But *only* if the launch vehicle is capable of lifting the extra mass.

Ares-I looks doubtful whether it can launch the full CEV as it is.   There's word on L2 now that the CEV may be cut down below 22mT...

I hope people here are understanding this is *all* happening because of the Ares-I.   And even more similar BS "solutions" are yet to come, I guarantee it.   Watch for them.

Ross.

Ross, I haven't chimed in yet, but I like the Direct approach.  It trully uses shuttle hardware and the modular approach just makes good sense.  And using the shuttle stack leaves lots of gravy in there for ATK so it should get political support.

Don't forget to send a copy to Bill Nelson and (as Kent Brockman might say) Our new Democratic Overlords.

There appears to be great potential in the idea.

I too am concerned about the Ares 1 and its impact on CEV size and ability with limited to no growth path.  Getting commited to the Ares 1 (with or without strap ons) seems to be little more than a 5 segment development program.  

Good luck.
Title: Re: "DIRECT" Goes Live
Post by: Avron on 11/12/2006 02:45 PM
Ross

Who is on the "official" distribution list for the presentation?

In terms of ATK... I don't really think that they feature very high outside of NASA high command... its not about Jobs.. its about money.


Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/13/2006 05:22 AM
Mostly the list consisted of NASA managers at various levels, specifically Cx-related.   NASA and contractor VP's and senior managers were contacted.   Also specific elements like ET & engines had specific contacts.   KSC and MAF managers were included because of the infrastructure issues.

It was sent to the NAC chair and CC'd to all members of the appropriate sub-committees.

It went personally to Sherwood Boehlert - Chairman of the House Committee on Science and Bart Gordon, his opposite number.

A copy went to the Presidential advisor on science.

Allen Li, the author of the recent GAO report was sent a copy.

Also all the people listed in the CBO document.

I didn't actually send anything to ATK or Scott Horowitz, because I figured they'd be against this from the start.


More people have been contacted, and I'm working on additional ones right now including suggestions made by people here recently.   I've also been waiting to see the results of the elections before approaching too many more politicians.   Bill Nelson's copy is going out this week, amongst others.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/13/2006 12:06 PM
Another small technical thought made from too little data.

Its not a good idea for Direct since the whole idea is to minimise cost by minimise the ammount of change but it is fun too speculate.

Would it be possible to move the SRB attachment points upwards and thus move the LH2 tank downward removing the need for an infill structure between the LH2 tank and RS-68 engine mounts?

A naive uneducated thought is that it ought to be structurally efficient to have SRB attachment points at the connection between the LOX tank end dome and barrel section with local thickening of the LOX tank skin and deepening of the stringer reinforcement as the load is distributed to the tank skin and perhaps an internel beam in the lox tank between the two attachment points. The barrel section could then also be shortened with at least the height of the reinforcement beam wich removes mass in the intertank skin and the dual use of the same metal for holding preassure and distributing thrust might be more mass efficient.

Perhaps this idea isent workable due to thick metal at the attachment points leaking too much heat into the LOX tank. It would be intresting with a comment about the structural soundness of the idea. It ought to have a potential for removing mass at three places in the structure.


Title: RE: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/13/2006 12:12 PM
Are there any plans for updates of the electrical system in the Ares development?

It ought for instance be reasonable to have no galvanic data handling connectors to the SRB:s only limiting the electrical connectors to power feed during ground handling and power interconnect during boost for electrical supply redundancy.  It should be easy to have a set of shielded antennae handling all the data via a set of ethernet connections and thus remove mass and mechanical parts that can corrode or break.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 11/13/2006 12:46 PM
Quote
Magnus_Redin - 13/11/2006  7:49 AM

Perhaps this idea isent workable due to thick metal at the attachment points leaking too much heat into the LOX tank. It would be intresting with a comment about the structural soundness of the idea. It ought to have a potential for removing mass at three places in the structure.


One goal of LV design is to minize tank penetrations.  This idea would have many.  More of an issue would be LOX leaks vs heat leaks.  Also, the SRB attachment and SRB itself would be subjected to cryogenic temps
Title: RE: "DIRECT" Goes Live
Post by: Jim on 11/13/2006 12:55 PM
Quote
Magnus_Redin - 13/11/2006  7:55 AM

Are there any plans for updates of the electrical system in the Ares development?

It ought for instance be reasonable to have no galvanic data handling connectors to the SRB:s only limiting the electrical connectors to power feed during ground handling and power interconnect during boost for electrical supply redundancy.  It should be easy to have a set of shielded antennae handling all the data via a set of ethernet connections and thus remove mass and mechanical parts that can corrode or break.

Doubtful.  This wouldn't be "reusing" existing systems.  Also using a "WAN"  would cause interference problems adn some reliablity issues too.  Another LV design goal is to minimize EMI
Title: RE: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/13/2006 12:57 PM
Quote
Jim - 13/11/2006  2:29 PM

One goal of LV design is to minize tank penetrations.  This idea would have many.  More of an issue would be LOX leaks vs heat leaks.  Also, the SRB attachment and SRB itself would be subjected to cryogenic temps

I dont immediately get why there must be manny tank penetrations. Has it something to do with the thrust transfer and  separation hardware being deep and designed in a way that demands bolting onto the tank with penetrating holes?

I understand that it isent only a LOX boiloff problem but also a SRB temperature problem. I have no idea on how to transer lots of mechanical stress thru a good thermal insulator.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/13/2006 01:07 PM
There is a large internal I beam in the intertank that reacts to the SRB's loads (both lateral and thrust).  This would pentrate the propose LOX tank
Title: Re: "DIRECT" Goes Live
Post by: vda on 11/13/2006 02:44 PM
Quote
SMetch - 25/10/2006  10:10 PM
Designing and producing a machine to add 7x the explosive power of dynamite to you and then remove that energy safely in order to return you back to earth will never be safe, simple or soon.

Just for the record: however, there are different ways to "add 7x the explosive power of dynamite to you", and solids aren't safest, cheapest or environmentally-cleanest way. In current economic realities, tho, we probably are stuck with them for many decades...
Title: RE: "DIRECT" Goes Live
Post by: on 11/13/2006 04:20 PM
Quote
Jim - 13/11/2006  7:38 AM

Quote
Magnus_Redin - 13/11/2006  7:55 AM

Are there any plans for updates of the electrical system in the Ares development?

It ought for instance be reasonable to have no galvanic data handling connectors to the SRB:s only limiting the electrical connectors to power feed during ground handling and power interconnect during boost for electrical supply redundancy.  It should be easy to have a set of shielded antennae handling all the data via a set of ethernet connections and thus remove mass and mechanical parts that can corrode or break.

Doubtful.  This wouldn't be "reusing" existing systems.  Also using a "WAN"  would cause interference problems adn some reliablity issues too.  Another LV design goal is to minimize EMI

What about the wireless technology (and I'm sorry, I sat in on the design review but don't remember which wireless technology it is) that is (going to be) used in the shuttle's wing leading edge sensors?
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 11/13/2006 04:23 PM
Quote
kraisee - 13/11/2006  12:05 AM

I didn't actually send anything to ATK or Scott Horowitz, because I figured they'd be against this from the start.

Against yes, but if the Stick looks read to die, this is a much better option for them than an EELV solution that would give everything to ULA...

And whether he likes the idea or not, it is rather Horowitz's bailiwick; I'd put the push on him the most, in fact...

Simon ;)
Title: RE: "DIRECT" Goes Live
Post by: tgrundke on 11/13/2006 04:52 PM
I am hoping that someone here can run down a list of pros and cons for using the Direct versus current AtlasI/AtlasV plans that NASA has.

I've been following this discussion for a while, and from a *non-technical* vantage, the Direct alternative seems to propose a much better solution to the VSE requirements than what NASA is apparently already working on for launch vehicles.

My question more or less boils down to this: If the Direct alternative is as superior to the Atlas I/V launch configuration currently proposed, what is the holdup at NASA with pausing and re-grouping? More specifically, are there legitimate technical reasons why Direct would be considered inferior?

I'm very curious to hear the reactions from those who have received copies of the Direct proposal, as well as a push to see if any media outlets are willing to pick up on this story.  We've got one chance to do this right, and if NASA screws the pooch right now, we're back to LEO for another 30 years.
Title: Re: "DIRECT" Goes Live
Post by: simcosmos on 11/13/2006 05:11 PM
Hello:

Please allow me just a small side note / request: I'm trying to visually hint about the transition to supersonic for a DIRECT CLV launch (note: this is not really simulated, the *special effects* will be, at least for now, *hard-coded* to happen at a given MET >> I'm still tweaking the automatic ascent so that the effects will match with the BANG! :) ).

The objective is just to hint about that transition and I do not pretend to be 100% realistic but would appreciate some inputs about things like:

a) where should I start the condensation effects in DIRECT CLV?
b) how "wide" should they be?

Just to give a first clumsy example, please visit *now* my LivePics page (DIRECT CLV "Mach1" image to later be moved to my flickr space).

I suppose that the effect in the center should start more at the CEV's capsule level than what is displayed in the picture, yes? no?

Perhaps someone in the field could just give one or two hints (here or by private message): I found some images in Internet (STS, Delta, etc) but would like to read a little about the subject but more related with DIRECT's specific launcher configuration.

Thanks,
António
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/13/2006 05:34 PM
Afaik the condensation effect start when the thing is transonic, ie well before it reaches mach 1. The picture of the F-18 with a "cloud" is almost always mislabeled as it "breaking the sound barrier". Mary Shafer of NASA Dryden explained it very well in some newsgroup, probably sci.space.history.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 11/13/2006 05:37 PM
Quote
tgrundke - 13/11/2006  12:35 PM

I am hoping that someone here can run down a list of pros and cons for using the Direct versus current AtlasI/AtlasV plans that NASA has.

I've been following this discussion for a while, and from a *non-technical* vantage, the Direct alternative seems to propose a much better solution to the VSE requirements than what NASA is apparently already working on for launch vehicles.

My question more or less boils down to this: If the Direct alternative is as superior to the Atlas I/V launch configuration currently proposed, what is the holdup at NASA with pausing and re-grouping? More specifically, are there legitimate technical reasons why Direct would be considered inferior?

I'm very curious to hear the reactions from those who have received copies of the Direct proposal, as well as a push to see if any media outlets are willing to pick up on this story.  We've got one chance to do this right, and if NASA screws the pooch right now, we're back to LEO for another 30 years.


The pros and cons are on the Direct website.
You mean ARES vs Atlas.
Title: Re: "DIRECT" Goes Live
Post by: simcosmos on 11/13/2006 05:38 PM
Quote
meiza - 13/11/2006  6:17 PM

Afaik the condensation effect start when the thing is transonic, ie well before it reaches mach 1. The picture of the F-18 with a "cloud" is almost always mislabeled as it "breaking the sound barrier". Mary Shafer of NASA Dryden explained it very well in some newsgroup, probably sci.space.history.

Yes, in the picture above I think that the launcher was *subsonic* (somewhere between Mach0.9 and 0.95, need to coordinate that too): then, when the condensation +/- went way >> Mach1, then a little after BANG is heard. Still need to check / research (have a few videos / links, for example http://www.fluidmech.net/  here) ;)

António

Note: I know that what want to suggest is not 100% realistic: just want to implement some eye/sound-"candy", kind of like the equivalent to lens flare, to spice up just a little the simulation. Will play a bit more with particle settings, in a later occasion (removed "smoky" image).
Title: Re: "DIRECT" Goes Live
Post by: RedSky on 11/14/2006 04:16 PM
Guess NASA won't be switching to Direct any time soon...

http://www.spaceref.com/news/viewsr.html?pid=22553
Title: Re: \
Post by: Crispy on 11/14/2006 04:39 PM
Quote
We will continue to get these faux expressions of concern from those who wish to see us fail.

They will be disappointed.

Oh well. They're gonna do it their way and that's final. La la la I can't hear you :(
Title: Re: "DIRECT" Goes Live
Post by: JWag on 11/14/2006 04:39 PM

Quote
RedSky - 14/11/2006  10:59 AM  Guess NASA won't be switching to Direct any time soon...   http://www.spaceref.com/news/viewsr.html?pid=22553

 

Quote
Jeff Hanley
We will continue to get these faux expressions of concern from those who wish to see us fail.

 

Sigh.   Is he deliberately misunderstanding just to spite his "opponents"?   He's completely missed the point.

Ah, stubborn pride and the inertia of bureaucracy.
 

Title: Re: "DIRECT" Goes Live
Post by: BogoMIPS on 11/14/2006 04:56 PM
Quote
MondoMor - 14/11/2006  11:22 AM

Quote
RedSky - 14/11/2006  10:59 AM  Guess NASA won't be switching to Direct any time soon...   http://www.spaceref.com/news/viewsr.html?pid=22553

 

Quote
Jeff Hanley
We will continue to get these faux expressions of concern from those who wish to see us fail.

 

Sigh.   Is he deliberately misunderstanding just to spite his "opponents"?   He's completely missed the point.

Ah, stubborn pride and the inertia of bureaucracy.
 


Well, his quote towards the end was that 'most other alternatives' didn't take the budgetary restrictions into account.  That statement seems directed more at Atlas/Delta/cleansheet alternatives.  If you believe the numbers that the DIRECT proposal has, they seem to take this items into account rather well, if not better, than the Ares designs.

I don't expect NASA to abandon Ares unless a truly unresolvable conflict is encountered, and that wouldn't happen until much later in the process, after much $$$ is expended getting there.  Honestly, I hope such a showstopper isn't encountered, but at least when comparing paper rockets, DIRECT makes more sense to me.

NOTE: I'm completely unqualified to make such a statement though.  Perhaps I should run for Congress. ;)
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/14/2006 06:03 PM
Hanley's comments make it clear that DIRECT's Proposal hasn't even been read, let alone actually considered.   It seems there is just no talking to the administration, or at least no listening.

I don't believe further persuit of the proposal at this point serves any purpose.

At this point, I just hope NASA can achieve what they say they can.   And I'm sure we all pray that the current plans do not prove to cause any serious problems for the greater vision.   Given their choice, I hope Ares-I really can perform well enough to be usable, and does not cause the expected successive compromises in other systems.   And I hope Ares-V does not get cancelled at any point in the next three presidential terms.

If NASA can overcome all those obstacles, I have no doubts that NASA will still get to the moon.   It will be at twice the cost, with far longer schedule, lower safety and lower performance to the lunar surface.   But it can still be done.

Only time will show whether NASA's blind confidence is ultimately justified or not.

And a message to Jeff: "They will be disappointed".   This isn't a battle.   We would only be dissapointed if you fail.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/14/2006 06:16 PM
"...NASA's blind confidence..." how do you figure that? In other words your hobby rocket has more testing, thought and experience in it than NASA's? Seems to me NASA considered your idea and rejected it even before you reinvented it! Frankly I'm getting a little tired of the "I'm the little guy and they are the big government agency so by the rules of Frank Capra movies I MUST be right" attitude. I think you could easily give Griffin a run for his money in the arrogance and ego department! That's not to say I don't respect your hard work and your desire to see the space program succeed, because I honestly do. I just think your fervor is misplaced and ultimately detrimental and divisive.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/14/2006 06:32 PM
"Blind" from the point of view of not considering any alternatives.

Hanley's comments very clearly indicate that he has not read the DIRECT proposal.   Many of his comments apply to some of the various proposals, but not to ours.

For example: "our strategy is within our budgetary means for developing the associated launch infrastructure – something that most ‘alternative’ architectures largely ignore".   We had a full apple-to-apples cost comparison worked up using ESAS's own techniques and methods.   If he had read the DIRECT proposal, he would be aware of that.

If he had ever bothered to read the proposal, he would know that comment was not appropriate.

If you don't bother to read an alternative, it's a bit difficult to say you've considered it.   Instead, you've just "blindly" stayed your own course and ignored everything else, while condemning them at the same time.

It's his right of course, to read or not read any proposals.   But to condemn them without bothering to read it, just doesn't seem logical, nor appropriate - IMHO.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/14/2006 06:33 PM
NASA considered (and rejected) your proposal before you even considered it. Get over it.
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/14/2006 07:13 PM
Quote
tom nackid - 14/11/2006  11:16 AM

NASA considered (and rejected) your proposal before you even considered it. Get over it.

Congress won't
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/14/2006 07:32 PM
Tom, I'm never going to convince you, because you've hard & fast convinced yourself against it already.

I've demonstrated very clearly the critical oversight made in the ESAS regarding an EDS on LV-24/25.   That oversight changes the entire dynamic of ESAS and affects its conclusions enormously.

Anyone, who's mind is not already made up, can see that NASA's direction is based on ESAS Report - which missed this approach completely.   Every other section of the ESAS (Lunar Architecture, CEV, Cost etc) all confirm that the 2-launch archietcture which DIRECT employs, has advantages over the 1.5 solution which actually got recommended.

The data shows it.   Double check it for yourself if you don't believe me.   But I doubt you will.

When the data is re-examined, with just the missing use of LV-27.3's EDS also applied to LV-25, it is very clear that the recommended vehicles would have lost in every assessment - except safety - and today, we're facing a Crew launcher which has a safety factor lower than even the rejected EELV's would have been.

But I doubt you'll ever seriously go and check that data again with the change I have suggested.   You've already made up your mind, Tom.   So I won't try to convince you any longer.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/14/2006 07:40 PM
I haven't made up my mind. NASA has made up its mind--a crucial point you seem to fail to grasp. It doesn't matter what I think--I freely admit I'm not any kind of professional engineer, economist or politician. The biggest problem I have with Direct is the amount of integration needed for even a "taxi run" to LEO. Its too complex for a milk run but not powerful enough to do everything that NASA wants to do on the moon and Mars. The basic idea HAS been explored--almost since the beginnimg of STS development. But again I'm no expert.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/14/2006 07:45 PM
Quote
tom nackid - 14/11/2006  7:59 PM

"...NASA's blind confidence..." how do you figure that? In other words your hobby rocket has more testing, thought and experience in it than NASA's? Seems to me NASA considered your idea and rejected it even before you reinvented it! Frankly I'm getting a little tired of the "I'm the little guy and they are the big government agency so by the rules of Frank Capra movies I MUST be right" attitude. I think you could easily give Griffin a run for his money in the arrogance and ego department! That's not to say I don't respect your hard work and your desire to see the space program succeed, because I honestly do. I just think your fervor is misplaced and ultimately detrimental and divisive.

Ross is not right due to hollywood movie logic.
Ross is right since it is a good idea to plan the missions to use the launcher that is easiest to develop and cheapest to produce and run given the current knowledge and infrastructure.
He is also obviously right in one new large launcher being cheaper to develop and use then two.

Nasa seems to have started with the same idea, to reuse what they already have, and probably also with a desire to be independant from the two already excisting EELV:s. Perhaps they also figured that developing one small and then one large launcher would be politically easier then starting with a large one. Then it seems like the Ares I development started to fail and the failure hurts its missions and forces the large launcher to become larger then the present infrastructure can handle.

Ross optimization of the old ideas is a reasonable solution for these development problems. One major problem, NASA acceptance of RS-68 instead of SSME, is already solved.

I hope Ross continue his efforts since it would be great to watch USA succeed in doing lots of new space science!
I hope little tiny Sweden from where I watch this can help in some of the efforts but please dont waste your resources in inefficent ways even if you have the worlds largest economy.


Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/14/2006 07:53 PM
Quote
tom nackid - 14/11/2006  9:23 PM
The biggest problem I have with Direct is the amount of integration needed for even a "taxi run" to LEO. Its too complex for a milk run but not powerful enough to do everything that NASA wants to do on the moon and Mars.

What do you mean by amount of integration?

Producing the SRB:s and direct core is almost identical to produce SRB:s and a ET for a shuttle launch and manufacturing two RS-68:s is probably easier then producing and maintaining Shuttle engines.

Could you please explain what NASA plans that cant be done with Direct?
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/14/2006 08:04 PM
Integration, i.e. putting everything together for a launch (and making sure it all is working!). NASA wants to keep it to a minimum especially for the CLV. They also want the minimum number of engines practical for a CLV. You can argue over their logic but that is what they are looking for--and Direct doesn't provide what they are looking for.  Direct isn't an alternative to the Ares I, it is asking NASA to completely reconfigure their chosen architecture--a major expense in itself.

I'm not saying Direct is a bad idea in and of itself or isn't well thought out. I'm saying, and apparently NASA is saying, it doesn't fit into their picture for manned space exploration. That is a minimal launcher for people plus a HLLV. We can go over and over till the end of time if this philosophy is sound or not--more likely its "6 of one, a half dozen the other". But that is what the plan is.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/14/2006 08:18 PM
Quote
tom nackid - 14/11/2006  1:59 PM
Frankly I'm getting a little tired of the "I'm the little guy and they are the big government agency so by the rules of Frank Capra movies I MUST be right" attitude. I think you could easily give Griffin a run for his money in the arrogance and ego department!
You know Tom, everyone's entitled to their own opinion, including you. But that doesn't give you the right to be insulting, especially in a public forum. If you want to insult the man, have the decency to call him up on his telephone and do it to his face.

I am also entitled to my opinion, and I think you owe Ross an apology.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/14/2006 08:25 PM
I also complimented his work and dedication on the Direct proposal in the very next paragraph (which you conveniently left out). So I figure its a wash! Anyway if Ross is submitting this to the US government as a serious engineering proposal I think he has to be willing to take at least as much criticism as he is dishing out to NASA! I'm sure Ross can take some ribbing and doesn't need you grandstanding on his behalf.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/14/2006 08:39 PM
Quote
tom nackid - 14/11/2006  9:47 PM

Integration, i.e. putting everything together for a launch (and making sure it all is working!). NASA wants to keep it to a minimum especially for the CLV. They also want the minimum number of engines practical for a CLV. You can argue over their logic but that is what they are looking for--and Direct doesn't provide what they are looking for.  Direct isn't an alternative to the Ares I, it is asking NASA to completely reconfigure their chosen architecture--a major expense in itself.

My care is not about political expense.

I am a technology nerd that likes well thought out systems and Direct and the reasoning behind it is giving me a very good impression.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/14/2006 08:52 PM
Quote
Magnus_Redin - 14/11/2006  3:22 PM

Quote
tom nackid - 14/11/2006  9:47 PM

Integration, i.e. putting everything together for a launch (and making sure it all is working!). NASA wants to keep it to a minimum especially for the CLV. They also want the minimum number of engines practical for a CLV. You can argue over their logic but that is what they are looking for--and Direct doesn't provide what they are looking for.  Direct isn't an alternative to the Ares I, it is asking NASA to completely reconfigure their chosen architecture--a major expense in itself.

My care is not about political expense.

I am a technology nerd that likes well thought out systems and Direct and the reasoning behind it is giving me a very good impression.

Well, politics and economics is just as real as physics.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/14/2006 08:55 PM
Ross,

I think you may be misreading the message behind Jeff Hanley’s email. My take on it is that DIRECT is getting serious attention from serious people and they are starting to ask the upper management at NASA difficult questions that they do not have answers for.

The wording of the email suggests that there is a very good chance that he has read, or at least paged through the DIRECT proposal, He did say “most”.

As Mr. Cowing pointed out this is not an adversarial situation. We don’t want the VSE to fail we don’t even want Ares to fail. I believe that, through the DIRECT proposal, you are contributing an affordable, practical solution that is superior to the current Constellation plan. You, yourself, have stated that this should be about the numbers not about whose idea it is.

I think you should proceed with polishing the concept, proceed with distributing more copies of the proposal. It is too good an idea, with too many opportunities built into it to allow it to die while there is still hope that some use may come out of it.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/14/2006 09:16 PM
Quote
tom nackid - 14/11/2006  10:35 PM
Well, politics and economics is just as real as physics.

Not realy.

You cant cheat in physics, mother nature is a bitch.
You can cheat a lot of the time in economics, especially if what you do is physically possible.
You can cheat quite a lot in politics but you can only cheat economics for a short while and physics only as long as you can delay people from searching for the success.

Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/14/2006 10:03 PM
Quote
Norm Hartnett - 14/11/2006  10:38 PM
I think you should proceed with polishing the concept, proceed with distributing more copies of the proposal. It is too good an idea, with too many opportunities built into it to allow it to die while there is still hope that some use may come out of it.

Direct could still make sense as a low cost Ares V if Ares I is pressed into service.

I cant say if that would mean slimmed down moon missions using an Ares I and a 5 segment SRB  3xRS-68 "Directy" Ares V or launch of two "Directy" Ares V:s.

It might however make it logical to start with the biggest Direct version and then have cost and capacity downscaling options that might make sense if they require fewer RS-68:s
Wonder if a four segment SRB could still be regarded as standard off the shelf when the five segment SRB is in production?
Could starting with the largest Direct allow scaling down to one central mounted RS-68?

It might be significant that one backup plan for Ares I seems to be two three segmet SRB:s and one J-2X engine. Why not two three segment SRB:s, one RS-68 and a shorted structurally bloated tank originally designed for the largest Direct version with 3xRS-68 filled with a partial fuel load?

If NASA realy want to have several different sized launchers in their inventory instead of unused capacity it might be one way to fill the order.
Title: Re: "DIRECT" Goes Live
Post by: HD209458 on 11/14/2006 10:12 PM
I second Norm's reading of these events. Mr. Hanley is acting to shut-down discussions about VSE alternatives precisely because the powers-that-be are giving them serious air-time (or are at least considering it). I suspect that Hanley views arguing back and forth about architectures as only taking away from Ares' momentum, which is only just now starting to get off the ground.

To a certain extent I believe that that is correct, as the whole strategy of Griffin, et. al has been to "sink" Ares and Orion so firmly into the mud that when political support expires (as it surely will, at some point) it is too costly to rip it back out and start again. Hence, we have had the final flight of the shuttle moved up to 2010, and plans already in place (such as reconfiguring the MLP) that once executed will force the politicians to follow through on Ares' development. Needless to say, diverting ourselves with different plans only makes this "sinking" more difficult.

Having said that, I have no desire to argue over whether or not DIRECT is conducive to an eventual return to the Moon, and the politcal realities facing the VSE. I only mean to point out that I have no doubt that your proposal is causing little alarm bells to go off in the heads of the stick supporters, and that you should not think that Mr. Hanley's statement means it is getting nowhere.
Title: Re: "DIRECT" Goes Live
Post by: Mark Max Q on 11/14/2006 10:23 PM
Just come on line now and there's already a 50 post thread on L2 about Hanley's e-mail. With a battle of engineers, with ATK on one corner and it seems everyone else in the other. Hanley's made a huge mistake in this e-mail with the admission of problems, when he seemed to be aiming at taking a swipe at the alternatives and people speaking of problems.
Title: RE: "DIRECT" Goes Live
Post by: clongton on 11/14/2006 10:46 PM
Quote
kraisee - 14/11/2006  1:46 PM
I don't believe further persuit of the proposal at this point serves any purpose.
In this case Ross, I believe you are not correct.

This proposal is incredibly revealing of the problems faced by the designers and engineers, and how just a slight adjustment in thinking can lead to a totally different solution to the same problem. It just so happens, oh by the way, that the Direct proposal serves the interest of the VSE SO much better than the current Ares I/V approach. While I don't wish this upon anyone, it has to be more than a little embarassing to have such a totally solid proposal come from outside the normal channels. In point of fact, I believe that if Dr Griffin had subjected the ESAS recommendations to a peer review, something which is usually standard practice in engineering and design firms, the Ares I/V approach would have been sent back for further study. Granted, that's my opinion about what "could have been", but there you have it.

The Direct concept, if nothing else, *forces* the top management at NASA to be aware of what is actually going on in the minds of its designers and engineers. I have been thru this kind of corporate trauma personally, and it *always* ends up forcing top management to back a better product design. In the case at hand, that may or may not be Direct, but it will be a better product because they will know that the scrutiny has become very widely based and intense.

DO NOT STOP! If anything, now is the time to intensify the effort. The fact that this statement was made at all is an admission that they are feeling the pressure, even if they haven't actually read the paper in detail. Now is the time to bring Congressional pressure to bear, and Industry pressure to bear.

NASA does not operate in a vaccuum (bad joke) and *will* sit up and take notice when the masters come calling and asking for an accounting of the *missing* $35 billion dollars Direct can supply to the stripped science programs. Send the paper, together with a 'science oriented' cover letter, to every program which was sacrificed at the Ares altar. As names begin to become known in Congress and the various committees, send the paper to each of them, again with a cover letter, but this time address the fiscal realities and waste of Ares v.s. Direct. MOST IMPORTANT: Ask EACH of them what they would want NASA to do with the EXTRA $35 billion dollars.

Send the proposal, again with an appropriate cover letter, to every industrial leader which could have skin in this game, including ATK. In their case, emphase that the 5-seg SRB is still in the mix, but point out how their ROI would be improved by better amortization of the development costs, along with a constant and continuing need to refurbish the 4-seg solids. Good business for them. Good business for PWR, and for many, many others.

But taylor each cover letter specifically to the receiptiant. That letter will determine if they look at the paper or toss it. It has to speak directly to their bottom line, right away. That will get them reading.

NASA is feeling the heat, and have begun to look up from their blinders and say "what the hell is happening?" That memo proves it.

Hold NASA's feet to the fire, they are already crying 'hot'.

It's working - they are noticing. But corporations, and government agencies operate on blind momentum. When a big ship begins to turn, it's time to hold onto the wheel harder. Help them steer in the direction that will have the most benefit for them, for the American manned spece program, and for the United States.

Dont stop!
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/14/2006 11:12 PM
Quote
tom nackid - 14/11/2006  4:08 PM
...doesn't need you grandstanding on his behalf.
Your words, in a public forum, were abusive. I don't call standing up and speaking out against verbal abuse "grandstanding".
If you want to discuss this further, do it with a PM. Public forums are not the place for this.
Title: Re: "DIRECT" Goes Live
Post by: Chris Bergin on 11/14/2006 11:27 PM
Quote
clongton - 14/11/2006  11:55 PM

Quote
tom nackid - 14/11/2006  4:08 PM
...doesn't need you grandstanding on his behalf.
Your words, in a public forum, were abusive. I don't call standing up and speaking out against verbal abuse "grandstanding".
If you want to discuss this further, do it with a PM. Public forums are not the place for this.

I agree.

Tom, tone it down. We have zero tolerance here for any form of distruption, period. No further posts 'debating' my call on this are not allowable. Any problems with that, PM me.
Title: Re: "DIRECT" Goes Live
Post by: hop on 11/15/2006 12:33 AM
Quote
Magnus_Redin - 14/11/2006  2:46 PM
It might be significant that one backup plan for Ares I seems to be two three segmet SRB:s and one J-2X engine. Why not two three segment SRB:s, one RS-68 and a shorted structurally bloated tank originally designed for the largest Direct version with 3xRS-68 filled with a partial fuel load?
The whole point of direct is to only develop one new vehicle, and only maintain infrastructure for one vehicle.  Developing a three segment SRB and a new vehicle variant would only make sense if it saved more than the development costs, and that seems extremely unlikely. I don't know what the marginal cost of an SRB segment is, but it has to be a pretty small portion of the total launch cost.

It's also worth noting that Jeff Hanley's memo did nothing to negate the logic of this. He just says that the stick is roughly on track. Even if that is accurate, NASA is still developing two vehicles instead of one, and each of these vehicles requires more development and infrastructure changes than direct.

Quote
tom nackid
The biggest problem I have with Direct is the amount of integration needed for even a "taxi run" to LEO. Its too complex for a milk run but not powerful enough to do everything that NASA wants to do on the moon and Mars.
Direct is plenty powerful to do what NASA has Aries I/V doing on the moon, and there are no concrete plans for mars with either scenario. Direct is overkill for ISS missions, but no one has convincingly shown that developing and operating two new LVs is cheaper. Direct may be more costly to integrate and launch than the Stick , but with the Stick, NASA has to maintain teams and infrastructure for two different vehicles. The "overkill" argument only holds water if the total program cost is more.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/15/2006 12:41 AM
Exactly hop. The entire DIRECT vs. Ares I discussion is invalid and also detrimental to the DIRECT proposal. The correct discussion should be DIRECT vs. Constellation. I think Kraisee may have made a mistake in including the Ares I issues in the proposal to begin with. It really doesn't matter if there are problems with Ares I or not, what matters is that Constellation is expensive and possibly not politically viable.

DIRECT is a overall program change not the replacement of one LV with another.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/15/2006 12:51 AM
I'm interested in the somewhat further future, does NASA indeed intend to launch Ares V once every few months? It could perhaps do without the Stick by then, launching the CEV in the same launch and doing quick moon missions. LEO would be COTS territory.
That should lower the price per flight of Ares V significantly.
A greater part of the human spaceflight time would be spent on the moon since there would be no EOR, resulting in more cost effective mission control.
I guess the lunar base plans and ISRU figure into this heavily.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/15/2006 01:22 AM
Current plans indicate the Ares V would only fly twice a year and would not be capable of lifting the entire stack plus the CEV.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/15/2006 02:08 AM
My problem with the whole "just develop one vehicle" approach is that we would just be going down the same road we did with STS. I fear DIRECT would just give us a "shuttle with a capsule" instead of a comprehensive lunar exploration system. IF STS taught us one thing it is if you have to pinch pennies don't do it on development costs or you will regret it later.  Also NASA's whole philosophy since Columbia has been to find a way to separate crew and cargo launches, with crewed vehicles launched with the minimum practical number of engines. As Norm said DIRECT would not just be a replacement for Ares I it would be asking them to rethink a strategy they have been developing and studying for several years now.
Title: Re: "DIRECT" Goes Live
Post by: Flightstar on 11/15/2006 02:14 AM
Quote
tom nackid - 14/11/2006  8:51 PM

My problem with the whole "just develop one vehicle" approach is that we would just be going down the same road we did with STS. I fear DIRECT would just give us a "shuttle with a capsule" instead of a comprehensive lunar exploration system. IF STS taught us one thing it is if you have to pinch pennies don't do it on development costs or you will regret it later.  Also NASA's whole philosophy since Columbia has been to find a way to separate crew and cargo launches, with crewed vehicles launched with the minimum practical number of engines. As Norm said DIRECT would not just be a replacement for Ares I it would be asking them to rethink a strategy they have been developing and studying for several years now.

You raise a good point. NASA certainly wants to keep crew and cargo seperate from now on, and that's a kicker. Of course DIRECT is fun to read and interesting to get people involved in what's involved. NASA obviously won't change course.
Title: Re: "DIRECT" Goes Live
Post by: kool-aid on 11/15/2006 02:15 AM
Quote
tom nackid - 14/11/2006  8:51 PM

My problem with the whole "just develop one vehicle" approach is that we would just be going down the same road we did with STS. I fear DIRECT would just give us a "shuttle with a capsule" instead of a comprehensive lunar exploration system. IF STS taught us one thing it is if you have to pinch pennies don't do it on development costs or you will regret it later.  Also NASA's whole philosophy since Columbia has been to find a way to separate crew and cargo launches, with crewed vehicles launched with the minimum practical number of engines. As Norm said DIRECT would not just be a replacement for Ares I it would be asking them to rethink a strategy they have been developing and studying for several years now.

I wonder if DIRECT is what NASA should have built back in the 1970s instead of Shuttle in the first place.

Think about it: they could have used the big solids and the tank, developed a simpler engine than the SSME in the form of the RS-68, and kept using J-2 engines for the upper stage.  The Apollo capsule (or something bigger) could have gone on top for missions where they wanted a crew.  As far as separating crew from cargo, sometimes you would fly with a Apollo capsule on top, sometimes you wouldn't.  Saving the crew from a launch accident means putting an escape rocket on it.

They would have had heavy-lift capability throughout the 1980s and might have gone to the Moon again.  Could have sent up big telescopes or big probes.  Could have built a Skylab-like space station in a single launch.

Isn't what we are doing today in Constellation kind of an admission that the Shuttle was the wrong way to go?
Title: Re: "DIRECT" Goes Live
Post by: hop on 11/15/2006 02:20 AM
Quote
Norm Hartnett - 14/11/2006  5:24 PM

Exactly hop. The entire DIRECT vs. Ares I discussion is invalid and also detrimental to the DIRECT proposal.
Sensationalizing the problems with Ares I is detrimental, but I wouldn't say mentioning them is. I don't doubt that NASA can make Ares I fly, given enough money and compromises on capabilities, but that isn't the same as living up to the "safe, simple, soon" promise. When the initial assumptions come up short, it is a good time to step back and re-evaluate the alternatives, before you spend a boatload of money.

I agree with the others who say the chances of this happening are very slim, but it doesn't hurt to try.

Quote
tom nackid
My problem with the whole "just develop one vehicle" approach is that we would just be going down the same road we did with STS.
That's a big stretch. If you think the Ares I/V is cheaper than DIRECT, point out which of the numbers in the DIRECT proposal are wrong.
Title: Re: "DIRECT" Goes Live
Post by: mike robel on 11/15/2006 02:33 AM
Quote
kool-aid - 14/11/2006  9:58 PM

Quote
tom nackid - 14/11/2006  8:51 PM

My problem with the whole "just develop one vehicle" approach is that we would just be going down the same road we did with STS. I fear DIRECT would just give us a "shuttle with a capsule" instead of a comprehensive lunar exploration system. IF STS taught us one thing it is if you have to pinch pennies don't do it on development costs or you will regret it later.  Also NASA's whole philosophy since Columbia has been to find a way to separate crew and cargo launches, with crewed vehicles launched with the minimum practical number of engines. As Norm said DIRECT would not just be a replacement for Ares I it would be asking them to rethink a strategy they have been developing and studying for several years now.

I wonder if DIRECT is what NASA should have built back in the 1970s instead of Shuttle in the first place.

Think about it: they could have used the big solids and the tank, developed a simpler engine than the SSME in the form of the RS-68, and kept using J-2 engines for the upper stage.  The Apollo capsule (or something bigger) could have gone on top for missions where they wanted a crew.  As far as separating crew from cargo, sometimes you would fly with a Apollo capsule on top, sometimes you wouldn't.  Saving the crew from a launch accident means putting an escape rocket on it.

They would have had heavy-lift capability throughout the 1980s and might have gone to the Moon again.  Could have sent up big telescopes or big probes.  Could have built a Skylab-like space station in a single launch.

Isn't what we are doing today in Constellation kind of an admission that the Shuttle was the wrong way to go?

Arguably what NASA should have done was continue to use the Saturn V for heavy lift projects, develop the Titan 3C into a booster to loft the Apollo into LEO for Skylab crew rotation and resupply, and perhaps developed some of the really heavy lift Saturns some with 120 inch solids, 260 inch solids, or liquid strap ons with 1 or 2 F-1 Engines.  We could have been on Mars in 1986 with such a development program, had a rotating Space Station based on the S-II stage, and maybe had a moon base.

Of course, the President, Congress, and the Public thought other things were more important, so perhaps we were lucky we got the shuttle.

Now, after two fatal missions, we are going back to the past with different vehicles and a new development program, instead of 30 years of evolution and refinement to what was arguably a real work horse and success story.

I can only hope we sustain this course this time, regardles if it is Ares I and V or Direct.
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/15/2006 02:38 AM
Quote
mike robel - 14/11/2006  7:16 PM

Quote
kool-aid - 14/11/2006  9:58 PM

Quote
tom nackid - 14/11/2006  8:51 PM

My problem with the whole "just develop one vehicle" approach is that we would just be going down the same road we did with STS. I fear DIRECT would just give us a "shuttle with a capsule" instead of a comprehensive lunar exploration system. IF STS taught us one thing it is if you have to pinch pennies don't do it on development costs or you will regret it later.  Also NASA's whole philosophy since Columbia has been to find a way to separate crew and cargo launches, with crewed vehicles launched with the minimum practical number of engines. As Norm said DIRECT would not just be a replacement for Ares I it would be asking them to rethink a strategy they have been developing and studying for several years now.

I wonder if DIRECT is what NASA should have built back in the 1970s instead of Shuttle in the first place.

Think about it: they could have used the big solids and the tank, developed a simpler engine than the SSME in the form of the RS-68, and kept using J-2 engines for the upper stage.  The Apollo capsule (or something bigger) could have gone on top for missions where they wanted a crew.  As far as separating crew from cargo, sometimes you would fly with a Apollo capsule on top, sometimes you wouldn't.  Saving the crew from a launch accident means putting an escape rocket on it.

They would have had heavy-lift capability throughout the 1980s and might have gone to the Moon again.  Could have sent up big telescopes or big probes.  Could have built a Skylab-like space station in a single launch.

Isn't what we are doing today in Constellation kind of an admission that the Shuttle was the wrong way to go?

Arguably what NASA should have done was continue to use the Saturn V for heavy lift projects, develop the Titan 3C into a booster to loft the Apollo into LEO for Skylab crew rotation and resupply, and perhaps developed some of the really heavy lift Saturns some with 120 inch solids, 260 inch solids, or liquid strap ons with 1 or 2 F-1 Engines.  We could have been on Mars in 1986 with such a development program, had a rotating Space Station based on the S-II stage, and maybe had a moon base.

Of course, the President, Congress, and the Public thought other things were more important, so perhaps we were lucky we got the shuttle.

Now, after two fatal missions, we are going back to the past with different vehicles and a new development program, instead of 30 years of evolution and refinement to what was arguably a real work horse and success story.

I can only hope we sustain this course this time, regardles if it is Ares I and V or Direct.

Actual NASA has place over 10,000 mT in LEO in the last 25 years.  Its just that 9,000 mT came back in the form of the Space Shuttle.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/15/2006 02:38 AM
Reusability was the holy grail of STS development. Unfortunately so many comprmises were made in the name of reducing development costs (mostly due to the huge increase in inflation during the 70s) that what little reusability remained in the system became and albatross around NASA's neck rather than an asset.  At the beginning of Constellation I actually hoped NASA would choose their version of DIRECT or one of the side mounted "shuttle-c" derivatives for the same reasons Ross cites--lower development costs and presumably faster development (and they look cool!). I thought the stick was just plain goofy and the "Magnum" and "Longfellow" concepts (which morphed into Ares V) were too divergent to really be shuttle derived.  However it became clear tha NASA was adament about separating crew and cargo and that more than almost anything else drove the choice for two launch vehicles.  Even a Boeing exec conceeded that launching a Delta IV Heavy was equivalent to launching three Delta IV Mediums.  Maybe fewr engines doesn't equal fewer problems, but when you've been accused of negligent homicide by media pundits you get a bit skittish.  Anyway I can see NASA getting money to develop 2 new vehicles if they say they are going to the moon and launching people more sefely than the shuttle can. I can't see them getting the same amount of money if they say they are goinng to build one new cheap vehicle and that they'll put the rest towards science projects. It isn't fair or right but that's the way it goes. And I say this as someone who once (in pre Challenger days)  had hopes of flying science experiments on the shuttle. Someday google "An analysis of the gravitropic response in kalenchoe stems" for some light reading.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/15/2006 02:56 AM
Quote
Flightstar - 14/11/2006  6:57 PM

Quote
tom nackid - 14/11/2006  8:51 PM

My problem with the whole "just develop one vehicle" approach is that we would just be going down the same road we did with STS. I fear DIRECT would just give us a "shuttle with a capsule" instead of a comprehensive lunar exploration system. IF STS taught us one thing it is if you have to pinch pennies don't do it on development costs or you will regret it later.  Also NASA's whole philosophy since Columbia has been to find a way to separate crew and cargo launches, with crewed vehicles launched with the minimum practical number of engines. As Norm said DIRECT would not just be a replacement for Ares I it would be asking them to rethink a strategy they have been developing and studying for several years now.

You raise a good point. NASA certainly wants to keep crew and cargo seperate from now on, and that's a kicker. Of course DIRECT is fun to read and interesting to get people involved in what's involved. NASA obviously won't change course.

That is a good point. Unfortunately it is true of Constellation too. If one of the 5 segment SRBs goes boom the whole program is shut down. With DIRECT NASA might have enough "extra" cash to fund development of an EELV alternative. With Constellation there is barely enough funding to keep it flying let alone try to develop options.

While DIRECT is asking NASA to rethink a strategy they have been developing for a couple of years it is asking them to go back to strategies developed and redeveloped since the 80's in study after study. In fact it is suggesting that they reevaluate the ESAS in light of the current situation with Constellation and factor in the EDS with the 2 CaLV scenerio.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/15/2006 03:09 AM
Sorry Tom, I think I missed your good point.

It has been said over and over. There is no reason to carry cargo with the CEV on DIRECT. (Just very tempting)
Title: Re: "DIRECT" Goes Live
Post by: tesheiner on 11/15/2006 01:31 PM
... and there is no need to send people on Direct in the case of a cargo-only flight like is required on STS.

STS: You must send people & cargo together.
Direct: You can send people & cargo together.

It's a big difference.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/15/2006 02:08 PM
Unfortunately a CEV-only launch using DIRECT still takes four engines (2 SRBs and 2 liquid fueld) compared to one SRB for Ares I. Plus there is a second stage. Add to that the fact that you still have 2 segmented SRBs along side a gigantic cryogenic fuel tank with people sitting on top and I think you can see why NASA might be cool to the idea. Right or wrong launching people using the least number of engines practical, separating crew and cargo, and keeping SRBs away from fuel tanks on crew launchers are NASA's priorities for their 21st century launch vehicles. After the first glitch--and you know there will be one sooner or later--people are going to start asking "why do you need all of those engines just to launch a capsule into LEO?" Ares I may not be pretty--physically or mechanically--but NASA management is still insisting it will get the job done (and there jobs and reputations are just as much on the line as all those "unnamed whistle blowers") with a minimum of integration issues.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/15/2006 02:26 PM
Quote
tom nackid - 15/11/2006  9:51 AM
Unfortunately a CEV-only launch using DIRECT still takes four engines (2 SRBs and 2 liquid fueld) compared to one SRB for Ares I. Plus there is a second stage.
Minor correction: There is *no* second stage on Direct for the CLV. 2 SRB's & 2 RS-68's. That's one less engine than shuttle, 3 less if you count the OMS.
In the baseline configuration, a Direct 2nd stage is used only for heavy lift cargo, with *no* crew.
Chuck
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/15/2006 03:18 PM
"keeping SRBs away from fuel tanks on crew launchers are NASA's priorities for their 21st century launch vehicles"

There is no requirement for this
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/15/2006 03:19 PM
Quote
Norm Hartnett - 14/11/2006  10:39 PM
In fact it is suggesting that they reevaluate the ESAS in light of the current situation with Constellation and factor in the EDS with the 2 CaLV scenerio.
Specifically, it is asking them to re-evlauate LV-24/25, with the EDS added to LV-25, like they added to LV-27 to come up with the Ares V. NASA has already made the switch for LV-27 from SSME to RS-68, and the re-evaluation of LV-24/25 should do the same. All this is *because* of the magnatude of the problems with Ares I, not in spite of them.

The alarm bells began, not *because* of design changes, which absolutely was expected, but when the design changes started to drive the cost of Ares I thru the roof. If that vehicle had been able to be developed, essentially as envisioned, none of this conversation would have happened. But it couldnt. SSME could not be air started, so the J2-x was substituted, which, because it couldn't match the 2nd stage requirements of SSME, drove the 1st stage from an *existing* 4-seg SRB to a 3-year $5 billion dollar development program for a 5-seg SRB which wasn't slated to start for many years.

So now Ares I was 3 years behind schedule and $5 billion dollars over budget. Those are *not* minor items which could be *normally expected*. At that point, the ESAS LV-24/25 combination, when compared side by side with the LV-13.1/27 combination (Ares I/V), became superior in almost every way.

The Direct concept is nothing more than LV-24/25 fleshed out, with the EDS added for cargo, just like LV-27/Ares V. The major difference is that the only difference between the Direct CLV & Direct CaLV is the added 2nd stage, the EDS. That is unlike Ares I/Ares V, which are 2 entirely separate vehicles.

With Direct, you simply decide to fly the EDS or not, the LV is the same. That's a *huge* cost savings. LV-24 *IS* Direct. LV-25 *IS* LV-24 with the EDS.

Anyway, all this is to hopefully provide NASA with an alternative path to fulfill the VSE mandate, and still stay within the basic recommendations of the ESAS.

As envisioned in the beginning, LV-13.1/LV-27 (Ares) was the clear choice, with LV-24/25 (Direct) being 2nd; that's not the issue. But once real engineering began, and *envisioned* began to change to *reality*, it turned out to not be possible 'as envisioned'. If you change [as envisioned] to [reality] (considering ONLY those changes already made baseline [NOT all the *reported* problems]), LV-24/24 becomes far superior. And, like I said before, LV-24/25 *is* Direct. And Direct *is* ESAS.

Tom, specifically for you, because I know you don't like 'unnamed sources', the comparisons of LV-24/25 (Direct) to LV-13.1/27 (Ares) are based on the officially approved design baseline for Ares I: a 5-seg RSB with J2-X 2nd stage engine. All the problems noted by unnamed sources need not even be considered. Just as-is, Ares I is $5 billion over budget and 3 years behind schedule. That, by itself, would make any corporate board worth it's salt stop what they were doing and look for alternatives. The ESAS LV-24/25 (Direct) offers NASA a way out of this, to bring costs back inline, and back on track for schedule. I don't think it is unreasonable to ask NASA to do the same, especially since they are spending your money and mine.

As for myself, while I will continue to participate in conversations about reported problems as they arise, I will reserve all my critiques (not criticisms) to officially blessed design baselines. That should, hopefully, dispel any notions that I am "anti Ares-I", because I'm not. I *AM*, rather pro-VSE/Constallation.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/15/2006 04:11 PM
Let me add a tweak here.  DIRECT sees cost savings partially because it's a single core vehicle that uses existing infrastructure.  If someone were to propose DIRECT for CLV, but that we should continue to build Ares-V, that pulls us out of the overall price/performance sweet spot.

In other words, LV24/25 is a great answer, but LV-24/27 is NOT a good answer, because Direct by itself is more expensive per launch than Ares-I per launch.  Going fully DIRECT is cheaper in that you don't have 2 separate core vehicles and can save a good deal of infrastructure money.

But if Ares-I can git-r-done & do it well, and we're worried about issues that will be fixed, then press on.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/15/2006 06:26 PM
Quote
rumble - 15/11/2006  11:54 AM
But if Ares-I can git-r-done & do it well, and we're worried about issues that will be fixed, then press on.
I do believe that they can get-it-done, as you say. Some of the smartest engineers and designers in the world can be found at NASA and its Field Centers. If there’s a way, they will find it. But that’s not the issue. We have gotten away from the topic of the thread. We are focusing on the additional problems that have been reported and are speaking of them as if Direct were proposed to address them. It was not.

The Officially released baseline design of Ares I had been revised by changing the 2nd stage engine from SSME to J2-X. That drove a 1st stage change from an existing 4-seg RSRM to a new 5-seg RSRM, still to be developed. It was further determined to switch from SSME to RS-68 for the CaLV power plants, driving a change in ET diameter well beyond the existing size. This change alone drove a massive new design and construction effort for MLP and pads. Items which had previously been reusable from Shuttle would now be discarded and replaced with all new construction and facilities. This became the new official baseline design and resulted in Ares I alone becoming $5 billion dollars over budget and was pushing the entire program 3 years behind schedule. That condition made the ESAS #2 possible selection more viable than the original #1 choice, which was the LV-13.1/27 (Ares). The Direct paper was published to show what an ESAS #2 choice, LV-24/25, could look like when fleshed out.  All of its major points are based on an apples-to-apples comparison of the official baseline design of Ares I/V vs. the ESAS #2 possibility. The name of ‘Direct” was coined simply because it was descriptive of directly reusing so much existing Shuttle hardware and infrastructure.

In the process of preparing the study/paper, it was discovered that, properly implemented, the #2 selection not only eliminated the negative budget & schedule pressures, but actually saved $35 billion dollars over the 25 year ESAS projections and accelerated the schedule such that Orion would definitely fly by 2011, and possibly as early as late 2010 and it put Americans on the moon in 2016 rather than the original 2018/2020.

It is unfortunate that coincidently, some additional problems with the Ares I design began to be reported and, at first, were spoken of in relation to how Direct addressed them. As a matter of fact, Direct does not attempt to address them at all. Direct was published before these problems began to receive such attention. Direct was intended to speak only to the budget and schedule pressures created by the new baseline design of Ares I/V. It was hoped that by publishing the paper, NASA officials would see an extremely viable option to the Ares path, which was now projecting to cost so much more and take so much longer than had ever been anticipated. Direct offered a path which made the most use of the hard work done to produce the ESAS, and honored the valuable data it provided, by remaining strictly within the bounderies set by that NASA authorized document. But well meaning people unintentionally muddied the waters, so-to-speak, myself included, by making the additional reported problems part of the Direct conversation. In retrospect, they should not have been.

I say all this to try to return some prospective to the original purpose of this tread; the release of the Direct study proposal for NASA consideration.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/15/2006 06:54 PM
Eloquently put Chuck, much better than my one liner.

If you compare the DIRECT proposal with TeamVision’s proposal you can see that while DIRECT Phase I and Jupiter One are almost identical LVs the gist of DIRECT’s implementation of the VSE is the ESAS while TeamVision is a complete rewrite of the ESAS.

The heart of DIRECT is the cost and schedule savings compared to Constellation.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/15/2006 07:16 PM
I was thinking about how NASA could put a more acceptable face on transitioning from the Ares/Constellation to DIRECT. It seems to me that an announcement that the Ares I was not meeting their costs and shedule requirements and that they were proceeding with the development of Ares II (DIRECT Phase I) would allow the NASA administration to make DIRECT their own (which it is after all).
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/15/2006 07:26 PM
Quote
Norm Hartnett - 15/11/2006  11:37 AM

Eloquently put Chuck, much better than my one liner.

If you compare the DIRECT proposal with TeamVision’s proposal you can see that while DIRECT Phase I and Jupiter One are almost identical LVs the gist of DIRECT’s implementation of the VSE is the ESAS while TeamVision is a complete rewrite of the ESAS.

The heart of DIRECT is the cost and schedule savings compared to Constellation.

As Jim has pointed out the concept of an inline design uilizing the SSTS system in not new by any means.  The biggest difference then (1980’s) and now is the RS-68.

When we presenting this approach to HLV for VSE back when Sean was running the show it was DOA because EELV's was the selected approach.  When we presented it to Mike’s boys in Feb 2005 it was DOA because we ditched the stick in favor of ELV’s for ISS/CEV using either a 2 SDHLV EOR direct return or 1 SDHLV direct ascent/return mode (2 SDHLV EOR is a back-up should a Mission vs Lift problem develop in the preferred 1 SDHLV direct ascent/return).  We even presented the heretical idea at the Nov 2005 meeting of using RS-68’s because everyone knew that SSME’s were the way to go. Bow to the almighty ESAS.  Not 5 months later the SSME’s were out and the RS-68’s in.

We showed detailed launch trajectories based on the RS-68 that fixed the ESAS error/inconsistence that made RS-68 work just fine, detailed in Ross’s direct plan, we were told that the experts knew what they were doing.  Again we got ESAS Kool-aid back talk.  This meeting was in Nov 2005 before the detailed ESAS report was on the street.  The other issue raised was that our plan did not address the longer term goals “Mars & Beyond” something even ESAS is very silent on I might add.

Hence why we submitted and abstract for AIAA Space 2006 in January 2006 that would summarize once and for all our ideas (SSTS to Beyond) rejected  by two administrators over four years to set the record straight that a few of us out there were not completely drunk with the ESAS Kool-aid.

We were slatted to be on the ESAS team but something happened that represents deeper problems within NASA decision analysis process that I do not want to go into here.

I’ll give Sean and Mike Griffin both the benefit of doubt for all the above because we never cleared their respective gate keepers.  I'd like to think that had we been successful at getting to that level some of this could have all been prevented.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/15/2006 07:43 PM
SMetch, it was not my intention to spark a debate about the merits of DIRECT vs. TeamVision, although that would be a good topic for another thread. I only wanted to point out that while their approches were quite different both arrived at a similar launcher and that one worked within the constraints of the ESAS while the other did not.
Title: Re: "DIRECT" Goes Live
Post by: josh_simonson on 11/15/2006 08:26 PM
>We will continue to get these faux expressions of concern from those who wish to see us fail.
>They will be disappointed.

That's eloquent, but it's not like 'faux expressions of concern' can change the laws of physics and make the Aries 1 unviable.   They can change the political climate though..  Reading between the lines:

"We will continue to get these faux expressions of concern from those who wish to see us fail (to appropriate and dole out pork with the aries 1).

They will be disappointed (because aries 1 still technically do-able)."

If Aries 1 were free (and SRBs grew on trees...), everyone would be for it.  It's not free.  It's hellishly expensive, and that letter made no attempt to allieve our collective fear that the Aries I/V program will prove unsustainable and repeat the history of the apollo program.  

The defensive nature of that letter suggests that they're receiving scrutiny, a congressional investigation already found that the ESAS plan isn't very cost effective.  There's nothing wrong with opening our mouths when we see government waste, it's how a democracy is supposed to optimize itself.   Ross is a patriot for trying to push something better, and a little constructive criticism can only help NASA in the end.
Title: RE: "DIRECT" Goes Live
Post by: stargazer777 on 11/15/2006 10:19 PM
Ross:  I think you are wise to step back from your "Direct" proposal for the time being.  I certainly wouldn't assume NASA was "blind" to your proposal.  Whether the author of that memo read the actual proposal you developed I don't know.  However I am virtually certain that someone did even if it was not a principal.  It does seems clear though that ideas similar to your proposal were considered and rejected long ago.  Whether that was a mistake, only time will tell.  However, the broader point is that, to paraphrase Mark Twain, 'reports of the demise of Aires I have been greatly exaggerated.'  The mix of fact, rumor and innuendo on this site have led many people -- perhaps including you -- to jump to the conclusion that Ares I has failed.  It seems clear from the NASA memo that such is not the case.  As I have said repeatedly on this site, this is a work in process.  There will be many adjustments and some mistakes and corrections along the way. That is inevitable.  It is far too soon for any of us to conclude failure or success.  That would be the case regardless of which booster proposal NASA had chosen.  Lets all take a deep breath and step back from the brink.  Let these people work the problems and do their best to make this a success.  If it ever comes to a point where the numbers tell them that this path will not work out, then and only then should we search for alternatives and Direct may be among them.    Until then, lets wish them well and find other things to worry about.
Title: Re: "DIRECT" Goes Live
Post by: imcub on 11/15/2006 10:21 PM
Quote
tom nackid - 14/11/2006  7:21 PM

...

Reusability was the holy grail of STS development. Unfortunately so many comprmises were made in the name of reducing development costs (mostly due to the huge increase in inflation during the 70s) that what little reusability remained in the system became and albatross around NASA's neck rather than an asset.

...
 

I seem to remember that the original STS design had the fuel tanks internal to the spacecraft and the external tank came about to save money because the spacecraft would be much smaller.  Does anyone else remember it that way or are some of my old synapses misfiring?


Title: RE: "DIRECT" Goes Live
Post by: Smatcha on 11/15/2006 11:04 PM
Quote
stargazer777 - 15/11/2006  3:02 PM

Ross:  I think you are wise to step back from your "Direct" proposal for the time being.  I certainly wouldn't assume NASA was "blind" to your proposal.  Whether the author of that memo read the actual proposal you developed I don't know.  However I am virtually certain that someone did even if it was not a principal.  It does seems clear though that ideas similar to your proposal were considered and rejected long ago.  Whether that was a mistake, only time will tell.  However, the broader point is that, to paraphrase Mark Twain, 'reports of the demise of Aires I have been greatly exaggerated.'  The mix of fact, rumor and innuendo on this site have led many people -- perhaps including you -- to jump to the conclusion that Ares I has failed.  It seems clear from the NASA memo that such is not the case.  As I have said repeatedly on this site, this is a work in process.  There will be many adjustments and some mistakes and corrections along the way. That is inevitable.  It is far too soon for any of us to conclude failure or success.  That would be the case regardless of which booster proposal NASA had chosen.  Lets all take a deep breath and step back from the brink.  Let these people work the problems and do their best to make this a success.  If it ever comes to a point where the numbers tell them that this path will not work out, then and only then should we search for alternatives and Direct may be among them.    Until then, lets wish them well and find other things to worry about.

I’m still trying to discern whether it was cumulative weight of all the new proposals or a singular proposal that pushed him over the edge.  While the direct concept was internally circulated many other ideas had a lot more public exposure forcing a keep the faith letter to all hands who probable never saw the direct proposal in the first place.

I don’t question NASA ability to deliver a flyable stick they perform minor miracles every time they safely launch the most complicated launch vehicle every developed by man.  The issue is will it be worth the upfront and long term expense?  If the CBO is right we may eventually end up with a lunar system that works but one that will leave no margin for any other activities.

I also don’t think taking stock of the situation from time to time based on better information, new ideas and experience is bad.  We use trajectory corrections all the time in space why not use them in space programs.  This is a +30 year vision and 90 day studies shouldn’t dictate for all time across generations what we do.  Given the budget constraints of operating SSTS NASA hasn’t sunk the money necessary to claim the have a train or tracks let alone a train on tracks going over a cliff or to the promised land take your pick.

All things considered it’s ultimately going to come down to the US Congress and whether they want to spend an extra $35 billion and delay VSE four years in achieving the lesser ends of the current approach vs direct.  If the CBO did an analysis of direct vs ESAS’s evolving recommendation I’m sure it would come close to Ross’s projections and ultimate conclusions.

At this point the physics and economics are undeniable the only questions is when will the politics catch-up and how much energy, time and money will go under the bridge before that happens.

Title: RE: "DIRECT" Goes Live
Post by: imcub on 11/15/2006 11:25 PM
Sorry Stargazer777, I could not disagree with you more ...

Quote
stargazer777 - 15/11/2006  3:02 PM

It does seems clear though that ideas similar to your proposal were considered and rejected long ago.



Yes ... rejected when the Stick was 4 segment, had a SSME, and was going to cost $1 billion to develop.

Quote

The mix of fact, rumor and innuendo on this site have led many people -- perhaps including you -- to jump to the conclusion that Ares I has failed.  It seems clear from the NASA memo that such is not the case.  ...  

...  As I have said repeatedly on this site, this is a work in process.  There will be many adjustments and some mistakes and corrections along the way. That is inevitable.  It is far too soon for any of us to conclude failure or success.  


When a program goes from $1-2 billion to $3-5 billion, requires huge infrastructure changes, will take 3 years longer than expected ... that is not an adjustment ... that is a failured program.  It might still fly, but it is not what was promised or sold to the American public or to Congress.
 
Quote

Lets all take a deep breath and step back from the brink.  Let these people work the problems and do their best to make this a success.   If it ever comes to a point where the numbers tell them that this path will not work out, then and only then should we search for alternatives and Direct may be among them.    Until then, lets wish them well and find other things to worry about.


If the Army Corp of Engineers decided to spend a billion dollars to dam up the Colorado River, flooding all or part of the Grand Canyon (and yes, I believe this has been proposed by someone in the Department of Interior) to provide a couple thousand peak MWs of electricity ... would you stand back and say "well, they are the experts" ...  probably not.  You would voice your outrage, demand that the work be stopped, and demand an explaination.

NASA is no different  than any other governement agency in that they need to have the public's confidence in the decisions they are making are technically and fiscally correct.   Right now, they are not doing that.  

I am sure that Ares I will be able to fly in some form, but at what cost?  When the Stick was first proposed, it seemed like an elegant solution both technically and fiscally.   That elegant, 4 segment/SSME design was a paper rocket that will never fly.   Today's Ares I does not appear to be the technically and fiscally elegant solution Direct seems to be.    

If Ares I problems are simply a PR problem ... they should be quite simple to fix ... just a little information please.  

But it seems Ares I problems are at least big enough to require a $3-5 billion fix.  Since NASA only gets ~$17 billion a year, and since NASA is the only space agency I have any ownershiip in, I am going to continue to worry about how NASA spends those billions.



Title: RE: "DIRECT" Goes Live
Post by: stargazer777 on 11/15/2006 11:26 PM
Voltaire -- a genius in any century -- once wrote that, "The best (perfection) is the enemy of the good."  Wise words.  We are never going to have a perfect booster and it doesn't take much imagination to envision the moaning, groaning and complaining that would be going on if Direct had been chosen in stead of the current Ares concept.  The CBO study wasn't dispositive on the issue of boosters -- either Direct or any other alternative.  There are serious pluses and minuses with any choice that could have been made.  The Congress will realize this and they also understand that they do not have the expertise to override the considered decision NASA has already made.  Frankly, they won't want to take the risk or the responsibility for such an action unless they are presented with an imminent failure -- and that is not the case at the moment.  We have a workable course -- for the moment at least -- and it will permit us to develop the Ares V which will be crucial to our future exploration goals.  Lets stand pat and see how things develop.  I am sure there must be something else to worry about.  How about global warming?  Anybody want to buy some ocean front property?
Title: RE: "DIRECT" Goes Live
Post by: stargazer777 on 11/15/2006 11:30 PM
Your conclusions are not supported by the facts, no matter how many times you restate them.  Give it a rest.
Title: Re: "DIRECT" Goes Live
Post by: Flightstar on 11/15/2006 11:44 PM
NASAWatch have upped a gear, using e-mails, which from the lanuage of how they are written and by the amount of NASA people on that site, to respond to Hanley's e-mail.

http://www.nasawatch.com/archives/2006/11/nasa_responds_t.html#more
Title: Re: "DIRECT" Goes Live
Post by: Avron on 11/16/2006 04:36 AM
Just wondering how significant human safety is in the new house/congress...
Not only does Ross's direct hit the needs of timing, budget, political, reuse, minimal impact and keep the workforce employed, while keeping the contractors and their buddies in the bucks.
Direct make use of know items, items that have a track record, with some modification.. but known.. thus from a crew saftey point of view it must be many orders of magnitude safer to fly than something that is pure paper...

If human lives man anything, then Direct must be revisited, or at least rejected with a full explanation ( not because three people say so - NASA  belongs to the people not to three).
It must be demanded..
Two crews are at least owed that much
Title: RE: "DIRECT" Goes Live
Post by: MATTBLAK on 11/16/2006 05:10 AM
With each design review, the performance is admitted to be lower and the cost is admitted to be higher. Its happened several times already in the last 2 years and it this trend will continue. To paraphrase - "It's the engineering calculations, stupid."

Ares 1 was (originally) supposed to place into orbit 25 tons or more: It can't, at least not without bringing back the SSME/RS-25 upper stage engine. Now payload is a miserable 19+ tons - Anyone wanna bet how long it'll be before it slips to 18 tons, or LESS? It was supposed to cost $1 billion dollars: It wont. How are they going to recover the lost payload capability, without deleting all recovery systems from the SRB and/or using filament wound casings? (making it expendable, oh that's right: Delta & Atlas are expendable). How could you improve the Isp over 265 seconds? You can't. Anyone got a magic bullet solution? Anyone??

*1): Why, why WHY build new, expensive crawler Transporters when Delta IV & Atlas don't need them and Direct could use the existing, refurbished Crawlers?

*2): Delta IV Heavy: Man-rateable and upper stage upgradable with RL-60s -- Less than $3 billion, less than 3 years to fly. Ready before Orion could be. **Already flown in basic form.

*3): Atlas V Phase 2: Less than $5 billion, less than 5 years to fly. Ready before Orion could be. Safer hydrocarbon propellants.

*4): Direct: See Ross for cost and schedules -- Better than Ares 1, even if Ross' figures are off by a wide margin. Ready before Orion could be, most capable launcher(s) and best use of existing Shuttle infrastructure. The true meaning of "Simple, Safe & Soon".

ARES 1-"Stick": THE EMPORER HAS NO CLOTHES. :(  :(
Title: Re: "DIRECT" Goes Live
Post by: Andy L on 11/16/2006 05:17 AM
I don't work for NASA, so I don't deem my opinion as either relevant or important. If NASA say the Ares I is how they are going to do it, I trust that is the best decision. That's how I see this all.

I will say that it is very cool that there's so much "traffic" on both Ares and alternatives. A few of the established sites don't seem to be interested in either. This site's encouraging as it's full to the brim of people who do care, for both sides to this.

That's gotta be a good thing!
Title: Re: "DIRECT" Goes Live
Post by: NASA_LaRC_SP on 11/16/2006 05:39 AM
Always, repeat, always feel free to question the Agency, as it is you, the US taxpayers, who are funding it.

Chris has asked some of us involved with Constellation to restrain from making any claims without documentation to back up said claims, but I will say that Jeff Hanley's email wasn't the cleverest move in the history of NASA. Which is a shame, as he's a bright young man.
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/16/2006 06:52 AM
Ross,
Quote
Welcome to the site Jon.   Good piece you wrote on DIRECT.   Thanks.

You're welcome.

Quote
I heard $300m from PWR for a final flight version of the man-rated, NASA-spec version of the Regen '68.   I'm quoting $1Bn to cover all eventualities though.   I've taken that same overly cautious approach throughout the rest of the proposal too.

Yeah, it's better to have a large margin planned in on cost than to underball things and end up with massive cost overruns.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/16/2006 07:09 AM
Tom,
Quote
NASA considered (and rejected) your proposal before you even considered it. Get over it.

They considered and rejected it based on what even they now admit were incorrect assumptions.  They thought that they could air-start an SSME (in spite of many knowledgeable people wondering what crack they were smoking), and do the Shaft using a 4-segment RSRM for the first stage.  It turns out that that wasn't possible, so now we're 3 years behind schedule and $5B over budget.  

When it turns out that the assumptions you made in your study favoring your prefered scheme were *that* far off, asking for a reevaluation of other schemes doesn't seem that much to ask.

Especially seeing as how we, the taxpayers, are the ones footing the bill for this excercise.  The day NASA starts funding itself is the day they can blow off oversight from the public.  As long as they're a government agency, being funded by taxpayer money, they better darned well expect some of those taxpayers to demand oversight.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: braddock on 11/16/2006 10:24 AM
I keep hearing this "3 years behind and $5 billion over budget" due to the 5-seg SRB lately.  What is the source for those figures?
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/16/2006 01:04 PM
Quote
Andy L - 16/11/2006  12:00 AM

I don't work for NASA, so I don't deem my opinion as either relevant or important. If NASA say the Ares I is how they are going to do it, I trust that is the best decision. That's how I see this all.

I will say that it is very cool that there's so much "traffic" on both Ares and alternatives. A few of the established sites don't seem to be interested in either. This site's encouraging as it's full to the brim of people who do care, for both sides to this.

That's gotta be a good thing!
The Ares I is turning out to be a good rocket, and I think we'll be able to launch Apollo or Soyuz on it any time we want.  The problem is it's not the rocket NASA had originally hoped for.  It just doesn't have enough power to lift itself and 25mT to the desired trajectory.  It's ending up being a drop-in replacement for the Saturn IB.  But much taller & less stable.

Like many people have said, NASA can make some pretty unlikely things fly, but in this case, they don't HAVE to.  Using Ross's tweaks to ESAS LV 24&25 (a.k.a. "DIRECT"), NASA would be able to outperform the current Ares I & V vehicles.  Since Ares I is ending up not being the wonderful thing most people thought it was going to be, it makes sense to see if any other options now make more sense than AresI does.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/16/2006 02:01 PM
Quote
braddock - 16/11/2006  6:07 AM
I keep hearing this "3 years behind and $5 billion over budget" due to the 5-seg SRB lately.  What is the source for those figures?
Primarily - ATK.
The 5-seg SRB does not yet exist as a flyable rocket and is being developed.
The 3 year figure is how long it is going to take to do the development and make it available as a man rated item
The $5 billion dollar figure is the cost for the early development.

None of this was suppose to be applicable to Ares 1. None of it. Ares 1 was suppose to use the existing 4-segment SRB. Now everything has to be rescheduled and rebudgeted due to the 5-segment variant.

So Ares 1 now incurs the added cost of the new booster and has to wait for it to be designed, built, tested, certified and delivered. Ares 1 can't even be tested as a LV until ALL that is completed. It was originally supposed to be operationally flying long before the new testing will even begin.

3 years and $5 billion dollars.
That's high level, but the devil's in the details.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/16/2006 02:19 PM
Chuck,
Quote
clongton - 16/11/2006  6:44 AM

Quote
braddock - 16/11/2006  6:07 AM
I keep hearing this "3 years behind and $5 billion over budget" due to the 5-seg SRB lately.  What is the source for those figures?
Primarily - ATK.
The 5-seg SRB does not yet exist as a flyable rocket and is being developed.
The 3 year figure is how long it is going to take to do the development and make it available as a man rated item
The $5 billion dollar figure is the cost for the early development.

Hrmm...with the way you put that about the $5B just being for early development, it isn't quite so bad as things looked at first.  Sure, the Shaft is now being shoved out three years and $5B, but at the same time most of that was going to be spent anyway for the planned Ares V configuration.

I'd still prefer to just see something like DIRECT built, as that $5B expenditure would go away, but in that light the cost overrun isn't quite as ridiculous as it appears at first sight.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/16/2006 02:28 PM
Presumably what is spent on the 5 segment SRB now is money saved when they go to work on the Ares V later. I guess NASA is pretty confident that they will get Ares V or this is a move to tell congress "Look we've already gone this far are you guys serious or not about going beyond LEO."
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/16/2006 02:29 PM
"but in that light the cost overrun isn't quite as ridiculous as it appears at first sight."

It is ridiculous in any "light".  We could get a lot more and early with that money on other systems
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/16/2006 02:33 PM
Quote
jongoff - 16/11/2006  10:02 AM
Hrmm...with the way you put that about the $5B just being for early development, it isn't quite so bad as things looked at first.  Sure, the Shaft is now being shoved out three years and $5B, but at the same time most of that was going to be spent anyway for the planned Ares V configuration.

I'd still prefer to just see something like DIRECT built, as that $5B expenditure would go away, but in that light the cost overrun isn't quite as ridiculous as it appears at first sight.

~Jon
It's not really just 'early development'. That's why I said the devil's in the details. I limited the comment to Ares 1, which wasn't suppose to carry the cost of the 5-seg SRB. But if you want to look into the total program cost, while it is technically true that the Ares 5 5-seg will now be born by Ares 1, other things went on with Ares 5 which drive the cost for the program, as a whole, even higher.

When you say "it isn't quite so bad as things looked at first", that's not true. It's actually much worse from a program perspective. Changing the ET diameter for Ares 5 drives multiple billions in additional expendatures for infrastructure changes both at KSC and MAF. But even for the Ares 1, there will need to be massive upgrades to the 2 NASA ships which go out to recover the SRB's. That would have eventually been done for the Ares 5, but now all those kinds of expendatures will be born by the Ares 1. More details, which are not included in the "Ares 1 Overbudget" scenerio.

That's why I deliberately stuck to "high level". To go into the details, it is actually much worse.

All these kinds of things, which drive expenditures to the left into Ares 1, instead of program wide, are what is responsible for gutting all the science programs. Ask all those folks if they concur that "it isn't quite so bad as things looked at first". It is rippling throughout the entire scientific community in the United States, and could bring NASA itself to its knees if not carefully controlled.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: RedSky on 11/16/2006 02:40 PM
Also, don't forget the accelerated development required for the J-2X needed for Ares-I as a replacement for the air-lit SSME.  That, too, is a bottleneck, and also causing unanticipated delays and costs.  It wasn't expected to be needed until Ares-V.
Title: Re: "DIRECT" Goes Live
Post by: braddock on 11/16/2006 03:46 PM
So, how much has been spent to date on Constellation engineering?
Title: Re: "DIRECT" Goes Live
Post by: BogoMIPS on 11/16/2006 03:51 PM
Quote
jongoff - 16/11/2006  9:02 AM
I'd still prefer to just see something like DIRECT built, as that $5B expenditure would go away, but in that light the cost overrun isn't quite as ridiculous as it appears at first sight.

Assuming the DIRECT budget and time estimates stand up to professional scrutiny that I'm certainly not qualified to provide, The change in the Ares I budget and time seem like they should be a death knell to me.

Why spend an additional $2 Billion of taxpayer money when you just plain don't have to?

If Ares I had been able to become a reality with ain air-start SSME and a 4 Seg SRB, we might have a different debate, though that system has even less in common with the Ares V, making it even harder to technology-transfer between them.

The one thing DIRECT gets you, that I think makes it a clearly better plan, is that you only have to design one bloody rocket, and for considerably less $, since the majority of the thing already exists (in comparison to Ares I)!

If you're worried about that limiting you to a single system, then fine!  Take some of the money you saved and fund part of manrating an Atlas or Delta derived vehicle as a backup, or for the commercial market.

DIRECT seems to win the "Simpler" and "Sooner" arguments at this point.  The "Safer" argument is a good one that should still get hashed out, but it either should still be an order of magnitude more safe than the current system.

I have no doubt NASA can get Ares I to fly.  My only doubt is if it is the right vehicle to try and fly.
Title: Re: "DIRECT" Goes Live
Post by: Kelly Starks on 11/16/2006 04:02 PM

Quote
imcub - 15/11/2006 5:04 PM


I seem to remember that the original STS design had the fuel tanks internal to the spacecraft and the external tank came about to save money because the spacecraft would be much smaller. Does anyone else remember it that way or are some of my old synapses misfiring?


 

 

Yeah I talked with a guy who was once on the NASA shuttle dev team.  He said on Thursday afternoon the word came down they had to present a new concept to halve the shuttle program cost by Monday to Nixon.  So what you see now was their rushed job, which he thought was a stupid config.  Something like a biamese (sp?) (like I just posted in SA CEV / CLV / CaLV / MTV -> ORION (CEV) / ARES I (CLV)  -> Direct / Aries/etc Vrs a shuttle derived RLV) would have also halved the program costs, adn eliminate the major costs for the ET's and SRBs (about $150 million a launch?).

Opps!

Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/16/2006 04:13 PM
Jim,
Quote
It is ridiculous in any "light".  We could get a lot more and early with that money on other systems

Fair enough.  With a different architecture, like say EELV based, 2-person, you could probably have a safer lunar program with very little if any launch vehicle development that could be putting people on the moon before 2012, and could probably have more boots and cargo landed on the moon by the time ESAS could than ESAS will ever put on the moon...

But NASA's long since proven that actually accomplishing anything on the Moon in a cost-effective manner is nowhere near their top priority.  Pretending they're wunderkind rocket boys, and spreading pork in the right districts seems to be far more critical in their books.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: Kelly Starks on 11/16/2006 04:14 PM
Quote
jongoff - 16/11/2006  9:02 AM

Chuck,
Quote
clongton - 16/11/2006  6:44 AM

Quote
braddock - 16/11/2006  6:07 AM
I keep hearing this "3 years behind and $5 billion over budget" due to the 5-seg SRB lately.  What is the source for those figures?
Primarily - ATK.
The 5-seg SRB does not yet exist as a flyable rocket and is being developed.
The 3 year figure is how long it is going to take to do the development and make it available as a man rated item
The $5 billion dollar figure is the cost for the early development.

Hrmm...with the way you put that about the $5B just being for early development, it isn't quite so bad as things looked at first.  Sure, the Shaft is now being shoved out three years and $5B, but at the same time most of that was going to be spent anyway for the planned Ares V configuration.

I'd still prefer to just see something like DIRECT built, as that $5B expenditure would go away, but in that light the cost overrun isn't quite as ridiculous as it appears at first sight.

~Jon

Everytime I hear things like $5 bil for the stick, I keep remembering how McDonnel Douglas offered to build the full shuttle replacement DC-X for $3 billion adn 3 years back in the mid '90's.
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/16/2006 04:26 PM
RedSky,
Quote
Also, don't forget the accelerated development required for the J-2X needed for Ares-I as a replacement for the air-lit SSME.  That, too, is a bottleneck, and also causing unanticipated delays and costs.  It wasn't expected to be needed until Ares-V.

The most absurd thing about the J-2X decision is that a Centaur derived EDS would've been far more effective as an EDS, and wouldn't require developing new engines.  If I'm reading some of the info on the Wide Body Centaur program right, they use existing, higher performance engines, a much higher propellant fraction stage, have more experience in building such things (I mean heck, they've been building restartable LOX/LH2 stages for how many decades now?  They've had how many succesful centaur flights?  Isn't it over 150 now?), and can carry just as much if not more propellant.  I'm not 100% sure of that last one, but they mentioned that they could carry 1.5-6x as much propellant on one of those WBC designs (depending on the number of barrel sections the friction-stir-weld in) as their current Centaur, and their current Centaur is something like 50klb fully loaded.  I'm not sure when they'll field this if they do it entirely off of internal funding, but there's a non-zero chance that LM will field a commercial stage that is better than the EDS before NASA even starts developing the EDS.

Which really makes me curious what the real benefit of developing the J-2X is.  Sure it's high thrust, but the Isp isn't as good, it's expensive, it has no flight history, and just really isn't the right engine for the job.

What what do I know compared to the wunderkinden at NASA HQ?

~Jon Goff
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/16/2006 04:29 PM
Bogo,
Quote
The one thing DIRECT gets you, that I think makes it a clearly better plan, is that you only have to design one bloody rocket, and for considerably less $, since the majority of the thing already exists (in comparison to Ares I)!

If you're worried about that limiting you to a single system, then fine!  Take some of the money you saved and fund part of manrating an Atlas or Delta derived vehicle as a backup, or for the commercial market.

Exactly.  Killing the Shaft and Ares V in exchange for DIRECT would free up enough money to resuscitate the science part of NASA, pay for manrating Atlas and Delta, AND double or triple the funding for COTS and COTS-like programs.

It would be a lot safer, simpler, sooner, and give you a much more robust and cost effective lunar transportation architecture.

Which is precisely why they won't do it.  It makes too much sense.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/16/2006 04:35 PM
Quote
tom nackid - 15/11/2006  9:51 AM
Unfortunately a CEV-only launch using DIRECT still takes four engines (2 SRBs and 2 liquid fueld) compared to one SRB for Ares I.
Now that I think about it Tom, Ares is more complicated than that:

To fly Ares 1, as currently configured, requires 5 separate engine burn events, one after the other:
1. 1st stage RSRM
2. 2nd stage J2-x
3. Orion SM 1000 m/s delta v to -30 to 100 nm orbital insertion
4. Orion SM burn to raise orbit to 60 to 100 nm orbit
5. Orion circularization burn to 100 nm orbit

To fly Direct as currently proposed requires 4 engines, but only 2 events:
1. Light all 4 engines (2 SRB & 2 RS-68) on the ground. MECO is *IN* 100-160 nm orbit.
2. Orion does a circularization burn to a 160 nm orbit.

Remember, for Ares, those are 5 *separate* events. If any 1 doesn't come off as planned, the mission is aborted.
For Direct, it's only 2 events, and the 1st one actually puts you in a safe orbit.

Honestly, which is the simpler and safer solution?
And notice the orbits obtained.
Ares is circularized to a 100 nm orbit
Direct is circularized to a 160 nm orbit.
Which is the more useful *and* safer orbit?

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/16/2006 05:12 PM
Adding to the safety of the first DIRECT event, the RS-68 are started first and if there is a problem with either they can be shut down prior to the ignition of the SRBs and the launch aborted like the shuttle.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/16/2006 05:13 PM
Quote
Kelly Starks - 16/11/2006  11:57 AM
Everytime I hear things like $5 bil for the stick
Remember, that $5 billion is *extra* for early 5-segment RSRM development.
And, as pointed out above, that does *not* include the cost of J2-x development, which was also suppose to be an Ares 5 program. More cost driven to the left into Ares 1.
What science is going to suffer next? Physics textbooks for the high school kids?
I'm being tongue-in-cheek, but you can see how this *recklessness* is simply *killing* everything else.
For the record, I am not anti-Ares 1. I am anti-waste and pro-fiscal responsibility.
It's *not* NASA's money. It's mine and yours and everyone else who pays taxes.
I don't mind paying taxes, but I have the right to expect fiscal responsibility from the government agencies who spend my money.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/16/2006 05:24 PM
A couple of the pithier comments on Nasawatch. Both refer to the CAIB report.

Managers should take note of Dr. Rosemary O’Leary's response in Annex A of the report as well.  She talks about the specific dissent suppression of 'Groupthink' and states, "Groupthink is an insular decision-making process in which decision makers are so wedded to the same assumptions and beliefs, that they ignore, discount, or even ridicule information to the contrary (Janis 1972). Symptoms of groupthink include overestimations of the group’s power and morality, closed-mindedness, and pressure toward uniformity."

A guy by the name of Dan Crippen -- a rather accomplished bloke -- penned the following comments:
"NASA's leaders and managers must break this cycle of smugness substituting for knowledge."
"The Columbia Accident Investigation Board noted an air of arrogance within NASA that led leaders and managers to be dismissive of the views of others, both within the organization and, especially, from outside the Agency."
"The recurrence of apparently preventable accidents and the seeming unwillingness to learn should be sufficient to instill some humility to temper what often looks like arrogance.  During the past two years, we have not witnessed very much of such humility."
Title: Re: "DIRECT" Goes Live
Post by: copernicus on 11/16/2006 09:14 PM

   After looking at the DIRECT launcher proposal, I am amazed at how far the Stick
has gotten.  I am not a rocket scientist, but to me it would seem that a REAL rocket
scientist (engineer) would have dismissed the Stick as undoable after a brief examination
of the details.  I mean, really, wouldn't a real rocket engineer know that the SSME was
not designed to be an upper-stage engine?  Didn't NASA and ATK already know this
when they proposed the Stick?  If they didn't, then why didn't they?  I am picking this
as just one issue that indicates that the Stick (Ares-1) was a bizarre choice.  
My biggest gripe is the extra dollars that the Stick is wasting.  
   I am a big supporter of NASA's unmanned Science probes and
I don't want them cannabilized to support the VSE.  I am, however,
in favor of a cost-conscious VSE.  That is why I support the DIRECT proposal.  
   In fact, today, I contacted Senator Bill Nelson's office and talked
to one of his staff about the DIRECT launcher proposal.  I encourage
all of you out there who care about the success of the VSE to contact
members of Congress and educate them about the virtues of DIRECT and
how it can help make the VSE a reality.  





Title: Re: "DIRECT" Goes Live
Post by: Scotty on 11/16/2006 09:59 PM
Yes, that is Hanley's e-mail address.
Title: Re: "DIRECT" Goes Live
Post by: dbhyslop on 11/16/2006 09:59 PM
You should edit out that email address.  The last thing Direct needs is a flood of emails on its behalf into Hanley's in box from Joe Schmo US teen.

edit - looks like someone beat me to the punch
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/16/2006 10:41 PM
Quote
copernicus - 16/11/2006  4:57 PM


   After looking at the DIRECT launcher proposal, I am amazed at how far the Stick
has gotten.  I am not a rocket scientist, but to me it would seem that a REAL rocket
scientist (engineer) would have dismissed the Stick as undoable after a brief examination
of the details.  I mean, really, wouldn't a real rocket engineer know that the SSME was
not designed to be an upper-stage engine?  Didn't NASA and ATK already know this
when they proposed the Stick?  If they didn't, then why didn't they?  I am picking this
as just one issue that indicates that the Stick (Ares-1) was a bizarre choice.  
My biggest gripe is the extra dollars that the Stick is wasting.  
   I am a big supporter of NASA's unmanned Science probes and
I don't want them cannabilized to support the VSE.  I am, however,
in favor of a cost-conscious VSE.  That is why I support the DIRECT proposal.  
   In fact, today, I contacted Senator Bill Nelson's office and talked
to one of his staff about the DIRECT launcher proposal.  I encourage
all of you out there who care about the success of the VSE to contact
members of Congress and educate them about the virtues of DIRECT and
how it can help make the VSE a reality.  



Not just Direct but anything other than the Stick
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/16/2006 11:38 PM
Quote
RedSky - 16/11/2006  4:23 PM

Also, don't forget the accelerated development required for the J-2X needed for Ares-I as a replacement for the air-lit SSME.  That, too, is a bottleneck, and also causing unanticipated delays and costs.  It wasn't expected to be needed until Ares-V.

The accelerated J-2X develoment is usefull for Direct:s EDS, there should not be any reason to change that part of the Ares I program if you want to get to the moon faster.
Title: Re: "DIRECT" Goes Live
Post by: Avron on 11/17/2006 04:59 AM
Quote
BogoMIPS - 16/11/2006  11:34 AM


Why spend an additional $2 Billion of taxpayer money when you just plain don't have to?
/QUOTE]

Because they can.. and they cannot be stopped.. go ahead try! A lot of people worked really hard over a long period to get their hands on that multi-billion dollar prize...
Title: Re: "DIRECT" Goes Live
Post by: vda on 11/17/2006 08:44 AM
Quote
tom nackid - 14/11/2006  3:51 PM
Unfortunately a CEV-only launch using DIRECT still takes four engines (2 SRBs and 2 liquid fuel) compared to one SRB for Ares I.

But engines are at least far cheaper than SSME (SSME 60m, RS68 20m).

Quote
Add to that the fact that you still have 2 segmented SRBs along side a gigantic cryogenic fuel tank with people sitting on top

But the people are sitting on top. Even if you blow up the whole thing (technically incorrect - it does not blow up, it just burns rapidly), and even if escape tower does not fire, I bet crew survival chances are high.

Quote
Keeping SRBs away from fuel tanks on crew launchers are NASA's priorities for their 21st century launch vehicles.

Then remove SRBs altogether. Go Soyuz way with LRB. Oh yes, we were idiotic enough to not develop our own high-perf kerosene engine... but maybe it makes sense to at least plan for doing that while we fly what we have (SRBs)?
Title: Re: "DIRECT" Goes Live
Post by: Chris Bergin on 11/17/2006 09:24 AM
Quote
dbhyslop - 16/11/2006  10:42 PM

You should edit out that email address.  The last thing Direct needs is a flood of emails on its behalf into Hanley's in box from Joe Schmo US teen.

edit - looks like someone beat me to the punch

I took it off the second I saw it.
Title: Re: "DIRECT" Goes Live
Post by: simcosmos on 11/17/2006 09:51 AM
"DIRECT" Goes Live >> LIVE Test / Demo Orbiter Simulator Session today

Hello,

I will probably make a live test / demo session today (17th November) at +/- 18:00GMT. These are some of the objectives:
- to test the DIRECT CLV (PhaseII) - Mission to ISS: test of automatic guidance / ascent program (alpha)
- will also eventually show other launcher variants

Please have in mind that this will be a live *development* session: I might need to restart the simulation and you might see me editing configuration files :) Also note that all what you will see is in *alpha* state (hope there aren't CTD)

Despite that, I will try to roughly simulate a mission to ISS: this will include launch and orbital insertion transmitted in *real time* and, once CEV's safe orbital insertion is made, I will try to show things like the ET core reentry and, of course, some clumsy orbital procedures to bring the CEV into a safe ISS rendezvous + dock (using time acceleration during coast phases; please note that I will not make careful burns due to the nature of the test session!).

Giving the heads-up just in case someone wishes to join my site's LivePics page.
(please click in my signature's thumbnail, fresh images will be uploaded +/- each 10s, when starting the live session).

I'm trying to have *something* ready for a public release... At least the DIRECT CLV for a first v0.1: further incremental releases will correct details / temporary meshes, add new launcher variants and mission profiles, etc towards v1.0. But for the moment I'm just concentrating in DIRECT CLV - Phase II and related addon documentation.

Last note: during the live session (or before / after it) I might (not sure yet) be available in my site's chat: the viewers might wish to use it to interact during the live session.
(please see left menu, click SC_CHAT and follow instructions).

Ok, I think it is all for now: I leave the invitation in the air ;)

António


Edit: small update to what wrote above: I might try to simulate some kind of mission module and then use the CEV as a space tug to bring such mission module to ISS.

If doing it for today's live demo, please remember that things are not optimised yet: the launcher's guidance still needs lots of tweaks, the CEV addon that I'm using is not optimised to act as a space tug, the mission module itself is a kind of converted MPLM (Orbiter's sim default), Orbiter’s default ISS also does not have a working robotic arm, etc.

Despite all these *alpha* conditions it still should be nice to see the CEV doing a manoeuvre like Apollo (to dock / extract the mission module from the launcher's core) and then I will try to move that stack to ISS (but it will not be a perfect flight due to time constraints for the maximum duration of the demo and , never enough to remember, due to the alpha implementation status, it will probably be boring for some).
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/17/2006 02:24 PM
Quote
Magnus_Redin - 16/11/2006  7:21 PM
The accelerated J-2X develoment is usefull for Direct's EDS, there should not be any reason to change that part of the Ares I program if you want to get to the moon faster.
CLV doesn't need the EDS, only the CaLV. So the EDS doesn't need to be budgeted or scheduled until Direct Phase 1 is complete (CLV to ISS operations started). When attention would normally be turned to the CaLV, then we budget and schedule the EDS. That's basically all that would need to be developed, as opposed to developing a whole new LV (Ares V).

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/17/2006 04:50 PM
Quote
Avron - 16/11/2006  9:42 PM

Quote
BogoMIPS - 16/11/2006  11:34 AM


Why spend an additional $2 Billion of taxpayer money when you just plain don't have to?

Because they can.. and they cannot be stopped.. go ahead try! A lot of people worked really hard over a long period to get their hands on that multi-billion dollar prize...

Since Ares has passed its first SRR http://www.nasa.gov/home/hqnews/2006/nov/HQ_06354_Constellation.html yesterday I am coming to agree with Avron.

I only see three alternatives:

1) Wait and see: Hope that NASA does know what it is doing and that they do have the best interests of the nation and the VSE in mind.

2) Go into full opposition: Begin a full blown publicity and political campaign promoting DIRECT and targeting any and all NASA expenditures on the Ares system such as these http://www.spaceref.com/news/viewsr.html?pid=22585

3) Continue the current program: Hope that, behind the scenes, the obvious shortcomings of Ares and benefits of DIRECT become so powerful as to overturn the current program/administration.
Title: Re: "DIRECT" Goes Live
Post by: josh_simonson on 11/17/2006 06:51 PM
Sometime around 2020 a president or nasa administrator may simply cancel the Aries 1 and use the Aries V in a mega-direct scheme.  I can't see the president and congress sitting idly by while NASA is hemoraging money out the @$$ with two LVS who's combined flightrate is less than the shuttle's current one.

The most important thing is to make sure that they man-rate the Aries V so they can't keep Aries 1 alive by claiming it'll cost $5bln to upgrade the Aries V to be fit for people to fly on - and that they have a spare Aries V pad.
Title: Re: "DIRECT" Goes Live
Post by: Kelly Starks on 11/17/2006 07:20 PM
Quote
clongton - 16/11/2006  11:56 AM

Quote
Kelly Starks - 16/11/2006  11:57 AM
Everytime I hear things like $5 bil for the stick
Remember, that $5 billion is *extra* for early 5-segment RSRM development.
And, as pointed out above, that does *not* include the cost of J2-x development, which was also suppose to be an Ares 5 program. More cost driven to the left into Ares 1..

Oh my mistake.  [AAAAAAAAAAAAAAAAHHHHHHHHHHHHHHH!!!!!!]
So what is the total dev cost of the Areies 1, fielded to reduce costs, up to now?

Call me when you could fund a Star Raker dev program on the overruns.


Quote
clongton - 16/11/2006  11:56 AM
What science is going to suffer next? Physics textbooks for the high school kids?
I'm being tongue-in-cheek, but you can see how this *recklessness* is simply *killing* everything else.
For the record, I am not anti-Ares 1. I am anti-waste and pro-fiscal responsibility.
It's *not* NASA's money. It's mine and yours and everyone else who pays taxes.
I don't mind paying taxes, but I have the right to expect fiscal responsibility from the government agencies who spend my money.

Chuck

Oh major agree!!  Of course NASA Congressional master DEMAND waste in the right districts to get their votes (several personal horror stories come to mind).  So in a sence our demand to Congress, for jobs or whatever out of NASA budgets, in our areas - drives NASA to do things in watsefull ways.

8(
Title: Re: "DIRECT" Goes Live
Post by: Kelly Starks on 11/17/2006 07:26 PM
Quote
copernicus - 16/11/2006  3:57 PM


   After looking at the DIRECT launcher proposal, I am amazed at how far the Stick
has gotten.  I am not a rocket scientist, but to me it would seem that a REAL rocket
scientist (engineer) would have dismissed the Stick as undoable after a brief examination
of the details.  I mean, really, wouldn't a real rocket engineer know that the SSME was
not designed to be an upper-stage engine?  Didn't NASA and ATK already know this
when they proposed the Stick?  If they didn't, then why didn't they?  I am picking this
as just one issue that indicates that the Stick (Ares-1) was a bizarre choice.  
My biggest gripe is the extra dollars that the Stick is wasting.  
   I am a big supporter of NASA's unmanned Science probes and
I don't want them cannabilized to support the VSE.  I am, however,
in favor of a cost-conscious VSE.  That is why I support the DIRECT proposal.  
   In fact, today, I contacted Senator Bill Nelson's office and talked
to one of his staff about the DIRECT launcher proposal.  I encourage
all of you out there who care about the success of the VSE to contact
members of Congress and educate them about the virtues of DIRECT and
how it can help make the VSE a reality.  


Big agree.  The Sticks a rediculasly bad design.

As a side bit, my first thought was vibration.  SRBs shake the whole shutle stack so bad that astrounats refure to it as feeling like a long runing train wreack.  If 8 segments of SRB attached to close to a thousand tons of fueled orbiter stack shakes the astrounats that bad (watch some of the cockpit camera footage) whats it going to be like for a crew in a capsule on a little service module etc - on a 4-5 segment SRB?!!
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/17/2006 07:29 PM
Quote
tom nackid - 15/11/2006  9:51 AM
To fly Ares 1, as currently configured, requires 5 separate engine burn events, one after the other:
1. 1st stage RSRM
2. 2nd stage J2-x
3. Orion SM 1000 m/s delta v to -30 to 100 nm orbital insertion
4. Orion SM burn to raise orbit to 60 to 100 nm orbit
5. Orion circularization burn to 100 nm orbit


Orion needs a 1000m/s burn to achieve a -30x100?  Is this right? Is this for the ISS mission or for the lunar mission?  If the Stick requires this for lunar mission then it’s even more important to ditch the stick.  Carrying extra fuel tanks to the moon and back is very bad.  In fact to correctly compare the stick to other approaches you would have to penalize it for the additional mass needed for the selected mode of dragging the 2nd stage EOI tanks mass arround.

Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/17/2006 08:06 PM
Quote
SMetch - 17/11/2006  3:12 PM
Orion needs a 1000m/s burn to achieve a -30x100?  Is this right?
That's correct.
Orion SM acts as a 3rd stage to put the spacecraft into a 'suborbital' trajectory (-30 to 100nm), because Ares I is incapable of doing it. Then it has to fire again to make it become a *low* orbit, and finally, fire a 3rd time to circularize it.
Chuck
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/17/2006 08:12 PM
Chuck, SMetch,
Quote
clongton - 17/11/2006  12:49 PM

Quote
SMetch - 17/11/2006  3:12 PM
Orion needs a 1000m/s burn to achieve a -30x100?  Is this right?
That's correct.
Orion SM acts as a 3rd stage to put the spacecraft into a 'suborbital' trajectory (-30 to 100nm), because Ares I is incapable of doing it. Then it has to fire again to make it become a *low* orbit, and finally, fire a 3rd time to circularize it.
Chuck

My understanding (if there's any validity to the rumor at all--I don't have connections good enough to prove it one way or the other) was that the claim was 1000 *feet* per second DV, not 1000 *meters* per second.  There's a bit of a difference.  1000ft/s is only about 300m/s, which while annoying isn't a deal-killer.  I mean, if you already think that blowing $10B to do what could be done by existing vehicles isn't a deal killer, requiring the payload to help out to get into orbit because your booster can't hack it isn't that bad in comparison.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: hop on 11/17/2006 09:04 PM
Quote
clongton - 16/11/2006  9:56 AM

Quote
Kelly Starks - 16/11/2006  11:57 AM
Everytime I hear things like $5 bil for the stick
Remember, that $5 billion is *extra* for early 5-segment RSRM development.
Also, claiming that the $5 billion would be "spent anyway because you need it for the CaLV" is a bit disingenuous, since with the baseline DIRECT vehicles, you don't need the 5 seg solids *ever*.
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/17/2006 09:23 PM
Quote
jongoff - 17/11/2006  12:55 PM

Chuck, SMetch,
Quote
clongton - 17/11/2006  12:49 PM

Quote
SMetch - 17/11/2006  3:12 PM
Orion needs a 1000m/s burn to achieve a -30x100?  Is this right?
That's correct.
Orion SM acts as a 3rd stage to put the spacecraft into a 'suborbital' trajectory (-30 to 100nm), because Ares I is incapable of doing it. Then it has to fire again to make it become a *low* orbit, and finally, fire a 3rd time to circularize it.
Chuck

My understanding (if there's any validity to the rumor at all--I don't have connections good enough to prove it one way or the other) was that the claim was 1000 *feet* per second DV, not 1000 *meters* per second.  There's a bit of a difference.  1000ft/s is only about 300m/s, which while annoying isn't a deal-killer.  I mean, if you already think that blowing $10B to do what could be done by existing vehicles isn't a deal killer, requiring the payload to help out to get into orbit because your booster can't hack it isn't that bad in comparison.

~Jon

LOL, you’re right it would be nice to get the first order decisions correct before worrying about a second order problems.

From my perspective, putting all logical engineering issues aside, the $10 Billion problem is what is going to take the stick down at this point.

When you read into Jeff’s letter he misses entirely the salient topic of this debate.  I’m sure if we gave NASA the requirement of landing grand piano on Titan using a VW bug as the descent stage they could do it given enough time and money.  The more important question is why would you want to do that?

Title: Re: "DIRECT" Goes Live
Post by: hop on 11/17/2006 09:51 PM
Quote
SMetch - 17/11/2006  2:06 PM
When you read into Jeff’s letter he misses entirely the salient topic of this debate.
My impression is that Jeff's letter was in response to the "Stick is in trouble" articles on nasawatch and other sites, rather than a rebuttal of the various alternatives to NASAs selected architecture.
Title: Re: "DIRECT" Goes Live
Post by: Avron on 11/18/2006 02:19 PM
Quote
SMetch - 17/11/2006  5:06 PM


From my perspective, putting all logical engineering issues aside, the $10 Billion problem is what is going to take the stick down at this point.


Maybe its more than a $10 Billion problem... "Direct", would indicate a problem in the $30 Billion range..  and that is a lot of money to distribute.. my only question is how much in Billions does it take to call for a change, or at least a review?
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/18/2006 03:44 PM
Quote
hop - 17/11/2006  4:34 PM

Quote
SMetch - 17/11/2006  2:06 PM
When you read into Jeff’s letter he misses entirely the salient topic of this debate.
My impression is that Jeff's letter was in response to the "Stick is in trouble" articles on nasawatch and other sites, rather than a rebuttal of the various alternatives to NASAs selected architecture.
It sounds VERY defensive.  I wonder if they were entirely unprepared to see the level of scrutiny and comment as has been present on the message boards.  It's not always accurate, but it's always spirited!  NASA has never done a major manned LV project (counting Shuttle as their last major manned LV project) with message boards around, and I wonder if it's throwing them for a loop.

I'm wondering if they feel they CAN'T switch from Ares-I without appearing like they'll bend at the whim of message board pressure.  So, as a result, they'll make Ares-I fly, come hell or high water.  Being a publicly funded organization that everyone trusts as being the smartest people in the room, they may feel they now don't have the luxury of changing amidst pressure and therefore have to make A-I fly.  -- even if they might have otherwise considered switching.

I wish NASA could hear the LV24/25 (DIRECT, whatever...call it what you like) idea without being concerned about all the "hahahahaha!  your rocket bites!" stuff with it.  which isn't what we've been trying to do... but they may have read that into it.

LV24/25 is an idea with no strings attached.  How could there be?  It's THEIR idea...we've just played it out a bit.
Title: Re: "DIRECT" Goes Live
Post by: Stephan on 11/18/2006 05:20 PM
Quote
simcosmos - 17/11/2006  11:34 AM

"DIRECT" Goes Live >> LIVE Test / Demo Orbiter Simulator Session today

Hello,

I will probably make a live test / demo session today (17th November) at +/- 18:00GMT. These are some of the objectives:
- to test the DIRECT CLV (PhaseII) - Mission to ISS: test of automatic guidance / ascent program (alpha)
- will also eventually show other launcher variants
Simcosmos webcast is beginning.
Title: RE: "DIRECT" Goes Live
Post by: Zachstar on 11/18/2006 07:26 PM
I just saw the webcast.

Very impressive simC I am greatly looking forward to this addon.
Title: Re: "DIRECT" Goes Live
Post by: the_roche_lobe on 11/18/2006 11:07 PM
This DIRECT debate is very interesting. If you google terms like 'user generated content' and 'consumer co-creation' you'll see that the marketing world is abuzz with the seeming power of motivated, talented 'customers' who use YouTube, Flickr, blogging software and a whole bunch of 'content generating' applications [Orbiter!] to mod and design their own products. These are often as 'trivial' as new ads for existing products or new design aesthetics for 'fashion' niche consumer gizmos. The point is that businesses are starting to listen to this consumer co-creation din, and in fact ignore it at their own peril.

It's a long way from niche consumer electronics, cosmetics and clothing to a multi decade, multi billion dollar government program but the media dynamics are much the same. I'm sure governments and program directors have been absolutely blindsided by the creativity, passion, talent AND SENSE OF OWNERSHIP [which is only fair, at least for the US taxpayers that make up the majority of this community...err lobby group] evinced on places like this site. In the long run, maybe this is increasingly the only real democracy 'consumers' have. I'd suggest that one of these days even NASA may well be employing people to study posts in places like this very carefully indeed - and not just to prepare rebuttals, but to actually seriously consider them, and be seen to seriously consider them.

Imagine that eh?

P
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/18/2006 11:40 PM
Quote
hop - 17/11/2006  2:34 PM

Quote
SMetch - 17/11/2006  2:06 PM
When you read into Jeff’s letter he misses entirely the salient topic of this debate.
My impression is that Jeff's letter was in response to the "Stick is in trouble" articles on nasawatch and other sites, rather than a rebuttal of the various alternatives to NASAs selected architecture.

Not according to Keith, the statement “recent notoriety” in Jeff’s letter to the troops is telling.  Only one proposal hits on both marks.  Coming at the junction of the new leadership in congress, who are trying to find ways of restoring science and aeronautic pull backs, having better ideas on how to achieve VSE more efficiently and sooner is not welcome.

If I was Administrator I would want to incorporate every good idea I get my hands on.  Blunt their attack by aligning to a better plan and move the key dates back in time to protect the budget, ie accelerated CEV and Jupiter I.  Space is tough and doesn’t suffer arrogance gladly.  I could really care less where a good idea came from or what we thought the best approach was up to that point.  If its incorporation would reduce life cycle cost, increase safety, and speed up implementation so be it.  I think Spock would agree, Mike I’m not so sure of anymore.
Title: RE: "DIRECT" Goes Live
Post by: marsavian on 11/19/2006 02:42 AM
http://www.spaceref.com/news/viewnews.html?id=1173

Isn't this the same as Direct ?
Title: RE: "DIRECT" Goes Live
Post by: rumble on 11/19/2006 03:24 AM
Quote
marsavian - 18/11/2006  9:25 PM

http://www.spaceref.com/news/viewnews.html?id=1173

Isn't this the same as Direct ?
Nope.  This is a hybrid of many things.  It uses shuttle SRBs, but otherwise sounds more like the Atlas V phase III 8.4m core.

The core of Direct (ESAS LV24/25+EDS) still uses LH2 & LOX like the ET was designed for, and RS-68's instead of SSME's to substantially reduce cost.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/19/2006 05:19 PM
Apparently the AIAA has been getting a lot of alternatives to Ares recently and I am guessing that is what Hanley is reacting to. Not just the first one published on SpaceRef (smetch's) or the rumor of Ares I weight problems that Cowing posted. There were a whole batch done by LM that didn't exactly say they were an alternative, smetch's TeamVision proposal, the newest one linked above, and of course DIRECT which was not submitted to AIAA but was more of a grass roots distribution.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/20/2006 09:06 AM
Quote
jongoff - 10/11/2006  11:50 PM

Ross, JIS,

Quote
Quote
I think that regenerative nozzle is not directly related to ISP so how it will be increased. I suppose that by higher chamber pressure and bigger expansion ratio of nozzle.

That is my understanding.

As I understand it, regenerative cooling impacts Isp in a few ways:
1-You can typically run higher pressures


Why it should be related?

Quote
3-You're preheating the propellant a bit, and that extra thermal energy goes back into the engine.  This is usually a fairly small effect, but could be as much as 5-10s IIRC.

5-10s is quite big effect.

Quote
I used to be a huge fan of ablatives before I actually got involved with building rocket engines.  Now I'm definitely firmly in the Regen-Cooled camp as far as liquids go.  Ablatives have their place, but regen cooling has some real performance, reusability, and reliability benefits.  It's really nice being able to know that a piece of hardware you're flying on has been qualification tested and shown to work.  With ablatives, you're effectively testing a whole new engine each time.  Also I think failure modes with regen engines are a little less severe.  The engine will still have to be shut down in the event of a serious burnthrough, but the odds of punting a nozzle section like SpaceX managed (a year or so ago during some torture testing) are a lot lower.

Agree

Quote
The engine itself has already been tested to that level.   Making a new nozzle for it is not all that difficult.

I'd really be surprised if they ran into too many problems with it.  They've got to already know the thermal environment of that engine very well if they've got a working ablative design, so designing and implementing a regen nozzle should really not be that hard.  I'd be really amazed if it took them more than $50-100M to make the changes, and then qualify them with a bunch of firings on the test stand.

~Jonathan Goff
  Masten Space Systems

My only concern is the ISP. If the upgrade of RS-68 would be simple it can't be overlooked by NASA and it will be used for Ares V.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/20/2006 09:48 AM
Quote
tom nackid - 14/11/2006  12:59 PM

"...NASA's blind confidence..." how do you figure that? In other words your hobby rocket has more testing, thought and experience in it than NASA's? Seems to me NASA considered your idea and rejected it even before you reinvented it! Frankly I'm getting a little tired of the "I'm the little guy and they are the big government agency so by the rules of Frank Capra movies I MUST be right" attitude. I think you could easily give Griffin a run for his money in the arrogance and ego department! That's not to say I don't respect your hard work and your desire to see the space program succeed, because I honestly do. I just think your fervor is misplaced and ultimately detrimental and divisive.

I agree with Tom. Ross did a good job. But I never agreed with his way of spreading rumours.
Thanks to Hanley we know that Orion team is working towards mass of 22 mT and target for Ares 1 to -30 x 100 nm for ISS orbit is 23.6mT. The Ares 1 performance at the moment is somewhere at 26.3 mT.
These numbers are the same for 28.5deg 80 x 160 nm orbit.
Therefore, there is no underperformace for Ares 1 and all these rumours were false and misleading.
I'm sure that the Ares 1 development won't be always smooth but I believe that there is no showstopper at the moment.

Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/20/2006 10:06 AM
Quote
Magnus_Redin - 14/11/2006  2:28 PM

Ross is not right due to hollywood movie logic.
Ross is right since it is a good idea to plan the missions to use the launcher that is easiest to develop and cheapest to produce and run given the current knowledge and infrastructure.
He is also obviously right in one new large launcher being cheaper to develop and use then two.

Nasa seems to have started with the same idea, to reuse what they already have, and probably also with a desire to be independant from the two already excisting EELV:s. Perhaps they also figured that developing one small and then one large launcher would be politically easier then starting with a large one. Then it seems like the Ares I development started to fail and the failure hurts its missions and forces the large launcher to become larger then the present infrastructure can handle.

The true reason for the two launchers is not to spare money but to improve safety for the crew and improve responsibility of the CEV. This will be fullfilled by Ares 1.

Ares V will provide enough cargo mass to perform simple and affordable missions to Moon and Mars. Something that DIRECT won't.  

NASA apparently doesn't care about price as long as they will be able to fullfill the VSE goals and timetables and budget restriction. Something what DIRECT can't.

From this point of view I support NASA decision to reject cheaper but less ambitious (from exploration and safety point of view) options.

Title: RE: "DIRECT" Goes Live
Post by: simcosmos on 11/20/2006 10:07 AM
Quote
Zachstar - 18/11/2006  8:09 PM

I just saw the webcast.

Very impressive simC I am greatly looking forward to this addon.

Hello

About the 18th November 2006 LivePics demo:

I had a cool number of visitors (if remembering well, there were +/- 7 persons online in a given moment and perhaps 3 or 4 from start to end, despite the boring part (CEV + Mission Module and ISS approach / rendezvous / docking). After the DIRECT CLV and ISS mission I also showed an even more alpha state of the launch pad and of DIRECT + EDS configuration going up.

Back to DIRECT CLV: the ascent guidance + eye-candy seems more or less acceptable for an alpha and I think that will just freeze that and start thinking about releasing v0.1.

Such v0.1 will not contain a mission module like in the past weekend's LivePics demo (where happened a CTD that I'm trying to debug): it will only include the DIRECT CLV phase II with the CEV + ballast container and one automatic guidance for ISS launch. Other *toys*, missions and visual / performance upgrades will be included later.


Preparing the path for a first public release of DIRECT addon (v0.1)…

Meanwhile I'm writing a first version of the documentation: it will be also kind of incomplete but will hopefully include all what is needed (at least the most basic things).

By the way: given that this might be the first time some people try to install Orbiter I would like to know if there is the need to write a separated document with step by step instructions regarding how to prepare a basic Orbiter installation to optimally run DIRECT addon(?), I mean: it will mostly be all a matter of using zip files and unzip their contents into a specific directory (by keeping the folder structure).

The basic requisites to run DIRECT will be:

STEP1: Orbiter2006P1
http://orbit.medphys.ucl.ac.uk/download.html
- several mirrors available, Base (full) 060929 needed, for example, one of the mirror links:
http://download.orbit.m6.net/orbiter060929_base.zip
 
People can then also install the higher resolution packs for the planets, etc but no need to complicate ;)

To "install" Orbiter is very easy: it is just needed to create a new folder, for example, "Orbiter2006P1_DIRECT0.1" and then just unzip orbiter060929_base.zip contents into that folder (by keeping the folder structure, please let me know if needing help handling with zip files)
 
 
STEP2: DIRECT addon
I will then provide a download link for a DIRECT demo zip (v0.1) - which should be hosted at Orbit Hangar Mods ( http://www.orbithangar.com ): again, all what will be needed will be to just unzip the demo into the previous Orbiter folder.
 
Then it is just a question of opening Orbiter's folder, locate Orbiter.exe, click, check Video tab, Parameters tab for reality settings (all reality setting ON is recommended), etc: once done, the user will only need to select the Scenario tab and there will be a DIRECT folder with the demo scenario(s): one last click in the scenario and voilá… the scenario will load and people will just need to press "P" to launch the rocket (again, I will give more instructions and a kind of check-list for the ascent, all in the addon's documentation).
 
 
The above is just the basic: there are two extra steps that will provide a (much) greater experience:
 
STEP3: Orbiter Sound:
http://orbiter.dansteph.com/index.php?disp=d
The default Orbiter has not sound: it is then highly recommended to install OrbiterSound in order to hear DIRECT's countdown (borrowed from STS-115), SRB's *Ratatatatata* (like in DIRECT's demo video)... and... also to hear a small surprise that a few nasaspaceflight visitors will probably recognize... (ho, the mistery!)

 
STEP4: Franz Berner aka francisdrake's CEV addon:
http://www.orbithangar.com/searchid.php?ID=1972
(if wanting to have a functional CEV after DIRECT's core MECO, else people will end up with a dead CEV going down with the ET: in a much later moment I will continue to integrate Franz's CEV but will try to reduce this external addon requisite and include also a CEV of my own... but these things take time ;) )


Ok, just giving the heads-up in case someone wishes to start preparing stuff to launch DIRECT v0.1 addon in the comfort of your home PCs. If all goes well... Well, it should be ready within day(s) / week(s) time (can't really give a precise date): all what is missing for such first public release is the boring part (to write a first version of the documentation, re-check all components, test in a fresh Orbiter install, etc)

Work in progress,

António
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/20/2006 10:16 AM
Quote
Mark Max Q - 14/11/2006  5:06 PM

Just come on line now and there's already a 50 post thread on L2 about Hanley's e-mail. With a battle of engineers, with ATK on one corner and it seems everyone else in the other. Hanley's made a huge mistake in this e-mail with the admission of problems, when he seemed to be aiming at taking a swipe at the alternatives and people speaking of problems.

Can someone give me a hint about mistakes in Hanley's article? Sorry but I'm not intending to enter discussion at L2.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/20/2006 10:19 AM
Quote
Norm Hartnett - 14/11/2006  7:24 PM

Exactly hop. The entire DIRECT vs. Ares I discussion is invalid and also detrimental to the DIRECT proposal. The correct discussion should be DIRECT vs. Constellation. I think Kraisee may have made a mistake in including the Ares I issues in the proposal to begin with. It really doesn't matter if there are problems with Ares I or not, what matters is that Constellation is expensive and possibly not politically viable.

DIRECT is a overall program change not the replacement of one LV with another.

I agree.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/20/2006 10:51 AM
Quote
Jim - 16/11/2006  9:12 AM

"but in that light the cost overrun isn't quite as ridiculous as it appears at first sight."

It is ridiculous in any "light".  We could get a lot more and early with that money on other systems

That's the general problem of American approach.
Americans could stick to gemini and fly cheaply for decades. They are instead developing Apollo, STS, Orion etc.
On the other side, with this approach Americans wouldn't be where they are now.
Title: Re: "DIRECT" Goes Live
Post by: marsavian on 11/20/2006 11:25 AM
Hanley and Horowitz defend Ares 1 in quite a detailed article of its current progress.

http://www.space.com/spacenews/businessmonday_061120.html

relevant statements of position :-

'
But the NASA Watch post spurred him to action. Hanley sent his e-mail, he said, to “a few dozen Constellation leaders throughout the program“—a long enough distribution list, it would seem, to ensure the message leaked to an even wider audience.

“I thought it was important that we set the record straight on some of the external stuff that’s been going around. I don’t want people to think that because they don’t see us responding to it on a regular basis that has any basis in truth,” said Hanley, who spoke to Space News in a Nov. 15 telephone interview from Johnson Space Center in Houston, where the agency’s first systems requirement review for Orion and the Ares rocket had wrapped up the day before.

Hanley was joined on the interview by Cook and Scott Horowitz, NASA’s associate administrator for exploration systems.

Hanley said the review, which was attended by NASA Administrator Mike Griffin and the agency’s chief engineer, Chris Scolese, found that Ares I remains on track to lift the Orion spacecraft with performance to spare.  ......


......  Horowitz dismissed anonymous claims of trouble on Ares as “rumblings from people who didn’t get their particular favorite rocket design picked.”

Horowitz has championed the single stick design for Ares I since shortly after the 2003 Space Shuttle Columbia accident claimed the lives of seven of his fellow astronauts. He continued his advocacy for what some called “the Scotty rocket” during a brief stint at ATK Thiokol, the Promontory, Utah-based solid-rocket booster firm picked to build the Ares I main stage.

Horowitz said NASA looked at 10,000 to 20,000 iterations of different designs as part of an intensive Exploration Systems Architecture Study before selecting the crew and cargo launcher concepts the agency unveiled in September 2005.

“Are there other solutions that would work? Sure,” Horowitz said. “But so does this one. This is ours. And this is where we are going. And occasionally you’re just going to get noise in the system. We try to educate people. It’s just noise.”
'


Title: Re: "DIRECT" Goes Live
Post by: simcosmos on 11/20/2006 12:27 PM
Regarding CLV safety numbers:

Given that the simple, soon seems to be apparently gone, at least in the current iteration, we are kind of going around in circles in several arguments:

Yes, DIRECT CLV has one extra engine and one extra SRB than AresI… By other hand, Ares I 5 segment SRB is a new design and new launch configuration (the launch configuration has its advantages / disadvantages), the J-2X could also be called a new engine. Direct CLV would use existing 4 seg. SRB (in their traditional role as side boosters, again with both advantages and disadvantages) and its core engines (at first RS-68, then upgraded) would be fired before lift-off / before launch commitment, also providing partial engine out capability during ascent. Also, given that both DIRECT CLV and other DIRECT variants would share many design aspects, it is not as straightforward as it seems to compare safety numbers between the DIRECT CLV vs AresI designs, at least in my humble opinion.

Warning >> Please allow me to be a little ironic now: if safety concerns based in given assumptions (which are disputable from many points of view) would really be the most important reason of all and are above all other arguments I sometimes wonder how NASA astronauts were/are allowed to fly in Soyuz with 4 boosters + core stage (even despite the long flight story of this reliable rocket)… Or how NASA astronauts are still allowed to continue flying the Shuttle, with no escape system and despite all improvements.

Yes, there are other variables in the equation but that then means that the safety variable vs design considerations is perhaps not the holy graal it seems to be, else, under the same "safety" assumptions:
a) NASA astronauts on Soyuz and STS flights would perhaps not be allowed
b) In the future, after STS, we will never see NASA astronauts riding up something different from a two-stage launcher with a single engine in each stage
c) or, by other hand, the AresI design would need a lot more unmanned flights first or in parallel in order to build up some serious "reliability" numbers sooner, which will not happen because Ares I will mostly be used as a Crew Launch Vehicle.


Regarding heavy lift performance / VSE goals:

Leaving behind the discussion about if Heavy Lifter is strictly needed, at least for the Moon, I agree that Ares V is obviously more capable than any of the DIRECT’s basic variants (doh :)) but Ares V (with Ares I needing to be ready first) will also probably cost a lot more to implement and operate, even if comparing with DIRECT being upgraded later on… Even the basic DIRECT core could eventually use 5 segment SRB (at least there were some early studies regarding how to integrate 5 seg. SRB into STS by using a different attachment system).

Yes, DIRECT (2 x RS-68R + 2 x 4 segment SRB + 1 x J-2X EDS) delivers less in a single launch than the current AresV plans but, by other hand, it offers advantages regarding facilities handling, timeframe, launch rate, also dual launch mode (when comparing wit a standard AresI/V ESAS lunar mission) and even for additional single launch mode (regarding payload size) for a wider range of missions (other than being used to just deliver one-go big payloads), again, all using the same key components (thus building up the "safety" numbers due to *real life* higher flight rates).

This is the key point of DIRECT: it still delivers performance at a reasonable cost / timeframe for *immediate* VSE goals (or do people really think that we will go to Mars right after 2 or 3 lunar missions?) while keeping the door opened for +/- "smoother" upgrades, later on, for the more ambitious goals (if an increase in capability is really needed).


Yes, NASA's current AresI / V approach should be capable of fulfilling the basic VSE goals but... is it only that we, or better, the North-Americans really wish for VSE? To do the basic while spending a budget that could be better used to achieve even more goals? And what about money needed for other NASA projects / some of them that could even be used *now* to help VSE? From where will it come such money if NASA's budget is not increased? Although perhaps providing later savings, the current path is too much upfront loaded regarding several critical items.


NASA and Transition Between Programs

I think that already wrote this somewhere in the past - perhaps in the 5 segment alternatives thread, not sure - but will write it again here: I think that in concept, the idea of using a common first stage (and even upper stages, which is not the case here) for smaller crewed launch vehicles and for the heavy lifter (also using more common boosters for the "CLV" configuration in order to have a bridge in unmanned capability between CLV and HLV) is a good concept (imagine an updated Zenit and updated Energia design with variable number of boosters and where perhaps also the updated Zenit upper stages could be used as upper stages for HLV variants): but, and back to NASA (and passing by the arguments against / for using solid boosters or not), I'm not 100% sure about why it is really needed to build a separated and / or new launch capability for crewed launches (when comparing for example with other alternatives) or why it is really needed to make the kind of changes that are planned to be made for Ares I / V. But again, who am I?

At very least I hope that DIRECT and other proposals have an effect in some parts of the current AresV design (at least by considering again a performance / feasibility study of reducing the main core back to today's STS standard under an investigation about eventual RS-68 upgrade benefits vs VAB + Facilities + Support changes, etc): this is also something I'm curious about: weren't (+/- easy?) RS-68 upgrades considered in the AresV design, with all implications that would bring to several other related items? If so, why then propose an Ares V configuration like it is now?

Despite there is apparently money available the true question is if it will be enough and if it really wouldn't be better ways of achieving the same goals, with advantages for more NASA Departments / research areas and sooner in the timeline while, like written above, still keeping the door opened for more ambitious goals? I'm just afraid that the current path might simply dry up all the resources just to build launch capability and, once that done, there will be little else to spend in what really matters!

Despite all the successes of NASA, what I think that NASA always missed is a more continuous approach regarding space exploration hardware design: every time NASA needs new capabilities, it needs to almost completely adjust its launch structures having to spend more money in launchers design and facilities adjustments... This was not a problem during Mercury to Gemini to Apollo (given the cold war and Moon race and the money available)... Apollo to STS was less easy... STS to the planned Ares I and, much later, Ares V is still to be seen.

I just can't stop thinking that with a little more effort made in the conceptual phase NASA and the United States of America could perhaps make a smoother transition from STS while still keeping all under budget (plus having extra manoeuvring for other items) and while preparing the path for the immediate, middle-term and long-term future.

Else, perhaps within 30, 50 years or so, for those of us whom will still be around, we will be talking again about the same aspects (if meanwhile NASA's budget is not increased). Or perhaps not: new players are each time more appearing in this sector (countries with exploration goals, private companies, perhaps we will see new technical advancements, etc).

Again, these are just my humble opinions / concerns and I'm not even an US citizen! (most seem to not care anyway)
I apologize for another never-ending blablablablabla and if wrote any nonsense.  

Having written all that and as always: I wish good luck to NASA and to all working hard to achieve manned / unmanned exploration and scientific goals (inside and outside NASA / United States).

António
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/20/2006 12:50 PM
Quote
JIS - 20/11/2006  5:49 AM
Ares V will provide enough cargo mass to perform simple and affordable missions to Moon and Mars. Something that DIRECT won't.  

NASA apparently doesn't care about price as long as they will be able to fullfill the VSE goals and timetables and budget restriction. Something what DIRECT can't.
You need to get your facts straight before you post.
You are just flat wrong.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/20/2006 01:49 PM
Quote
clongton - 20/11/2006  7:33 AM

Quote
JIS - 20/11/2006  5:49 AM
Ares V will provide enough cargo mass to perform simple and affordable missions to Moon and Mars. Something that DIRECT won't.  

NASA apparently doesn't care about price as long as they will be able to fullfill the VSE goals and timetables and budget restriction. Something what DIRECT can't.
You need to get your facts straight before you post.
You are just flat wrong.

Yes, everybody is wrong. Direct (alias Ares II) is the most fantastic rocket never built. Fortunatelly Ares 1 and Ares V (or another member of Ares family able to lift about 130 mT) is not that far from this superior design.
Title: Re: "DIRECT" Goes Live
Post by: Kelly Starks on 11/20/2006 02:32 PM
Quote
SMetch - 18/11/2006  6:23 PM

-----
If I was Administrator I would want to incorporate every good idea I get my hands on.  Blunt their attack by aligning to a better plan and move the key dates back in time to protect the budget, ie accelerated CEV and Jupiter I.  Space is tough and doesn’t suffer arrogance gladly.  I could really care less where a good idea came from or what we thought the best approach was up to that point.  If its incorporation would reduce life cycle cost, increase safety, and speed up implementation so be it.  I think Spock would agree, Mike I’m not so sure of anymore.

That would be a profesional attitude, but as a couple Congressional shuttle loss investigations documented - that ain't how NASA works.

Also if you remember the Ares design wasn't one developed at NASA, it was one Griffen brought with him and ordered NASA to adopt.  So your expecting Griffen to accept HIS idea, that he shoved down NASA throat, was bad.

NOt politically likely.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/20/2006 03:05 PM
Quote
JIS - 20/11/2006  9:32 AM

Quote
clongton - 20/11/2006  7:33 AM

Quote
JIS - 20/11/2006  5:49 AM
Ares V will provide enough cargo mass to perform simple and affordable missions to Moon and Mars. Something that DIRECT won't.  

NASA apparently doesn't care about price as long as they will be able to fullfill the VSE goals and timetables and budget restriction. Something what DIRECT can't.
You need to get your facts straight before you post.
You are just flat wrong.

Yes, everybody is wrong. Direct (alias Ares II) is the most fantastic rocket never built. Fortunatelly Ares 1 and Ares V (or another member of Ares family able to lift about 130 mT) is not that far from this superior design.

I am not pushing Direct.  

I was making a comment about this statement "simple and affordable missions"
which is wrong
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/20/2006 03:06 PM
Quote
JIS - 20/11/2006  6:34 AM

Quote
Jim - 16/11/2006  9:12 AM

"but in that light the cost overrun isn't quite as ridiculous as it appears at first sight."

It is ridiculous in any "light".  We could get a lot more and early with that money on other systems

That's the general problem of American approach.
Americans could stick to gemini and fly cheaply for decades. They are instead developing Apollo, STS, Orion etc.
On the other side, with this approach Americans wouldn't be where they are now.

No, I am not for cheap and I am against bloated and wasteful program, which the ARES vehicles are
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/20/2006 05:05 PM
Quote
Jim - 20/11/2006  9:48 AM
I was making a comment about this statement "simple and affordable missions"
which is wrong

What is the most simple and affordable Lunar mission you could have?
There are many small launches at one side and one big launch on the other side.
The chosen approach is one big launch. With one exemption: the crew have its own CLV which can also service ISS.
This philosophy was chosen and Ares 1 and Ares V is the product. You can't change product not changing philosophy. It doesn't work.
DIRECT fans support one particular launch vehicle not thinking about exploration philosophy which is bad.
Ares 1 and Ares V are product of exploration philosophy which is good.
As I said before I have no doubt that EELV path could be adopted with Atlas phase 2 and phase 3 but we would essentilally end up (at the best) with system equivalent to Ares 1 and Ares V.
NASA has made a choice and it is time to respect it. Or get used to it.
 
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 11/20/2006 05:24 PM
Quote
JIS - 20/11/2006  11:48 AM

NASA has made a choice and it is time to respect it. Or get used to it.  

Or simply work with it. NASA management is headstrong about the launch vehicles it wants build, but the rest of the program (the important part of the program) is still up in the air and very open to new ideas. Lockheed Martin proved this by taking the basic design of Orion and completely reworking it to produce a better product, and getting a nice chunk of change in return. Indeed, at nearly every press conference, someone says that they have no idea what the eventual LSAM will look like...

Forget Ares, the Moon is where it's at...

Simon ;)
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/20/2006 05:51 PM
Quote
JIS - 20/11/2006  12:48 PM

NASA has made a choice and it is time to respect it. Or get used to it.
 


NO!

It is not too late to change.  LOR was a "late" change
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/20/2006 06:33 PM
Jim, do you mind if I ask what you do and what your experience is as it pertains to the aerospace industry? You have some strong opinions and I would really like to know how much credence I should be giving them. This is in no way intended as an insult or a challenge. I honestly want to know so I can come to some informed conclusions. Thanks :)
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/20/2006 07:01 PM
9 years USAF.  5 at Los Angeles AFB in the USAF shuttle program office working STS and ELV flight  requirements.  4 at the Cape, working spacecraft ground ops for Shuttle and ELV launches.  8 with McDonnell Douglas-Boeing on the Spacehab program.  Currently with NASA for the last six years in the NASA ELV program office, where I was the integration engineer for ICESAT, MER A&B and MRO.  Also worked OSP - EELV integration.  Currently working MSL and STSS LV integration and provide ELV "expertise" to the local Constellation office.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/20/2006 07:02 PM
Thanks!
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/20/2006 07:05 PM
Quote
JIS - 20/11/2006  11:48 AM

What is the most simple and affordable Lunar mission you could have?
There are many small launches at one side and one big launch on the other side.
Well, the choice isn't as simple as "many small or few big," as it depends on what constraints are put on the design.

Simple?  1 HUGE rocket.  Saturn V will be hard to beat there.
Affordable?  Find the sweet spot in:  1)  Greatest commonality with what already exists (lowest development costs), 2) lowest "per-flight" cost (lowest recurring cost), and 3) least infrastructure costs (combination of high flight frequency and reduced support costs).

There are many variables affecting all that.  IMHO, Ares doesn't score very well in all that.  Evolved Atlas does better with VERY high commonality...same with ESAS LV24/25 (a.k.a. DIRECT).
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/20/2006 07:34 PM
Quote
simonbp - 20/11/2006  1:07 PM
Quote
JIS - 20/11/2006  11:48 AM
NASA has made a choice and it is time to respect it. Or get used to it.  
Or simply work with it. NASA management is headstrong about the launch vehicles it wants build, but the rest of the program (the important part of the program) is still up in the air and very open to new ideas. Lockheed Martin proved this by taking the basic design of Orion and completely reworking it to produce a better product, and getting a nice chunk of change in return. Indeed, at nearly every press conference, someone says that they have no idea what the eventual LSAM will look like...

Forget Ares, the Moon is where it's at...
Simon ;)
I respectfully disagree.
The difficulty with that view is that it is not long term.

In the near term, we are going to need 2 types of LV to establish the VSE;
1. Light-weight people launcher: a taxi, and that will be Ares I (unless we get lucky [dare we hope])
2. Heavy lift. Sure, once we're on the moon doing *major* ISRU, we won't be flying mega tons at a time because a lot of what is needed will be produced/grown/manufactured on the moon. But the equipment to do that will have to initially come from the earth, and that stuff will be *heavy*. It will be mining equipment, machinery, etc, etc. Huge machines are not likely to be brought in piecemeal; the larger the pieces that can be brought at a time, the better it will be. Once the lunar *economy* begins to actually function, the need for that will be less, and the need for heavy lift will lessen (until the Mars effort). Until then, HL will be necessary.

But here's my point: Excepting all the effort to get a lunar economy *started*, the vast majority of flights from then on will be medium lift, to LEO. Transportation to and from the moon will be with vehicles which never enter earth's atmosphere, up or down. It just won't be economically viable, because there are too many compromises to be made to account for the atmosphere.

It's too simplistic to think that ISS will still be there in 30 years. It'll be at the bottom of the Pacific, but there WILL be other destinations in LEO, probably lots of them. Ares V will *not* be needed to service them, and Ares I will not be capable of doing it. Taking the long view - what is going to be the long-term sustaining LV for the VSE to work is a medium lift vehicle. A vehicle in to 50 to 100mT class will be what is needed for almost all the traffic between the earth's surface and LEO. Down cargo will probably be via an unmanned lander of some type, especially designed for atmospheric re-entry and flight (winged, lifting body, biconic, etc), just to get the cross range capability. Or maybe an unmanned conic re-entry vehicle like Orion, only bigger, parachuting into the western desert. But whatever it's shape, the cargo carrier will be unmanned. That vehicle will be launchable on a medium lift LV. (Edit: Check out this link for "down cargo" applications: http://spaceflightnow.com/news/n0611/19x37b/) Passenger flights will be on craft launched by this same class launcher, but probably a *lite* version of it.

Before I get too far, may I say that there is no such thing as the do-it-all perfect LV. But we cannot afford to develop several different kinds of LV, with all the infrastructure needed to support them. We just can't do it. We need a single LV which will *reasonably* fill a lot of roles in it's own iterations.

The point I'm making is that Ares I/V is, in actuality, a short-term answer and will, of necessity, be replaced with a medium lift LV because it is the meduim lift that will actually sustain the VSE.

So - all that to say this:

Before we spend too much money on the short term - why not flesh out some of the better medium lift ideas in the ESAS with a longer view than *just* get us on the lunar surface (Ares V). Maybe it's just possible that there are some medium lift possibilities that will serve the VSE better than the Ares I/V, which are short term solutions. With due respect to Dr Griffin (a brilliant engineer), NASA is not doing what the President directed. They have completely missed the *stay* part.

The ideal LV configuration is a medium lift launcher which can be extended/configured to meet the short term heavy lift requirements. That way we don't have to go thru all this pain again in a few years to develop the medium lift launcher which *WILL* be needed to sustain the VSE.

If we *must* stay with shuttle derived, then adopt something like the LV-24/25 (aka Direct), because that will work nicely (extendable to 175mT to LEO) and be sustainable for decades to come.

If we do *not* have to stay with shuttle derived, then there are several *VERY NICE* EELV options available. These need to be fleshed out to see what they would actually look like and what their growth options might be. The trick is to make them capable of playing the HL role when needed.

We *MUST* think long term here. And just getting to the moon is *not* long term. The VSE states that we are going back to stay. Ok, once we are there and we stay there, what would we use the Ares V for? Especially if we have a configurable medium LV that can do the HL with appropriate extensions. All that effort to get there and then throw it away and build a new rocket? That's dumb.

Passengers to and from LEO? If we really think about where the VSE is leading us, the people taxies will not be carrying 4 to 6 people; They will be carrying 10-15, maybe more, at a time. Ares I can *bearly* get a 4-6 professional crew aloft. Ares I will *NOT* be a sustainable LV for VSE. It will have to be a medium lift LV.

I agree with the OMB; NASA has committed too much money way too fast in the name of political expediancy. I *do not* believe that we should be spending so much money to develop and field such a short term solution to what is a long term vision.

The VSE is really a paradigm shift. NASA is not seeing that. They are building a better steam engine while the rest of the world is asking for nuclear power.


Chuck
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/20/2006 08:22 PM
marsavian,
Quote
Horowitz said NASA looked at 10,000 to 20,000 iterations of different designs as part of an intensive Exploration Systems Architecture Study before selecting the crew and cargo launcher concepts the agency unveiled in September 2005.

You'd think while they were doing all of those iterations, they would've discovered inconvenient facts like that the SSME/4-segment SRB version wouldn't work because air-starting an SSME is a dicey proposition.  The fact that they made obvious screw-ups of that magnitude really draw into question the rest of the conclusions they came to.  The fact that they just so happened to find that their prefered "Safe, Simple, Soon" solution was the best of 10-20k iterations is just coincidental of course.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/20/2006 08:36 PM
JIS
Quote
Quote
As I understand it, regenerative cooling impacts Isp in a few ways:
1-You can typically run higher pressures.

Why it should be related?

Well, heat flux tends to scale fairly close to linearly with chamber pressure.  My understanding is that higher heat fluxes with ablative liners lead to faster erosion, which means you need to start with a much heavier liner.  At some pressure level, it starts becoming substantially lighter and easier to just regen cool the thing.  This is even more the case with pintle injector based engines.

Quote
Quote
3-You're preheating the propellant a bit, and that extra thermal energy goes back into the engine.  This is usually a fairly small effect, but could be as much as 5-10s IIRC.

5-10s is quite big effect.

Yup, sure is.  Numbers probably vary quite a bit depending on the propellant combo, engine size, pressure, and a bunch of other variables.  But basically you're taking heat energy and pumping it back into the chamber, so you recover a bit of that energy in a tiny bit of extra performance.


Quote
My only concern is the ISP. If the upgrade of RS-68 would be simple it can't be overlooked by NASA and it will be used for Ares V.

Yeah, with the slightly higher Isp, and the slightly higher thrust, it makes sense to develop it regardless of what path NASA chooses for boosters.  Kind of like the Wide Body Centaur (aka Integrated Cryogenic Evolved Stage) for use as an EDS, NASA gains a whole bunch by helping those upgrades become a reality, and Boeing and Lockheed (and all their customers) benefit too.  But improvements like that are less likely to happen because they also weaken the case for Ares I/V, by making the competing systems more capable.  Alas, that's the challenge when supporting systems that don't make engineering or fiscal sense--you end up stifling other potentially useful ideas because you don't want to undermine the case for your preferred solution...

~Jon
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/20/2006 09:17 PM
Quote
jongoff - 20/11/2006  9:05 PM

marsavian,
Quote
Horowitz said NASA looked at 10,000 to 20,000 iterations of different designs as part of an intensive Exploration Systems Architecture Study before selecting the crew and cargo launcher concepts the agency unveiled in September 2005.

You'd think while they were doing all of those iterations, they would've discovered inconvenient facts like that the SSME/4-segment SRB version wouldn't work because air-starting an SSME is a dicey proposition.  The fact that they made obvious screw-ups of that magnitude really draw into question the rest of the conclusions they came to.  The fact that they just so happened to find that their prefered "Safe, Simple, Soon" solution was the best of 10-20k iterations is just coincidental of course.

~Jon

Yeah or the really narrow look at multi-launch scenarios. (ie one launcher, one pad, no spares)
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/20/2006 09:19 PM
Quote
jongoff - 20/11/2006  3:05 PM

marsavian,
Quote
Horowitz said NASA looked at 10,000 to 20,000 iterations of different designs as part of an intensive Exploration Systems Architecture Study before selecting the crew and cargo launcher concepts the agency unveiled in September 2005.

You'd think while they were doing all of those iterations, they would've discovered inconvenient facts like that the SSME/4-segment SRB version wouldn't work because air-starting an SSME is a dicey proposition.  The fact that they made obvious screw-ups of that magnitude really draw into question the rest of the conclusions they came to.  The fact that they just so happened to find that their prefered "Safe, Simple, Soon" solution was the best of 10-20k iterations is just coincidental of course.

~Jon

I don't see how this was a "screw up". It was just a matter of deciding how to spend the time and money. Everyone knew that an air start SME was going to be a challenge and that even a disposable SME was an expensive piece of hardware. In the end the powers that be (according to what I've read anyway) decided that the 5 segment SRB and a J-2 upper stage was a better investment since the Ares V was going need the 5 segment SRB anyway. The 5 SRB / J-2 upper stage was always on the table from the very beginning of the stick. The air start SME was seen as being more desirable but like losing the methane/lox SM and LM engines sometimes tough choices have to be made.

And that reminds me, why do stick opponents just assume that their favorite launch vehicle (be it DIRECT, Stumpy, an EELV or whatever) would sail through development and/or man rating without any "gotchas" of their own? If one did it would be a first for a launch vehicle i think!
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 11/20/2006 10:39 PM
Quote
clongton - 20/11/2006  2:17 PM

But here's my point: Excepting all the effort to get a lunar economy *started*, the vast majority of flights from then on will be medium lift, to LEO. Transportation to and from the moon will be with vehicles which never enter earth's atmosphere, up or down. It just won't be economically viable, because there are too many compromises to be made to account for the atmosphere.
...
Taking the long view - what is going to be the long-term sustaining LV for the VSE to work is a medium lift vehicle. A vehicle in to 50 to 100mT class will be what is needed for almost all the traffic between the earth's surface and LEO. Down cargo will probably be via an unmanned lander of some type, especially designed for atmospheric re-entry and flight (winged, lifting body, biconic, etc), just to get the cross range capability. Or maybe an unmanned conic re-entry vehicle like Orion, only bigger, parachuting into the western desert.

But you are putting the cart before the horse and assuming that we need 50-100 tonne rockets and then finding reasons to use them. If it takes a full Ares V and EDS and LSAM descent stage to land 20 tonnes on the moon, a 70 tonne launcher would probably be closer to 10 tonnes. If you are sending 10 tonne modules to the Moon, you might as well send two of them at a time and save money developing a third launcher...

And I'll dispute the assumption that NASA should "get a lunar economy started"; NASA is a space exploration government agency, not a for-profit corporation.  The only "downmass" that NASA should worry about is warm bodies and scientific samples. Leave the lunar mining economy to private industry...

Quote
clongton - 20/11/2006  2:17 PM
The VSE is really a paradigm shift. NASA is not seeing that. They are building a better steam engine while the rest of the world is asking for nuclear power.

Considering the massive restructuring and diversion of funds, I'm pretty sure they've realised how big a shift this is. And in case you don't know, almost all nuclear power plants are of the pressurised-water variety, basically "a better steam engine"... :)

Simon ;)
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/20/2006 10:57 PM
Quote
tom nackid - 20/11/2006  5:02 PM
And that reminds me, why do stick opponents just assume that their favorite launch vehicle (be it DIRECT, Stumpy, an EELV or whatever) would sail through development and/or man rating without any "gotchas" of their own? If one did it would be a first for a launch vehicle i think!

Because they are not 'new" developments and are being used in similar applications.  The stick is using an SRB as a first stage which is was not intended for and everything above it is brand new.  

EELV development did not start with negative margins and did not have severe issues this early in development.
Title: Re: "DIRECT" Goes Live
Post by: simonbp on 11/21/2006 12:09 AM
Quote
Jim - 20/11/2006  5:40 PM

Because they are not 'new" developments and are being used in similar applications.  The stick is using an SRB as a first stage which is was not intended for and everything above it is brand new.  

The Atlas V (Phase 1 or 2) was never intended to launch people, and it would also need a new upper stage (of very similar description to the current one)...

Simon ;)
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/21/2006 12:25 AM
It is not "new" upperstage just a derived one.  There aren't any "mods" required to launch people, just some extra systems
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/21/2006 01:23 AM
Quote
simonbp - 20/11/2006  6:22 PM
But you are putting the cart before the horse and assuming that we need 50-100 tonne rockets and then finding reasons to use them.
There have been multiple studies done by organizations, such as the Mars Society, among others, which have asserted that a LV in the 50-100mT range would more than likely be the mainstay LV for normal LEO operations. My remarks are based on those 'assumptions'.

Quote
If it takes a full Ares V and EDS and LSAM descent stage to land 20 tonnes on the moon, a 70 tonne launcher would probably be closer to 10 tonnes. If you are sending 10 tonne modules to the Moon, you might as well send two of them at a time and save money developing a third launcher...
1. You are assuming that we would still be sending that kind of tonnage to the moon. I am asserting otherwise. I'm speaking of an established presence on the moon which needs consumable resupply, not massive landings. A medium lift LV would take care of that nicely. For the times when more is needed, outfit the LV with the more powerful extensions and lift 175mT to LEO and send to the moon.
2. You missed the part that round trips would be in vehicles which go back and forth between the earth and the moon, not launched from the earth to the moon. Cargo will normally be transferred in LEO from the LV to the trans-lunar 'truck', whatever form that vehicle ultimately takes. Sending a payload up on an Ares V as the *entire* payload will be *generally* unnecessary by that time. If a heavy lift is needed for a special launch, assuming LV-25 (Direct), it will lift 175mT, *more* than the Ares V.
3. You miss the point completely. There is *no* 3rd (or even 2nd) rocket to develop. A properly sized medium lift that can be used as-is (low range) and extended with US EDS & Strap-ons, will cover the entire range of likely needed launches.

Quote
And I'll dispute the assumption that NASA should "get a lunar economy started"; NASA is a space exploration government agency, not a for-profit corporation.  The only "downmass" that NASA should worry about is warm bodies and scientific samples. Leave the lunar mining economy to private industry...

You're the one making the assumption that NASA gets the economy going. I didn't say that. Every person in NASA and the Bush Administration speaks of NASA's moon effort as a highway for others to follow on. We provide the ride. Others finance the building of a mining economy. NASA is out there as an *enabler*, not a builder. NASA stays cutting edge, and forges the way. Once established, it invites others, industry, to join in and profit from NASA's work. Industry puts skin in the game and invests in its own infrastructure, enabled by NASA. That's the vision. We own the trucks. Paying customers buy the ride. Down mass would be whatever the customer pays to bring down, including, but not limited to, warm bodies. Some of the details of how that works are not clearly spelled out, but basically, its a partnership with industry. Essentially, we build the highway and provide the trucks. What industry puts in LEO and on the moon is their call. We just make it possible. They use our trucks and our road. Meanwhile, NASA moves on to Mars and other NEOs. Read the VSE document and focus on the vision part, not the LV's.

Quote
Considering the massive restructuring and diversion of funds, I'm pretty sure they've realised how big a shift this is.
I don't think so. Otherwise they wouldn't be spending hundreds of billions on systems that will need to be discarded and replaced in order to sustain the VSE.

Quote
And in case you don't know, almost all nuclear power plants are of the pressurised-water variety, basically "a better steam engine"
The statement was simply comparative. I know what nuclear reactors are ... I design and build them for the US Navy's Nuclear Submarine fleet.
That's what I do for a living.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: lmike on 11/21/2006 05:00 AM
Quote
tom nackid - 20/11/2006  2:02 PM
...
And that reminds me, why do stick opponents just assume that their favorite launch vehicle (be it DIRECT, Stumpy, an EELV or whatever) would sail through development and/or man rating without any "gotchas" of their own? If one did it would be a first for a launch vehicle i think!

I don't know where this adversarial stance came from but...  As far as I'm concerned (an EELV proponent here ;) ) it's not about gotchas, I don't presume a development program free of corrections in mid-course.  It's the entire approach.  NASA's duplication of ELV's "in-house" serves no purpose in implementing strictly the VSE.  *Even* if they resolve the performance issues, and I have no information that they can't, it simply is not worth it.  It's the schedule and the cost, and the logistics of the *entire architecture* that concern me.  God speed to Ares-1, and I'll cheer for it, but I'd like to see more money spent on the Lunar bound payloads rather than on having NASA's "own" rockets.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/21/2006 05:43 AM
Quote
clongton - 20/11/2006  9:06 PM

1. You are assuming that we would still be sending that kind of tonnage to the moon. I am asserting otherwise. I'm speaking of an established presence on the moon which needs consumable resupply, not massive landings. A medium lift LV would take care of that nicely. For the times when more is needed, outfit the LV with the more powerful extensions and lift 175mT to LEO and send to the moon.

Chuck, forgive me for asking (and perhaps I missed where this was covered previosuly during the last week of discussions while I've been sick), but where does that 175mT figure come from?   175mT is actually a long way below the mark when it comes to what DIRECT could do for the same money as Ares requires.   Let me try to clarify it.


The current CLV program fixed costs will be $900 million to operate.   The second LV's costs will be an additional $1.3 Billion to operate yearly - plus another $900 million for the EDS.   On top of that are the flight costs per launch, of $120m and $250m respectively for Ares-I and Ares-V.

That means that NASA operates the Crew launchers anyway, but to launch the first Ares-V every year, they must spend $1.55 Billion on top of the CLV budget.


DIRECT doesn't use a second LV, and it's CLV costs are very similar to Ares-I ($1000m fixed, $140m per flight).   So the $1.3Bn of fixed costs for the second LV is simply deleted from the budget every year.

At a cost of $140 million for each DIRECT flight (whether it is flown with crew, cargo or both), the $1.55 Billion which NASA plans to spend for the first Ares-V every year could instead buy 11 DIRECT launches.

Given that each DIRECT launches a little over 70mT to LEO, that's a net payload total of 770mT - compared to 131mT - all for the same money.


Not to mention the $2Bn of extra infrastructure costs Ares requires over DIRECT, and that is worth 14 DIRECT launches, or 980mT extra in LEO.

Also not mentioning that *every* CLV flight can bring up 50mT of extra payload on every flight.

And that also doesn't take into account that the $20+ Billion of development cash going to build the Ares-V in addition to the CLV development, would pay for 143 DIRECT flights, placing 10 *THOUSAND* tons into orbit - all for the same money than it will cost for the very first Ares-V.

Together that's $23.55 Billion.   168 DIRECT launches.   11,760 tons to LEO.   For the total cost of the first Ares-V.   No wonder NASA rejected it.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 11/21/2006 06:10 AM
Ross, I'd just like to thank you for a very articulate and substantiated proposal for an alternate implementation of the VSE.  It's refreshing to see such extensive research.
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/21/2006 06:14 AM
Quote
kraisee - 20/11/2006  10:26 PM

Quote
clongton - 20/11/2006  9:06 PM

1. You are assuming that we would still be sending that kind of tonnage to the moon. I am asserting otherwise. I'm speaking of an established presence on the moon which needs consumable resupply, not massive landings. A medium lift LV would take care of that nicely. For the times when more is needed, outfit the LV with the more powerful extensions and lift 175mT to LEO and send to the moon.

Chuck, forgive me for asking (and perhaps I missed where this was covered previosuly during the last week of discussions while I've been sick), but where does that 175mT figure come from?

The current CLV program fixed costs will be $900 million to operate.   The second LV's costs will be an additional $1.3 Billion to operate yearly - plus another $900 million for the EDS.   On top of that are the flight costs per launch, of $120m and $250m respectively for Ares-I and Ares-V.

That means that NASA operates the Crew launchers anyway, but to launch the first Ares-V every year, they must spend $1.55 Billion on top of the CLV budget.


DIRECT doesn't use a second LV, and it's CLV costs are very similar to Ares-I ($1000m fixed, $140m per flight).   So the $1.3Bn of fixed costs for the second LV is simply deleted from the budget every year.

At a cost of $140 million for each DIRECT flight (whether it is flown with crew, cargo or both), the $1.55 Billion which NASA plans to spend for the first Ares-V every year could instead buy 11 DIRECT launches.

Given that each DIRECT launches a little over 70mT to LEO, that's a net payload total of 770mT - compared to 131mT - all for the same money.


Not to mention the $2Bn of extra infrastructure costs Ares requires over DIRECT, and that is worth 14 DIRECT launches, or 980mT extra in LEO.

Also not mentioning that *every* CLV flight can bring up 50mT of extra payload on every flight.

And that also doesn't take into account that the $20+ Billion of development cash going to build the Ares-V in addition to the CLV development, would pay for 143 DIRECT flights, placing 10 *THOUSAND* tons into orbit - all for the same money than it will cost for the very first Ares-V.

Ross.

Mo Money Mo Money, It’s just so ridiculous at this point what is it going to take Ross for these guys to get it?  


Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/21/2006 06:17 AM
Quote
SMetch - 21/11/2006  1:57 AM

Mo Money Mo Money, It’s just so ridiculous at this point what is it going to take Ross for these guys to get it?

They never will.

Its impossible to reason with anyone who flatly refuses to listen to anyone elses point of view.   It becomes even more difficult when insults start flying, especially when the opposing argument would appear to be stronger on all counts.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 11/21/2006 07:23 AM
Ross, If I may offer a piece of my humble advice -- don't give up. You've been noticed.  (Sufficient to elicit a strong reply, a marker that hasn't happened before)  I don't particularly agree with your architecture either, but I'm up for convincing and I strongly prefer it to the current ESAS.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 11/21/2006 07:53 AM
Quote
tom nackid - 20/11/2006  2:02 PM

Quote
jongoff - 20/11/2006  3:05 PM

marsavian,
Quote
Horowitz said NASA looked at 10,000 to 20,000 iterations of different designs as part of an intensive Exploration Systems Architecture Study before selecting the crew and cargo launcher concepts the agency unveiled in September 2005.

You'd think while they were doing all of those iterations, they would've discovered inconvenient facts like that the SSME/4-segment SRB version wouldn't work because air-starting an SSME is a dicey proposition.  The fact that they made obvious screw-ups of that magnitude really draw into question the rest of the conclusions they came to.  The fact that they just so happened to find that their prefered "Safe, Simple, Soon" solution was the best of 10-20k iterations is just coincidental of course.

~Jon

I don't see how this was a "screw up". It was just a matter of deciding how to spend the time and money. Everyone knew that an air start SME was going to be a challenge and that even a disposable SME was an expensive piece of hardware. In the end the powers that be (according to what I've read anyway) decided that the 5 segment SRB and a J-2 upper stage was a better investment since the Ares V was going need the 5 segment SRB anyway. The 5 SRB / J-2 upper stage was always on the table from the very beginning of the stick. The air start SME was seen as being more desirable but like losing the methane/lox SM and LM engines sometimes tough choices have to be made.
...

The airstart (single non-sea level start) SSME was indeed a "challenge" as in "okay, where do we begin?"  This was obvious in retrospect.  No need for the 2 (freaking) years and some millions in tax dollars to figure that out!
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/21/2006 11:46 AM
Quote
kraisee - 21/11/2006  12:26 AM


The current CLV program fixed costs will be $900 million to operate.   The second LV's costs will be an additional $1.3 Billion to operate yearly - plus another $900 million for the EDS.   On top of that are the flight costs per launch, of $120m and $250m respectively for Ares-I and Ares-V.

That means that NASA operates the Crew launchers anyway, but to launch the first Ares-V every year, they must spend $1.55 Billion on top of the CLV budget.

Ross,

Do you have detailed brake down of DIRECT costs compared to Ares 1 / Ares V? Your numbers are difficult to believe especially after false rumours and inaccuracies published in your study about Ares 1 performance.
I have problem with money allocated for EDS development for example. In your cost comparison you allocated $6.1 B for both Ares V and DIRECT EDS. But I think that many EDS subsystems must be developed for Ares 1 US already.
Sorry but without proper brake down of these costs it is of no value.

On the other hand I would expect higher investment into Ares launch infrastructure. These investments could be partially returned in lower operating costs compared to current STS launch infrastructure which will be mainly adopted by DIRECT. But again, its black box only.

What about manned flights? Have you already solved launch services for DIRECT with CEV and LSAM? What is the philosophy of this launch?
Ares 1 + CEV + MPL is checked in VAB then transported to the pad and launched in about week. How long would it take to DIRECT? There is an old MPL providing little support and two complex space ships along with crew.
STS spends month or more at the pad with lot of support infrastructure. What about DIRECT? Would it use heavily modified STS philosophy or more modern one?

[/QUOTE]
Title: RE: "DIRECT" Goes Live
Post by: marsavian on 11/21/2006 11:48 AM
Leaving aside cost I wonder if it would it be possible for Ares I/V proponents to inform this thread on what tangible advantages the current approach has over Direct ?
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/21/2006 12:17 PM
Quote
clongton - 20/11/2006  8:06 PM

There have been multiple studies done by organizations, such as the Mars Society, among others, which have asserted that a LV in the 50-100mT range would more than likely be the mainstay LV for normal LEO operations. My remarks are based on those 'assumptions'.

Ares V is for Lunar and Mars operation in minimum numbers of launches. NASA wants to be only costumer for LEO operations.
This is the right path to go. This philosophy has been chosen for future.

Quote
You are assuming that we would still be sending that kind of tonnage to the moon. I am asserting otherwise. I'm speaking of an established presence on the moon which needs consumable resupply, not massive landings.

20t landed moon cargo is not that much. It is about the same as ISS building blocks which proved to be quite small.
Even Ares V is too small for bigger than small Moon base. Another approach should be adopted in decades following the first lunar base.

Quote
You missed the part that round trips would be in vehicles which go back and forth between the earth and the moon, not launched from the earth to the moon. Cargo will normally be transferred in LEO from the LV to the trans-lunar 'truck', whatever form that vehicle ultimately takes. Sending a payload up on an Ares V as the *entire* payload will be *generally* unnecessary by that time.

This is a science fiction at the moment. It doesn’t work even for LEO. Even if it wouldn’t be science fiction it would be always easier to move bigger blocks than small ones.
NASA needs assured access to space beyond LEO. The lesson learned from Apollo, N1, Soyuz and STS is that you need something small and reliable for LEO and something big and simple beyond LEO.
DIRECT (and STS) falls between. It is too big for crew operation at LEO and too small beyond LEO.  
That is why I’ve rejected this idea few years ago. It would be cheaper only in short term. It seems to me that lot of people in NASA understand this.
Title: RE: "DIRECT" Goes Live
Post by: JIS on 11/21/2006 12:34 PM
Quote
marsavian - 21/11/2006  6:31 AM

Leaving aside cost I wonder if it would it be possible for Ares I/V proponents to inform this thread on what tangible advantages the current approach has over Direct ?

Safer operation (Ares 1 is predicted to be safer than DIRECT), Simplier operation (less docking), higher responsibility (one big launch followed by realtivelly simple standartized ARES 1 / Orion) higher flexibility (SINGLE serial Ares V + serial EDS can launch cargo / crew LSAM to Moon, LSAM derived vehicle to asteroids and really BIG cargos to LEO). That's it.

The disadvantages are higher short term costs and longer development of Ares 1 compared to DIRECT. The reason is upgrade of SRB acting as the 1st stage and longer development time of J-2X compared to manrated RS-68 (not the magic one).
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/21/2006 12:38 PM
" higher responsibility " is  meaningless

 "higher flexibility" is debatable

you forgot the following disadvantages:  More expensive overall ( near and long term),  longer delay to first flight and gaps in US manned spaceflight  and non viable CLV
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/21/2006 02:04 PM
Quote
Jim - 21/11/2006  7:21 AM

" higher responsibility " is  meaningless

Simpler and quicker to launch.

Quote
you forgot the following disadvantages:  More expensive overall ( near and long term)

Simpler and safer ISS and Moon missions makes up for big part of future costs.

Quote
Longer delay to first flight and gaps in US manned spaceflight

The past preliminary study (ESAS) estimated that EELV serving as CLV could be launched by 2012 but it was rejected because of other drawbacks. Considering what could happen if there is another failure I would rather choose higher safety and stick to the design which is already in design cycle and gathering momentum.
Changing the basis of design in the middle is not good idea. Every engineer would confirm that.

Quote
and non viable CLV

The question is what is viable CLV.
Sojuz is. Long march is. What about STS? Is STS viable?
Potentially viable CLV is Ares 1.
Much less potential have Ares V and Falcon V. Hopefully I haven't missed any other serious plan. There might be same not so serious plans however.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/21/2006 02:23 PM
Quote
JIS - 21/11/2006  9:47 AM

1.  Simpler and quicker to launch.

2.  Simpler and safer ISS and Moon missions makes up for big part of future costs.

3.  The past preliminary study (ESAS) estimated that EELV serving as CLV could be launched by 2012 but it was rejected because of other drawbacks. Considering what could happen if there is another failure I would rather choose higher safety and stick to the design which is already in design cycle and gathering momentum.
Changing the basis of design in the middle is not good idea. Every engineer would confirm that.


4. Potentially viable CLV is Ares 1.

1.  Not guaranteed

2.  No.  It is a blouted program that wastes money for little addtional return.  The Billions it wastes could be better used elsewhere

3.  It is not too late to stop and the amount of real work done is minimalo.  Safety is debatable

4.   The risks associates the stick proves it is non viable and shows it should have never gone forward.

your flag waving for the stick is sickening and based on misplaced blind faith with little regard to engineering.

The Stick is not an engineering solution.  The safety slant  is facade.  Plain and simple it is a political solutions
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/21/2006 02:50 PM
Quote
kraisee - 20/11/2006  11:00 PM

Quote
SMetch - 21/11/2006  1:57 AM

Mo Money Mo Money, It’s just so ridiculous at this point what is it going to take Ross for these guys to get it?

They never will.

Its impossible to reason with anyone who flatly refuses to listen to anyone elses point of view.   It becomes even more difficult when insults start flying, especially when the opposing argument would appear to be stronger on all counts.

Ross.

The hacking up of the science and aeronautics sides of NASA in order to execute on an inefficient approach is more than enough ammo for the big dogs.  While the President is the Executive the Congress can de-fund NASA programs and expand funding for others.  They also have some influence on who runs NASA.

My concern at this point is that the current management will attempt to “salt the earth” before we can reverse these horrid decisions.  Fortunately with the ongoing SSTS program there is not a lot of money for salt going down the wrong approach.  At this point we’re just giving the Chinese a year to year advantage to the moon.  I can’t think of anything better for the US space program than an Olympic year Apollo 8 shot at the moon by the Chinese/Russians.  It will be 1957 all over again.

You should also not underestimate of the power of good idea pursued over a long duration.  It took LOR almost four years from proposal to internal champion to adoption.

It’s not the big that eat the small it’s the fast that eat the slow.

The important thing at this point is to continue to refine a good concept while NASA effectively wanders in the desert.  Once they emerge an executable plan will be sitting right there for the new Administrator to move on.

I seem to remember a “Planetary Society” paper that only two years ago got us on the present path.  It’s not over until all the money is gone.

Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/21/2006 03:07 PM
Quote
Jim - 21/11/2006  9:06 AM

your flag waving for the stick is sickening and based on misplaced blind faith with little regard to engineering.

The Stick is not an engineering solution.  The safety slant  is facade.  Plain and simple it is a political solutions

What else to say. You have won. I can't resist your engineering arguments.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/21/2006 03:12 PM
Quote
JIS - 21/11/2006  9:50 AM

Quote
Jim - 21/11/2006  9:06 AM

your flag waving for the stick is sickening and based on misplaced blind faith with little regard to engineering.

The Stick is not an engineering solution.  The safety slant  is facade.  Plain and simple it is a political solutions

What else to say. You have won. I can't resist your engineering arguments.

You must be really sickened with everybody and most of all with yourself. You should take some rest not spend too much time on internet.
Title: Re: "DIRECT" Goes Live
Post by: meiza on 11/21/2006 03:15 PM
Surely the LOR change of mind didn't happen through congress but on technical merits...
Title: RE: "DIRECT" Goes Live
Post by: clongton on 11/21/2006 04:31 PM
Quote
JIS - 21/11/2006 8:17 AM

Safer operation (Ares 1 is predicted to be safer than DIRECT)
The safety numbers you refer to are no longer valid. They were based on an Ares I design which no longer exists. That was the 4-segment 1st stage and SSME powered 2nd stage. Both had very long and proven track records. The numbers were unbeatable. However, that vehicle has been replaced with a completely new design which resembles the old one in appearance only. The 5-segment SRB is not an upgrade of the 4-segment – it is a completely new design. Even the propellant formulation is different. The nozzle size is different; the TVC system is completely new, the parachute recovery system is new. Nothing on this vehicle has a track record, and it is therefore a completely new, untried LV. As for safety numbers, NASA has yet to publish any new numbers for this new LV, but they will be *much* lower than the originals. If you follow the same criteria used to establish the originals, the new LOM & LOC numbers will be approximately equal to Directs. And, *if* there is augmented thrust added, they will drop below Directs, *and* several of the EELV options. Bottom line – this is *not* a safer vehicle than Direct.

Quote
Simpler operation (less docking)
Less docking – yes – one less docking maneuver.
Simpler operation – no.
A.   Ares V
1.   Launch main stage & SRB’s
2.   Fire EDS to put EDS & LSAM into a 30 by 100nm orbit
3.   Fire EDS to raise orbit to 60 by 100 nm orbit
4.   Fire EDS to raise orbit to 60 by 160 nm orbit
5.   Fire EDS to circularize orbit to 160 by 160 nm
B.   Ares I
1.   Fire SRB 1st stage
2.   Fire J2-x 2nd stage to put Orion into a -30 by 100 nm *suborbital* trajectory (not even an orbit)
3.   Fire Orion SM to insert Orion into a 60 by 100 nm orbit
4.   Fire Orion SM to raise orbit to a 60 by 160 nm orbit
5.   Fire Orion SM to circularize orbit to 160 by 160 nm orbit

That’s *ten* (10) engine firing events to get Orion plus the LSAM & EDS into a circular 160nm orbit. Notice that Ares has to actually use Orion itself as a 3rd stage, because it cant do the job itsef. The low point of -30 altitude is actually 30 nm *INSIDE* the earth, *below* ground level. That's the best Ares I can do with Orion, and Orion must finish the job itself. Contrast that with Direct

A.   CaLV
1.   Launch main stage & SRB’s
2.   Fire EDS to put EDS into a 60 by 160 nm orbit.
3.   Fire EDS to circularize orbit to 160 by 160 nm
B.   CLV
1.   Launch main stage & SRB’s to put Orion into a 60 by 160 nm orbit
2.   Fire Orion SM to circularize orbit to 160 by 160 nm orbit
   
That’s *five* (5) engine firing events, vs. ten (10) for Ares.
Ares is *not* a simpler vehicle system to operate.

Quote
higher responsibility (one big launch followed by relatively simple standardized ARES 1 / Orion)
Ares: 1 big launch followed by a smaller launch (not simpler: see above)
Direct: 1 big launch followed by a truly simpler launch

You point is?

Quote
higher flexibility (SINGLE serial Ares V + serial EDS can launch cargo / crew LSAM to Moon
Ares I + Ares V are two (2) completely separate LVs, requiring 2 completely separate sets of infrastructure and launch facilities.
Direct is a *single* launch solution which can be configured to the specific launch requirement, and requires only one (1) infrastructure and launch facility.

Ares is *not* more flexible than Direct. It *is* more complex and costly

Quote
LSAM derived vehicle to asteroids and really BIG cargos to LEO)
Ares V lift capacity is 131.5 mT to a 30 by 100 nm orbit.
Direct lift capacity is 137.5 mT to a 60 by 160 nm orbit.
Direct lifts 6 mT *more* than Ares
Also, notice the orbit. Ares 30 by 100 nm orbit is useless and will degrade quickly. It has to be raised rapidly or the orbit will degrade and the mission will be lost. Direct does not suffer from this disastrous condition.

Quote
The disadvantages are higher short term costs and longer development of Ares 1 compared to DIRECT
And higher long term costs than Direct, to the tune of $35 billion dollars over the ESAS projected 25 year budget.

Quote
The reason is upgrade of SRB acting as the 1st stage and longer development time of J-2X compared to man-rated RS-68 (not the magic one)
1. As stated above, the 5-seg SRB is *NOT* an upgrade; it is a *new* LV.
2. I do wish you would stop referring to the regenerative R-68 as a *magic engine*. It is not, as has been pointed out to you time and time and time again, over and over and over again on this forum, by people who are already using its performance numbers in their decision making capacities. It is already developed. The chamber pressures are already rated for it, and it is already in the loop for use on upgraded Deltas. It’s not flying yet only because it’s not in the production loop yet. The hardware is on the test bench and has been tested already. The numbers are real. The engine is real. Please stop demeaning the work of hundreds of design engineers by calling their work “magic”. It's not magic, it's solid engineering and hard work. The only magic going on here is that you make a completely unfounded statement, get corrected by people who actually have their hands on the hardware, and you keep saying the same thing as if no one ever spoke to you. Why is that?
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/21/2006 05:02 PM
Quote
kraisee - 20/11/2006  10:26 PMChuck, forgive me for asking (and perhaps I missed where this was covered previosuly during the last week of discussions while I've been sick), but where does that 175mT figure come from?
OOPS!! That's 1[3]7.5 (137.5mT), not 175. I dropped the "3" and never saw it until you pointed it out.
Thank you.
Chuck
p.s. But that's still 6mT *more* than Ares V.
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/21/2006 05:11 PM
Quote
meiza - 21/11/2006  7:58 AM

Surely the LOR change of mind didn't happen through congress but on technical merits...

Actual it was a technical solution to a political problem.  The 2 man Direct Ascent/Return was the best technical/economic solution.  This approach though favored a derivative of the Gemini capsule which would in turn would have eliminate the need of the three man Apollo capsule and subsequent LM altogether resulting in billions of dollars savings in wasted space hardware on each mission.  Perhaps this switch would have made the Apollo program affordable enough to have saved the Saturn V which in turn would have put us on Mars by now.

Despite what Mike said the best path to the future is not necessarily achieved by re-creating a more efficient past.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/21/2006 05:32 PM
Quote
JIS - 21/11/2006  10:55 AM

Quote
JIS - 21/11/2006  9:50 AM

Quote
Jim - 21/11/2006  9:06 AM

your flag waving for the stick is sickening and based on misplaced blind faith with little regard to engineering.

The Stick is not an engineering solution.  The safety slant  is facade.  Plain and simple it is a political solutions

What else to say. You have won. I can't resist your engineering arguments.

You must be really sickened with everybody and most of all with yourself. You should take some rest not spend too much time on internet.

just you with your "NASA can do nothing wrong" postings
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/21/2006 05:39 PM
Quote
lmike - 21/11/2006  3:06 AM

Ross, If I may offer a piece of my humble advice -- don't give up. You've been noticed.  (Sufficient to elicit a strong reply, a marker that hasn't happened before)  I don't particularly agree with your architecture either, but I'm up for convincing and I strongly prefer it to the current ESAS.

Truth be told LMike, my personal preference would actually be to get rid of the standing army of STS workers and start with a far more 'lean' system.   Of the available options presented to the ESAS, the Atlas Phase-2 to Phase-3 approach is actually the best IMHO.

However, to do that would ignore the political masters wishes to retain work in their states, and they are the ones who allocate budgets to NASA, so without their political support, we won't be going anywhere.   It's just a sad fact of being a government program.

DIRECT does retain that workforce whilst also massively improving the cost:performance ratio to levels which are far more appropriate for a new system.   That's why I believe it could work.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: imcub on 11/21/2006 07:52 PM
Quote
Jim - 21/11/2006  7:06 AM

The Stick is not an engineering solution.  The safety slant  is facade.


Jim,

Would you do me/us a favor and list what you see as the Stick's safety issues.  I am aware that putting the CP in front of the CG might be a problem (but then then F117 shouldn't really fly either).  And I am aware that this is an entirely new system.  What else?

Thanks,

Dave


Title: RE: "DIRECT" Goes Live
Post by: JWag on 11/21/2006 08:29 PM

The stick no longer has much in common with the relatively safe Shuttle RSRMs.  The motor casings (and aft skirt?) are all that are left of the RSRMs.  The addition of a fifth segment, different propellant properties, and new nozzle makes the Ares I first stage a new vehicle  from an engineering point of view.  It has no real link with the RSRMs that have flown for the past ~17 years.

Flying new vehicles is risky.

Ares I started as an appealing concept because it was using RSRMs that were identical to Shuttle SRBs (with obviously new forward skirt and frustum, etc.)  That's no longer true, but it is with DIRECT.

And as Ross has said, the five-segment boosters could still be used with DIRECT eventually, once sufficient confidence had been achieved with the rest of the machine.  The research already done on five-segment boosters wouldn't need to be abandoned.

Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/21/2006 08:54 PM
Quote
JIS - 21/11/2006  7:29 AM

Do you have detailed brake down of DIRECT costs compared to Ares 1 / Ares V?

The numbers come directly from the ESAS Report cost analysis data used in the various trade options (a lot [not all] is based on LV-24/25, with the EDS from LV27.3).   The DIRECT numbers were actually analysed by two of the same guys who put the ESAS costs together in the first place.   Given that it's the same people behind both, I feel it is a fair apples-to-apples analysis.


Quote
I have problem with money allocated for EDS development for example. In your cost comparison you allocated $6.1 B for both Ares V and DIRECT EDS. But I think that many EDS subsystems must be developed for Ares 1 US already.
Sorry but without proper brake down of these costs it is of no value.

The costs for the EDS were taken from the budget analysis provided for the EDS in the ESAS Report.   Table 12.8 (attached below) demonstrates the graphical representation of the costs from the ACI version of the ESAS Report.   We actually used the numbers which were used to make that analysis, sourced from the exact trade studies ESAS also used.

We didn't include them in the DIRECT Proposal because it was already getting pretty long at 33 pages (now 40!), but it's not a secret as far as we're concerned and you're the first person to ask for it!   Here are the annual breakdown numbers from ESAS:

Assuming First Lunar landing in 2018, the costs for DIRECT's EDS is precisely the same as ESAS' LV-27.3 analysis:


2012   2013   2014   2015   2016   2017   2018
0.2    0.8    1.0    1.0    1.2    1.2    0.7



However, because DIRECT saves money from the very first year (mainly by deleting the $4Bn near-term cost for the 5-seg SRB needed for Ares-I), the EDS can be funded two years earlier - thus expedited by two years.   Assuming First Lunar Landing is accelerated to 2016, the cost becomes:


2010   2011   2012   2013   2014   2015   2016
0.2    0.4    0.5    1.4    2.5    2.9    3.0



Quote
On the other hand I would expect higher investment into Ares launch infrastructure. These investments could be partially returned in lower operating costs compared to current STS launch infrastructure which will be mainly adopted by DIRECT. But again, its black box only.

Actually that assumption is the wrong way around.   Let me explain...

DIRECT can take advantage of every single operating cost saving Ares expects to.   There is nothing preventing DIRECT using them all.

However, it can do so without requiring *any* of the new/modified facilities needed to support 5-segment SRB's.

DIRECT can also retain all of the existing tooling and processing faiclities currently handling the 8.4m External Tank.

Ares however, requires all-new facilities to handle the new 5.5m Ares-I US.   PLUS another set of facilities for making and processing the 10.0m Ares-V core tank, and still has to also keep the 8.4m tanking for the EDS.

DIRECT requires very few manufacturing, transportation, checkout, assembly, pad, VAB and MLP modifications in comparison to either the Ares-I or Ares-V - let alone both programs running concurrently.



Infrastructure costs were somewhat detailed in the ACI copy of the ESAS Report at the start of the year (one part - table 12-17 - is attached below as an example).   The numbers which created that analysis are in the trade studies, which have never been made public - and can't be because they are still considered ACI.   Anyone on the "inside" should be able to obtain them, but they can't be published.   They show that the current Ares-I & V configurations will require $3.8 Billion(*) of modifications.   DIRECT requires far fewer modifications, because it reatins the exact same 8.4m tank structure and 4-seg SRB arrangement as Shuttle today.   Just $1.8 Billion worth.

* Note:   The Ares infrastructure figure above was done BEFORE brand-new MLP's for Ares-I or new Crawler Transporters for Ares-V where deemed necessary, so the Ares figure is grossly underestimated.


Quote
What about manned flights? Have you already solved launch services for DIRECT with CEV and LSAM? What is the philosophy of this launch?

I'm a little unsure of your terminology, but from the context, perhaps you are referring to how the various modules (CEV, LSAM, EDS) are to be launched, integrated in orbit, sent to the moon, and then deployed to their target locations?

If so, then yes, there are many solutions.   Please see Appendix 3 "Example Lunar Mission Models" for four examples of different configurations which DIRECT can support.   Analysis results for performance are included.   Any of the options can be utilised depending on the performance:safety ratio desired.   The closest method to Apollo would be example 1, the best possible performance is in example 4.

 
Quote
Ares 1 + CEV + MPL is checked in VAB then transported to the pad and launched in about week. How long would it take to DIRECT?

Somewhere between one and two weeks, given the streamlined process being planned.

As you say, Ares-I is planned to take about a week.   But Ares-V is more like three.   DIRECT would be somewhere in the middle.

Stacking and assembly for STS today would provide a good guide.   This current mission has demonstrated that STS can be done in about 2 weeks.   Being that the attachment of the payload on top does not require the extensive work needed to connect the Orbiter's propellant lines to the ET, I would make an educated guess that a slightly shorter timescale than STS is possible.


Quote
There is an old MPL providing little support and two complex space ships along with crew.

Sorry?   I don't understand the question.

All three MLP's used by Shuttle have recently been completely refurbished and overhauled - during the 4 year downtime after STS-107.   They are virtually like new according to everyone I have spoken to.

They currently support a launch system (Shuttle) which is considerably more complex, which weighs more, and which has mass loads during processing which are far more difficult to handle than DIRECT's.   Engineering analysis has actually been performed on NASA's original concept, which DIRECT is very similar to - and the MLP's are ideally suited to support such a configuration, assuming the relatively moderate change of opening of the extra exhaust chamber between the current SRB chambers.

Does that help answer your Q?


Quote
STS spends month or more at the pad with lot of support infrastructure. What about DIRECT? Would it use heavily modified STS philosophy or more modern one?

DIRECT would process SRB's the same as STS, Ares-I and Ares-V plan to - just with the existing 4-segment versions.

The Core would be processed in the same fashion as ET is today.   Main Propulsion System processing would probably occur more like Delta-IV than STS - which is considerably faster and cheaper.

Payload Processing would not be done in the VAB.   It would be done in the industrial area of KSC.   For example, the "payload" would be integrated into its aero shroud, checked out and then transported sealed and "ready to fly" to the VAB to be stacked on top of the booster, where it will be checked out one more time.   This is exactly the same process arrangement as most other launchers, such as Atlas-V and Delta-IV.

If an Orion CEV is to fly too, the aero shroud for the regular payload would have an attachment ring on top to seat the CEV.   Again, the CEV will be processed fully before delivery to the VAB, and then just be checked out prior to roll-out.

After roll-out, the entire system will be connected to the propellant, electrical, N2 Purge, He, communication feeds as normal.   Then everything will be checked out one more time, and finally the SRB's will all be primed.

Shuttle has to have its payload loaded while out at the Pad.   That is what takes much of that month out there - integrating it all into the payload bay and checking it all out from start to finish at the Pad.   Virtually all that work can be done prior to stacking, with just the double- and triple-checks being required after assembly and rollout.

That basic approach can potentially save an ENORMOUS amount of time both in the VAB and at the Pad, and applies equally to Ares as it does to DIRECT.

Hope that lot helps.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: nathan.moeller on 11/22/2006 03:02 AM
I'm sure this has been discussed but I must ask out of sheer curiosity.  What would be wrong with bringing back the Saturn V as a launch vehicle for Orion/CEV?
Title: Re: "DIRECT" Goes Live
Post by: JWag on 11/22/2006 03:08 AM

Quote
nathan.moeller - 21/11/2006  9:45 PM  I'm sure this has been discussed but I must ask out of sheer curiosity.  What would be wrong with bringing back the Saturn V as a launch vehicle for Orion/CEV?

http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=5378

This would make a good FAQ, as it pops into the head of every space enthusiast at one time or another.

Title: Re: "DIRECT" Goes Live
Post by: imcub on 11/22/2006 03:14 AM
Quote
nathan.moeller - 21/11/2006  7:45 PM

I'm sure this has been discussed but I must ask out of sheer curiosity.  What would be wrong with bringing back the Saturn V as a launch vehicle for Orion/CEV?

Yes, it has been discussed before ...  while the design has been archived, the tooling is gone, the engineers familiar with the design are (mostly) retired, and it would be very, very expensive.  Its going to cost $3 billion to build a 5 segment stick when we know all about the 4 segment SRBs.  Can you imagine how expensive the F1s would be to redesign (from scratch) and re-qualify.   It also seems that someone mentioned that Saturn V wasn't really very efficient ... but I could be wrong on that.  

But yeah ... it would be cool!
Title: Re: "DIRECT" Goes Live
Post by: Avron on 11/22/2006 04:44 AM
Quote
SMetch - 21/11/2006  12:54 PM

Quote
meiza - 21/11/2006  7:58 AM

Surely the LOR change of mind didn't happen through congress but on technical merits...

Actual it was a technical solution to a political problem.  

Not so sure that this is a "technical" solution, in its pure form.. but more "technical" in terms of  re-distribution of wealth so to speak... why do I feel like the current selected options are not supposed to fly... all the inputs for NASA and contractor folks, plus a few reactions from NASA high command (ref NASAwatch).. don't help.
Title: Re: "DIRECT" Goes Live
Post by: MATTBLAK on 11/22/2006 07:09 AM
Quote
nathan.moeller - 22/11/2006  1:45 PM

I'm sure this has been discussed but I must ask out of sheer curiosity.  What would be wrong with bringing back the Saturn V as a launch vehicle for Orion/CEV?

Since Ares V or a 'stretched' Direct can slightly exceed the performance of the Saturn and many components already exist, there would be no point.
Title: RE: "DIRECT" Goes Live
Post by: JIS on 11/22/2006 11:31 AM
Quote
clongton - 21/11/2006  11:14 AM

The safety numbers you refer to are no longer valid. They were based on an Ares I design which no longer exists.

LOC and LOM numbers were evaluated In ESAS for current ARES 1 configuration. LOC is 1 in 1,918.

 
Quote
Simpler operation (less docking)
Less docking – yes – one less docking maneuver.
Simpler operation – no.
A.   Ares V
1.   Launch main stage & SRB’s
2.   Fire EDS to put EDS & LSAM into a 30 by 100nm orbit
3.   Fire EDS to raise orbit to 60 by 100 nm orbit
4.   Fire EDS to raise orbit to 60 by 160 nm orbit
5.   Fire EDS to circularize orbit to 160 by 160 nm
B.   Ares I
1.   Fire SRB 1st stage
2.   Fire J2-x 2nd stage to put Orion into a -30 by 100 nm *suborbital* trajectory (not even an orbit)
3.   Fire Orion SM to insert Orion into a 60 by 100 nm orbit
4.   Fire Orion SM to raise orbit to a 60 by 160 nm orbit
5.   Fire Orion SM to circularize orbit to 160 by 160 nm orbit

I don’t know why you still referring to -30 x 100 nm 51.6 deg injection orbit for Ares V. As I understand this is for ISS flights only. Injection orbit for Moon missions is 80 x 160 nm 28.5 Deg. The mass injected to these two different orbits is exactly the same.
So Ares 1 injects Orion to one of these orbits (depends on mission) and Orion SM burns to go to whatever orbit necessary.
I can’t see many differences between -30 x 100 nm and 80 x 160 nm injection orbits from safety point of view. Both would end up in re-entry.
Orion will have plenty of time to use it’s main engine or RCS backup engines to go to whatever orbit necessary.
There will be some reserve in Ares 1 performance anyway so at the end it could be used for higher injection orbit to spare Orion fuel.

Quote
Notice that Ares has to actually use Orion itself as a 3rd stage, because it cant do the job itsef. The low point of -30 altitude is actually 30 nm *INSIDE* the earth, *below* ground level. That's the best Ares I can do with Orion, and Orion must finish the job itself. Contrast that with Direct.
That’s *five* (5) engine firing events, vs. ten (10) for Ares.
Ares is *not* a simpler vehicle system to operate.
In fact there can’t be no significant difference between Ares 1 and DIRECT injection. The only significant difference is that DIRECT wants to put two complex vehicles to orbit at once (Orion + LSAM) and complicate design of LSAM and EDS by docking requirements which doesn’t exists with ESAS mission.  

Quote
Ares: 1 big launch followed by a smaller launch (not simpler: see above)
Direct: 1 big launch followed by a truly simpler launch

You point is?

Launch of Ares V + EDS + LSAM will be quite complicated. It is possible to expect multiple delays. BUT infrastructure (MPL) will be built for this.

Launch of Ares 1 should be significantly less complicated as Ares 1 + CEV + MPL is completed & checked inside VAB transported to launch pad and launched. There will be minimum operations done at the pad mostly connected with US (two tanks one engine) and Crew.

Launch of Direct with EDS should be doable but Launch of DIRECT with LSAM and CEV will be extremely complicated as it uses current STS MPL and launch philosophy. It includes tanking&preparing of core, tanking&preparing of descend/ascend module of LSAM, preparing CEV for launch and Crew. Much more work will be done at launch pad compared to Ares1/CEV (wiring and checkout between vehicle, old MPL and pad infrastructure which can’t be done inside VAB). It could be more complicated than launching of STS.

The problem is that STS is launched regularly but DIRECT+CEV+LSAM for the moon mission will be rare event. Ares1 + CEV will be just another common flight same as to ISS.

   
Quote
Ares I + Ares V are two (2) completely separate LVs, requiring 2 completely separate sets of infrastructure and launch facilities.
Direct is a *single* launch solution which can be configured to the specific launch requirement, and requires only one (1) infrastructure and launch facility.

Ares is *not* more flexible than Direct. It *is* more complex and costly


STS is even more flexible from this point of view as it can launch people, modules, probes, satellites, perform construction and scientific missions and bring lot of cargo back to Earth.  

Quote
Ares V lift capacity is 131.5 mT to a 30 by 100 nm orbit.
Direct lift capacity is 137.5 mT to a 60 by 160 nm orbit.
Direct lifts 6 mT *more* than Ares
Also, notice the orbit. Ares 30 by 100 nm orbit is useless and will degrade quickly. It has to be raised rapidly or the orbit will degrade and the mission will be lost. Direct does not suffer from this disastrous condition.
I don’t know what will be the real lift capability of Ares V but original ESAS design quote 148.3 mT to 28.5 deg.30 x 160 nm
There is no need to go to whatever different orbit (unlike Ares 1 to ISS).
By the way 30x100 or 60x160 orbits are about the same in how much it takes to re-entry.

Quote
I do wish you would stop referring to the regenerative R-68 as a *magic engine*.

This has simple reason. You can design whatever you want but you have to prove that it works. It is proved by measuring at the test stand. When RS-68 regenerative will be tested on the test stand and it achieves 820 klbf and 435.4 ISP it can be considered real engine. After it is proved reliable at these conditions it would be GREAT success. I hope it will happen because it could be used in Ares V and improve performance significantly or delete cost of changing CORE diameter to 10m. Imagine what payload Ares V could lift with this engine!!!
I believe that this option is closely watched but until this concept is confirmed you can’t build entire VSE philosophy on that assumption. ISP and thrust of an engine is one of the most important parameter in rocket design and you must be absolutely sure that it is right. That is why I call it “magic” as it would be great success to build such engine. However I can be wrong and human rated RS-68 regenerative with “magic” parameters is really easily achievable.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/22/2006 11:40 AM
Quote
nathan.moeller - 21/11/2006  9:45 PM

I'm sure this has been discussed but I must ask out of sheer curiosity.  What would be wrong with bringing back the Saturn V as a launch vehicle for Orion/CEV?

Very good question. I think that answer is "F1 doesn't exist and SRB does"
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/22/2006 11:52 AM
"Launch of Direct with EDS should be doable but Launch of DIRECT with LSAM and CEV will be extremely complicated as it uses current STS MPL and launch philosophy. It includes tanking&preparing of core, tanking&preparing of descend/ascend module of LSAM, preparing CEV for launch and Crew. Much more work will be done at launch pad compared to Ares1/CEV (wiring and checkout between vehicle, old MPL and pad infrastructure which can’t be done inside VAB). It could be more complicated than launching of STS.


Totally wrong.  There is no difference in the MLP's for Direct, ARES I or V wrt "launch philosophy"  The Direct will be just as easy as Ares I.  The wiring and checkout of Direct can and would be done in the VAB

ARES V would have an EDS and LSAM to fuel and checkout.  No different than Direct

This is not a viable issue
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/22/2006 11:56 AM
JIS,

You have too many errors in your post to even bother pointing out,

I am sorry, but you are aren't an expert and your constant "ESAS is the bible and therefore is without flaw" mantra doesn't hold water
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/22/2006 01:27 PM
Quote
Jim - 22/11/2006  6:35 AM

ARES V would have an EDS and LSAM to fuel and checkout.  No different than Direct

This is not a viable issue

You say that:

Ares V (core + EDS + LSAM ) = DIRECT (core+EDS) = DIRECT (core + LSAM + CEV)

Yes, I'm really not an expert.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/22/2006 01:36 PM
I think it is safe to say that no matter what architecture or launch vehicle NASA chose for VSE there would be equal numbers of people grumbling abut how their alternative is better. It happened with:

Mercury--
Put a man on an Atlas ICBM--what are you guys nuts! Just keep working with the rocket planes until you FLY to orbit and leave the "Spam in a can" to the Russkies.

Gemini--
Ejection seats? Fuel cells? Electronics exposed to vacuum? And your going to stick it on a Titan? Do we even need a "Mercury part II in the first place? Why waste time and money? We want to go to the moon!

Apollo--
Some Titans and a few Gemini capsules will get you to the moon sooner and cheaper. LOR? Why not a direct flight? Or EOR--that's much safer.

Skylab--
The whole point was to launch the workshop "wet" so we can figure out how to make space stations from fuel tanks! I know it was designed to be temporary, but you should find a way to keep resupplying it.

STS--
Ok, pretty much nobody was happy with how this turned out! But it was ground breaking and pushed technology to its limits--on a shoestring budget!
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/22/2006 01:37 PM
My point was:

Ares 1 and lunar DIRECT goes from VAB as (neglecting SRBs):

Ares 1 (MPL providing interface between vehicle and infrastructure + US + CEV)
Lunar DIRECT ("clasic" MPL + core + LSAM + CEV)

Operation at launch pad:
Ares 1 (connecting MPL to pad infrastructure, fueling US, crew ingress)
Lunar DIRECT (connecting MPL and DIRECT to pad infrastructure, connecting LSAM + CEV to infrastructure, fueling 2 stages of LSAM, fueling core, crew ingress)

I admit that I know little about this but it shouldn't be big problem for expert like you to explain it.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/22/2006 01:42 PM
Quote
Jim - 22/11/2006  6:39 AM

JIS,

You have too many errors in your post to even bother pointing out,

I am sorry, but you are aren't an expert and your constant "ESAS is the bible and therefore is without flaw" mantra doesn't hold water

If your attitude is common in NASA nobody should be wonder why they don't bother to speak to amateurs.
Title: RE: "DIRECT" Goes Live
Post by: rumble on 11/22/2006 01:51 PM
Quote
JIS - 22/11/2006  6:14 AM

Quote
clongton - 21/11/2006  11:14 AM
I do wish you would stop referring to the regenerative R-68 as a *magic engine*.

This has simple reason. You can design whatever you want but you have to prove that it works. It is proved by measuring at the test stand. When RS-68 regenerative will be tested on the test stand and it achieves 820 klbf and 435.4 ISP it can be considered real engine. After it is proved reliable at these conditions it would be GREAT success. I hope it will happen because it could be used in Ares V and improve performance significantly or delete cost of changing CORE diameter to 10m. Imagine what payload Ares V could lift with this engine!!!
I believe that this option is closely watched but until this concept is confirmed you can’t build entire VSE philosophy on that assumption. ISP and thrust of an engine is one of the most important parameter in rocket design and you must be absolutely sure that it is right. That is why I call it “magic” as it would be great success to build such engine. However I can be wrong and human rated RS-68 regenerative with “magic” parameters is really easily achievable.
JIS,
By your own reasoning, the J-2X is total "magic."  It doesn't even exist yet.  So claims of 275,000 lbf and 448sec isp are irresponsible??  Why should we expect the ARES-I upper stage or the ARES-V EDS to perform as NASA claims?

I disagree.  The people building these engines know the physics behind them as well as what it takes to achieve certain specs.  For example, when P&W Rocketdyne says they can make a J-2X engine with 275,000 lbf thrust and 448sec vacuum isp, I believe them.  Just as much as when P&W Rocketdyne says thay can upgrade the nozzle on the RS-68 and increase the performance to the neighborhood of 820klbf and 435.4 sec isp.  I believe that also.  The RS-68 doesn't already get those numbers because it goes beyond the spec of the ablative nozzle.

Frankly, I tend to put more trust in the RS-68regen numbers than I do the J-2X numbers, because the RS-68 exists, and "regen" is a relatively simple upgrade.  The J-2X doesn't exist yet, much less the 294,000 lbf version Danny Davis was hoping for to power the Ares-I upper stage.

Either equally call everything magic, or give it a rest.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/22/2006 01:52 PM
Ross, thank you for your explanation about costs. I have some comments, I'll put it in here soon as I have to design some piece of real equipment meanwhile.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/22/2006 02:29 PM
Improvements of RS-68 to RS-68 regenerative:
thrust from 745 to 820 klbf (by 10.1%)
ISP from 410 to 435.4 s (by 6.2%)

Improvements of J-2S to J-2S+ (according to ESAS):
thrust from 256 to 274.5 klbf (by 7.2%)
ISP from 436 to 451 s (by 3.4%)

I think that it is generally more difficult to increase ISP than thrust. In case of J-2S it is done simply by higher expansion nozzle. But I agree that both engine upgrades are somewhat in "magic" region. It is therefore appropriate to apply some margins.
In case of DIRECT+EDS we have even three engines in "magic" region. (Ooops did I write "magic" again?)
NO, don't take me serious. I was just wonder why NASA easily accepts upgrade of one key ESAS engine and overlooks upgrade of another key engine.
Maybe the only reason is that upgrade of RS-68 is not necessary for VSE at the moment. May be not.
Title: Re: "DIRECT" Goes Live
Post by: nathan.moeller on 11/22/2006 02:38 PM
Quote
JIS - 22/11/2006  6:23 AM

Very good question. I think that answer is "F1 doesn't exist and SRB does"

Short and sweet!  Wasn't too sure what had been done with all the old hardware...as the F1 was developed and built over 20 years before I was even born ;) Here's to open minds! *holds up a Chocolate Milk Chug* Cheers folks!
Title: Re: "DIRECT" Goes Live
Post by: texas_space on 11/22/2006 02:42 PM
Hi all...new here.

The cost argument hits the issue right on the head.  The Ares-1/Ares-5 launch architecture CAN be made to work from a technical standpoint.  However, the cost issue is the real deal killer.  NASA's budget will not increase significantly in the future, so we need a solution (DIRECT or otherwise) that can get the job done and be cost-effective.  As far as convincing people, make sure to write your senators and member of congress about this issue.  Congress is the ultimate authority on what gets done, not NASA.
Title: Re: "DIRECT" Goes Live
Post by: nathan.moeller on 11/22/2006 02:48 PM
Welcome to the site James.  Be careful it's been hot in here!! :) Yeah budget is definitely going to be a huge driving factor.  It's why a lot of people from Boeing/Lockheed Martin aren't happy over the Ares program period.  They feel they could man-rate a Delta or an Atlas sooner and at a substantially lower cost (ask Kayla).  Not only will Congress be a big driver here but NASA politics are going to have a huge affect here as well on whether they decide to stick (okay, pun intended) with a NASA-only human vehicle or have an open mind to a man-rated Atlas or Delta.  We're pretty sure they're going to go ahead with Ares I/V but of course all this is years away.  Not to imply it doesn't matter now but this is where we are.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/22/2006 02:58 PM
Quote
JIS - 22/11/2006  3:12 PM
I agree that both engine upgrades are somewhat in "magic" region.

This may be somewhat pedantic but who are you 'agreeing' with? Nobody other than yourself considers these engine upgrades to be 'magic'.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/22/2006 03:15 PM
Rumble (Posted 22/11/2006 8:34 AM (#86545 - in reply to #86521)) said that J-2X is even more "magic" than RS-68 regenerative. I was reffering to his post.
I said before that ISP for RS-68 regenerative looks somewhat "magic" to me as only change really affecting ISP is higher chamber pressure.
I'm not an expert so I have to believe my bible (ESAS) or some oficial source.
As I don't know about any oficial source I'm carfull to accept that. Sorry about that. If I'm inconsistent just tell me.
Title: Re: "DIRECT" Goes Live
Post by: simcosmos on 11/22/2006 03:49 PM
I'm not an expert in the field either so please someone correct me if writing nonsense, ok?

J-2S+ (J-2X or any other designation), Vulcain 1/2 (from Ariane), RS-68, RS-68R are more or less all in the same "boat".

For J-2 derived engines information please see:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=3124&start=1
(in particular, check J-2S evolution table info table somewhere in one of the pages at http://www.aiaa-houston.org/newsletter/jan06/jan06.pdf )

For a comparison between Vulcain 1 / 2:
http://www.spacenews.be/dossiers/Ariane_5/le_moteur_vulcain_1.html
http://www.spacenews.be/dossiers/Ariane_5/le_moteur_vulcain_2.html
http://www.spacenews.be/dossiers/Ariane_5/comparaison_du_vulcain.html

As I understand it, the RS-68 to RS-68R upgrade passes by implementing the regenerative nozzle, perhaps extending it a little plus other tweaks like in Vulcain, the ones planned to J-2X, etc, but having in mind that the current RS-68 seems already to have been conceived with such upgrade path in mind.

Just as reference, the ISP for some engines (haven't confirmed, these are from memory):
J-2 ~426s
J-2S ~436s
(J-2X ~448s to 450s, 453s max)
Vulcain I ~431s
Vulcain II ~434s
RS-68 ~410s
(RS-68R ~435s)

If remembering well, J-2S and Vulcain are +/- similar in terms of thrust / ISP

RS-68 is a first stage engine (but with + thrust, etc) but of the same type of +/- the previous ones (gas generator)

António
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/22/2006 03:53 PM
Quote
JIS - 22/11/2006  9:20 AM

My point was:

Ares 1 and lunar DIRECT goes from VAB as (neglecting SRBs):

Ares 1 (MPL providing interface between vehicle and infrastructure + US + CEV)
Lunar DIRECT ("clasic" MPL + core + LSAM + CEV)

Operation at launch pad:
Ares 1 (connecting MPL to pad infrastructure, fueling US, crew ingress)
Lunar DIRECT (connecting MPL and DIRECT to pad infrastructure, connecting LSAM + CEV to infrastructure, fueling 2 stages of LSAM, fueling core, crew ingress)

I admit that I know little about this but it shouldn't be big problem for expert like you to explain it.

Both are the same.  Both use modified MLP's .  Ross "preferences" for an umbilical tower vs LUT still means that all the connections of the DIRECT and spacecraft are through the MLP.  There are only MLP to pad connections for DIRECT also.  Crew access would be from the pad and that is not a big deal.  But if NASA were to go with Direct, they would probably have a LUT.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/22/2006 03:56 PM
Quote
JIS - 22/11/2006  9:10 AM

Quote
Jim - 22/11/2006  6:35 AM

ARES V would have an EDS and LSAM to fuel and checkout.  No different than Direct

This is not a viable issue

You say that:

Ares V (core + EDS + LSAM ) = DIRECT (core+EDS) = DIRECT (core + LSAM + CEV)

Yes, I'm really not an expert.


Ares V (core + EDS + LSAM ) + ARES I (Core and CEV) = DIRECT (core+EDS) + DIRECT (core + LSAM + CEV)
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/22/2006 03:57 PM
Quote
JIS - 22/11/2006  9:25 AM

Quote
Jim - 22/11/2006  6:39 AM

JIS,

You have too many errors in your post to even bother pointing out,

I am sorry, but you are aren't an expert and your constant "ESAS is the bible and therefore is without flaw" mantra doesn't hold water

If your attitude is common in NASA nobody should be wonder why they don't bother to speak to amateurs.

My post count of  over 5000 show my willing to converse to all
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/22/2006 04:44 PM
Quote
JIS - 22/11/2006  10:12 AM

Improvements of RS-68 to RS-68 regenerative:
thrust from 745 to 820 klbf (by 10.1%)
ISP from 410 to 435.4 s (by 6.2%)

Improvements of J-2S to J-2S+ (according to ESAS):
thrust from 256 to 274.5 klbf (by 7.2%)
ISP from 436 to 451 s (by 3.4%)

I think that it is generally more difficult to increase ISP than thrust. In case of J-2S it is done simply by higher expansion nozzle. But I agree that both engine upgrades are somewhat in "magic" region. It is therefore appropriate to apply some margins.
In case of DIRECT+EDS we have even three engines in "magic" region. (Ooops did I write "magic" again?)
NO, don't take me serious. I was just wonder why NASA easily accepts upgrade of one key ESAS engine and overlooks upgrade of another key engine.
Maybe the only reason is that upgrade of RS-68 is not necessary for VSE at the moment. May be not.

JIS,
   However, remember that the J-2S (and J-2 before it) was *already* a regeneratively cooled engine, so it was starting from a higher general spec in the first place.

   Changing from regen to different regen will not produce anywhere near as large an improvement as from ablative to regen.

   435s Isp from the RS-68 is what the engine was originally designed to do, but was 'tuned down' when the cheaper ablative nozzle was selected for the very competative Delta-IV market.   The performance increase simply isn't all that great in that application because the first stage does not fly all the way to orbit.   For a booster where the Isp increase is used throughout the entire flight, it can make a bigger difference to ultimate payload performance.


   Overall the performance increase comes from an optimized nozzle for vacuum operations, not atmospheric, and regen cooling allowing the powerpack to operate at higher levels.   This allows the engine to be operated 'normally' again, which with the Regen engine would produce 774,000klbf.   Rocketdyne believe that, like the SSME, the unit can actually be operated above it's 100% mission power rating though - 106% is the guaranteed expectation (one they are 100% confident in), 109% (probably) or 111% may be possible, although less likely.   820,000klbf/435s is equivalent to the 273,500klbf/448s quote for the J-2X - it is what they are totally confident of and might be able to still improve on.


   Magic?   Doesn't bother me all.   Grinding?   Nah, that's not my teeth grinding! :)


   NASA can look at the RS-68 Regen for any other LOX/LH2 booster.   It would offer performance benefits to the Delta-IV and Ares-V alike.   However the 'trick' is in funding.   DIRECT can afford to spend the extra $1 Billion to develop the Regen engine because it saves $35 Billion elsewhere.   Ares-V already costs about $20 Billion.   The question is going to be whether that $1 Billion on top of that substantial cost, in return for ~10mT extra performance, will be all that worthwhile?   While I don't speak for NASA, I'm not sure it is a worthwhile cost in that particular application.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/22/2006 05:35 PM
Quote
JIS - 22/11/2006  4:14 AM

Quote
clongton - 21/11/2006  11:14 AM

The safety numbers you refer to are no longer valid. They were based on an Ares I design which no longer exists.

LOC and LOM numbers were evaluated In ESAS for current ARES 1 configuration. LOC is 1 in 1,918.

JIS

I went back to the ESAS just to double check and the numbers you quoted above are for the 4-segment/SSME configuration of the Ares I.

I do not see any LOC/LOM numbers for the 5-segment/J-2X configuration. Surely you are not claiming that the LOC/LOM numbers would remain unchanged when the SRB is in a never flown configuration and the J-2X is a brand new engine?
Title: Re: "DIRECT" Goes Live
Post by: Flightstar on 11/22/2006 06:20 PM
Well the acquisition of the major Ares I overview and risk documents on the L2 section here, showing performance, among other things, to be "red risks" are not a portrayal of what Constellation have publically said about those same specifics. I wonder where we're all heading with this?
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/22/2006 11:44 PM
JIS,
Quote
I said before that ISP for RS-68 regenerative looks somewhat "magic" to me as only change really affecting ISP is higher chamber pressure.

I'm sorry that I completely forgot this during my initial post, but Ross reminded me of one additional area of Isp increase (that probably accounts of most of it):

For booster engines, you're exhausting into an atmosphere at the start of your firing.  If you expand the gasses too far, the nozzle outlet pressure can actually be less than the ambient pressure.   That's called overexpansion.  If you take the nozzle outlet area multiplied by the difference in the pressures, the resulting force can often be quite significant.  If you go too far below ambient (somewhere around 30% or so of ambient), the gas flow in the nozzle will actually separate, and if it doesn't separate cleanly, it can damage the nozzle and create violent thrust oscillations.  So for booster engines, you can only have so much of an expansion ratio for a given engine pressure.  But if a regen nozzle allows you to run the engine at a higher pressure, that means you can up the expansion ratio of the nozzle a bit more, and that little increase can make a *huge* difference for space rated vehicles.

Just a quick alt.space example.  Armadillo Aerospace uses similar propellants to us (they use Methanol with their LOX while we use Isopropyl Alcohol).  But their chamber pressure is about 200-300psi, while ours is 500psi.  Ours has a much bigger expansion ratio than theirs (they have a 2:1, we have greater than 5:1).  The end result is that their Isp is in the 180-210s range, while ours is in the 230-250s range.  If we kept our expansion ratio to 2:1 like theirs, we would still have a little better performance (IPA is slightly more energetic than Methanol, and our engines have better performance, and our engines don't have to film cool, etc), but nowhere near as big a difference as you see in practice because of our larger expansion ratio.

So, if you up the pressure by a couple percent, you can also up the expansion ratio by a couple percent, and between the two of them it makes a big deal Isp-wise.

Sorry I completely forgot about this effect when discussing stuff earlier.

~Jon
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/23/2006 01:25 AM
Quote
Norm Hartnett - 22/11/2006  1:18 PM

I went back to the ESAS just to double check and the numbers you quoted above are for the 4-segment/SSME configuration of the Ares I.

I do not see any LOC/LOM numbers for the 5-segment/J-2X configuration. Surely you are not claiming that the LOC/LOM numbers would remain unchanged when the SRB is in a never flown configuration and the J-2X is a brand new engine?

Actually, JIS is correct in saying that 1 in 1918 Loss of Crew (LOC) is for the ESAS-spec 5-seg/J-2X derivative.

The ESAS recommended 4-seg/SSME version of the Stick was actually 1 in 2021 LOC.   I've reproduced the ESAS Report table below.

However - the ESAS variant did not consider the roll-control problems inherent in a single-engined SRB first stage configuration, nor the addition of two ground-lit GEM-60 Solids being required to fix the roll control and slow TVC concerns, nor the three burns of the Service Module to achieve its final orbit.

I have seen with my own eyes a NASA document showing the current Ares-I configuration has an LOC figure dropped down to just 1 in 940.


As an aside:   Did anybody else notice that the LV-27.3 CaLV had no published LOC numbers at all, while all of it's rivals showed theirs?   Do you think that was a simple oversight, or a deliberately removed piece of data because the numbers were very poor?   You decide for yourself.   I've been lucky enough to see the actual trades ;)

Ross.
Title: RE: "DIRECT" Goes Live
Post by: JIS on 11/23/2006 08:59 AM
Quote
kraisee - 22/11/2006  8:08 PM

However - the ESAS variant did not consider the roll-control problems inherent in a single-engined SRB first stage configuration, nor the addition of two ground-lit GEM-60 Solids being required to fix the roll control and slow TVC concerns, nor the three burns of the Service Module to achieve its final orbit.

I have seen with my own eyes a NASA document showing the current Ares-I configuration has an LOC figure dropped down to just 1 in 940.

Ross.

Roll-control really adds to safety numbers. I'm wonder what torgues could be there. Most likely the failure of roll controll would mean lost of mission as with any other flight. Fortunatelly it shouldn't be catastrophic failure.

xxxx

These additional strap on solids seems to me as nonsense. It would ruin safety and economics adding very little value. I think it was one of many case studies rejected along the first evaluation.

xxxx

I don't know how many burns are necassary for CEV to get to final orbit but I think that this is not big issue. STS OMS does many burns as well and nobody cares much. Last STS launch OMS were burn even before ET separation to help SSMEs. I'm not sure if firing OMS 5 times per mission or 6 times per mission makes big difference. Especially when it is more about length of burns in this case.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/23/2006 09:22 AM
Quote
jongoff - 22/11/2006  6:27 PM

JIS,
Quote
I said before that ISP for RS-68 regenerative looks somewhat "magic" to me as only change really affecting ISP is higher chamber pressure.

I'm sorry that I completely forgot this during my initial post, but Ross reminded me of one additional area of Isp increase (that probably accounts of most of it):

......................

So, if you up the pressure by a couple percent, you can also up the expansion ratio by a couple percent, and between the two of them it makes a big deal Isp-wise.

Sorry I completely forgot about this effect when discussing stuff earlier.

~Jon

Yes, that is what I was talking about. It is possible to increase expansion ratio and get higher ISP and higher thrust. The "magic" part is amount of this increase. Ross convinced me that it is possible to increase parameters of RS-68. I'm still not convinced that it could be "magic" 6.2% ISP increase.
I take it as Ross' assumption based on preliminary vendor data. Or maybe its unofficial vendor estimation based on preliminary data?
In case of J-2 it is 3.4% ISP increase based on official vendor estimation.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/23/2006 09:45 AM
Quote
simcosmos - 22/11/2006  10:32 AM

Just as reference, the ISP for some engines (haven't confirmed, these are from memory):
J-2 ~426s
J-2S ~436s
(J-2X ~448s to 450s, 453s max)
Vulcain I ~431s
Vulcain II ~434s
RS-68 ~410s
(RS-68R ~435s)

If remembering well, J-2S and Vulcain are similar in terms of thrust / ISP / job

RS-68 is a first stage engine (bigger, more thrust, etc) but of the same type of +/- the previous ones (gas generator)

António

This is actually quite good reference.

Vulcain has chamber pressure 100 bar which is similar to RS-68 (97 bar).
Increasing chamber pressure of Vulcain to 115 bar and ducting gas back to nozzle they were able to increase ISP by 3 (three) s. The chamber pressure was increased by 15% and thrust by 26%.
The main difference between Vulcain and RS-68 is in thrust and nozzle area ratio (which is 45 for vulcain and 21.5 for RS-68). I don't know what is the nozzle area ratio for Vulcain 2 but it seems to me that RS-68 would need to increase nozzle ratio massivelly to increase ISP.
This would be exactly the same approach adopted by J-2 engine upgrade.
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/23/2006 09:54 AM
JIS,
Quote
Yes, that is what I was talking about. It is possible to increase expansion ratio and get higher ISP and higher thrust. The "magic" part is amount of this increase. Ross convinced me that it is possible to increase parameters of RS-68. I'm still not convinced that it could be "magic" 6.2% ISP increase.
I take it as Ross' assumption based on preliminary vendor data. Or maybe its unofficial vendor estimation based on preliminary data?
In case of J-2 it is 3.4% ISP increase based on official vendor estimation.

Well, I ran a preliminary calculation or two on a simple online Isp calculator: http://rocketworkbench.sourceforge.net/equil.phtml

And I had to increae the pressure by quite a bit to get the increase in performance from pressure gain/expansion ratio lengthening alone.  The vacuum Isp number for the RS-68 from Mark Wade's site came out to about 100% of the frozen vacuum Isp number (the real maximum theoretical Isp number is usually a bit higher than the frozen, but a bit lower than the shifting).  But there are a lot of assumptions that went into my analysis.  

-I don't know what the mixture ratio the current RS-68 uses, and what the Regen uses.  The current RS-68 may well have to use a lot of hydrogen as film coolant.  Hydrogen doesn't cost as much for film cooling as Kerosene does, but it can add up.
-I didn't account for heat input from the combustion chamber into the propellants, which can make a decent difference, sometimes as much as 1-2%.
-Ross also mentioned that the engine was optimized more towards upper stage use.  The current RS-68 according to my calculations has an outlet pressure of about 0.4 atm.  You can often push designs down to 0.3 atm or so before you get flow separation at sea level.  The original RS-68 was designed as an engine that had to operate in some cases without solids from sea level to space, so it was biased more toward sea level.  But with Direct you're using solids for most of the thrust at low altitude, so you can push the outlet pressure down toward the flow separation point which is around 0.3 atm, and just accept a really crappy thrust level on takeoff in exchange for a much higher mission-averaged-Isp.  Going from 0.407 to 0.3 atm at nozzle outlet upped the performance by 1.5% by itself.
-There may have been other detuning in the injectors or things like that to eliminate hot streaks on the walls (which regen engines are far less sensitive to than ablative engines) that when retuned might give back a bit of performance....

Basically, while I can't prove that the upgrade Ross is talking about is doable, there at least appears to be enough potential factors in play that it doesn't appear ludicrase.

Of course, I might be able to get some more direct info on the topic.  My coworker's father-in-law was involved in the RS-68 project, so maybe he could vouch for if those numbers are reasonable or not.  I'm not sure if he can actually discuss that sort of information (and I don't know him personally), but I might be able to independently verify Ross's claims.

I won't be seeing Pierce till next Monday, but if your curiousity can wait, I'll ask him then and see if I can get any info.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/23/2006 11:11 AM
Thanks for info.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/23/2006 11:19 AM
Quote
kraisee - 21/11/2006  3:37 PM

Assuming First Lunar landing in 2018, the costs for DIRECT's EDS is precisely the same as ESAS' LV-27.3 analysis:


2012   2013   2014   2015   2016   2017   2018
0.2    0.8    1.0    1.0    1.2    1.2    0.7



However, because DIRECT saves money from the very first year (mainly by deleting the $4Bn near-term cost for the 5-seg SRB needed for Ares-I), the EDS can be funded two years earlier - thus expedited by two years.   Assuming First Lunar Landing is accelerated to 2016, the cost becomes:


2010   2011   2012   2013   2014   2015   2016
0.2    0.4    0.5    1.4    2.5    2.9    3.0


OK but the point is that under current scheme the J-2X engine is developed for Ares 1 already (instead of air started SSME).
Actually all your numbers are referring to original ESAS design. NASA claims that current design spares lot of money (billions). If we believe ESAS should we believe this new claim?  

Quote

* Note:   The Ares infrastructure figure above was done BEFORE brand-new MLP's for Ares-I or new Crawler Transporters for Ares-V where deemed necessary, so the Ares figure is grossly underestimated.


Yes, that’s what I’m saying. Infrastructure cost of Ares 1 / Ares V seems to be under estimated for current design. You are comparing some black box DIRECT numbers with numbers for old ESAS vehicles.

Quote
As you say, Ares-I is planned to take about a week. But Ares-V is more like three.   DIRECT would be somewhere in the middle.

Wouldn’t be big difference between DIRECT with EDS and DIRECT with CEV +LSAM? I was worried that the more difficult launch comes after the easier one. This complicates the Lunar mission and even common ISS mission.
When I look at Ares V + EDS + LSAM I think it could take about the same time to launch as Direct + CEV+ LSAM. Maybe even less. That was my point.

Quote

Does that help answer your Q?

Thank you for your A.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/23/2006 11:35 AM
Quote
Jim - 22/11/2006  10:36 AM

Quote
JIS - 22/11/2006  9:20 AM

My point was:

Ares 1 and lunar DIRECT goes from VAB as (neglecting SRBs):

Ares 1 (MPL providing interface between vehicle and infrastructure + US + CEV)
Lunar DIRECT ("clasic" MPL + core + LSAM + CEV)

Operation at launch pad:
Ares 1 (connecting MPL to pad infrastructure, fueling US, crew ingress)
Lunar DIRECT (connecting MPL and DIRECT to pad infrastructure, connecting LSAM + CEV to infrastructure, fueling 2 stages of LSAM, fueling core, crew ingress)

I admit that I know little about this but it shouldn't be big problem for expert like you to explain it.

Both are the same.  Both use modified MLP's .  Ross "preferences" for an umbilical tower vs LUT still means that all the connections of the DIRECT and spacecraft are through the MLP.  There are only MLP to pad connections for DIRECT also.  Crew access would be from the pad and that is not a big deal.  But if NASA were to go with Direct, they would probably have a LUT.

Thanks for explanation I forgot that Ross puts new LUT on MPL. It is probably doable. Does Ross want to have universal LUT for both DIRECT + EDS and DIRECT + LSAM + CEV? What about inter MPL pipework/umbilicals for LUT? Is it possible to use anythink from STS or will it be completelly rerouted?
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/23/2006 07:10 PM
Quote
JIS - 23/11/2006  7:18 AM
Thanks for explanation I forgot that Ross puts new LUT on MPL. It is probably doable. Does Ross want to have universal LUT for both DIRECT + EDS and DIRECT + LSAM + CEV? What about inter MPL pipework/umbilicals for LUT? Is it possible to use anythink from STS or will it be completelly rerouted?

JIS,
Got a few minutes here before I go to a Thanksgiving celebration with friends, so I thought I'd show these:



and



Being that the Core tank is very similar capacity to the current ET, many of the current STS connections (propellant and electrical) could be re-used.   The EDS would probably require extra connections though, because the LOX & LH2 feeds are much lower capacity.

There are other possible alternatives too.   One alternative which has been proposed to maybe route the main lines up the FSS, to heat exchangers located up there (much closer to the rocket, which is a good thing), and then across to the MLP's "Minimal LUT" above the main deck.

The final decision would come down to detailed analysis of the pros and cons - which has not been completed yet.   The key decider would be the "balance" between cost of implementation vs. the time it requires to hook everything up and check it out after roll-out.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/23/2006 07:30 PM
Quote
JIS - 23/11/2006  7:02 AM

OK but the point is that under current scheme the J-2X engine is developed for Ares 1 already (instead of air started SSME).
Actually all your numbers are referring to original ESAS design. NASA claims that current design spares lot of money (billions). If we believe ESAS should we believe this new claim?

The ESAS numbers have been published by NASA, so they are the only ones which the public can actually compare to.   The real numbers have changed somewhat.   The 5-seg SRB and J-2X development moved to Ares-I, two new MLP's for Ares-I have impacted near-term development costs very badly.   Changing to 10.0m diameter core, requiring extensive changes everywhere, plus the realization of needing two brand-new Crawlers for Ares-V have increased long-term costs too, although RS-68 has reduced flight costs a bit compared to SSME version.

On balance though the "improvements" since ESAS are massively overrun by the vast increases caused by some of the changes.   All infrastructure costs have increased - costing billions extra.   Ares-I flight costs have increased with the switch to 5-seg and J-2X.   Ares-V flight costs have reduced only by about $50-75m per year.    It doesn't take much to work out how many years that saving will take to recoup the infrastructure cost increases totalling about $1.8 Billion above ESAS estimates.   I make it about 24 years!

But DIRECT's greatest bebnefit is the deletion of the $14 Billion for the second vehicle.   That would take about 185 years to pay back, and I don't think these systems will be flying anywhere near that long...


Quote

Wouldn’t be big difference between DIRECT with EDS and DIRECT with CEV +LSAM? I was worried that the more difficult launch comes after the easier one. This complicates the Lunar mission and even common ISS mission.
When I look at Ares V + EDS + LSAM I think it could take about the same time to launch as Direct + CEV+ LSAM. Maybe even less. That was my point.


Stacking a CEV alone for ISS missions would take no longer than placing the CEV on top of Ares-I, so ISS missions aren't really affected.

For lunar missions, stacking the LSAM and CEV on a Core-only vehicle has been assessed to take about 2 weeks.   Without the LSAM on top, stacking just the EDS would take far less time than stacking the Ares-V.

So we're talking about two flights taking about 4 work weeks to process.   That's the same as Ares-I (1 week) and Ares-V (three weeks).

It just balances out in a different way :)

Ross.

Happy TG, gotta run.
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/23/2006 07:38 PM
JIS,
Quote
OK but the point is that under current scheme the J-2X engine is developed for Ares 1 already (instead of air started SSME).

An important point to remember is that EDS work doesn't start for several years, and there are already other alternatives to a J-2X powered EDS that actually look a lot better already.  IOW, if for some reason the Shaft went away next month, it wouldn't necessarily impede the development of a good EDS one bit.  Using a 6 RL-10 ICES/WBC stage like what Lockheed is working on would actually be a lot better.  Better mass ratio, engine-out reliability (which probably drops the LOM numbers a lot), and the design would be field tested on dozens of Atlas V launches before ever being used for lunar missions.

So the whole "we need 5-segment SRB and J-2X anyway" argument is a little thin.  We really don't, unless people think that the ESAS way is the only way.  It isn't.

~Jonathan Goff
Title: RE: "DIRECT" Goes Live
Post by: clongton on 11/23/2006 08:09 PM
Quote
JIS - 23/11/2006  4:42 AM
I don't know how many burns are necassary for CEV to get to final orbit but I think that this is not big issue. STS OMS does many burns as well and nobody cares much. Last STS launch OMS were burn even before ET separation to help SSMEs. I'm not sure if firing OMS 5 times per mission or 6 times per mission makes big difference. Especially when it is more about length of burns in this case.
There is a major difference here which you are overlooking: In an STS flight, the SSME/ET is perfectly capable of inserting the shuttle into orbit by itself. But the engines are shut down with fuel still in the tank, for two reasons:

1. To prevent the ET itself from going into orbit. The engines are shut down, the ET is jetisoned while still suborbital, and orbital insertion is completed with an OMS burn, leaving the ET to drop into the sea.
2. To prevent the SSME's from "running out of gas", so to speak, because that would cause big problems with the engines.

The main thing to remember is that while the SSME/ET is completely capable of putting the shuttle into orbit by itself, the Ares I *IS NOT CAPABLE* of doing this for Orion. Therefore, Orion must do the job itself. That increases demand and performance pressures on Orion and its Service Module, which it was not supposed to have to deal with. The performance capabilities of the Orion spacecraft suffers because of this.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/24/2006 12:00 AM
Quote
jongoff - 23/11/2006  9:21 PM
Using a 6 RL-10 ICES/WBC stage like what Lockheed is working on would actually be a lot better.  Better mass ratio, engine-out reliability (which probably drops the LOM numbers a lot), and the design would be field tested on dozens of Atlas V launches before ever being used for lunar missions.

What gives the low limit for the EDS thrust/mass ratio?
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/24/2006 12:27 AM
Magnus,
Quote
What gives the low limit for the EDS thrust/mass ratio?

I'm not sure I understand the question.

~Jon
Title: RE: "DIRECT" Goes Live
Post by: JIS on 11/24/2006 08:57 AM
Quote
clongton - 23/11/2006  2:52 PM

Quote
JIS - 23/11/2006  4:42 AM
I don't know how many burns are necassary for CEV to get to final orbit but I think that this is not big issue. STS OMS does many burns as well and nobody cares much. Last STS launch OMS were burn even before ET separation to help SSMEs. I'm not sure if firing OMS 5 times per mission or 6 times per mission makes big difference. Especially when it is more about length of burns in this case.
There is a major difference here which you are overlooking: In an STS flight, the SSME/ET is perfectly capable of inserting the shuttle into orbit by itself. But the engines are shut down with fuel still in the tank, for two reasons:

1. To prevent the ET itself from going into orbit. The engines are shut down, the ET is jetisoned while still suborbital, and orbital insertion is completed with an OMS burn, leaving the ET to drop into the sea.
2. To prevent the SSME's from "running out of gas", so to speak, because that would cause big problems with the engines.

This is not relevant to discussed issue. I was reacting to claims that -30x100 or 80x160 orbits impact substantially the safety.
There is no difference. If you have surface infrastructure to support emergency reentry it makes no difference.
OMS would simply burn longer to get whatever vehicle to whatever orbit.    

Quote
The main thing to remember is that while the SSME/ET is completely capable of putting the shuttle into orbit by itself, the Ares I *IS NOT CAPABLE* of doing this for Orion. Therefore, Orion must do the job itself. That increases demand and performance pressures on Orion and its Service Module, which it was not supposed to have to deal with. The performance capabilities of the Orion spacecraft suffers because of this.

Not relevant again. Last STS flight OMS had to burn suborbitally (along with SSMEs) to get Shuttle to injection orbit. Whithout that OMS burn Shuttle would have to abort mission.
Ares 1 is designed primarily to get Orion to injection orbit 28.5 deg 80x160 nm for lunar mission.
This is equivalent to 51.6 deg -30x100nm for ISS mission. This is of no problem for Orion because it is heavily overdesigned for ISS mission.
I think that at the and there will be enough margin to theoretically get Ares 1 US to orbit too but there is no reason whatsoever to design Ares 1 for this. STS is not designed for this option neither. Actually STS can't make orbit with ET and do any usefull mission.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/24/2006 09:17 AM
Quote
jongoff - 23/11/2006  2:21 PM

JIS,
Quote
OK but the point is that under current scheme the J-2X engine is developed for Ares 1 already (instead of air started SSME).

An important point to remember is that EDS work doesn't start for several years,

Actually EDS work began with Ares 1 US development. Both stages apparently shares same subsystems (e.g. avionics, engine).

Quote
and there are already other alternatives to a J-2X powered EDS that actually look a lot better already.  IOW, if for some reason the Shaft went away next month, it wouldn't necessarily impede the development of a good EDS one bit.  Using a 6 RL-10 ICES/WBC stage like what Lockheed is working on would actually be a lot better.  Better mass ratio, engine-out reliability (which probably drops the LOM numbers a lot), and the design would be field tested on dozens of Atlas V launches before ever being used for lunar missions.
LM will be flying 6x RL-10 uperstage on Atlas mission? Why they would do that? It would still be somewhat different stage to EDS because of different requirements.

Quote
So the whole "we need 5-segment SRB and J-2X anyway" argument is a little thin.  We really don't, unless people think that the ESAS way is the only way.  It isn't.

Of course, if you cancel VSE there would be no need to develop any hardware. However, president of USA would have to do that.
Or NASA could run another ESAS study and choose completelly different VSE architecture. It is not likely as current architecture works fine and changes would cause delays and additional costs. At least I haven't heard anything from official sources saying oposite.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/24/2006 10:19 AM
Quote
kraisee - 23/11/2006  2:13 PM

The ESAS numbers have been published by NASA, so they are the only ones which the public can actually compare to.   The real numbers have changed somewhat.   The 5-seg SRB and J-2X development moved to Ares-I, two new MLP's for Ares-I have impacted near-term development costs very badly.   Changing to 10.0m diameter core, requiring extensive changes everywhere, plus the realization of needing two brand-new Crawlers for Ares-V have increased long-term costs too, although RS-68 has reduced flight costs a bit compared to SSME version.

You are right. Comparing original Ares 1 (with 4seg SRB +SSME US) to new Ares 1 (5seg SRB + J-2X US) increase near term costs because developing 5seg SRB and J-2X. This is however not many bilions increase because new 1st stage subsystems would have been developed anyway (e.g roll controll, interstage) and new US deleted costs asociated with air started expendable SSME.

Development of Ares V is in fact development of Core (similar to DIRECT except of diameter) and EDS (sharing subsystems with Ares 1 US).  

The fact is that NASA is claiming long term savings in ESAS architecture. If you use ESAS numbers you should be very carefull what numbers to use.

Unfortunatelly I'm not able to decode your and ESAS numbers not speaking about current NASA numbers. Therefore I can't put too much trust in them.

Quote
All infrastructure costs have increased - costing billions extra.
That was my point too. ESAS infrastructure cost apparently increased.
 
Quote
Ares-I flight costs have increased with the switch to 5-seg and J-2X.
I don't think so.

Quote
Ares-V flight costs have reduced only by about $50-75m per year.
Maybe

Quote
It doesn't take much to work out how many years that saving will take to recoup the infrastructure cost increases totalling about $1.8 Billion above ESAS estimates. I make it about 24 years!

I think that major saving comes from deleting SSME and using common SRBs and US/EDS engine.

Quote
But DIRECT's greatest bebnefit is the deletion of the $14 Billion for the second vehicle.   That would take about 185 years to pay back, and I don't think these systems will be flying anywhere near that long...

This second vehicle doesn't exist. There is Ares V core to develop. It is one rocket stage. It can't take $14Billion.
Note that 5-seg SRBs will be developed and EDS shares subsystems with ARES 1 US (and you have allocated $6.1B for this as if it would be completelly new).
Ares V core takes exactly the same time and money to develop as any other rocket stage based on proved heritage.

Quote

Stacking a CEV alone for ISS missions would take no longer than placing the CEV on top of Ares-I, so ISS missions aren't really affected.

Yes, they are. You propose using spare capacity of DIRECT ISS flights for secondary payload. This is aditional requirement. Current NASA vision wants to use commercial alternatives.

Quote

For lunar missions, stacking the LSAM and CEV on a Core-only vehicle has been assessed to take about 2 weeks. Without the LSAM on top, stacking just the EDS would take far less time than stacking the Ares-V.

I'm  considering stacking and launching of DIRECT+LSAM+CEV more demanding than ARES V+EDS+LSAM. Am I wrong? Especially when ESAS plans to spend bilions on new pad infrastructure?

Quote
So we're talking about two flights taking about 4 work weeks to process.   That's the same as Ares-I (1 week) and Ares-V (three weeks).
Partially agree. Direct + EDS could really take 1 week followed by DIRECT+LSAM+CEV with >three weeks.

Quote
It just balances out in a different way :)

Yes, the wrong way. We should mention docking operation between EDS and LSAM+CEV stack at LEO which is something really weird. It puts new requirements on both EDS and LSAM which simply don't exist with current ESAS architecture.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/24/2006 10:19 AM
Quote
jongoff - 24/11/2006  2:10 AM

Magnus,
Quote
What gives the low limit for the EDS thrust/mass ratio?

I'm not sure I understand the question.

~Jon

What is the lowest ammount of thrust that an EDS stage can get away with?
What gives the optimal ammount of thrust?

A low total mass for the EDS stage is good for its performance and it is already in orbit.
Why is it then not enough with one RL-10 below a giant fuel tank? A lot cheaper then
one J2 and less mass. It would look like towing a truck with a lawn mover but so what?

Is it a matter of time? That it takes too long to get up to speed, perhaps with manny
burns during manny orbits around earth. Could this give several passes or too slow
passe thru the von allen belts?

Or isent the EDS in orbit? Is the issue that you can get higer total performance by
using part of its fuel load to enter LEO?

Is it still a question of gravity losses?

Sorry for having such basic questions.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/24/2006 10:43 AM
Quote
JIS - 24/11/2006  12:02 PM

I'm  considering stacking and launching of DIRECT+LSAM+CEV more demanding than ARES V+EDS+LSAM. Am I wrong? Especially when ESAS plans to spend bilions on new pad infrastructure?

...

Yes, the wrong way. We should mention docking operation between EDS and LSAM+CEV stack at LEO which is something really weird. It puts new requirements on both EDS and LSAM which simply don't exist with current ESAS architecture.

Or DIRECT+EDS+LSAM and DIRECT+EDS+CEV(perhaps carrying more fuel for the LSAM) and then docking in moon orbit as suggested in the latest DIRECT paper.

The biggest performance loss ought to be that a cargo only mission DIRECT+EDS+LSAM brings less cargo to the moon then ARES-V+LSAM, but you can launch more of them with the savings.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/24/2006 10:47 AM
Quote
Magnus_Redin - 24/11/2006  5:02 AM

What is the lowest ammount of thrust that an EDS stage can get away with?
What gives the optimal ammount of thrust?

The best efficiency is of course with short impulse. The longer impulse the higher losses. Orbital burn lasting few minutes usually decrease efficiency by few percent.
For manned flight the EDS impulse must be of few minutes long for 3 day Earth-Moon transfer.

EDS acting as uper stage must have thrust/weight ratio close to 1. Low thrust US would require highly lofted trajectories which are less efficient and not suitable for manned flights.

Quote
Why is it then not enough with one RL-10 below a giant fuel tank? A lot cheaper then
one J2 and less mass.

Actually I think that 6 x RL-10 is significantly more expensive than single J-2X. The differnce is in development cost. RL-10 would need some aditional development too.

Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/24/2006 10:55 AM
Quote
Magnus_Redin - 24/11/2006  5:26 AM

Or DIRECT+EDS+LSAM and DIRECT+EDS+CEV(perhaps carrying more fuel for the LSAM) and then docking in moon orbit as suggested in the latest DIRECT paper.

The biggest performance loss ought to be that a cargo only mission DIRECT+EDS+LSAM brings less cargo to the moon then ARES-V+LSAM, but you can launch more of them with the savings.

That's better approach. Clasic two launch.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/24/2006 01:48 PM
"Ares-I flight costs have increased with the switch to 5-seg and J-2X."

It most certainly has.

"RL-10 would need some aditional development too. "

It does not

"There is Ares V core to develop. It is one rocket stage. It can't take $14Billion.
Note that 5-seg SRBs will be developed and EDS shares subsystems with ARES 1 US (and you have allocated $6.1B for this as if it would be completelly new).
Ares V core takes exactly the same time and money to develop as any other rocket stage based on proved heritage."

It is a completely new vehicle. It is isn't  just the core.  New fairing, new upperstage, new lifting hardware, new transport hardware, New MLP, New crawler, New pad mods, new payload processing facility, new GSE, new analyses, etc.  14 billion is maybe too low

"

I'm considering stacking and launching of DIRECT+LSAM+CEV more demanding than ARES V+EDS+LSAM. Am I wrong"

Yes.  Not that big of deal.  most of the "extra" work is done before the launch site
Title: Re: "DIRECT" Goes Live
Post by: Generic Username on 11/24/2006 01:54 PM
Quote
Jim - 24/11/2006  7:31 AM


"There is Ares V core to develop. It is one rocket stage. It can't take $14Billion.
Note that 5-seg SRBs will be developed and EDS shares subsystems with ARES 1 US (and you have allocated $6.1B for this as if it would be completelly new).
Ares V core takes exactly the same time and money to develop as any other rocket stage based on proved heritage."

It is a completely new vehicle. It is isn't  just the core.  New fairing, new upperstage, new lifting hardware, new transport hardware, New MLP, New crawler, New pad mods, new payload processing facility, new GSE, new analyses, etc.  14 billion is maybe too low

Yeah, but the avionics is the same, so it's not a new vehicle.

(ducks)
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/24/2006 02:00 PM
That is one thing is has going for it but it is negated by the developing organization.

Unlike the Atlas V phase II, the CLV and CaLV have less in common
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/24/2006 02:00 PM
Quote
JIS - 24/11/2006  11:02 AM
You propose using spare capacity of DIRECT ISS flights for secondary payload. This is aditional requirement. Current NASA vision wants to use commercial alternatives.

This isn't a valid argument. Use of the additional payload capacity of DIRECT is an option, not a requirement, and can never be used as anything other than an argument is favour of DIRECT.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/24/2006 02:13 PM
Quote
Jim - 24/11/2006  2:31 PM

It is a completely new vehicle. It is isn't  just the core.  New fairing, new upperstage, new lifting hardware, new transport hardware, New MLP, New crawler, New pad mods, new payload processing facility, new GSE, new analyses, etc.  14 billion is maybe too low


What uperstage? There is $6.1B for EDS in Ross's estimation.
Isn't the MPL, crawler, pad etc. called generally an infrastructure?
Shouldn't payload processing facility fall under payload (CEV, LSAM) cost?
We are talking about $14B Ross alocated for CaLV development and claims that DIRECT has $0,00 cost for CaLV.
I thought that completelly new vehicle should fly on its own. Ares V core doesn't.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/24/2006 02:28 PM
Quote
Kaputnik - 24/11/2006  2:43 PM

Quote
JIS - 24/11/2006  11:02 AM
You propose using spare capacity of DIRECT ISS flights for secondary payload. This is aditional requirement. Current NASA vision wants to use commercial alternatives.

This isn't a valid argument. Use of the additional payload capacity of DIRECT is an option, not a requirement, and can never be used as anything other than an argument is favour of DIRECT.

But it doesn't change the fact that it would be bad option.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/24/2006 02:53 PM
It must be a *VERY* bad option if it is worse than paying c.$500m to launch that same 48t payload on another launcher
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/24/2006 03:08 PM
Yes, launch it unmaned. That's the right philosophy.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/24/2006 03:17 PM
Fine, if you must, launch crew and cargo separately. That is not an argument against DIRECT, though. If DIRECT+CEV were used for ISS flights most of these flights would be unmanned resupply flights anyway.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/24/2006 03:57 PM
JIS,
The costs for Ares-I and Ares-V have changed since the ESAS came out, but in typical NASA program fashion,  both have gone up from the original estimates, mainly because new hardware is required which wasn't accounted for in the ESAS estimates (new ML's and 5-seg and J-2X all now needed for Ares-I, Ares-V requires all new manufacturing and processing facilities to process the far larger 10.0m diameter core configuration).

I'll cut straight to the chase and provide the bottom-line "apples-to-apples" comparative numbers for developing these birds:


CLV:
ESAS: Ares-I:
20.8  24.8 (+19%)


CaLV (inc. EDS)
ESAS: Ares-V:
27.8  28.2 (+1%)


TOTALS:
ESAS: Ares:
48.6  53.0 (+9%)


(All costs in billions)

Both of these Ares costs factor in the development of the 5-seg/J-2X being absorbed by the CLV now, and include the new ML's and Crawlers required to support.


Now, just for completeness sake: Lets see the "ESAS Equivalent" cost comparison for DIRECT:


DIRECT (inc EDS):
19.3


and apply the *worst-case* percentage increase from Ares-I to get the highest possible 'cost creep':


TOTAL DIRECT (inc EDS) with worst-case 19% "Ares-I" cost-creep:
22.96


TOTAL SAVINGS:
30.04



In short - even assuming the worst possible case of cost creep any single element of Ares is experiencing, the current cost structure comparing to the current Ares plan looks about a LOT better for DIRECT than it did even using purely ESAS numbers.

$30 Billion saving = 214 DIRECT flights = 15,172.6 tons to LEO.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: ANTIcarrot on 11/24/2006 04:10 PM
From memory, Aries II costs $10M more per launch than Aries I and can carry an extra 40mT of cargo. If you're going to be launching the missions *anyway* you could always sell it to anyone who wanted at the low low price of £250/kg + misc costs. I know low costs to space is another topic, but this could allow NASA to test the waters to see if a *non-traditional* market does or does not exist for such payloads, and settle the question once and for all.

NB: To the person who asked, the LV-27.3 CaLV has no Loss of Crew figures because it doesn't carry any. ;)
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/24/2006 04:13 PM
Quote
JIS - 24/11/2006  10:51 AM

Yes, launch it unmaned. That's the right philosophy.

I'm sorry but this is all based on an incorrect assumption.

The issue is has never been that cargo and crew should not fly on the same launcher - it is that crew and cargo must not fly IN THE SAME SPACECRAFT.


DIRECT follows the classic, highly successful and well-proven, method used by Gemini, Saturn-I and Saturn-V programs.

A separate Spacecraft Adaptor contains cargo, with crew capsule mounted on top.   It was a brilliant idea during the 60's and 70's, and remains the "way to go" for the maximum versatility into the future.

The "mistake" on Shuttle was having the payload mounted inside the spacecraft also containing the crew - that increases the complexity of the *spacecraft* and THAT is why it should not be done any more.


In point of fact, a cargo flying immediately under the CEV would actually *increase* safety during a launch.    It would offer another 'barrier layer' in case of a critical failure of the launcher.   It would act as a 'shield' for any shrapnel coming towards the crew module.


This also removes cost and complexity too.   For any missions to LEO where we might want crew and cargo coming together (Hubble Servicing Missions and future expansion of ISS are prime examples of such activities) they would always require additional launches with Ares-I, each costing hundreds of dollars per mission and *doubling* the risk of a mission failure by doubling the number of launches required.

DIRECT would lose if it cost significantly more than Ares-I, but it doesn't.   It can fly CEV-only missions OR ones with payload.   DIRECT can even launch an Orion CEV to High Earth Orbit/Geosynch on a single launch.   Ares-I couldn't ever do that.   DIRECT just opens up possibilities which are shut-out by Ares-I, and does so for NO EXTRA COST.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/24/2006 07:19 PM
JIS,
Quote
LM will be flying 6x RL-10 uperstage on Atlas mission? Why they would do that?

The ICES upper stage they're working on can support 1-6 RL-10 engines, and can easily vary the tank lengths to provide for higher fuel capacities for flights that need them.  For the biggest of those designs currently planned (the one that would go with the Atlas V Heavy, if that ever flies) would need 6 engines because the Centaur stage alone would carry about 300,000lb of propellant (50% more than EDS).  Now, it's a valid question if ICES will ever fly (fairly likely), or whether Atlas V Heavy will ever fly (less likely).  But even if Heavy doesn't fly, you could use the 6-engine design for EDS and still get the benefit of flight experience with the smaller ICES upper stages.

Quote
It would still be somewhat different stage to EDS because of different requirements.

Not so much as you would think.  The main difference between EDS and the stock ICES is how long it has to operate in orbit.  Lockheed was already working on "mission kits" that would allow their ICES stages to handle missions as long as 1 *year* in orbit.  Quite frankly, an ICES derived EDS would likely be cheaper, more capable, and more reliable than an Ares I US derived upper stage.  

Quote
Of course, if you cancel VSE there would be no need to develop any hardware. However, president of USA would have to do that.

ESAS =! VSE  

If ESAS were scrapped, the vision laid out in the President's Vision for Space Exploration would be more likely to be fulfilled, not less.

Quote
Or NASA could run another ESAS study and choose completelly different VSE architecture. It is not likely as current architecture works fine and changes would cause delays and additional costs. At least I haven't heard anything from official sources saying oposite.

Because we all know that official sources whose jobs depend on the success of a given program are the most unbiased and dependable sources for information about problems with said program.

NASA already paid 6 or 7 different companies to come up with potential exploration architectures (the CE&R studies).  It didn't really cost them much at all, and most of them were better than what NASA is pursuing right now.  But as with Apollo, NASA felt that they knew better than all those others.  I mean, what do Boeing and Lockheed know about developing and fielding new launch vehicles?  

~Jon
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/24/2006 07:29 PM
Magnus,
Quote
What is the lowest ammount of thrust that an EDS stage can get away with?
What gives the optimal ammount of thrust?

I can't answer that quite as explicitly as I would like, since I don't have ready access
to POST or some other similar performance software (though maybe Ross could run
an ICES derived EDS design on his software).  But my guess is that since most of the
EELVs do just fine with getting stuff to orbit with upper stages that have fairly low T/W
ratios, that the same would apply for EDS.

Quote
A low total mass for the EDS stage is good for its performance and it is already in orbit.
Why is it then not enough with one RL-10 below a giant fuel tank? A lot cheaper then
one J2 and less mass. It would look like towing a truck with a lawn mover but so what?

The problem is that the EDS actually participates in putting itself into orbit, so it needs
enough T/W to make it there.  I'm not sure what the actual numbers are, but my guess
is that somewhere around 0.5G is just fine.  

Quote
Or isent the EDS in orbit? Is the issue that you can get higer total performance by
using part of its fuel load to enter LEO?

The current plan as I understand it is to use the EDS to perform the final burns to orbit
itself and the LSAM.

Quote
Is it still a question of gravity losses?

I think so.

Quote
Sorry for having such basic questions.

I wouldn't worry too much.  This stuff *is* complex, and the implications of each decision
aren't entirely clear.  Having a simulator you can run would probably help a lot, but I don't
have one handy at the moment.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/24/2006 07:45 PM
JIS,
Quote
EDS acting as uper stage must have thrust/weight ratio close to 1. Low thrust US would require highly lofted trajectories which are less efficient and not suitable for manned flights.

Are we forgetting that the EDS is only lofting the unmanned LSAM to orbit?  For unmanned flights, much lower T/W ratios on the upper stage are perfectly acceptable, and yield a much better performance for the in-space part of their flight.

One of the drawbacks to using an EDS derived from the Ares I US is that the EDS will likely have much higher T/W than it really needs at the expense of lower overall performance.  Deriving an EDS from a similar system (an upper stage used to put satellites in GSO) is likely to yield a much more optimized EDS for the job.

Quote
Actually I think that 6 x RL-10 is significantly more expensive than single J-2X.


I would be extremely amazed if that were the case.  RL-10s are actually quite inexpensive for being some of the highest performance engines ever built.  The thing is that every single Atlas V or Delta IV flight ends up using them, so they're already in production in decent quantities.  Which means that NASA isn't their only customer.  All things told, I wouldn't be surprised at all if 6-RL-10s ended up being substantially cheaper than a single J-2X.

Quote
The differnce is in development cost. RL-10 would need some aditional development too.

What makes you think so?  The EDS flight profile is pretty much identical to the mission that the RL-10 was originally designed for--one or two burns to reach orbit, then another big burn to place something into a transfer trajectory.  As I understand it, a Centuar derived EDS could use stock RL-10s for the job.  No need for extra development.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/24/2006 08:06 PM
Ross given a two launch EOR approach (EDS followed by CEV/LSAM) how do you purpose docking with the EDS stage?

Title: Re: "DIRECT" Goes Live
Post by: imfan on 11/24/2006 09:15 PM
for cev+lsam-eds docking I would propose that cev+lsam RCS should cooperate. looks pretty simple to me. and the docking mechanism should not be problem too since only thing it provides is mechanical connection.
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/25/2006 12:44 AM
Quote
imfan - 24/11/2006  1:58 PM

for cev+lsam-eds docking I would propose that cev+lsam RCS should cooperate. looks pretty simple to me. and the docking mechanism should not be problem too since only thing it provides is mechanical connection.

The CEV/LSAM is fine but what is the connection between the LSAM base and the EDS look like.  Right now the EDS and LSAM are connected on the ground and the CEV via the stick docks with the LSAM for an eye balls out trip to the moon.

Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/25/2006 03:31 AM
SMetch,
Luckily for us, the LSAM will already have ground facing radar and cameras for the lunar surface landing.   These could very easily be used to also perform the docking to the EDS in LEO.   Camera-based docking maneuvers are used currently for Progress deliveries to ISS, and are planned for COTS too.   So a camera approach is already a well known procedure.   With the LSAM already having cameras and radar, there is no mass penalty for these items either - which is a nice side-effect.   This should be relatively easy to implement with success being primarily down to the quality of the astronaut training.

The key is going to be the docking mechanism design itself.

When the LSAM is launched, it will be mounted upon a trusswork 'cradle', something like this one:


(154049main_Earth_space_bkdrop.jpg - Click for larger image)


DIRECT EOR-LOR missions require two of these cradles.   One for launching the LSAM, and the other afixed to the EDS itself.   My understanding is that NASA is currently planning to attach the LSAM to these cradles at four locations on it's lower DS structure.   The LSAM will be held in place at these locations by some form of release mechanisms.   Currently, these are likely to be pyro bolts which blow and release the module.

For DIRECT, we propose that these not be one-use only pyro bolts, but instead, a relatively simple, strong, reusable mechanical design.   The same cradles and mechanisms would be used on both the launcher and the EDS, which keeps manufacturing costs down too.

After launch, the LSAM would be mechanically released from that vehicles cradle.

An identical cradle & release mechanisms is then used to dock to the EDS later.   To aid the docking manoeuver, the LSAM's legs will be splayed apart prior to the rendezvous.   This mechanism releases it again after the TLI.


As an aside: There is actually an "eyeballs in" option available for DIRECT too - which provides excellent abort options during the LSAM/EDS docking too.   It is option 2 in Appendix 3 of the DIRECT Proposal "Example Lunar Mission Models".   It takes a hit of 3mT to TLI, but would still offer a solution with 14mT more payload going Lunar than Ares does.   Here it is:


(DIRECT_Lunar_Mission_Model_2.jpg - Click for larger image)

Ross.
Title: Re: "DIRECT" Goes Live
Post by: lmike on 11/25/2006 09:05 AM
Could the Direct be 'split' even further?  Half 70mt is a good capsule taxi (tm?  based on Griffin's statements with Orbital)  We could do some real orbital assembly with this.  [edit] in case someone thinks "orbital assembly" is a by-word for failure, it's not.  It's our next step for space transport.  The sooner we get used to it the better.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/25/2006 02:33 PM
Quote
JIS - 24/11/2006  9:56 AM

Quote
Jim - 24/11/2006  2:31 PM

It is a completely new vehicle. It is isn't  just the core.  New fairing, new upperstage, new lifting hardware, new transport hardware, New MLP, New crawler, New pad mods, new payload processing facility, new GSE, new analyses, etc.  14 billion is maybe too low


What uperstage? There is $6.1B for EDS in Ross's estimation.
Isn't the MPL, crawler, pad etc. called generally an infrastructure?
Shouldn't payload processing facility fall under payload (CEV, LSAM) cost?
We are talking about $14B Ross alocated for CaLV development and claims that DIRECT has $0,00 cost for CaLV.
I thought that completelly new vehicle should fly on its own. Ares V core doesn't.

"I thought that completelly new vehicle should fly on its own. Ares V core doesn't."

don't understand this



Title: Re: "DIRECT" Goes Live
Post by: imfan on 11/25/2006 06:43 PM
ross: abort mode is nice thing to have, but it is the only advantage of this configuration. but you lose 3mt of TLI mass (your figure) and that is IMHO quite lot(lets say 1,5t on surface?). I am concerned with manouverability of this configuration. LSAM RCS are useless unless you make holes in  SLA. I like the idea of grapples, I was thinking about something similar.
In my mind it should be like this:
1. direct+eds launch
2. direct+cev+lsam
3.cev transposes into "apollo" configuration(last one on your diagram)
4.randezvous with eds(dont know if burns should be done by lsam or cev. using both you dont need rcs on both cev and lsam right now)
5.docking to EDS(you need both RCS now)
6.TLI

there is also possibility for abort during TLI. it would be performed by lsam. since it would be powered(at least partially) during docking anyway, this should be no problem. I ll take a look at esas to find some numbers  usefull for acceleration in both cases of abort(cev+lsam-burning to cev alone burning). my assumption(based on no numbers) is that cev wuould accelerate about 3-4m/ss while lsam 2m/ss. will post as soon as I have some figures

*edit* I wrote it late in the night and got pretty embarassed while reading it. now corrected to make sence
Title: Re: "DIRECT" Goes Live
Post by: imfan on 11/25/2006 07:26 PM
looked into esas and there is 66.7kN engine for cev and 4x66.7kN engine for lsam. since no one really knows the masses, I would suppose very dirty assumption that CEV is 20mt and LSAM is 40mt.
a=F/m  gives:
66.7/20=3.3m/ss for cev abort
4*66.7/60=4.4m/ss for LSAM abort.

given that in case of abort you want to get as far as possible as fast as possible, variant proposed by me is slightly better, allows for using LSAM(descent+ascent) for abort MCC,saves 3mt TLI capacity by throwing away SLA and imho makes things easier during docking to EDS.
only disadvantage I see is that it requieres powered LSAM.
Title: Re: "DIRECT" Goes Live
Post by: PaulL on 11/26/2006 03:29 AM
Ross, in your reply to JIS on 21/11/2006 your provided the following figures for early Direct EDS development cost:

2010   2011   2012   2013   2014   2015   2016
0.2    0.4    0.5    1.4    2.5    2.9    3.0

That would mean an EDS development cost of $10.9B instead of $6.1B for the ESAS EDS. Is that a typo error or extra money to cover the development cost of items that would have been included in the ARES-I development (J-2X, 2nd stage avionics,...)?

PaulL
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/26/2006 05:27 AM
PaulL,
   Yes, that is correct.

   As you can see from the charts below, the standard EDS development schedule does not change the development costs, but the "expedited" version (for a 2016 Lunar Landing) brings forward both the EDS and LSAM development programs by 2 years from 2013 to 2011.

   The expedited schedule starts off with an initially slower development, so needs extra funds put in later to speed things back up again.   The second & third years of the EDS development are half the budget allocation as on the regular schedule, allowing only really for initial design and long lead items to be paid for.   This means that NASA must basically 'throw extra money at it' in the later years of development, in order to greatly accelerate it.   A similar situation also exists for the LSAM too.

   By 2011 point DIRECT is saving the LV program re between $1 - 2Bn each year compared to Ares, so that is where all of this "extra" funding is found.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/26/2006 05:52 AM
Quote
imfan - 25/11/2006  2:26 PM

ross: abort mode is nice think to have, but it is the only advantage of this configuration this configuration. but you lose 3mt of TLI mass (your figure) and that is IMHO quite lot(lets say 1,5t on surface?). I am concerned with manouverability of this configuration. LSAM RCS are useless unless you make holes in  SLA. I like the idea of grapples, I was thinking about something similar.
{SNIP}

Imfan,
Yes there are a lot of different approaches which DIRECT can support.

The Ares- verhicles only allow for one basic approach, with no alternatives.

DIRECT's biggest strength is that it is versatile enough to support whatever mission approach is deemed best - not just whatever mission its physical limitiations permit it.

There are actually four different approaches suggested in the DIRECT Proposal.   Each has its own set of pros and cons.   Assuming safety is key, then keeping the CEV and LSAM attachined inside the SLA in launch configuration may offer the widest range of abort modes.   If performance is the biggest driving force, then an LOR-only approach offers the maximum amount of payload to the Lunar surface - especially so if using the L2-rendezvous option.

For my money, I would *start* these missions following your approach - CEV to LSAM transition occuring before docking to the EDS - ideally occuring before the circ. burn if time will allow.   That is the closest method to the already proven Apollo profile.

But I would like to have the OPTION to change the profile later to improve performance when we start getting used to it.   They did exactly that during Apollo.   Early Apollo missions performed teh CSM transition before TLI.   Later missions performed it after TLI - and there was actually a slight performance benefit in doing so.   *Perhaps* (I don't have confirmed data) the same thing might occur with DIRECT too.

Of course, NASA needs to choose a launch family capable of supporting other options before they become possible...

Ross.
Title: Re: "DIRECT" Goes Live
Post by: imfan on 11/26/2006 11:58 AM
Quote
kraisee - 26/11/2006  7:35 AM

Quote
imfan - 25/11/2006  2:26 PM

ross: abort mode is nice thing to have, but it is the only advantage of this configuration. but you lose 3mt of TLI mass (your figure) and that is IMHO quite lot(lets say 1,5t on surface?). I am concerned with manouverability of this configuration. LSAM RCS are useless unless you make holes in  SLA. I like the idea of grapples, I was thinking about something similar.
{SNIP}
For my money, I would *start* these missions following your approach - CEV to LSAM transition occuring before docking to the EDS - ideally occuring before the circ. burn if time will allow.   That is the closest method to the already proven Apollo profile.

But I would like to have the OPTION to change the profile later to improve performance when we start getting used to it.   They did exactly that during Apollo.   Early Apollo missions performed teh CSM transition before TLI.   Later missions performed it after TLI - and there was actually a slight performance benefit in doing so.   *Perhaps* (I don't have confirmed data) the same thing might occur with DIRECT too.

Of course, NASA needs to choose a launch family capable of supporting other options before they become possible...

Ross.
I think that CEV to LSAM transition even before circularization burn adds  too much risk for not much gain. lets say circularization burn is about 100m/s for 60mt(cev+LSAM) or 63(CEV+LSAM+SLA). For TLI where we are talking about dV of 3km/s I see no reason to take 3mt of useless mass. But I dont hesitate to call docking while on orbit that leads you into atmosphere in about an hour a stunt.
What apollo missions are you referig to? As I am aware, all missions did transposition after TLI. I am no expert, but I think you are wrong in this. otherwise I appologize and thank for spreading my knowledge. and where would be that performance benefit in case you get fairing mass through TLI compared to the case when you dont do this?
Title: Re: "DIRECT" Goes Live
Post by: MikeEarnest on 11/26/2006 03:03 PM
Apollo 7 and 8 did not require transposition and docking, Apollo 9 performed the whole maneuver on Earth orbit, and Apollo 10-17 performed the maneuver post TLI burn.

My two cents...
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/26/2006 05:16 PM
Quote
kraisee - 22/11/2006  9:27 AM

Quote
JIS - 22/11/2006  10:12 AM

Improvements of RS-68 to RS-68 regenerative:
thrust from 745 to 820 klbf (by 10.1%)
ISP from 410 to 435.4 s (by 6.2%)

Improvements of J-2S to J-2S+ (according to ESAS):
thrust from 256 to 274.5 klbf (by 7.2%)
ISP from 436 to 451 s (by 3.4%)

I think that it is generally more difficult to increase ISP than thrust. In case of J-2S it is done simply by higher expansion nozzle. But I agree that both engine upgrades are somewhat in "magic" region. It is therefore appropriate to apply some margins.
In case of DIRECT+EDS we have even three engines in "magic" region. (Ooops did I write "magic" again?)
NO, don't take me serious. I was just wonder why NASA easily accepts upgrade of one key ESAS engine and overlooks upgrade of another key engine.
Maybe the only reason is that upgrade of RS-68 is not necessary for VSE at the moment. May be not.

JIS,
   However, remember that the J-2S (and J-2 before it) was *already* a regeneratively cooled engine, so it was starting from a higher general spec in the first place.

   Changing from regen to different regen will not produce anywhere near as large an improvement as from ablative to regen.

   435s Isp from the RS-68 is what the engine was originally designed to do, but was 'tuned down' when the cheaper ablative nozzle was selected for the very competative Delta-IV market.   The performance increase simply isn't all that great in that application because the first stage does not fly all the way to orbit.   For a booster where the Isp increase is used throughout the entire flight, it can make a bigger difference to ultimate payload performance.


   Overall the performance increase comes from an optimized nozzle for vacuum operations, not atmospheric, and regen cooling allowing the powerpack to operate at higher levels.   This allows the engine to be operated 'normally' again, which with the Regen engine would produce 774,000klbf.   Rocketdyne believe that, like the SSME, the unit can actually be operated above it's 100% mission power rating though - 106% is the guaranteed expectation (one they are 100% confident in), 109% (probably) or 111% may be possible, although less likely.   820,000klbf/435s is equivalent to the 273,500klbf/448s quote for the J-2X - it is what they are totally confident of and might be able to still improve on.


   Magic?   Doesn't bother me all.   Grinding?   Nah, that's not my teeth grinding! :)


   NASA can look at the RS-68 Regen for any other LOX/LH2 booster.   It would offer performance benefits to the Delta-IV and Ares-V alike.   However the 'trick' is in funding.   DIRECT can afford to spend the extra $1 Billion to develop the Regen engine because it saves $35 Billion elsewhere.   Ares-V already costs about $20 Billion.   The question is going to be whether that $1 Billion on top of that substantial cost, in return for ~10mT extra performance, will be all that worthwhile?   While I don't speak for NASA, I'm not sure it is a worthwhile cost in that particular application.

Ross.

Ross, did the sea level ISP increase as well for the RS-68 Regen?
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/27/2006 09:59 AM
Quote
Jim - 25/11/2006  3:16 PM

"I thought that completelly new vehicle should fly on its own. Ares V core doesn't."

don't understand this


Don't worry. Nobody understand these black box development and infrastructure costs.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/27/2006 10:14 AM
I've changed my mind about DIRECT. DIRECT (Ares II) is actually very good option for two launch, lunar orbit randezvous. For lunar missions it could start with ARES II+EDS+LSAM which would place LSAM into low lunar orbit. The second launch Ares II+EDS+CEV would place CEV into lunar orbit and perform randezvous at LLO.
The ISS mission would be done by Ares II + CEV (without EDS).
This would mean Ares 1 cancellation and bigger CEV's SM. It still could spare a lot of money and be relativelly simple and safe mission. I think that it should be better than current Ross's DIRECT with LEO randezvous.

The slight disadvantage could be that two EDSs are required for Lunar mission but EDS could use RL-10 engine the same as for LSAM descent stage.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/27/2006 11:21 AM
Thank goodness for that.
If you read the proposal Ross suggests that Lunar Orbit Rendezvous is in some ways preferable- but as I see it the whole thrust of the proposal was to make DIRECT a simple replacement for Ares which would allow the rest of the ESAS architecture to remain unchanged. In this way those who view ESAS as some sort of bible would be sated.
Personally I see outstanding logic in the use of a ICES/Wide-Body-Centaur stage as the EDS; deletion of the J2X from the EDS requirement would be another hammer blow to Ares 1.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/27/2006 11:50 AM
It is not about cancelling Ares 1 or EDS design but about changing ESAS philosophy. The biggest Ross's mistake with DIRECT proposal is basing it on Ares 1 alleged problems. I still think that Ares 1 could work fine.
The alternative must be based on alternative exploration philosophy which proves that it is safe enough but less expensive than ESAS approach.
DIRECT is nothing new to NASA. The only thing to do is to present new architecture from safety and cost point of view. I'm afraid that Ross's document is not sufficiently clear in this.
I don't agree with messing two different designs together. If you can't have the proper new architecture. Stick to selected one. Ares 1/Ares V still have some advantages. Although the lower cost is not one of them and I never said the oposite.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/27/2006 11:54 AM
Quote
JIS - 27/11/2006  7:33 AM
 I still think that Ares 1 could work fine.

Ares 1/Ares V still have some advantages

Based on what?

And they are?


safety numbers are not an exact science and not should be used to base decisions on solely.
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/27/2006 12:03 PM
Quote
JIS - 27/11/2006  12:33 PM
 The biggest Ross's mistake with DIRECT proposal is basing it on Ares 1 alleged problems.

If the proposal comes across as being founded upon the alleged problems associated with Ares 1, then that is perhaps unfortunate. The DIRECT concept dates back to before these problems became widely publicised and was borne of a recognition that development of two new LVs was poor value for money when a single universal vehicle could be developed by sticking much mroe closely to the existing STS design. The problems being encountered by the Stick have simply served to bolster the arguments in favour of DIRECT.
Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/27/2006 01:06 PM
JIS,
Quote
I've changed my mind about DIRECT. DIRECT (Ares II) is actually very good option for two launch, lunar orbit randezvous. For lunar missions it could start with ARES II+EDS+LSAM which would place LSAM into low lunar orbit. The second launch Ares II+EDS+CEV would place CEV into lunar orbit and perform randezvous at LLO.
The ISS mission would be done by Ares II + CEV (without EDS).
This would mean Ares 1 cancellation and bigger CEV's SM. It still could spare a lot of money and be relativelly simple and safe mission. I think that it should be better than current Ross's DIRECT with LEO randezvous.

The slight disadvantage could be that two EDSs are required for Lunar mission but EDS could use RL-10 engine the same as for LSAM descent stage.

That's not a bad approach at all actually.  Especially if you were talking about say using a Centaur derived EDS, it could keep the costs way down, and the new development costs to a minimum.  

I'm still not a huge fan of anything with one of those segmented SRBs in it, but if keeping those in the mix is a fixed requirement, this is one of the better ways of dealing with that in an affordable manner.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: Dan Moser on 11/27/2006 03:14 PM
The DIRECT concept has many undeniable advantages, and I have no doubt it could fly sooner, cost less, and may well be safer as well.  Plus it has the potential political advantage of preserving shuttle jobs in place and keeping current plants and facilities in operation.  However, NASA management is stubbornly backing their own 1.5 launch plan (appropriate, since the stick is a half-baked design), so pushing to get the DIRECT accepted over NASA's baseline is like trying to swim upstream.

My question:  What are the realistic prospects for getting the DIRECT concept accepted?  Since DIRECT is a grass-roots effort, there is not a strong, co-ordinated, centralized advocacy effort.  NASA's chosen architecture is now entrenched with agency pride and they seem to be resisting oversight and outside design alternatives on principle.  To NASA outsiders, the stick is becoming a symbol of NASA's incompetence.  To NASA insiders, the DIRECT is a direct threat to agency pride of ownership and autonomy.  NASA management seems unwilling to even take closer look at the DIRECT concept, because doing so is seen a tacit admission of incompetence.  It has become an very emotional issue, so even though the DIRECT makes sense on a factual-logical basis, huge obstacles of pride, politics and emotionalism still remain.  What chance does DIRECT realistically have?  If the Bush administration and the new Demo-controlled congress were to team up and apply budget pressure to NASA along with a mandate to fly sooner and avoid another 5 year gap in manned spaceflight capability, then NASA management would have a face-saving excuse for going back to the drawing board and looking at alternatives.  Perhaps then the DIRECT concept may have a chance for a fair hearing.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/27/2006 03:33 PM
Wow.   I've convinced even our JIS?   Very Cool!   I don't know why, but I always thought JIS had room to manoeuver, and was "convincable".   There were always a few who aren't willing to even consider the possibility still, but I'm glad JIS can be persuaded by a reasoned argument.   I'm more glad he (she? enquiring minds want to know...) was persistent and asked so many critical questions of the system.   Those actually helped solidify the arguments even further.   It gave us a chance to put the counterpoints on paper (so to speak).   That has been a valuable contribution for us, so Thank-you.


The LOR-only option (which was actually mentioned in the very first release of the DIRECT proposal BTW, but only more recently has been updated to include an example Mission Model diagram too) does seem to offer the greatest performance.

Mind you, don't forget the dose of reality:   Adding the EDS increases complexity to the Crew launch vehicle, so the LOC safety numbers drop.   Current predictions go from 1 in 1355 for the standard DIRECT to 1 in 1257 for the EDS variant CLV.

That's still not a bad LOC number, but I don't want to be accused of attempting to hide it! :)


As for RL-10/ICES upper stage:   I have not yet had the opportunity to investigate this option fully.   I would really like to put some time and effort into working out an ICES-based EDS stage in the 8.41m (27'5") diameter range.

I don't have much in the way of specific data on the ICES, other than the proposals we all saw a few months back, so here's a general request:   If there's anybody on here who is very familiar with the ICES project already and can offer some consultation, anonymously of course, please contact me by Private Message.   In particular, I want confirmation that ICES could use the RL-10B-2 engine, could support 7 of them (6 around the rim, 1 in the center), and I need to get an idea of mass for an 8.41m diameter configuration containing somewhere in the ballpark of 350 - 380,000lb of propellant.


With only the limited info available so far, I think ICES is probably the best approach out there, and could potentially offer a lot of flexibility, but until a lot more questions are answered, there's no guarantees that it'll be a good combination with this particular configuration.   It needs, and is worthy of, investigating further.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/27/2006 03:52 PM
No the RL-10B-2 engine,
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/27/2006 04:20 PM
Quote
Jim - 27/11/2006  11:35 AM

No the RL-10B-2 engine,

I know that the original ICES proposal used the RL-10A-4-2, but RL-10's have a fairly high degree of commonality between them.

Given that this entire concept is still at the drawing phase, and no metal exists, I just want to know whether this concept can be "scaled up" to the requirements to be useful on DIRECT, or not.

With 663s [EDIT: oops, that's 463s] Isp, and about 25,000lb thrust on tap, the RL-10B-2 offer better performance while still retaining a lot of RL-10 commonality.

Seven of those very high efficiency engines, combined with that higher thrust, would 'appear' to offer a well balanced "drop in" replacement package for the J-2X EDS we're using now.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/27/2006 04:37 PM
Quote
JIS - 27/11/2006  7:33 AM
The biggest Ross's mistake with DIRECT proposal is basing it on Ares 1 alleged problems. I still think that Ares 1 could work fine.
Ross did not base the Direct proposal on Ares I problems. He based it *purely* on MONEY.

The original Ares I design of a 4-seg RSRM and SSME US, coupled with an existing ET for Ares V was a *reasonable* proposal. But the design changes to Ares I to a 5-seg RSRM and J2-x US, coupled with the change in ET diameter to 10m for Ares V, drove the cost of the Ares design approach through the roof, far, far beyond anything that had been previously expected or promised. It also did major damage to the schedule.

This made it far more expensive and less safe than other *reasonable* proposals in the ESAS. All Ross did was to apply the exact same ESAS criteria for Ares design, development and deployment, and apply them to the ESAS LV-24.25 proposal, and see what came out. The result was Direct, which put Orion in service by 2010/2011 instead of late 2014, put us on the lunar surface in 2016 instead of 2020, and did it all for $35 billion less than the new, improved Ares.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/27/2006 05:11 PM
Quote
kraisee - 27/11/2006  12:03 PM

Quote
Jim - 27/11/2006  11:35 AM

No the RL-10B-2 engine,

I know that the original ICES proposal used the RL-10A-4-2, but RL-10's have a fairly high degree of commonality between them.

Given that this entire concept is still at the drawing phase, and no metal exists, I just want to know whether this concept can be "scaled up" to the requirements to be useful on DIRECT, or not.

With 663s Isp, and about 25,000lb thrust on tap, the RL-10B-2 offer better performance while still retaining a lot of RL-10 commonality.

Seven of those very high efficiency engines, combined with that higher thrust, would 'appear' to offer a well balanced "drop in" replacement package for the J-2X EDS we're using now.

Ross.

It has too many SPF's.   Not worth the headache.  It was an issue for OSP

Title: Re: "DIRECT" Goes Live
Post by: imcub on 11/27/2006 05:16 PM
Quote
Jim - 27/11/2006  9:54 AM

It has too many SPF's.   Not worth the headache.  It was an issue for OSP


I try keeping up Jim, but SPF's are ???

Thanks

Title: Re: "DIRECT" Goes Live
Post by: JWag on 11/27/2006 05:43 PM

Quote
imcub - 27/11/2006  11:59 AM
I try keeping up Jim, but SPF's are ???  Thanks  

 

Single-point failures

Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/27/2006 06:12 PM
Some people seem to think that the anti-Ares-I sections in the DIRECT proposal is detracting from the document.   Is this a widely held belief?

I ask because given NASA completely ignored the concept anyhow, the key audience has now shifted to the politicians above NASA.

I still feel it is better to inform *them* of the problems with Ares-I, because they don't know about them at all.   DIRECT largely deletes these problems entirely, so I feel it is worthwhile keeping that information available.

Is the feeling very strong that this section is detracting, given the fact that the main audience is no longer NASA, but the politico's?

Ross.
Title: Re: "DIRECT" Goes Live
Post by: imcub on 11/27/2006 06:18 PM
Quote
MondoMor - 27/11/2006  10:26 AM

Quote
imcub - 27/11/2006  11:59 AM
I try keeping up Jim, but SPF's are ???  Thanks  

Single-point failures.


Thank You.
Title: Re: "DIRECT" Goes Live
Post by: kevin-rf on 11/27/2006 06:18 PM
Quote
kraisee - 27/11/2006  11:03 AM
With 663s Isp, and about 25,000lb thrust on tap, the RL-10B-2 offer better performance while still retaining a lot of RL-10 commonality.

Ross

663 Isp? For real? Typo?  

A glance at atronautix ( http://www.astronautix.com/engines/rl10a42.htm ) lists the ISP as 451...

What is the max achievable LH LOX Isp? The SSME is often quoted at 455 ISP.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/27/2006 06:19 PM
Quote
Jim - 27/11/2006  12:54 PM

It has too many SPF's.   Not worth the headache.  It was an issue for OSP

There is a fairly strong argument that the redundancy of multiple engines actually removes the SPF's entirely.


While a catestrophic engine failure on J-2X or multi-RL-10 will cause an abort anyway, having 7 engines would allow some pretty serious engine-out capability.

A single J-2X premature shutdown causes a guaranteed mission failure.

But a single RL-10 premature shutdown would not compromise the mission.   I've been running a few sims, and it looks like maybe 5 x RL-10's is all that is actually required, so 6 or 7 engines provides multiple redundant 100% engine out capability.


The argument boils down to more components which can go wrong vs. more redundancy.   It's a hard call to make.   I think it's worth putting it on the table to be discussed - especially if it may increase performance noticably.

Certainly not having to develop the J-2X, and man-rating an existing proven engine would offer cost reductions.   Potentially the same engine could also be used elsewhere, for LSAM DS or MTV for example, and such re-use would reduce overall program costs even further.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/27/2006 06:25 PM
Quote
kevin-rf - 27/11/2006  2:01 PM

663 Isp? For real? Typo?  

463s.   If I wrote 663, that was a typo.   Been doing those a lot today, sorry.   Ill again :(

I'm going by an AIAA paper I have here and http://www.astronautix.com/engines/rl10b2.htm says 462s - which is very close and seems to basically confirm the ballpark.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kevin-rf on 11/27/2006 06:33 PM
Ross,

Thats okay, I have a keyboard that keeps dropping keys... Really makes you scratch your head at some of my posts.

Doing a little digging I noticed some of the paper RL-10 designs are quoted with ISP's of 470. Pretty interesting if you ask me.

Anyway back to the topic.
Title: RE: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/27/2006 06:51 PM
Quote
kraisee - 27/11/2006  10:55 AM

Some people seem to think that the anti-Ares-I sections in the DIRECT proposal is detracting from the document.   Is this a widely held belief?

I ask because given NASA completely ignored the concept anyhow, the key audience has now shifted to the politicians above NASA.

I still feel it is better to inform *them* of the problems with Ares-I, because they don't know about them at all.   DIRECT largely deletes these problems entirely, so I feel it is worthwhile keeping that information available.

Is the feeling very strong that this section is detracting, given the fact that the main audience is no longer NASA, but the politico's?

Ross.

I have always felt that the Ares-I section was not necessary to the proposal. As the song goes "accentuate the positive, eliminate the negative..." One of the reasons upper management maybe ignoring the proposal is that it is easy to interpret it as being overcritical of the current approach and to get defensive. Given that the apparent problems with the Ares-I are mostly rumor based (informed rumor true) it would better to leave it out of the proposal. As Clongton said the true strength of the proposal is the cost and versatility of DIRECT. The target audience should not matter since the Politicians are going to ask NASA about each of the points and if their responses can invalidate even one of the anti-Ares-I points it will call the entire proposal into question.
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/27/2006 06:52 PM
Quote
kraisee - 27/11/2006  11:08 AM

Quote
kevin-rf - 27/11/2006  2:01 PM

663 Isp? For real? Typo?  

463s.   If I wrote 663, that was a typo.   Been doing those a lot today, sorry.   Ill again :(

I'm going by an AIAA paper I have here and http://www.astronautix.com/engines/rl10b2.htm says 462s - which is very close and seems to basically confirm the ballpark.

Ross.

Ross while we are on the ISP subject what was the RS-68 Regen's sea level ISP?
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/27/2006 07:04 PM
Quote
SMetch - 27/11/2006  2:35 PM
Ross while we are on the ISP subject what was the RS-68 Regen's sea level ISP?

383s.

Ross.
PS - No typo's this time :)
Title: RE: "DIRECT" Goes Live
Post by: clongton on 11/27/2006 07:22 PM
Quote
kraisee - 27/11/2006  11:16 AM
Wow.   I've convinced even our JIS?   Very Cool!
Ross, if you can turn JIS, a senate subcommittee can't be that hard. :)
Title: RE: "DIRECT" Goes Live
Post by: braddock on 11/27/2006 10:12 PM
Quote
kraisee - 27/11/2006  1:55 PM
Some people seem to think that the anti-Ares-I sections in the DIRECT proposal is detracting from the document.   Is this a widely held belief?

I think it detracts.

Title: RE: "DIRECT" Goes Live
Post by: Smatcha on 11/27/2006 10:35 PM
Quote
kraisee - 27/11/2006  10:55 AM

Some people seem to think that the anti-Ares-I sections in the DIRECT proposal is detracting from the document.   Is this a widely held belief?

I ask because given NASA completely ignored the concept anyhow, the key audience has now shifted to the politicians above NASA.

I still feel it is better to inform *them* of the problems with Ares-I, because they don't know about them at all.   DIRECT largely deletes these problems entirely, so I feel it is worthwhile keeping that information available.

Is the feeling very strong that this section is detracting, given the fact that the main audience is no longer NASA, but the politico's?

Ross.

Addressing the Ares I’s performance issues will detract from your proposal because NASA is committed to spending whatever amount of money and taking all the time in the world to make this work.  As such you will be trying to hit a moving target with floating definitions of technical success save disintegration on ascent.

While the thrust of Jeff’s letter to the troops was based on NASA’s ability to perform minor miracles he completely misses the point.  If the objectives of VSE were about continuing to spend large amounts of money performing minor miracles we wouldn’t be retiring the Space Shuttle.

The primary points articulated and detailed very well in your direct proposals is economics and efficiency not feasibility or NASA’s capability.  And now we find from Doug the answer to the question below is a definite No.
Title: RE: "DIRECT" Goes Live
Post by: Bill White on 11/27/2006 10:42 PM
Quote
braddock - 27/11/2006  4:55 PM

Quote
kraisee - 27/11/2006  1:55 PM
Some people seem to think that the anti-Ares-I sections in the DIRECT proposal is detracting from the document.   Is this a widely held belief?

I think it detracts.


I concur. Remember to tailor arguments to the audience and Congress is not filled with rocket scientists (whether that is good or bad, I reserve comment).

Focus on the MONEY not the technical or engineering merit.  Also the SCHEDULE. There is the gap between orbiter stand down and CEV flying. Senator Hutchinson is big on that. And whether we return to the Moon in 2016 or 2020. That is a sound bite even Katie Couric can understand.

Ares I & V? Moon in 2020. Direct? Moon in 2016, at a lower cost.

The EELV advocates are already bashing the Stick. IMHO, to criticize the Stick risks your proposal being conflated with those who mourn the end of spiral development and an all EELV VSE. Someone posted above the assertion that the Stick would work, but Direct would work better.

IMHO this is how to present it -- not to an audience of rocket scientists but to Congress and the media.
Title: Re: "DIRECT" Goes Live
Post by: rumble on 11/27/2006 11:17 PM
I think it is useful to mention that concerns exist with the performance of the Ares I, and while NASA is perfectly capable of working minor miracles, these miracles come at a cost.  Stating it this way points the technical concerns back to funding, which is accurate and good for a non-technical audience.

I agree with the general sentiment that lacing the document with slaps for the A1 (AresI) have a cumulative effect of detracting from the presentation, but if the A1 comments could be contained in 1 or 2 paragraphs, they could add to the power of the content.

Since DIRECT will share so much commonality with the Shuttle, it might be worth mentioning the ways DIRECT scores over the shuttle in safety, fixed costs, and recurring costs.

IMHO, of course.
Title: Re: "DIRECT" Goes Live
Post by: hop on 11/27/2006 11:17 PM
I tend agree. Noting that the stick may be turning out more expensive and risky than originally thought is reasonable IMO, but it isn't the core argument for DIRECT, so it doesn't need to be a major feature of the proposal.

The core argument is one truly shuttle derived vehicle instead of two that aren't. That would stand on it's own even if the stick wasn't having any trouble.

edit:
The sticks troubles are a good way of driving home the fact that the Ares I/V plan is higher technical risk, but that could be covered in a brief footnote.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/27/2006 11:55 PM
Okay, the general concensus is to change.   I will look at doing a v1.2 release. mainly removing the "Flaws with Ares" section and re-working a few of the other sections to re-direct it (no pun intended).

Thanks for the opinions guys.

R.
Title: RE: "DIRECT" Goes Live
Post by: texas_space on 11/28/2006 03:21 AM
Ross,
I also agree with the others.  Mentioning Ares-1 problems isn't necessarily bad, but they could provide ammunition to those looking to discredit the proposal.  I look forward to V1.2 of the proposal.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/28/2006 04:46 AM
Back on the other topic: ICES w/ cluster of RL-10's...

I can't get my sims to make it fly successfully.   It looked promising at first, but the lower thrust is causing serious problems, wven with the considerably higher efficiency.

Looks like DIRECT will be sticking with the J-2X for now.   Although I have decided to try to analyse some more variants with more J-2X's on to see if performance can be improved.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: Smatcha on 11/28/2006 05:08 AM
Quote
kraisee - 27/11/2006  9:29 PM

Back on the other topic: ICES w/ cluster of RL-10's...

I can't get my sims to make it fly successfully.   It looked promising at first, but the lower thrust is causing serious problems, wven with the considerably higher efficiency.

Looks like DIRECT will be sticking with the J-2X for now.   Although I have decided to try to analyse some more variants with more J-2X's on to see if performance can be improved.

Ross.

Thrust is more important than efficiency for a large upper stage upto a point.  Also you have to watch your ISP vs. kg/s numbers.  There may not be enough room in the interstage to fit the size of engine bells that corresponds with both at same time.  We have run over 10 million configurations and we are pretty close to a configuration we really like.  The J2X engine specs will be key in pulling this off though.

We mentioned in the AIAA paper of the importance of designing the J2X to maximize the HLV not the Shaft.  Yet another cart before the horse problem with the current approach.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/28/2006 05:28 AM
The "nominal" J-2X engine spec of 448s/273,500lbf is what was used to create the DIRECT+EDS performance of 98,232kg lift capacity.

With the highest performance 451.5s/293,750lbf variant of the J-2X so far mentioned, the payload increases only marginally - by about 800kg.   So it isn't really worthwhile spending all that extra development cash for use on DIRECT.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: JIS on 11/28/2006 09:47 AM
Quote
Norm Hartnett - 27/11/2006  7:34 PM
The target audience should not matter since the Politicians are going to ask NASA about each of the points and if their responses can invalidate even one of the anti-Ares-I points it will call the entire proposal into question.

True
Title: RE: "DIRECT" Goes Live
Post by: JIS on 11/28/2006 10:25 AM
Quote
kraisee - 27/11/2006  4:16 PM

Wow.   I've convinced even our JIS?   Very Cool!


Well the reason is apparently that I was always big fan of similar approach but I've seen it as "not big enough" for lunar base. With Ares 1 inherently safer approach the Ares V seemed to be a good choise.

Quote

There were always a few who aren't willing to even consider the possibility still, but I'm glad JIS can be persuaded by a reasoned argument.   I'm more glad he (she? enquiring minds want to know...) was persistent and asked so many critical questions of the system.  

I'm a male. And my wife tells me that I'm changing my mind too often.
But in this case I've started to see the two launch concept as not so bad at all.  

But again I would still prefare DIRECT + EDS + CEV and DIRECT + EDS + LSAM option over your approach because of the mission philosophy.
It's mainly because DIRECT + CEV safety numbers won't be much worse than Ares 1 ones and DIRECT + EDS + CEV should be only little worse.
It is obvious that Ares 1 / Ares V approach is more expensive, but I still see Ares 1 as quite a good and workable concept.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 11/28/2006 11:19 AM
Quote
JIS - 28/11/2006  6:08 AM
 but I still see Ares 1 as quite a good and workable concept.

You need to get better glasses then.  It is far from good and workable is up in the air.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 11/28/2006 11:21 AM
Quote
Bill White - 27/11/2006  6:25 PM

The EELV advocates are already bashing the Stick. IMHO, to criticize the Stick risks your proposal being conflated with those who mourn the end of spiral development and an all EELV VSE. Someone posted above the assertion that the Stick would work, but Direct would work better.


There is nothing wrong with being lumped in with the EELV advocates.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/28/2006 01:43 PM
While you are considering making changes to the proposal I would like to suggest a change that might make it more palatable to NASA upper management (NASAUM), nothing substantive, merely a few name changes.

Direct Phase One renamed to Ares-II
62.5mT to 60x160nm 28.8deg, 2xRS-68, 2x4segSRB, ETA 2011

Direct Phase Two renamed to Ares-III
70.9mT to 60x160nm 28.8deg, 2xRS-68R, 2x4segSRB, ETA 2013

Direct Phase Three renamed to Ares-IV
98.2mT to 60x160nm 28.8deg, 2xRS-68R, 2x4segSRB, EDS 1xJ-2x, ETA 2015

Ares V could be either the currently conceived model or the Direct Enhanced barrel stretch.
130+mT to 60x160nm 28.8deg, 3xRS-68R 2x5segSRB, ETA 2018?

These name changes could allow NASAUM a face saving route to change direction without actually saying they were wrong. They could simply say that Ares-I failed to pass an SRR secondary review due to escalating costs in both development and infrastructure and they were moving to the Ares-II. Ares-III may not be a necessary designation since the changes are minor. Ares-IV follows logically as a precursor to the Ares-V whichever version they chose.
Title: Re: "DIRECT" Goes Live
Post by: JIS on 11/28/2006 01:52 PM
That's a good idea.
Title: RE: "DIRECT" Goes Live
Post by: simcosmos on 11/28/2006 03:18 PM
Hello all,

Going back to the EDS stuff, I have been preparing a few notes and was to post them yesterday but... was trying to get the text a bit shorter to avoid some boring reading (argh) :)

Here it goes anyway, without the "cuts" and without a math / physics revision (Ross, you too have reached at some of the same conclusions meanwhile). Ok, maybe better to not delay it too much, it might still have a few interesting pieces here and there, even if it could be shorter and have a better wording ;)




I. Centaur / ICES and DIRECT EDS

Just as a side note, and as mentioned in previous posts, the EDS 3D model is based in something like an evolution of Centaur / ICES plans, (except for the engine, and the stage diameter) and the same can also be said when looking at the representations in the current DIRECT proposal.

However, there is still a bit of work ahead:
- calculating the length of the 8.4m diameter EDS for a given propellant mass should not be too much hard (although it is not trivial, given the common bulkhead)
- and I guess that our other more difficult unknown variable is perhaps to achieve a better estimative for the empty mass of such EDS design


By the way, ICES plans are for a 5.4m diameter stage and ranging from 1.5x (31008Kg) up to 6x (124032Kg) of the current Centaur propellants quantity (20672Kg).

Empty Centaur mass = 1914Kg (SE) / 2106Kg (DE = +192Kg for adding extra engine)

Starting then with 1722Kg and applying a few proportional "dummy and clumsy rules" + inserting a little extra for margins, I have these (very rough) estimative for empty masses in function of propellant quantity (they are probably lower, if taking out the somehow artificially added margins or maybe not, do not know)..

Rough Estimative for Empty Mass (not considering engines) of a Centaur like stage vs Prop. Quantity
~10330Kg for 124032Kg prop.
~12500Kg for 150000Kg prop.
~14575Kg for 175000Kg prop
(at least these should give a starting point)

Now adding engines to the above empty masses:
6 x 301Kg RL-10-B2 = 1806Kg
1 x 1800Kg J-2Xiss*  = 1800Kg

Note1: *Assuming here that J-2X will have a mass of ~1700Kg up to 1800Kg (the 274Klbf / 448s ISP version), perhaps a maximum of 1900Kg (for an uprated variant?)

This means that in terms of mass, 1 J-2X is comparable to 6 x RL-10-B2. The RL-10 version used in the EDS would probably be a variant having an already extended nozzle, if wanting to keep the 462s ISP and to avoid some complexity.

Note2: Just as comparison, the current DIRECT EDS (pdf v1.1.1) is powered by the 448s ISP J-2X variant, and has 175129Kg of propellants, 14352Kg empty mass.



II. EDS design, ascent to LEO and missions

There is however one thing that concerns me a little: gravity losses during the ascent (when comparing with J-2X thrust).

For a TLI payload of ~38t (considering DIRECT single launch), one EDS with 125000Kg of propellants and 6 or 7 RL-10-B2 could perhaps do the job but we would perhaps be playing with safety margins and also perhaps with a *non-standard* ascent profile...

I'm not sure, but given the basic DIRECT core, 4 segments SRB and payload constraints (for example, if considering a 38t to 40t LSAM going to the Moon in a single DIRECT launch) I would prefer to have some more thrust for the ascent into LEO given that we can't extract much more dV for EDS + Payload injection without going for DIRECT core and /or boosters upgrade paths.

By gravity losses, I'm talking about:
1218KN (J-2Xiss) or 1307KN (J-2Xmoon) vs 6 x 110KN = 660KN (RL-10-B2* cluster)

Without doing further math or experimentation this is just me talking to the air: I'm not sure if, giving DIRECT's basic configuration, it pays off to have RL-10 powering its EDS. It depends also of what we choose for J-2X numbers. The question would be different if comparing two EDS with equivalent propellant load (one with J-2X, the other with 6 x RL-10-B2*) but already in a stable orbit or if talking about launching one 125t EDS alone.

Some calculations needed but, giving the launcher's basic design, it would probably be better to have something like the J2-X (or even two of them if going for higher EDS propellant loads but using DIRECt basic core), and perhaps try to implement all other cool Centaur / ICES improvements (common bulkhead, boil-off reduction tech, perhaps transfer capability, etc) adapted to a 8.4m diameter design and in a phased way.

Again, RL-10 could be more attractive if the EDS + payload were almost inserted into orbit by the core. However that would require the DIRECT upgrade paths, bringing more costs upfront and kind of going against DIRECT's possibility of a phased upgrade path (later on), if needed.

Having written this, I would love to read about a more accurate empty mass estimative for a propellant load of 106t, 125t, 150t, 175t and perhaps also 200t, and respective required length variations, assuming an EDS with 8.4m diameter and powered by 1 x J-2X (or two for the 175t and 200t variants)

PS: the best of the best would really to have something with J-2X thrust and RL-10-B2 ISP but that is just me stating the obvious :)
   

IIa. More Loose thoughts, still related with EDS

As a side note, I have been playing with DIRECT and the following EDS design:

EmptyMass=12130Kg
PropMass=125000Kg
Thrust=1218000N
ISP=448s


Assuming:
4210Kg for payload fairing (22m length, 8.4m diameter)
4800Kg for interstage
40000 Kg for payload (big module, LSAM design, etc)

I was then able to inject the EDS + LSAM into 150Km x 220Km (launching East) having ~59274Kg of propellants in the EDS, which gives an ideal dV budget of ~3337m/s. In fact, was able to perform a ~3154m/s TLI and still have something like 1.7% of propellants in EDS tanks.

This also means:
~76674Kg of propellants if launching EDS + 22.6t CEV, dV budget = 5121 m/s, which could be enough, as also mentioned in one of my past long posts, to fully deliver the CEV + EDS into lunar orbit with the possibility of using the EDS as a later propellants depot in lunar orbit. "Just" replace the CEV mass by a 22t tank (something like the common centaur with no engines?) to make such propellant delivery (in future missions just for that objective or by using spare props from other missions)


~99274Kg of propellants if launching the EDS alone, which would be enough for an ideal TLI of ~3438m/s, considering 71500Kg as payload (which could be a 22t container + LSAM, from other DIRECT) or even greater payload mass if using a more conservative TLI dV.

Of course that this simulation is very simplistic (real life is a lot more complicated!) but it should probably and at least hint about some eventual single / dual launch DIRECT capabilities regarding lunar missions (some of this is already mentioned in the proposal, just adding a few numbers / results from the current worki in progress inside Orbiter sim).

Perhaps it would be interesting to investigate the following points:

i) DIRECT EDS Size

How big DIRECT EDS really needs to be? Maybe it is because of the simple simulation I have been doing here but it seems that a 125t EDS is able to do the same as the 175t EDS in v1.1.1 of the proposal, given that it has a lower total mass and we can better use J-2X capabilities during the ascent that way.

As another side note, and to compare performance estimative in the simulator, launching DIRECT CLV v0.1 simplistic / alpha development version (it will be uploaded one of these days) I was able to inject 75.5t into ~380Km x 65Km - ISS inc (22.6t CEV + 48.9t ballast container + 4t SLA) and still have ~1% propellants in the ET at MECO, which seems to be +/- in accordance with the numbers in the proposal.

Just curious about something: Ross could you please plug the above EDS numbers into your simulations?

I'm not too sure but perhaps there is not the need to have the EDS with 175t. Have you played with different EDS propellants loads vs payload to LEO (by updating empty mass accordingly with prop. load and by using the same J-2X configuration?). I still need to do more tests but perhaps something like a <~125t to 150t of propellants maximum capability would be better for DIRECT EDS, at least for a first phase and considering ascent risks. Of course that the higher the propellant capability, the higher will be the payload allowed, if we think about using prop. transfer tech more down the road or even in the middle term and if thinking about starting missions with an EDS having full tanks in LEO but, considering all, and given that Mars might still be a good years ahead, I think that would be best to have one as small as possible EDS design while still keeping performance goals for the Moon, I mean: not sure but suspect that the same work of the 175t prop. EDS could be done with a smaller design (unless I messed numbers somewhere: it would be nice if someone could double check this: I have too many things going on in my plate in these days :) )


ii) Another point that we could think about would be regarding LSAM design:

What can we land in the Moon with a 38t to 40t LSAM (including payload). Have here some past studies that show landers with a mass of 40t, hummm (more things to read).

Related with that, could the LSAM be configurable and modular enough to be used in a *lighter mode* (for DIRECT single launches) and in a *heavy mode* (for DIRECT dual launches) and thus, in the *heavy mode* maintain or have greater capability than ESAS planned ones?

What can be done to optimise such LSAM design, under these conditions?
(and perhaps also having a blink of an eye regarding Mars)

Ho, and of course that for now I'm just talking about of LEO or lunar orbit rendezvous approaches but when we think about a possibly higher flight rate eventually allowed by DIRECT launcher, we could also think in a number of alternative ways of doing exploration, after a first "test" phase (prop. transfer tech for later missions, partially reusable landers, other rendezvous options...)

I still think that DIRECT + exploration goals would greatly benefit with something similar to LM lander proposal both when thinking in single and dual launch mode... Hummm, maybe one day I will make such a lander design integration, just for fun and to better demonstrate these ideas ;)

António
Title: RE: "DIRECT" Goes Live
Post by: jongoff on 11/28/2006 03:37 PM
Ross, Simcosmos,
There's a very real chance that maybe the RL-10 version of the ICES stage might not do the trick for EDS.  I'm looking into one last option.  There was a version of the RL10 called the RL10-C that had been worked on back in the 90's.  I'm not positive, but I think they took it all the way to prototype firings--about as far as the RL-10B variants got before they finally had a customer pull them off-the-shelf.  It has about 35klbf per engine, weighs similar to the RL-10B (about 320kg IIRC), and provides somewhere around 450s Isp.  

The nice thing about RL10s is that they're quite inexpensive (usually about $5M stock), and this might be a good engine to pull of the shelf anyway for Lockheed and Boeing's commercial man-rated EELV projects.  That extra 50% thrust should make it a lot easier to close the dead-zones on single engine upper stage designs.  If it turned out that the RL10-C would help out the man-rated Atlas designs (as well as the other LEO Atlas versions as opposed to the GTO ones where Isp matters a lot more than T/W), and if Lockheed were willing to place orders for a few up front, I wouldn't be surprised if the engine could be in operations by the time Atlas V manrating is winding down (say 2008ish).

Alas it's a long shot, I didn't think that gravity losses would be quite so bad with a WBC design, but then again, the Atlas V core may provide more of the thrust and delta-V than DIRECT does for EDS.  I don't have access to a good simulator, so this sort of thing is the one thing I have to lean heavily on someone else for.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: Smatcha on 11/28/2006 04:18 PM
There are a number of good reasons why the second stage of the Saturn V was designed the way it was.  You will get closer to an optimal design by understanding that one.  Hint ditch the RL-10's your're designing a HLV not an ELV.
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/28/2006 04:51 PM
Since the work I have scheduled for this week is dull, repetitive, and persnickety I decided to give myself over to a flight of fantasy. Feel free to cast stones.

Ares Mission descriptions

2011
Ares-II-1: Payload – CEV test vehicle, Secondary Payload – mass simulator – Purpose: verify that the SRBs are recoverable, 51deg (1)

Ares-II-2: Payload – CEV test vehicle, Secondary Payload – mass simulator – Purpose: verify CEV, 28deg

2012
Ares-II-3m: Payload – CEV Manned, Secondary Payload – mass simulator – Purpose: Crewed operations, 28deg

Ares-II-4: Payload – CEV test vehicle, Secondary Payload – ATV – Purpose: ATV test, ISS re-supply, 51deg

Ares-II-5m: Payload – CEV Manned, Secondary Payload – mass simulator – Purpose: ISS Crew, 51deg

Ares-II-6m: Payload – CEV Manned, Secondary Payload – LSAM simulator 1 (2) – Purpose: LIDS test, docking tests, 28deg

2013
Ares-II-7: Payload – MPLM Module – ATV Tug – Purpose: test ATV tug, ISS re-supply, 51deg (3)

Ares-III –1m: Payload – CEV Manned, Secondary Payload – ATV – Purpose: ISS crew/re-supply, 51deg (4)

Ares-III-2m: Payload – CEV Manned, Secondary Payload – LSAM simulator 2 (5) – Purpose: Joint maneuvering tests, simulated EDS rendezvous and docking tests, 28deg

Ares-III-3: Payload – Habitat module – ATV Tug – Purpose: ISS Module, 51deg (6)

Ares-III-4m: Payload – CEV Manned, Secondary Payload – ATV – Purpose: ISS crew/re-supply, 51deg

2014
Ares-III-5m: Payload – CEV Manned, Secondary Payload – ATV – Purpose: ISS crew/re-supply, 51deg

Ares-III-6 & 7m
     6: Payload – EDS simulator/new ISS module (50-60mT), 51deg
     7m: Payload – CEV Manned, Secondary Payload – LSAM Simulator/ATV Tug, 51deg
Purpose: Dual launch, CEV to LSAM docking, CEV-LSAM to EDS docking, ISS module (7)

Ares-III-8m: Payload – CEV Manned, Secondary Payload – ATV – Purpose: ISS crew/re-supply, 51deg

2015
Ares-III-9m: Payload – CEV Manned, Secondary Payload – ATV – Purpose: ISS crew/re-supply, 51deg

Ares-III-10m & Ares-IV-1
Ares-III-10m: Payload – CEV Manned, Secondary Payload – LSAMC-1, 28deg
Ares-IV-1: Payload – EDS, 28deg
Purpose: Docking, rendezvous and docking, LSAM-EDS TLI, LSAMC-1 LOI, landing. (8)

Ares-III-11m: Payload – CEV Manned, Secondary Payload – ATV – Purpose: ISS crew/re-supply, 51deg

Ares-III-12m & Ares-IV-2
Ares-III-12: Payload – CEV Manned, Secondary Payload – LSAM 1, 28deg
Ares-IV-2: Payload – EDS
Purpose: return to the moon.

Mission Footnotes
(1)   Sorry, a little Ares-I-1 joke, obviously this mission would test real issues.
(2)   LSAM simulator 1, I am envisioning an ATV with a LSAM front end, docking equipment etc.
(3)   Total fantasy, one of the MPLM hard mated to an empty ATV with the ATV docking antenna moved to the front of the MPLM. The ATV would bring the MPLM into grasping range of the station arm and go inert. The station arm would dock the stack to the station and re-supply would take place. The station arm would undock the stack and the ATV would deorbit the stack. Probably wouldn’t fly worth beans but one possibility for getting modules to the station.
(4)   First full up ISS crew and re-supply mission. CEV separates from Ares and proceeds to ISS, ATV separates from Ares and loiters in either low orbit or near ISS orbit until CEV is docked then docks itself.
(5)   This mission is dependant on LSAM development. When LSAM propulsion and guidance is ready LSAM simulator 2 is built and docking and maneuver tests conducted.
(6)   Another fantasy flight based on Ares-III-7. In this mission the ATV tug would be soft mated to the Habitat module and would again fly to within reach of the arm and go inert. The arm would dock the stack to the station and the ATV would de-mate and dock in its normal position. ATV antenna would be temp mounted on the Habitat.
(7)   This one is even weirder, I wanted to get one of Ross’ large modules to the station and I wanted an early test of dual launches with the CEV-LSAM-EDS rendezvous and docking without completed LSAM and EDS equipment. Don’t ask me how it is supposed to work.
(8)   First lunar precursor mission LSAM Cargo module. CEV separates and returns to earth while stack goes to the moon.

Well there you go, one of the best things about DIRECT is the flexibility. I have deliberately kept the flight rate low presuming that NASA would be spending its money on resurrecting its science program, man-rating EELVs, purchasing COTS flights, robotic lunar exploration, resurrecting and developing ISS modules, and developing the RS-68R, J-2X, LSAM, EDS.
Back to work now.

Edit: I will cast the first stone: I see that the Orion won't be ready until 2013 according to page 6 of the proposal.
Title: RE: "DIRECT" Goes Live
Post by: Bill White on 11/28/2006 05:26 PM
Quote
kraisee - 27/11/2006  6:38 PM

Okay, the general concensus is to change.   I will look at doing a v1.2 release. mainly removing the "Flaws with Ares" section and re-working a few of the other sections to re-direct it (no pun intended).

Thanks for the opinions guys.

R.

Another potential talking point to emphasis as part of Direct's flexibility is the ability to deliver large payloads to ISS with "last mile" guidance. This means modules. Ross does mentions this however it could be a huge selling point worth stressing to the ISS huggers.

Years ago I followed a debate about using Shuttle C to complete ISS. Stand down orbiter in 2004 and complete ISS with shuttle C. The objection was the lack of last mile guidance. If the CEV can detach from the upper stage and dock with the cargo payload, last mile guidance to ISS is achieved.

Neither Ares I or Ares V can do that nor can an EELV CEV.

How quick can Direct be deployed? In time to replace a final few orbiter missions to ISS before 2010?
Title: Re: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/28/2006 06:04 PM
Ross lists 2011 as the eta for the Ares II (Direct Phase One). I think NASA would have to cut missions now to have the cash to develop DIRECT any sooner. Page 6 of the proposal seems to indicate that the earliest the Orion will be ready is 2013.
Title: RE: "DIRECT" Goes Live
Post by: Norm Hartnett on 11/28/2006 06:26 PM
Quote
Bill White - 28/11/2006  10:09 AM

Another potential talking point to emphasis as part of Direct's flexibility is the ability to deliver large payloads to ISS with "last mile" guidance. This means modules. Ross does mentions this however it could be a huge selling point worth stressing to the ISS huggers.

Years ago I followed a debate about using Shuttle C to complete ISS. Stand down orbiter in 2004 and complete ISS with shuttle C. The objection was the lack of last mile guidance. If the CEV can detach from the upper stage and dock with the cargo payload, last mile guidance to ISS is achieved.

Neither Ares I or Ares V can do that nor can an EELV CEV.

How quick can Direct be deployed? In time to replace a final few orbiter missions to ISS before 2010?

I had suggested using the ATV in that roll in the post above yours but using the CEV is more efficent. If, heaven forbid, the shuttle was grounded between now and 2010 switching to the Ares-II and accelerating the Orion development could offer an alternative method of completing the station.
Title: RE: "DIRECT" Goes Live
Post by: Bill White on 11/28/2006 07:06 PM
Quote
Norm Hartnett - 28/11/2006  1:09 PM

Quote
Bill White - 28/11/2006  10:09 AM

Another potential talking point to emphasis as part of Direct's flexibility is the ability to deliver large payloads to ISS with "last mile" guidance. This means modules. Ross does mentions this however it could be a huge selling point worth stressing to the ISS huggers.

Years ago I followed a debate about using Shuttle C to complete ISS. Stand down orbiter in 2004 and complete ISS with shuttle C. The objection was the lack of last mile guidance. If the CEV can detach from the upper stage and dock with the cargo payload, last mile guidance to ISS is achieved.

Neither Ares I or Ares V can do that nor can an EELV CEV.

How quick can Direct be deployed? In time to replace a final few orbiter missions to ISS before 2010?

I had suggested using the ATV in that roll in the post above yours but using the CEV is more efficent. If, heaven forbid, the shuttle was grounded between now and 2010 switching to the Ares-II and accelerating the Orion development could offer an alternative method of completing the station.

I will stop after this post with respct to the ISS angle (unless Ross encourages more) but it seems to me that Ares-II (Direct with crew & cargo) could deliver TWO ISS assembly modules per launch rather than one using orbiter.

70.9 MT to 28 degrees surely equals two shuttle payload bays to 51 degrees with mass left over. Every Ares II launch tasked to ISS assembly would replace TWO orbiter launches plus whatever sundry supplies could by stashed in the nooks and crannies of the cargo module.  Also, if CEV flew partial crew then there would be at least some down mass capability as well, correct?

It seems to me that the Direct architecture not only gets us to the Moon sooner and cheaper but it also allows ISS to remain more than fully functional and quite possibly expanded, without massive budget increases.

If Ross is looking for political support for Direct then an increased capability to complete, maintain and actually use ISS without sacrifices from "Moon, Mars and Beyond" would be altogether good.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/28/2006 07:14 PM
Bill,
   Because so much of the hardware DIRECT re-uses is already flight-proven, development for DIRECT is in the 4-5 year timeframe.   That puts it late 2011 if the decision were made to switch right now.   The later the decision is made, the later DIRECT becomes operational.   If NASA waits 6 months, it would delay DIRECT 6 months to summer of 2012.


   The changes are far less than for Ares-I or Ares-V.   The SRB's don't change at all, so there's no costs or delays there (although upgrading the avionics package is a good idea at this time).

   Because most of the tanking structure does not change significantly, we expect construction of the first DIRECT Core stage could begin within 3 months of the final Shuttle ET going through the production line.   The tanking structures only require that the milling machines be adjusted to cut the Al-Li a little thicker than perviously - to make the tanks stronger.   The Intertank can remain largely unchanged too, except slightly thickened walls too.   And the tank domes require virtually no modifications at all.   The new LOX tank fwd dome would use much of the same gores as the aft LOX tank does today, and dome, tank wall and payload interface structure would share a lot of commonality to the existing LOX tank>Interstage assembly.

   The specific hardware for attaching the Orbiter can all be deleted, and replaced with a new Interface above the LOX tank for payloads, but that isn't a difficult change.

   New plumbing is required for the LH2 tank to vent down into the Thrust Structure instead of up and out of the sidewall, but that's a well practiced method on other LV's, so isn't a particularly big deal.

   The biggest change, and the one which will likely set the final schedule, is going to be the creation of the all-new thrust-structure on the aft.   That will have to be all-new and all-new manufacturoing hardware will be required.   But Ares-I's US also requires all-new hardware for it's Thrust Structure, so in practice, there is very little difference there.   Not to mention that Ares-V requires an even bigger TS anyway, in addition.

   The two big "pacing" items for Ares-I are the development work required for recreating the J-2X and developing the all-new 5-seg SRB's.   DIRECT deletes both of these time-critical items.

   The RS-68 is already a flight proven engine, and the first versions of DIRECT do not require the Regen nozzle, so we don't have to wait for that.   Because it's already a flight-qualified engine, it is already a fair ways towards man-rating, but I would expect most of the 4-5 year timing to be used in modifying and man-rating that engine.

   The pacing items for DIRECT will be the RS-68 man-rating, and the development and construction of the Thrust Structure.

   There could be a time element regarding the MLP modifications, but I don't believe they will take more than 2 years.

Ross.
Title: RE: "DIRECT" Goes Live
Post by: Jim on 11/28/2006 07:18 PM
Quote
Bill White - 28/11/2006  1:09 PM


Another potential talking point to emphasis as part of Direct's flexibility is the ability to deliver large payloads to ISS with "last mile" guidance. This means modules. Ross does mentions this however it could be a huge selling point worth stressing to the ISS huggers.

Years ago I followed a debate about using Shuttle C to complete ISS. Stand down orbiter in 2004 and complete ISS with shuttle C. The objection was the lack of last mile guidance. If the CEV can detach from the upper stage and dock with the cargo payload, last mile guidance to ISS is achieved.

Neither Ares I or Ares V can do that nor can an EELV CEV.


No CEV can do it.  

All the sensors required for rendevous and "last mile" guidance are situated on the apex of the CM around the LIDS.  Anything docked to the CEV would render all these sensors useless.  Also it would block the crew visiblity.  

Adding the sensors to the "payload" is not a cheap nor easy solution.  misalignments  and structure flexing would  introduce errors.  Also data connections would have to handle high data rates.

Ross,  you need to rethink this aspect.
Title: RE: "DIRECT" Goes Live
Post by: Bill White on 11/28/2006 07:36 PM
Quote
Jim - 28/11/2006  2:01 PM

Quote
Bill White - 28/11/2006  1:09 PM


Another potential talking point to emphasis as part of Direct's flexibility is the ability to deliver large payloads to ISS with "last mile" guidance. This means modules. Ross does mentions this however it could be a huge selling point worth stressing to the ISS huggers.

Years ago I followed a debate about using Shuttle C to complete ISS. Stand down orbiter in 2004 and complete ISS with shuttle C. The objection was the lack of last mile guidance. If the CEV can detach from the upper stage and dock with the cargo payload, last mile guidance to ISS is achieved.

Neither Ares I or Ares V can do that nor can an EELV CEV.


No CEV can do it.  

All the sensors required for rendevous and "last mile" guidance are situated on the apex of the CM around the LIDS.  Anything docked to the CEV would render all these sensors useless.  Also it would block the crew visiblity.  

Adding the sensors to the "payload" is not a cheap nor easy solution.  misalignments  and structure flexing would  introduce errors.  Also data connections would have to handle high data rates.

Ross,  you need to rethink this aspect.

Has any CEV metal been cut, yet?

Am I correct that the Russian KURS system uses a boom or antenna extended from the Soyuz? Add sensors to an extendable boom (or three) to the exterior of CEV and those can guide CEV to ISS when it is in cargo tug mode. Keep the sensors integral to CEV.

Perhaps an ISS CEV version would have these booms while a lunar CEV would not.

Re-designed avionics strikes me as an easier issue to solve than not having sufficient LEO lift capability to loft an ISS module in the first place (Ares 1 & EELV) or the lack of a piloted vessel (Ares V).
Title: Re: "DIRECT" Goes Live
Post by: josh_simonson on 11/28/2006 07:49 PM
Too bad the RL-60 is lost in limbo.  It might come back with the wide body centaur though.

There's talk of using the RL-10 on the LSAM descent stage, so it may end up in flying somewhere in the stack anyway.
Title: RE: "DIRECT" Goes Live
Post by: kraisee on 11/28/2006 07:54 PM
Jim,
   The CEV does not have to perform the docking manoeuvers at all.   Instead it could just rendezvous in close enough proximity for the station's RMS arm to grab the module.   At that point the CEV separates and the module is finally docked with the arm.   The CEV then performs its own docking manoeuver independantly.   By not requiring the CEV to perform the actual docking, this approach greatly reduces the complexity and requirements on the CEV itself.

   Of course, DIRECT's EOR/LOR mission profile requires that the LSAM have a pack of sensors designed to perform rendezvous and docking anyway.   If designed correctly, it should not be all that difficult to take these packs and use them on something else - especially if that 'something else' is of a similar size and mass.


   To that end, I would suggest creating a standardised "mission module" profile.   It would always with the same mass, CofG and physical size for all non-LSAM payloads.   Perhaps it could match the LSAM's profile to create the greatest possible commonality, but that may be more hassle than its worth.   Either way, a standard size and mass would simplify things enormously.

   Any unused mass and re-balancing the CofG would be performed by simply adding water tanks to the structure carrying the payload.


   Regarding control, the CEV is already being designed to be capable of controlling an unpowered 45mT LSAM using the CEV's own RCS.   While this will not be *necessary* for most flights, the *ability* is still being integrated for unforseen contingency situations which may arrise during any Lunar missions.   A "similar" capability to this one is what is required for CEV to perform rendezvous operations with ISS missions, so much of the control software will exist already.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: rsp1202 on 11/28/2006 08:00 PM
Ross,
Have you run any sims proving the control authority necessary for docking the CEV/SM/fairing/LSAM to EDS? You've kinda glossed over this whole critical procedure.
Title: RE: "DIRECT" Goes Live
Post by: clongton on 11/28/2006 08:02 PM
Quote
Jim - 28/11/2006  3:01 PM
Quote
Bill White - 28/11/2006  1:09 PM
Another potential talking point to emphasis as part of Direct's flexibility is the ability to deliver large payloads to ISS with "last mile" guidance. This means modules. Ross does mentions this however it could be a huge selling point worth stressing to the ISS huggers.

Years ago I followed a debate about using Shuttle C to complete ISS. Stand down orbiter in 2004 and complete ISS with shuttle C. The objection was the lack of last mile guidance. If the CEV can detach from the upper stage and dock with the cargo payload, last mile guidance to ISS is achieved.

Neither Ares I or Ares V can do that nor can an EELV CEV.


No CEV can do it.  

All the sensors required for rendevous and "last mile" guidance are situated on the apex of the CM around the LIDS.  Anything docked to the CEV would render all these sensors useless.  Also it would block the crew visiblity.  

Adding the sensors to the "payload" is not a cheap nor easy solution.  misalignments  and structure flexing would  introduce errors.  Also data connections would have to handle high data rates.

Ross,  you need to rethink this aspect.
This is exactly the issue I had in mind when I discussed cargo capability with Ross last month.
See his post #79711, close to the top, with graphic.

Essentially, it notes that the CM and SM are really 2 'separate' vehicles, integrated to create 'Orion'. There is no technical reason that they *must* be directly connected to each other. My suggestion was to create a cargo 'cage' that would mount between them, to secure any cargo being brought up. Services from the SM to the CM would be via a spine running the length of one side of the cage. Services would connect to the CM in the normal manner. Orion would do 'last mile' station keeping, and the station arm would remove any cargo modules. Orion would then move to and dock with ISS.

The issue with the safety of carrying cargo (from the CAIB) is addressed in that the LAS would still function to pull the CM away if need be. Once it is jetisoned, the SM engine would serve that role. Once in orbit, the SM engine does any orbital adjustments, the same way as if Orion was flying in passenger-only mode.

At the end of the mission, the SM does the de-orbit burn and the SM/Cargo cage are jetisoned while the CM re-enters normally.

Note, however, that this configuration would only be flown when there was valid reason for a crew to accompany the cargo. If a crew was not required, Direct would lift the cargo only, using an unmanned version of Orion, outfitted for automated approach and docking/station keeping. Lesson from the CAIB: do *not* fly crew and cargo together unless *absolutely* necessary. While this configuration does fly them together, it does so in a manner which completely addresses the underlying reason for that prohibition, and does so without endangering the crew, like shuttle does.

A passenger-only configuration would connect CM & SM in the configuration everyone is used to seeing.

All this is, of course, speculative, but would definetely be the best of both worlds (passenger-only vs. passenger+cargo)

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/28/2006 08:04 PM
lining up to dock isn't the hard part.   TV is only needed for docking.   Rendezvous is the hard part and that is what most of the sensors support.


"Has any CEV metal been cut, yet?"

In essence, yes, its shape has been baseline.  As for booms and such, there is no place to put them since the CEV is an aerodynamic vehicle and it is also covered by a BPC.    The Progress/Soyuz is inside of a fairing during launch and therefore can have protuberances.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/28/2006 08:12 PM
"There is no technical reason that they *must* be directly connected to each other."

1.  the CM heat heat shield must be covered
2.  Fluids (GN2, O2, glycol, etc) was flow between the two modules
3.  Thrusters must be at the cg or 2 sets would be required
4. The RMS can't pluck a payload out of a "undocked" vehicle.  The deliver vehicle must be secured
5.  The SM engine would not be able to do an abort to orbit or a retro abort  during launch with the extra mass and inertia.
Title: Re: "DIRECT" Goes Live
Post by: Bill White on 11/28/2006 08:27 PM
Quote
Jim - 28/11/2006  2:47 PM

lining up to dock isn't the hard part.   TV is only needed for docking.   Rendezvous is the hard part and that is what most of the sensors support.


"Has any CEV metal been cut, yet?"

In essence, yes, its shape has been baseline.  As for booms and such, there is no place to put them since the CEV is an aerodynamic vehicle and it is also covered by a BPC.    The Progress/Soyuz is inside of a fairing during launch and therefore can have protuberances.

Even if the CEV crew capsule shape cannot be disturbed (I am not qualified to dispute that point) why couldn't we put [retractable] booms on the service module?
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/28/2006 08:31 PM
Quote
Jim - 28/11/2006  3:55 PM

"There is no technical reason that they *must* be directly connected to each other."

1.  the CM heat heat shield must be covered
2.  Fluids (GN2, O2, glycol, etc) was flow between the two modules
3.  Thrusters must be at the cg or 2 sets would be required
4. The RMS can't pluck a payload out of a "undocked" vehicle.  The deliver vehicle must be secured
5.  The SM engine would not be able to do an abort to orbit or a retro abort  during launch with the extra mass and inertia.
1. It would be. The fwd end of the cage would mimic the fwd end of the SM, and completely enclose & protect the heat shield.
2. All services to CM from SM would flow normally, thru umbilical in cage spine. Then connect to CM just like they do with SM directly attached. Essentially, the fwd end of the cage *is* a SM fwd end.
3. 2 sets should be used anyway, cm/sm thrusters working together. To design otherwise is to deliberately design in a lack of flexability. We should learn from past experience, not repeat known shortcomings.
4a. Then dock the spacecraft and then use the station arm to extract payload.
4b. Station keeping extraction is the basis of ATV and Dragon. Essentially it's 4a, only the station arm captures and docks the spacecraft, rather than the spacecraft docking itself.
5. Yes it could, but the profile might not be pretty. But if things were really that bad, then they could do an abort to suborbit and come down in the ocean. We've been there - done that.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/28/2006 08:47 PM
Quote
clongton - 28/11/2006  4:14 PM
3. 2 sets should be used anyway, cm/sm thrusters working together. To design otherwise is to deliberately design in a lack of flexability. We should learn from past experience, not repeat known shortcomings.
5. Yes it could, but the profile might not be pretty. But if things were really that bad, then they could do an abort to suborbit and come down in the ocean. We've been there - done that.

Chuck


3.  CM thrusters are only for entry, are on on side of the CM, since they are only for CM rotation and can't rotate the CM/SM together.  the existing SM thrusters are redundant.  

5.  that is the retro abort.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/28/2006 08:55 PM
Quote
Bill White - 28/11/2006  4:10 PM
Even if the CEV crew capsule shape cannot be disturbed (I am not qualified to dispute that point) why couldn't we put [retractable] booms on the service module?

One of the sensor packages is the star trackers, which must be rigidly attached to the frame of the CEV.   There is a picture on L2 of all the sensors.  I need more time to find it.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/28/2006 08:58 PM
Quote
Jim - 28/11/2006  4:30 PM

3.  CM thrusters are only for entry, are on one side of the CM, since they are only for CM rotation and can't rotate the CM/SM together.  the existing SM thrusters are redundant.  

5.  that is the retro abort.
3. As currently configured you mean. I'm saying change it. If it's even *remotely* possible that Orion *might* be able to use this flexability at some time in the future, then design it in now, rather than a retrofit later. It's the smart thing to do. Besides, even without the cargo cage, redundancy is a good safety thing.

5. That's what I meant. I was having a brain fart and couldn't think of the term  :)

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Bill White on 11/28/2006 09:05 PM
Quote
Jim - 28/11/2006  3:38 PM

Quote
Bill White - 28/11/2006  4:10 PM
Even if the CEV crew capsule shape cannot be disturbed (I am not qualified to dispute that point) why couldn't we put [retractable] booms on the service module?

One of the sensor packages is the star trackers, which must be rigidly attached to the frame of the CEV.   There is a picture on L2 of all the sensors.  I need more time to find it.

If an attached LSAM would not block the star tracker why would a payload module designed to the same external parameters of the LSAM block the star trackers?
Title: Re: "DIRECT" Goes Live
Post by: kool-aid on 11/28/2006 09:12 PM
All this thruster talk makes me wish for a good Canfield joint!
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/28/2006 10:00 PM
Quote
clongton - 28/11/2006  4:41 PM

3. As currently configured you mean. I'm saying change it. If it's even *remotely* possible that Orion *might* be able to use this flexability at some time in the future, then design it in now, rather than a retrofit later. It's the smart thing to do. Besides, even without the cargo cage, redundancy is a good safety thing.

Chuck

The CM thrusters use GOX and ethanol.  SM is hypergol.  CM has 2 sets of six thrusters just like Apollo that are flush with the skinline.  One thruster provides the impluse to rotate the CM (only) in one direction on one axis.  

Totally redesign of the system would be required.  the CM would increase in weight and the current shape won't work.  Also the redundacy on CM still doesn't mean those thrusters can provide a translation.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/28/2006 10:02 PM
Quote
Bill White - 28/11/2006  4:48 PM

Quote
Jim - 28/11/2006  3:38 PM

Quote
Bill White - 28/11/2006  4:10 PM
Even if the CEV crew capsule shape cannot be disturbed (I am not qualified to dispute that point) why couldn't we put [retractable] booms on the service module?

One of the sensor packages is the star trackers, which must be rigidly attached to the frame of the CEV.   There is a picture on L2 of all the sensors.  I need more time to find it.

If an attached LSAM would not block the star tracker why would a payload module designed to the same external parameters of the LSAM block the star trackers?

Because the LSAM provides all the navigation, control and propulsion while the CEV is attached.
Title: Re: "DIRECT" Goes Live
Post by: Bill White on 11/28/2006 10:21 PM
Quote
Jim - 28/11/2006  4:45 PM

Quote
Bill White - 28/11/2006  4:48 PM

Quote
Jim - 28/11/2006  3:38 PM

Quote
Bill White - 28/11/2006  4:10 PM
Even if the CEV crew capsule shape cannot be disturbed (I am not qualified to dispute that point) why couldn't we put [retractable] booms on the service module?

One of the sensor packages is the star trackers, which must be rigidly attached to the frame of the CEV.   There is a picture on L2 of all the sensors.  I need more time to find it.

If an attached LSAM would not block the star tracker why would a payload module designed to the same external parameters of the LSAM block the star trackers?

Because the LSAM provides all the navigation, control and propulsion while the CEV is attached.

Good answer. :-)
Title: RE: "DIRECT" Goes Live
Post by: copernicus on 11/28/2006 10:22 PM
And now back to our regularly scheduled program.

Please check out this link to Hobby Space's web site and
their update concerning DIRECT, along with several comments.

 http://hobbyspace.com/nucleus/index.php?itemid=2673

 I want to point out the comment by Anonymous and
say that I agree with his opinions of Griffin and Horowitz
and their "expertise."
I think that Congress has given Griffin a "free ride" for
too long.  By that, I mean that they have assumed that he
is a "real rocket scientist" and that his ESAS was
the only way to implement the VSE.  They need
to learn that there are alternatives to Griffin's plan.  
It is not the ESAS or nothing.


The incoming Congress, however,
may be more willing to entertain alternatives to Griffin's ESAS,
especially if they are informed about the details of proposals
such as DIRECT.  
I think that members of Congress will be very interested in
the Budget charts included in the DIRECT proposal.  I know that
they are very eye-opening as to the huge appetite of Griffin's
ESAS in the next decade.  If anything else is to be done by
NASA, especially unmanned Space Science, then the ESAS
"Beast" needs to be tamed.  I think that DIRECT shows
us the way to pursue a "doable' course to the Moon and Mars.  



Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/29/2006 12:20 AM
Quote
Jim - 28/11/2006  5:43 PM

The CM thrusters use GOX and ethanol.  SM is hypergol.  CM has 2 sets of six thrusters just like Apollo that are flush with the skinline.  One thruster provides the impluse to rotate the CM (only) in one direction on one axis.  

Totally redesign of the system would be required.  the CM would increase in weight and the current shape won't work.  Also the redundacy on CM still doesn't mean those thrusters can provide a translation.
Hmm .... ok. CM is not hypergol. I forgot about that.
That's a more than reasonable argument against mixing them.

How about the fwd end of the Cargo Cage [CC], which is - in essence - the fwd end of a SM, having its own hypergol thrusters to match the thrusters on the SM? They would be used in conjunction with the SM thrusters for manuevering. Makes the CC a *little* more expensive, but not much. It's worth it.

When the CC is installed, the CM thruster controls default to the CC/SM thrusters. When the CC is *not* installed, the CM thruster controls default to the CM/SM thrusters. That makes it more of a software/firmware adaptation, with minimal impact on the Orion CM design.

So, of your 5 original comments/thoughts, where do we stand?
Is this doable?

Chuck
Title: Re: "DIRECT" Goes Live
Post by: josh_simonson on 11/29/2006 01:34 AM
Sounds like it would be heavier, and probably cost about the same, as simply designing a streched SM.
Title: RE: "DIRECT" Goes Live
Post by: texas_space on 11/29/2006 03:17 AM
Quote
copernicus - 28/11/2006  5:05 PM

And now back to our regularly scheduled program.

Please check out this link to Hobby Space's web site and
their update concerning DIRECT, along with several comments.

 http://hobbyspace.com/nucleus/index.php?itemid=2673

 I want to point out the comment by Anonymous and
say that I agree with his opinions of Griffin and Horowitz
and their "expertise."
I think that Congress has given Griffin a "free ride" for
too long.  By that, I mean that they have assumed that he
is a "real rocket scientist" and that his ESAS was
the only way to implement the VSE.  They need
to learn that there are alternatives to Griffin's plan.  
It is not the ESAS or nothing.


The incoming Congress, however,
may be more willing to entertain alternatives to Griffin's ESAS,
especially if they are informed about the details of proposals
such as DIRECT.  
I think that members of Congress will be very interested in
the Budget charts included in the DIRECT proposal.  I know that
they are very eye-opening as to the huge appetite of Griffin's
ESAS in the next decade.  If anything else is to be done by
NASA, especially unmanned Space Science, then the ESAS
"Beast" needs to be tamed.  I think that DIRECT shows
us the way to pursue a "doable' course to the Moon and Mars.

Copernicus,
Totally agree.  My concern is that the costs of ESAS will cause more attempts to sacrifice space science dollars down the road.  Space science's supporters will force the money to flow back where it was and then there will be no exploration plans due to lack of money.  ESAS will become a black hole sucking up money (unnecessarily I might add) to the detriment of the ENTIRE space program.  NASA doesn't need to be in the budgetary "either or" choice if it plans things right up front.

As someone said once, all issues are political issues.  Recommend DIRECT to your representative and senators in Congress (especially if they do anything space-related in their committee work).  THEY are the real decision-makers, not NASA management.  Besides, I doubt NASA management can be convinced to change course.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/29/2006 06:09 AM
Norm,
I'm actually talking about DIRECT being ready for a *crewed* flight in 2011, not just test flights like "Ares-I-1".

Below is the schedule through 2020 which we believe is realistic on the 'normal' budget in the DIRECT proposal, this is not the 'expedited' one.

All the extra missions are funded by the $35 Billion saved over Ares and do not require NASA's budget to be increased.


2009:
Q4: Ares-1/Orion-I - Payload: CEV test vehicle, Secondary Payload: Flight Sensor Package - Purpose: Verify SRB's & RS-68's on full flight, Secondary Purpose: Include abort @ max g (suggest MECO -1s), thus also testing emergency Core shut-down procedures in flight.

TOTAL: 1xDIRECT, 2xRS-68, 1xCEV test


2010:
Q2: Ares-2/Orion-II - Payload: CEV test vehicle, Secondary Payload: ATV - Purpose: Second test flight to reproduce previous results, with plan to recover CEV CM.   Secondary Purpose:   After abort and shutdown, attempt to deliver ATV to ISS.   Contents should be non-essential.

TOTAL: 1xDIRECT, 2xRS-68, 1xCEV test, 1xATV


2011:
Q1: Ares-3/Orion-III - Payload: Flight-spec CEV test vehicle, Secondary Payload: ATV & Flight Sensor Package - Purpose:  Fly a full mission to stable orbit, perform orbital manoeuvering under remote control including de-orbit, re-entry and recovery of CM after flight, Secondary Purpose: Independant ISS Resupply.

Q2: Delta-IV - First Test flight of RS-68R development engine.

Q4: Ares-4/Orion-IV - Payload: Manned CEV.   Secondary Payload: Inert Mass Simulator - Purpose: FIRST MANNED CEV. Test Rendezvous, Docking, Undocking and leaving procedures for future ISS missions.

TOTAL: 2xDIRECT, 2xRS-68, 1xRS-68R, 1xDelta-IV, 1xManned CEV, 1xCEV test, 1xATV


2012:
Q1: Delta-IV - Second Test flight of RS-68R development engine.

Q2: Ares-5/Orion-V - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q3: Ares-6 - Payload: CEV test vehicle, Secondary Payload: Flight Sensor Package - Purpose: First Test of the new "Regeneratively Cooled RS-68".

Q4: Ares-7/Orion-VI - Payload: Manned CEV, Secondary Payload: "Shuttle Cargo Delivery Module" (SDCM) with Russian Science Power Platform - Purpose: ISS Crew Rotation, Secondary Purpose: Continue construction of ISS even after the retirement of Shuttle.

TOTAL: 3xDIRECT, 4xRS-68, 3xRS-68R, 1xDelta-IV, 2xManned CEV, 1xCEV test, 1xSDCM, 1xATV


2013:
Q1: Ares-8 - Payload: CEV test vehicle, Secondary Payload: Flight Sensor Package - Purpose: Second Test of the new "Regeneratively Cooled RS-68".

Q2: Ares-9/Orion-VII - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q2: Ares-10 - Payload: EDS test stage - without engine, Secondary Payload: 55mT Propellant - Purpose: Begin long duration boiloff experiment (12/24 month study of 55mT boiloff).

Q3: Ares-11/Orion-VII - Payload: Manned CEV, Secondary Payload: LSAM Simulator - Purpose: FIRST MANNED FLIGHT OF RS-68R "Regen" VARIANT - ISS Crew Rotation, Secondary Purpose: First test of an LSAM engineering simulator to LEO.   Discard and de-orbit prior to rendezvous with ISS.   All subsequent flights use "Regen".

Q4: Ares-12/Orion-VIII - Payload: Manned CEV, Secondary Payload: "Shuttle Cargo Delivery Module" (SDCM) with Habitation Module - Purpose: ISS Crew Rotation, Secondary Purpose: Continue construction of ISS even after the retirement of Shuttle.

Q4: Ares-13/Orion-IX - Payload: Manned CEV, Secondary Payload: "Shuttle Cargo Delivery Module" (SDCM) with Hubble Servicing Mission 5 - Purpose: Continue maintaining and upgrading the Hubble Space Telescope even after Shuttle has retired.

TOTAL: 6xDIRECT, 4xRS-68, 8xRS-68R, 3xEDS, 3xJ-2X, 4xManned CEV, 1xCEV test, 2xSDCM, 1xLSAM Simulator, 1xATV, 1xHSM


2014:
Q1: Ares-14 - Payload: EDS test stage, Secondary Payload: 98mT Propellant - Purpose: First test of the J-2X, Secondary Purpose: Begin test of long duration vac-soak on J-2X.   Re-fire the J-2X once every week until it fails or runs out of propellant.

Q2: Ares-15/Orion-X - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q2: Ares-16 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Test EDS and J-2X in long-term exposure conditions.   Re-fire the J-2X once every week until it fails or runs out of propellant.

Q3: Ares-17/Orion-XI - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: First test of a flight-spec LSAM to LEO, Secondary Purpose: Rendezvous and Dock with Ares-16 EDS, and fire J-2X engine to test the integrity of the CEV/LSAM/EDS 'stack'.   Does not leave LEO (Apollo-9 style mission).

Q4: Ares-18/Orion-XII - Payload: Manned CEV, Secondary Payload: "Shuttle Cargo Delivery Module" (SDCM) with Centrifuge Accomodations Module along with either the Interim Control Module or the - Purpose: COMPLETE THE ISS.   Deliver the remaining elements to station to complete as originally was planned.

Q4: Ares-19/Orion-XIII - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

TOTAL: 5xDIRECT, 12xRS-68R, 2xEDS, 2xJ-2X, 4xManned CEV, 1xLSAM, 1xSCDM, 2xATV


2015:
Q1: Ares-20 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q2: Ares-21/Orion-XIV - Payload: Manned CEV, Secondary Payload: Inert Mass Simulator - Purpose: LUNAR FLYBY MISSION.   Dock with & evaluate Ares-20 EDS, then perform an Apollo-8 style Lunar Fly-by Mission including LOI and TEI burns.   Remain in LLO for ~4 days, examining potential landing sites and broadcasting from the moon.

Q2: Ares-22/Orion-XV - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q3: Ares-23 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q3: Ares-24/Orion-XVI - Payload: Manned CEV, Secondary Payload: ISS Upgrade Systems - Purpose: To add/replace sufficient equipment to extend ISS's useful life for a further 10-15 years.

Q4: Ares-24/Orion-XVI - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q4: Ares-25/Orion-XVII - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: Test the LSAM in Lunar Orbit.

TOTAL: 7xDIRECT, 14xRS-68R, 2xEDS, 2xJ-2X, 5xManned CEV, 1xLSAM, 2xATV, 1xISS Upgrade


2016:
Q1: Ares-26 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q2: Ares-27/Orion-XVIII - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q2: Ares-28/Orion-XIX - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-I" FIRST RETURN TO THE LUNAR SURFACE MISSION.

Q3: Ares-29 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q4: Ares-30/Orion-XX - Payload: Manned CEV, Secondary Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q4: Ares-31/Orion-XXI - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-II" Second Lunar Surface Mission @ Christmas/New Year.

TOTAL: 6xDIRECT, 12xRS-68R, 2xEDS, 2xJ-2X, 4xManned CEV, 2xLSAM, 2xATV


2017:
Q1: Ares-32 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q1: Ares-33/Orion-XXII - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-III" Lunar Surface Mission.

Q2: Ares-34/Orion-XXIII - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q2: Ares-28 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q3: Ares-33/Orion-XXIV - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-IV" Lunar Surface Mission.

Q3: Ares-34 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-V" Cargo Delivery to Lunar Base.

Q4: Ares-35/Orion-XXV - Payload: Manned CEV, Secondary Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q4: Ares-36 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-VI" Cargo Delivery to Lunar Base.

TOTAL: 8xDIRECT, 16xRS-68R, 4xEDS, 4xJ-2X, 4xManned CEV, 2xLSAM, 2xCargo LSAM, 2xATV


2018:
Q1: Ares-37 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q1: Ares-38/Orion-XXVI - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-VII" Lunar Surface Mission.

Q2: Ares-39/Orion-XXVII - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q2: Ares-40 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-VIII" Cargo Delivery to Lunar Base.

Q2: Ares-41 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q3: Ares-42 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-IX" Cargo Delivery to Lunar Base.

Q3: Ares-43 - Payload: JIMO - Purpose: Launch the Jupiter Icy Moons Orbiter mission.

Q3: Ares-44/Orion-XXVIII - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-X" Lunar Surface Mission.

Q4: Ares-45 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-XI" Cargo Delivery to Lunar Base.

Q4: Ares-46/Orion-XXIX - Payload: Manned CEV, Secondary Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q4: Ares-47 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-XII" Cargo Delivery to Lunar Base.

TOTAL: 11xDIRECT, 22RS-68R, 6xEDS, 6xJ-2X, 4xManned CEV, 2xLSAM, 4xCargo LSAM, 2xATV, 1xJIMO


2019:
Q1: Ares-48 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q1: Ares-49/Orion-XXX - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-VI" Lunar Surface Mission.

Q2: Ares-50/Orion-XXXI - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q2: Ares-51 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-XIII" Cargo Delivery to Lunar Base.

Q2: Ares-52 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-XIV" Cargo Delivery to Lunar Base.

Q3: Ares-54/Orion-XXXII - Payload: Manned CEV, Secondary Payload: "Shuttle Cargo Delivery Module" (SDCM) with Hubble Servicing Mission 6 - Purpose: Continue maintaining and upgrading the Hubble Space Telescope even after Shuttle has retired.

Q3: Ares-53 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q3: Ares-55/Orion-XXXIII - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-XV" Lunar Surface Mission.

Q4: Ares-56 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-XVI" Cargo Delivery to Lunar Base.

Q4: Ares-57 - Payload: EDS, Secondary Payload: 38mT Cargo LSAM - Purpose: "Constellation-XVII" Cargo Delivery to Lunar Base.

Q4: Ares-58/Orion-XXXIV - Payload: Manned CEV, Secondary Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

TOTAL: 11xDIRECT, 22RS-68R, 6xEDS, 6xJ-2X, 5xManned CEV, 2xLSAM, 4xCargo LSAM, 2xATV, 1xHSM


2020:
Q1: Ares-59 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q1: Ares-60/Orion-XXXV - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-XIX" Lunar Surface Mission.

Q1: Ares-61 - Payload: EDS & Mars Transport Vehicle Construction Element #1 - Purpose: Begin construction of the first Mars-bound vehicle: 95mT IMLEO.

Q2: Ares-62/Orion-XXXVI - Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

Q2: Ares-63 - Payload: EDS & Mars Transport Vehicle Construction Element #2 - Purpose: Begin constructing the first Mars-bound vehicle: 190mT IMLEO.

Q2: Ares-64 - Payload: EDS & Mars Transport Vehicle Construction Element #3 - Purpose: Continue constructing the first Mars-bound vehicle: 285mT IMLEO.

Q3: Ares-66 - Payload: EDS & Mars Transport Vehicle Construction Element #4 - Purpose: Continue constructing the first Mars-bound vehicle: 380mT IMLEO.

Q3: Ares-65 - Payload: EDS, Secondary Payload: 98mT Propellant - Purpose: Operational EDS for Lunar-bound mission.

Q3: Ares-67/Orion-XXXVI - Payload: Manned CEV, Secondary Payload: LSAM - Purpose: "Constellation-XXI" 21st Lunar Surface Mission.

Q4: Ares-68 - Payload: EDS & Mars Transport Vehicle Construction Element #5 - Purpose: Continue constructing the first Mars-bound vehicle: 475mT IMLEO.

Q4: Ares-69/Orion-XXXVII - Payload: Manned CEV, Secondary Payload: Mars Transport Vehicle Construction Element #6 - Purpose: LAUNCH THE FIRST MARS TRANSFER VEHICLE.   Complete constructing the first Mars-bound vehicle and launch it towards Mars: 525mT IMLEO + CEV.

Q4: Ares-70/Orion-XXXVIII - Payload: Manned CEV, Secondary Payload: Manned CEV, Secondary Payload: ATV - Purpose: ISS Crew Rotation, Secondary Purpose: Independant ISS Resupply.

TOTAL: 12xDIRECT, 24RS-68R, 7xEDS, 7xJ-2X, 5xManned CEV, 2xLSAM, 2xATV, 1xMTV (525mT)



In total, that is 70 DIRECT launches, 32 of which fly an EDSplacing a total of 5,800 metric tons in LEO.   35 manned CEV flights launch about 150 astronauts.   TWENTY ONE Lunar missions and the first Mars Transport Vehicle sent on it's merry way.   ISS is actually completed, we get two Hubble Servicing Missions and JIMO gets away.

All for less cost than Ares, which at the present forecast will get, at best, just 3 lunar missions completed by the end of 2020.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: MATTBLAK on 11/29/2006 07:52 AM
Quote
josh_simonson - 29/11/2006  6:32 AM

Too bad the RL-60 is lost in limbo.  It might come back with the wide body centaur though.

There's talk of using the RL-10 on the LSAM descent stage, so it may end up in flying somewhere in the stack anyway.

The RL-60 is an excellent concept and I'm dissapointed it isn't operational: if it were, there may be no need to develop the J-2X. The RL-60 would be the same physical size as the RL-10B but produce twice the thrust and for slightly more Isp (465 seconds, I think). Also in terms of relevance to the LSAM, the Delta Clipper DCX used a throttle-able version of the RL-10. There's some relevant technology for ESAS etc right there...
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/29/2006 12:20 PM
Quote
josh_simonson - 28/11/2006  9:17 PM

Sounds like it would be heavier, and probably cost about the same, as simply designing a stretched SM.
No, we wouldn’t want to do that. The SM is expensive enough as it is without creating design variations. No, leave the SM ‘as-is’ and design the CC to interface with it at the aft end and interface with the CM at the fwd end.

The SM should not double as a cargo carrier. Its function is to provide power, control and services to the CM. Leave it just like that. The CC would be an insertable module which would protect the aft end of the CM, the fwd end of the SM, and funnel all the power and services to the CM thru a spine tunnel down one side. It would simply provide the capability to enclose and secure a large payload and use Orion to deliver it.

When the mission is completed, the CM/CC/SM stack would de-orbit, the CC/SM would be jetisoned, and the CM would return to the ground for refurbishment and reuse, in the normal manner.

This configuration would allow either a manned or unmanned Orion to deliver a large cargo to some orbital destination. The manned version of the CM would be used only when it was advisable for the mission that a crew accompany it for some reason. Otherwise an unmanned version would be used. This concept takes advantage of the modular approach to the Orion design and allows it's capabilities to be extended without altering the spacecraft itself.

The unmanned version of the CM would be stripped of all life-support and human needs functionality, and provide only the guidance and control functions needed to deliver the cargo. If the destination is the ISS, or its successor, significant down-mass could be returned to the ground.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Drapper23 on 11/29/2006 01:45 PM
Ross, Will the JIMO use a nuclear-electric propulsion system in the Direct VSE architecture? Thanks for your excellecnt post!
Title: Re: "DIRECT" Goes Live
Post by: Bill White on 11/29/2006 01:48 PM
Politics and more politics

If NASA upper management desired to embrace "Direct" with a cat-like smoothness (*1) perhaps they could advocate the benefits of an enhanced CEV which will of course have a higher mass than the current CEV. Adding a cargo module between the SM and CC is one option and a stretched SM is another.

This way NASA upper management can say: "Ares 1 is working out just fine, but we would really like the option of using the extra capabilities of an enhanced (heavier) CEV and Direct lets us do that. And look! We are saving money at the same time, so its a Win-Win."

And (as others have noted) Direct does allows an Ares V class vehicle as a direct improvement of the base design.

An enhanced CEV would also preclude anyone thinking that Direct would be a dandy political tool for peeling NASA off ESAS, with the later intention of bringing back an all EELV VSE. (*2)

= = =

(*1) Cats always land on their feet and never admit error.

(*2) Yes, yes, I understand that there is no EELV (sorry, need to stop here for a second and just say that I have to use stupid words to get my point across. I know that means I must have a weak argument, but that's why I use bad words).. But I'm just thinking "what if" -- using Direct for an enhanced CEV cuts 'em off at the pass.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/29/2006 02:01 PM
"An enhanced CEV would also preclude anyone thinking that Direct would be a dandy political tool for peeling NASA off ESAS, with the later intention of bringing back an all EELV VSE. (*2)

(*2) Yes, yes, I understand that there is no EELV (sorry, need to stop here for a second and just say that I have to use stupid words to get my point across. I know that means I must have a weak argument, but that's why I use bad words).. But I'm just thinking "what if" -- using Direct for an enhanced CEV cuts 'em off at the pass. "

There EELV countermoves for every anti EELV move.

 EELV derivatives that can handle any CEV proposed.

There never was an "all" EELV VSE, it is EELV derivatives and they are not bad or wrong.   And no I am not part of the "EELV (sorry, need to stop here for a second and just say that I have to use stupid words to get my point across. I know that means I must have a weak argument, but that's why I use bad words)." but I know that EELV derivatives can perform some VSE jobs (such as CLV) better than the current proposals

Title: Re: "DIRECT" Goes Live
Post by: nathan.moeller on 11/29/2006 02:14 PM
Quote
Jim - 29/11/2006  8:44 AM

There EELV countermoves for every anti EELV move.

 EELV derivatives that can handle any CEV proposed.

There never was an "all" EELV VSE, it is EELV derivatives and they are not bad or wrong.   And no I am not part of the "EELV (sorry, need to stop here for a second and just say that I have to use stupid words to get my point across. I know that means I must have a weak argument, but that's why I use bad words)." but I know that EELV derivatives can perform some VSE jobs (such as CLV) better than the current proposals


Just to make sure I'm on the same page with you, aren't a lot of people wanting to man-rate the Atlas to support CEV ops?  I remember Kayla saying something about it but I deleted her e-mail a long time ago.  And what are the possibilities of NASA looking for alternatives to the Stick?  I guess I'm still confused by some parts of this discussion and I'm trying to catch up.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/29/2006 02:21 PM
Atlas V Phase 2 is what could be a CLV.   I am just saying that there are other alternatives than the current Ares vehicles.  Direct and EELV derivatives are among them.  And furthermore, Direct and EELV derivatives are not mutually exclusive.
Title: Re: "DIRECT" Goes Live
Post by: Generic Username on 11/29/2006 03:51 PM
Quote
nathan.moeller - 29/11/2006  7:57 AM

Just to make sure I'm on the same page with you, aren't a lot of people wanting to man-rate the Atlas to support CEV ops?

For some rather obvious and important geopolitical reasons, Atlas - and any derivatives using the current propulsion system - is a nonstarter for a long-term program like CLV.

Here's hints:

http://www.csmonitor.com/2006/0103/p01s04-woeu.html

http://www.usatoday.com/news/world/2006-11-23-spy-illness_x.htm

Russia: not the country with which to pin your requirements on.

Now, if the RD-180 was manufactured in the US, Atlas might stand a chance. But as it is... shrug.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/29/2006 04:27 PM
Quote
Jim - 29/11/2006  10:04 AM
Direct and EELV derivatives are not mutually exclusive.

Very true.

Once the workforce is 'saved' with the DIRECT CLV, there's no real reason why an inexpensive EELV could not be man-rated to act as a backup system.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/29/2006 04:31 PM
Quote
Drapper23 - 29/11/2006  9:28 AM

Ross, Will the JIMO use a nuclear-electric propulsion system in the Direct VSE architecture? Thanks for your excellecnt post!

In this scenario, it will use whatever it will use :)

Our proposal doesn't have any effect on JIMO other than offering a heavy lifter allowing it to be launched in one single shot, and by freeing up spare funding from NASA's budget allowing the project to be re-started and completed.

How the JIMO team decides to accomplish the mission is outside of the scope of this proposal, although a strong argument could be made for funding nuclear propulsion technologies which would also benefit the Mars missions later.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: nathan.moeller on 11/29/2006 05:02 PM
Quote
Jim - 29/11/2006  9:04 AM

Atlas V Phase 2 is what could be a CLV.   I am just saying that there are other alternatives than the current Ares vehicles.  Direct and EELV derivatives are among them.  And furthermore, Direct and EELV derivatives are not mutually exclusive.

See that's what I was gathering.  It sucks that it doesn't seem like NASA will change, or at least open, their minds to new concepts for VSE.  The Stick is an interesting and nifty idea but with everything we've heard about it's performance, or lack thereof, they need to be open to another idea.  Forgive me for asking a really stupid question, as I was up all night working on projects and am delirious, but what is "mutually exclusive" again?
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/29/2006 05:19 PM
Mutually exclusive? When one option rules the other out. So in this instance Jim is saying that just because you adopt DIRECT doesn't mean that you can't *also* use EELV... it is not an 'either-or' situation.
Title: Re: "DIRECT" Goes Live
Post by: Bill White on 11/29/2006 05:50 PM
Quote
nathan.moeller - 29/11/2006  11:45 AM

Quote
Jim - 29/11/2006  9:04 AM

Atlas V Phase 2 is what could be a CLV.   I am just saying that there are other alternatives than the current Ares vehicles.  Direct and EELV derivatives are among them.  And furthermore, Direct and EELV derivatives are not mutually exclusive.

See that's what I was gathering.  It sucks that it doesn't seem like NASA will change, or at least open, their minds to new concepts for VSE.  The Stick is an interesting and nifty idea but with everything we've heard about it's performance, or lack thereof, they need to be open to another idea.  Forgive me for asking a really stupid question, as I was up all night working on projects and am delirious, but what is "mutually exclusive" again?

Looking at this from the politics side of the politics <==> engineering interface, I believe that asking NASA upper management to (1) scrap ESAS & (2) go back to the drawing board would be a total non-starter.

Creating an option for Direct to launch an enhanced CEV service module (add a mT here or there to the SM such as avionics for ISS manuevers with substantial payload or adding a cargo module between the CC and SM) assures that EELV cannot replace shuttle derived as the CEV lifter and this resolves the workforce issues and helps assure that Mars missions remain on the table sooner rather than later. NASA upper management can then change course without admitting error.

Thereafter, adding a light EELV crew taxi capsule/spaceplane (not CEV) to the mix is altogether good (IMHO) and I have read that Lockheed is looking at possibly man-rating Atlas V on its own dime to sell rides to Bigelow. If that happens, buying seats off-the-shelf to ISS from Lockheed, RpK or SpaceX would be another Win-Win for everyone.

Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/29/2006 06:22 PM
I can see DIRECT as a nice addition to a launch vehicle fleet, or if it was DIRECT or nothing I would find it more than acceptable but I would still rather have Ares I/Ares V combo. (I'm not convinced that the "unnamed sources" know what they are talking about. I've come across some serious errors concerning SRBs, among other things, on the "NASA Watch" blog.)  

DIRECT just seems too complex for an ISS milk run and too anemic on its own for serious, beyond Apollo, lunar exploration. Multiple DIRECT launches, or DIRECT upgrades gets you back to the complexity issue again. Putting 2 SRBs next to a fuel tank and two liquid fueled engines under it for EVERY flight you need to make from a cargo only run to a crew rotation results in many many extra man/hours in safety checks.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/29/2006 06:42 PM
Quote
tom nackid - 29/11/2006  2:05 PM

I've come across some serious errors concerning SRBs, among other things, on the "NASA Watch" blog.)
I'd be *very* careful about what I take away from THAT blog. 'nuf said
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/29/2006 06:50 PM
Quote
tom nackid - 29/11/2006  7:05 PM
DIRECT just seems too complex for an ISS milk run

I think it's unfair to level criticism at DIRECT in the ISS role. Under the current Ares flight manifest there are only two manned CEV flights to the ISS (plus, I think, four unmanned) before the station is decommissioned. So there will be no 'milk run'. More CEVs will fly test flights than fly operational ISS missions.
In any case DIRECT/CEV would likely have a better chance of an on-time launch than STS, the original 'ISS milk run' vehicle, so it is still an improvement.

You could, of course, argue that ISS decommissioning will be delayed (but ISS cannot operate without substantial new investment for more than a couple of years past 2016) or that DIRECT would allow CEV-ISS operations to begin much earlier. If both scenarios came true there might be a five year 'window' in which the CEV would fly to the ISS. But this is pushing the limits of what is likely. And if we want to do that, why not man-rate an EELV to fly the CEV, with some of the cash saved under DIRECT?
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/29/2006 07:00 PM
Quote
tom nackid - 29/11/2006  8:05 PM

I can see DIRECT as a nice addition to a launch vehicle fleet, or if it was DIRECT or nothing I would find it more than acceptable but I would still rather have Ares I/Ares V combo.

My main worry for the big picture is the combination of global warming and peak oil. The USA seems to be a society that in general is dependant on unexpensive wehicle fuel. Cheap oil will be gone in a few years from the physical reason of depleting easy to pump oil wells or geopolitical reasons such as war, oil producing nation witholding production for later sales or fierce competition with growing economies such as China and India. In reality there will be a mix of reasons. When that day comes you might get a depression and if big launcher development is not finished by then and the production line isent running there will not be an Ares V or any moon missions.

You need to build your big launcher ASAP and make the space program a source of national pride.
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/29/2006 07:32 PM
Quote
Magnus_Redin - 29/11/2006  1:43 PM

Quote
tom nackid - 29/11/2006  8:05 PM

I can see DIRECT as a nice addition to a launch vehicle fleet, or if it was DIRECT or nothing I would find it more than acceptable but I would still rather have Ares I/Ares V combo.

My main worry for the big picture is the combination of global warming and peak oil. The USA seems to be a society that in general is dependant on unexpensive wehicle fuel. Cheap oil will be gone in a few years from the physical reason of depleting easy to pump oil wells or geopolitical reasons such as war, oil producing nation witholding production for later sales or fierce competition with growing economies such as China and India. In reality there will be a mix of reasons. When that day comes you might get a depression and if big launcher development is not finished by then and the production line isent running there will not be an Ares V or any moon missions.

You need to build your big launcher ASAP and make the space program a source of national pride.

We already had a moon program based on national pride. It was called Apollo and we got their first. No one can beat us to the moon anymore. Rather than a quick and dirty approach I would much rather see a more comprehensive system developed with future growth and eventual high (relatively speaking) flight rates to support a lunar base and eventual mars mission. Personally I am rather glad that most American's don't know or care much about Project Constellation. The space program isn't run by direct referendum. The less publicity the less chance people will complain about "wasting money on space". Believe me even in Apollo's heyday at the height of the cold war there were plenty of people calling for its cancellation--national pride not withstanding. And I'm not talking about anti-war hippies or radical leftists. Many a "Joe six pack" considered the space program to be a big waste of money. A certain populist senator from the midwestern, as all-American-as-you-can-get state of Wisconsin comes to mind. Any appeal for DIRECT based on "national pride" or "getting people excited about space exploration" is doomed to backfire in my opinion.

Its clear that NASA is positioning Ares I to be the American counterpart to the Soyuz launcher. It will (hopefully) be a utilitarian, not especially sexy or high performance, simple to launch (at least compared to the shuttle) workhorse for putting medium sized payloads, including people, into LEO. I expect NASA plans to be using Ares I or some variant to put crews into LEO for one reason or another for decades to come. ISS will have a successor either in the form of a new station, a series of smaller more specialized stations or commercial stations that NASA will rent space in. Either way things for people to do in LEO will not go away with ISS. Anyway the most important job of Ares I is to ferry crews to Lunar and eventual Mars transfer vehicles. The strict division between crew and cargo that the Ares I/V plan gives will allow independent development of these stages and will result in greater long term flexibility and capability.

PS: And remember what saving developmental costs at the expense of operational costs did to the shuttle program!
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/29/2006 07:34 PM
Quote
Kaputnik - 29/11/2006  2:33 PM
You could, of course, argue that ISS decommissioning will be delayed (but ISS cannot operate without substantial new investment for more than a couple of years past 2016) or that DIRECT would allow CEV-ISS operations to begin much earlier. If both scenarios came true there might be a five year 'window' in which the CEV would fly to the ISS. But this is pushing the limits of what is likely.
I don’t think that 2016 will see the end of the ISS. The 2016 date is when GW says we (Americans) will no longer use the station, not when it will be de-orbited. If Direct flies, I believe the station will continue to function for quite a while, because it will be able to be properly maintained. If it doesn’t, the Russians will keep it repaired and patched up, like Mir, until it actually becomes a hazard before abandoning it. They only abandoned Mir because of the need to funnel scarce funds into the ISS. They are *not* going to abandon ISS just because an American president says so. They have too much pride for that.

Maybe Americans will become few and far between aboard ISS as we push out of LEO, but the station will have lots of Russian and ESA crews, with visiting specialists from all over the globe. If Direct flies, they will be contracting for the occasional launching of heavy cargo, you can count on it. They will want to continue the station for as long as it is useful, and will pay for the services to do it with.

Plus, if Direct flies, the American presence on the ISS will more than likely continue.

Quote
And if we want to do that, why not man-rate an EELV to fly the CEV, with some of the cash saved under DIRECT?
That is the best of both worlds. If it weren’t for the congressional mandate to keep the shuttle workforce essentially intact, EELV would already be the designated CEV launcher.

Warning: Soapbox coming:

Even though NASA (currently) intends to abandon LEO operations, that does not mean that everyone else will. It will be the continuing destination for the Russians and Chinese, and other nations as well, as their space programs come on-line, and don’t forget SpaceX, Bigalow, and others like them who will follow. LEO will be a lot more crowded then than it is now. I really don’t think future presidents will be dumb enough to just give away the high ground. The moon is *not* the high ground; it is a different place. LEO is the high ground.

Look for LM to crew the Atlas V, at the very least.

Ok, I'm off my soapbox now

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/29/2006 08:03 PM
Quote
tom nackid - 29/11/2006  2:05 PM

I. Putting 2 SRBs next to a fuel tank under it for EVERY flight you need to make from a cargo only run to a crew rotation results in many many extra man/hours in safety checks.

This is not issue.  Never was

And still the Stick is a pig that can't do the job.  keep drinking the koolade
Title: Re: "DIRECT" Goes Live
Post by: tom nackid on 11/29/2006 08:07 PM
Quote
Jim - 29/11/2006  2:46 PM

Quote
tom nackid - 29/11/2006  2:05 PM

I. Putting 2 SRBs next to a fuel tank under it for EVERY flight you need to make from a cargo only run to a crew rotation results in many many extra man/hours in safety checks.

This is not issue.  Never was

And still the Stick is a pig that can't do the job.  keep drinking the koolade

Tell the crew of Challenger that this is not an issue! Actually you will have to tell their families. And stop with the condescending "Drink the kool aid" stuff please. It's starting to make me doubt your alleged professional credentials.

Also, in the future if you wish to quote me DO NOT edit out words from the middle of my sentences. That is very rude and unprofessional. I think we should all try to keep any difference of opinion civil and above all HONEST.
Title: Re: "DIRECT" Goes Live
Post by: clongton on 11/29/2006 08:16 PM
Quote
Generic Username - 29/11/2006  11:34 AM

For some rather obvious and important geopolitical reasons, Atlas - and any derivatives using the current propulsion system - is a nonstarter for a long-term program like CLV.
This is a non-issue. If it were, the United States government wouldn't have Atlas in the EELV mix.

Quote
Now, if the RD-180 was manufactured in the US, Atlas might stand a chance. But as it is... shrug.
If you put Atlas in the CLV mix, RD-180 *will* be manufactured in the US. Might even happen anyway.

Chuck
Title: Re: "DIRECT" Goes Live
Post by: Kaputnik on 11/29/2006 08:22 PM
Quote
clongton - 29/11/2006  8:17 PM
I don’t think that 2016 will see the end of the ISS.

I used to think this too, but have changed my mind. It has been discussed in a couple of threads:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=3486&posts=13&start=1
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=2881&posts=67&start=1

In 2016 parts of the station will have been in orbit for 18 years. Mir stayed up for only 15. If the US want to get out of the ISS they cannot hand over control to anybody else, they would have to de-orbit the USOS (taking the relatively young KIBO and Colomus modules with it). This would leave the RS aloft which the Russians/ESA could manage, but the core module would be the 16+ year old SM which would need imminent replacement. Basically it is not a good scenario for prolonged ISS usage.
Title: Re: "DIRECT" Goes Live
Post by: Magnus_Redin on 11/29/2006 08:40 PM
Quote
tom nackid - 29/11/2006  9:15 PM

We already had a moon program based on national pride. It was called Apollo and we got their first. No one can beat us to the moon anymore. Rather than a quick and dirty approach I would much rather see a more comprehensive system developed with future growth and eventual high (relatively speaking) flight rates to support a lunar base and eventual mars mission. Personally I am rather glad that most American's don't know or care much about Project Constellation. The space program isn't run by direct referendum. The less publicity the less chance people will complain about "wasting money on space".

You mean that your space program runs on inertia?  :(

The tiny Swedish space industry runs on the generic research and technology development budgets and european cooperation for guaranteed access to key technologies such as communication and positioning systems. And there is a commercial part in engine bells for Arianne, spacecraft computers and other small pieces. The large part of our aerospace industry is the Saab Gripen fighter and servicing and components for jet engines. Every ten years some engineer proposes a launcher and everybody yawns and shakes their heads.

We have some of the pride PR now when our first astronaut is to be launched on the next shuttle mission.

I see Direct as a quick and elegant system development that fills the need for the medium sized laucher with economical series production of a large launcher.  

If Direct isent good enough as a medum sized launcher due to aesthetics you can either waste money on shrinking it to a two or three segment SRB single RS-68 launcher or buy EELV:s.

If Direct isent good enough due to economical reasons due to high volume of medium sized payload that dont need extra capacity you can use EELV:s. If you need economical launching of very manny payloads you can develop liquid fueled flyback boosters.

Or you could build the Ares I after building the Direct version of Ares V and thus develop the non uniqe capbility after securing the uniqe and moon and mars mission essential capability.

I would prefer quick successes if I lived on inertia.
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/29/2006 10:32 PM
Quote
Kaputnik - 29/11/2006  1:02 PM

Mutually exclusive? When one option rules the other out. So in this instance Jim is saying that just because you adopt DIRECT doesn't mean that you can't *also* use EELV... it is not an 'either-or' situation.

One further comment here, Ares makes an EELV backup impossible, simply because of the sheer cost just to keep Ares-I and Ares-V flying.   Griffin has already said that there isn't going to be any spare cash to use the Ares to its full capability, so there is not chance at all of NASA paying to develop and fly any additional launchers.

DIRECT, saving $35Bn however, makes an awful lot of other things affordable.

Ross.

Title: Re: "DIRECT" Goes Live
Post by: jongoff on 11/29/2006 10:33 PM
Tom,
Quote
We already had a moon program based on national pride. It was called Apollo and we got their first. No one can beat us to the moon anymore. Rather than a quick and dirty approach I would much rather see a more comprehensive system developed with future growth and eventual high (relatively speaking) flight rates to support a lunar base and eventual mars mission.

That's rather ironic seeing how much of a fan you are of the ESAS approach.  ESAS is pretty lousy at allowing for future growth and high flight rates, for the very reason that it's so darned expensive.  Since payloads aren't free, after you've paid half of your yearly Exploration budget just for keeping the doors open on the Ares I, V, and EDS programs, you'll never be able to afford high flight rates.  Even getting up to shuttle flight rates of 4-6 per year for Ares I or for Ares V is going to be more than we can realistically afford.

Basically, while I agree 100% with  what you said in your quote, I don't think that the solution you support actually provides what you say you would rather see.

Quote
Any appeal for DIRECT based on "national pride" or "getting people excited about space exploration" is doomed to backfire in my opinion.

I agree.  Apollo was a dead end.  Racing to repeat history is not smart.

Quote
Its clear that NASA is positioning Ares I to be the American counterpart to the Soyuz launcher. It will (hopefully) be a utilitarian, not especially sexy or high performance, simple to launch (at least compared to the shuttle) workhorse for putting medium sized payloads, including people, into LEO.

Comparing Ares I to Soyuz would probably be considered insulting to most Russians.  Simple, utilitiarian, workhorse systems are a good thing.  Ares I is a very expensive, high performance, and completely new system that has just about nothing in similar with Soyuz.

Quote
I expect NASA plans to be using Ares I or some variant to put crews into LEO for one reason or another for decades to come.

You say that as though it's a good thing.  Sure, I give a decent percent chance that you'll be right.  Unfortunately it still won't be a cheap or effective way of doing things.  It'll be pork on a stick.

Quote
Anyway the most important job of Ares I is to ferry crews to Lunar and eventual Mars transfer vehicles. The strict division between crew and cargo that the Ares I/V plan gives will allow independent development of these stages and will result in greater long term flexibility and capability.

For a Mars trip, the crew facilities Orion will provide are so woefully inadequate, that you'll need a better module anyhow.  Which begs the question then, why the heck do you need such a bloated Winnebago of a crew vehicle?  If you absolutely must launch the crew on a separate vehicle from the rest of the stack, make the crew capsule as small as possible, and shove as much of the other habitation requirements off on the actual lunar or martian vehicles.  The whole idea that we somehow need this ultra massive spacehotel/reentry capsule to safely and effectively explore space boggles the mind.

Quote
PS: And remember what saving developmental costs at the expense of operational costs did to the shuttle program!

I'd rather save development costs at the expense of operational cost than have both of them be higher!  Just because you spend a bunch of money up front doesn't mean that the design will automatically be cheaper to operate.

~Jon
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/30/2006 12:03 AM
Tom,
After ISS is retired in 2016, there are only planned to be two Ares-1 flights each year.   The cost for those two flights every year will be $1,040 million.   That averages out to $520 million per flight.   That is NOT cheap for such a booster with limited performance of just 22mT and is laughable to compare to Soyuz.

Ares-V costs are ON TOP OF THAT, with two of those costing an extra $2,700 million every year (starting 2019) - $1,350 million each.


NASA can not afford any more than these four launches every year, at a total cost of $3,720 million.   That averages out to $935 million - which is the same as Shuttle today.   That places 306mT in LEO, and flies only 2 Lunar missions, per year, and just 8 astronauts.


For the exact same yearly budget, DIRECT can launch fourteen (14) flights, placing 992mT (324%) into LEO and flying three times as many astronauts AND missions every year.

And that completely ignored the $22 Billion saved in the development phase alone - which is worth a further 170 DIRECT flights (12,053mT to LEO)

Ross.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/30/2006 12:16 AM
Quote
tom nackid - 29/11/2006  3:50 PM

Tell the crew of Challenger that this is not an issue! Actually you will have to tell their families. And stop with the condescending "Drink the kool aid" stuff please. It's starting to make me doubt your alleged professional credentials.

It still is not an issue. Challenger did not have an escape system, that was the problem.  The CEV on Direct has an escape system.  SRB's next to an ET not an issue PERIOD.  It wasn't in the Challenger report as an issue and it is not not a lesson learned.

Your continuous cheerleading and pumping of the Stick and NASA can do no wrong attitude is more sickening.  I know the problems and they are real.  X-33 all over again.  Were you there with you pompoms also?
Title: Re: "DIRECT" Goes Live
Post by: kraisee on 11/30/2006 12:16 AM
Quote
jongoff - 29/11/2006  6:16 PM
It'll be pork on a stick.

Jon,
I got a shiver of recognition up my spine when I saw that.   Perhaps that really *is* what this is all about, from start to finish.

I pray not, but I'm becomming skeptical.

Ross.
Title: Re: "DIRECT" Goes Live
Post by: Jim on 11/30/2006 12:28 AM
Quote
Bill White - 29/11/2006  1:33 PM


Creating an option for Direct to launch an enhanced CEV service module (add a mT here or there to the SM such as avionics for ISS manuevers with substantial payload or adding a cargo module between the CC and SM) assures that EELV cannot replace shuttle derived as the CEV lifter and this resolves the workforce issues and helps assure that Mars missions remain on t