Author Topic: DIRECT v2.0 - Thread 3  (Read 390875 times)

Offline mmeijeri

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Re: DIRECT v2.0 - Thread 3
« Reply #2310 on: 03/28/2009 02:26 AM »
Remove all those costs and you could afford to spend a lot more on Orion instead.

Would that help though? In software development there is the famous Brooks 'law', which states that adding man-power to a project that is already late makes it even more late. I can see how not having Ares-I throw problems at them would make the Orion team go faster. Other than that, is there much that can be done? Especially if it's true that flight software development is one of the long poles.
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Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #2311 on: 03/28/2009 02:30 AM »
We were always told Orion won't be ready before Ares-I.

Robert, I think you have been mis-informed.

Orion could always have been made ready before Ares-I.   CxP have restricted its budget so that it is designed to finish at the same time as it's launcher will, but that really is an artificial limitation.

The long-pole for the pair has always been the development schedule of the J-2X engine, followed by the schedule of the 5-segment booster.

Ross.
« Last Edit: 03/28/2009 02:31 AM by kraisee »
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Offline clongton

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Re: DIRECT v2.0 - Thread 3
« Reply #2312 on: 03/28/2009 02:34 AM »
Remove all those costs and you could afford to spend a lot more on Orion instead.

Would that help though? In software development there is the famous Brooks 'law', which states that adding man-power to a project that is already late makes it even more late. I can see how not having Ares-I throw problems at them would make the Orion team go faster. Other than that, is there much that can be done? Especially if it's true that flight software development is one of the long poles.

Software development will be the long pole. There is only so much that can be done to accelerate that. But the rest of the spacecraft is screaming for only two things:
1. "Ares- STOP CHANGING ME AND LET ME GET ON WITH IT!"
2. More money.
Chuck

Offline gladiator1332

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Re: DIRECT v2.0 - Thread 3
« Reply #2313 on: 03/28/2009 02:41 AM »
Hm, very suspicious.  What with the recent rumors of a successful NASA Administrator pick....  I wonder...  Could this so-called 'drinks and dinner' date in Florida really be.... a SECRET ANNOUNCEMENT party?!??

Sorry to carry the pin for your balloon there, but, errr, no.

I think we're about to announce a baseline change to SSME as our baseline engine though.

But that won't be secret if/when we have all voted on the change.

Ross.

The change to SSME does make sense in my book. Have you gotten any word on what NASA has found in there own studies on the potential switch to SSME on Ares V? This could be of some help.

On one hand, the SSME switch is good, but on the other hand is there any worry that such a change will cause confusion? We saw this when Direct switched to 2.0 and NASA used numbers from 1.0. I guess this is the one risk you take when changing things up.

On another note, didn't some of the early "Direct-like" proposals use SSMEs?


Offline mmeijeri

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Re: DIRECT v2.0 - Thread 3
« Reply #2314 on: 03/28/2009 02:45 AM »
Software development will be the long pole. There is only so much that can be done to accelerate that. But the rest of the spacecraft is screaming for only two things:
1. "Ares- STOP CHANGING ME AND LET ME GET ON WITH IT!"
2. More money.

OK, sounds like a good reason to give them more money. But it sounds as if we're going to have to live with the fact that Orion is going to be late.
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Offline yinzer

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Re: DIRECT v2.0 - Thread 3
« Reply #2315 on: 03/28/2009 02:56 AM »
A question for the DIRECT folks.

NASA's Constellation organization and the launch vehicle development group in particular appear to be highly dysfunctional.  Based on the latest news, in the three and a half years since the ESAS was released, IOC for Ares/Orion has slipped six years.

Do the cost and schedule models you use for DIRECT have any corrections applied to account for the demonstrated difficulty Constellation and MSFC have performing up to industry standard expectations?
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Re: DIRECT v2.0 - Thread 3
« Reply #2316 on: 03/28/2009 04:04 AM »
A question for the DIRECT folks.

NASA's Constellation organization and the launch vehicle development group in particular appear to be highly dysfunctional.  Based on the latest news, in the three and a half years since the ESAS was released, IOC for Ares/Orion has slipped six years.

Do the cost and schedule models you use for DIRECT have any corrections applied to account for the demonstrated difficulty Constellation and MSFC have performing up to industry standard expectations?

Does anyone remember "Safe, simple, soon".  If 12 years is soon (2004 - 2016), i would hate to see what late is!!!

Online HIP2BSQRE

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Re: DIRECT v2.0 - Thread 3
« Reply #2317 on: 03/28/2009 04:08 AM »
Does anyone remember the ESAS study?  Did they study the TLI being done by RL10's?

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Re: DIRECT v2.0 - Thread 3
« Reply #2318 on: 03/28/2009 04:18 AM »
Tell me if I have got it wrong for Direct:

J-232 uses RS68 and J2.      needs money for development for J2.
J-246 uses SSME and RL10.  No development of new engines.

Do you have LOC\LOM number for new J-246?

Is the Direct team not leading themselves open if they switch to the J-246, like NASA that they keep on refining their plans?  All good, PM know that Planning is good, and there will be refinement as you know more but at some point you have to implement.  Is the Direct team basically saying that the Constellation team really needs to revaluate the whole program due to the wrong assumptions that they made in the ESAS study.  That would take a strong leader at NASA to say, we may have made a mistake in the ESAS study.
« Last Edit: 03/28/2009 04:20 AM by HIP2BSQRE »

Online MP99

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Re: DIRECT v2.0 - Thread 3
« Reply #2319 on: 03/28/2009 08:51 AM »
Tell me if I have got it wrong for Direct:

J-232 uses RS68 and J2.      needs money for development for J2.
J-246 uses SSME and RL10.  No development of new engines.

Do you have LOC\LOM number for new J-246?

Is the Direct team not leading themselves open if they switch to the J-246, like NASA that they keep on refining their plans?  All good, PM know that Planning is good, and there will be refinement as you know more but at some point you have to implement.  Is the Direct team basically saying that the Constellation team really needs to revaluate the whole program due to the wrong assumptions that they made in the ESAS study.  That would take a strong leader at NASA to say, we may have made a mistake in the ESAS study.


J-232:-

Probable major RS-68 mods to regen nozzle.
Human-rate RS-68.
J2-X.

Two major engine development programmes.


J-246:-

SSME as is.
Human-rate RL-10, which is already in the plan for Altair, but needs to be moved forwards.

One engine development programme that you were going to do anyway (and I think smaller than J2-X development, but stand to be corrected on that).


Both engines are extremely efficient - they achieve the same mission whilst having to lift less into orbit. Both have long and hugely successful flight heritage. If you had a clean sheet of paper and asked "what engines would I use to guarantee the safety of the crew", they are probably the ones you would pick regardless of their performance advantages.

From an outsiders' perspective, these just feel like the right choices, regardless of whether NASA publicly choose SSME for Ares-V. Shuttle extension (if it happens), also keeps the SSME infrastructure alive & vibrant [edit: which would previously have been a major impediment to baselining SSME for Jupiter].

Sad to say, the "fall back" to RS-68 would be a little disappointing at this point! Several times Chuck has had to remind us that RS-68 is still the baseline, but the buzz is around SSME.

cheers, Martin
« Last Edit: 03/28/2009 09:59 AM by MP99 »

Online MP99

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Re: DIRECT v2.0 - Thread 3
« Reply #2320 on: 03/28/2009 09:27 AM »
Do you have LOC\LOM number for new J-246?

Sorry forgot to mention...

LOM/LOC numbers are pretty artificial. If I was sitting on top of a launch vehicle I would want:-

1) Engines that demonstrably fail very infrequently
2) ...and fail benignly when they do fail.
3) A vehicle that has margin to cope with a failed engine
4) ...and pushes as few new technological boundaries as possible.

Regardless of numbers, that's the vehicle that's least likely to kill a crew on the first dozen flights (IMO).



Quote
Is the Direct team not leading themselves open if they switch to the J-246, like NASA that they keep on refining their plans?  All good, PM know that Planning is good, and there will be refinement as you know more but at some point you have to implement.  Is the Direct team basically saying that the Constellation team really needs to revaluate the whole program due to the wrong assumptions that they made in the ESAS study.  That would take a strong leader at NASA to say, we may have made a mistake in the ESAS study.

As I understand, DIRECT have always kept their vehicle as similar as possible to Ares-V. When Ares chose RS-68, DIRECT were "stuck with it" (and J2-X), too. (Not that it doesn't perform fine).

DIRECT's decision to look again at SSME was driven by news that ablative RS-68 probably won't work with Ares, and by implication may be marginal at best with Jupiter. Apparently Ares baseline has switched to SSME, but this has not been announced externally.

This came out of NASA research that is way beyond DIRECT's ability to fund. It validates DIRECT's policy of keeping their designs "as close as possible", since that research is directly applicable. Most issues that Ares-V suffers will be present to some degree with Jupiter, but usually scaled back to around the levels with which the Shuttle design & components already cope. And that's the whole rationale behind "Shuttle Derived Launch Vehicle" - reuse of mature technology.

cheers, Martin

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Re: DIRECT v2.0 - Thread 3
« Reply #2321 on: 03/28/2009 09:54 AM »
Would SSME Jupiter be v3.0?


Probably not even V2.1 - more likely v2.0, with Jupiter LV40.


Don't forget that v2.0 refers to DIRECT (the overall mission plan), not the Jupiter launch vehicle (which has the LVnn version numbers).

V1.0 of DIRECT was a sort of 1.5 architecture (J-232 + J-120, I think), and comprehensively dismissed by NASA.

V2.0 of DIRECT is a 2.0 architecture (EDS CaLV, Altair + Orion CLV). To a large extent, the details of the Jupiter launcher are irrelevant to the architecture, so I'm not convinced that a mere engine swapout justifies even a point difference. It slightly adjusts the IMLEO & EDS burnout figures, and that's about it.

cheers, Martin

PS I recently suggested changing DIRECT to Crasher + Altair (CaLV), Orion + EDS (CLV). That's the sort of thing that would justify a revision to the DIRECT version number (2.1, maybe).

Offline marsavian

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Re: DIRECT v2.0 - Thread 3
« Reply #2322 on: 03/28/2009 11:24 AM »
I disagree, changing to SSME (and RL10/RL60)) would be a far more radical change in design than going from regen RS-68 Direct V1 to RS-68B Direct V2. It clearly is a version 3 and more than that if you get rid of the J2-X too you are following the DIRECT guiding principle completely, no new engine development ! It also gives NASA the PR cover to use the concept, add the J2-X and still allow them to say it is not DIRECT ;).
« Last Edit: 03/28/2009 12:23 PM by marsavian »

Offline kraisee

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Re: DIRECT v2.0 - Thread 3
« Reply #2323 on: 03/28/2009 12:20 PM »
I am pleased to announce that by almost unanimous vote of both our engineering team and our public team together, we have decided to break with the Constellation Program's baseline choices and DIRECT is officially moving to a position of baselining the Space Shuttle Main Engine as our primary Main Propulsion System for the Jupiter launchers.

The provisional plan for Jupiter is to utilize older flown SSME's during the testing phase of the program and some early IOC flights, to build some new SSME's and then at some yet-to-be-determined point in the future to fund a new development program intended to reduce the production costs of the SSME.

The cost for the SSME, per unit, is higher than the RS-68, although it completely avoids all up-front development costs and schedule impacts, so overall it is a much faster and cheaper alternative in the short- to -mid-terms.   In the quantities which DIRECT plans to build the SSME's, their production costs significantly drop compared to current low-volume production runs used previously for the Shuttle Program.

When re-developed into a cheap alternative in the future, the cost profile is extremely competitive with the RS-68 Regen, yet offers significantly greater performance in the Jupiter configuration.

The RS-68 option does not completely 'disappear', but becomes the secondary option instead of the primary.


Switching to the SSME for our baseline does not imply any change at this time regarding using the J-2X verses the RL-10 or even an RL-60 option.   At this moment the J-2X remains our baseline, although discussions are on-going.

Ross.
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Offline robertross

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Re: DIRECT v2.0 - Thread 3
« Reply #2324 on: 03/28/2009 12:32 PM »
I am pleased to announce that by almost unanimous vote of both our engineering team and our public team together, we have decided to break with the Constellation Program's baseline choices and DIRECT is officially moving to a position of baselining the Space Shuttle Main Engine as our primary Main Propulsion System for the Jupiter launchers.

The provisional plan for Jupiter is to utilize older flown SSME's during the testing phase of the program and some early IOC flights, to build some new SSME's and then at some yet-to-be-determined point in the future to fund a new development program intended to reduce the production costs of the SSME.

The cost for the SSME, per unit, is higher than the RS-68, although it completely avoids all up-front development costs and schedule impacts, so overall it is a much faster and cheaper alternative in the short- to -mid-terms.   In the quantities which DIRECT plans to build the SSME's, their production costs significantly drop compared to current low-volume production runs used previously for the Shuttle Program.

When re-developed into a cheap alternative in the future, the cost profile is extremely competitive with the RS-68 Regen, yet offers significantly greater performance in the Jupiter configuration.

The RS-68 option does not completely 'disappear', but becomes the secondary option instead of the primary.


Switching to the SSME for our baseline does not imply any change at this time regarding using the J-2X verses the RL-10 or even an RL-60 option.   At this moment the J-2X remains our baseline, although discussions are on-going.

Ross.

Great news Ross. I'm really pleased your team made this decision to go with SSME. Again, another case when it JUST MAKES SENSE. I say this, due to the pressures of the timeline and the fairly accurate costing information you and others have provided us. It's an engine we have, no mods needed, and we can fly very quickly.

I'm still at odds over the J-2X, mainly due to the unknown issue. Maybe it's funding, maybe it's lack of expected performance, we don't know. That's a bit worrying. At least having RL-10 in the back pocket helps, but I would throw some many that way to help man-rate it anyways, just as a fall-back.

You guys continue to impress with great decision making. You need a new job: at NASA.  :)
Best wishes to Jules Bianchi for a speedy recovery after the F1 crash at Suzuka

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