Author Topic: Do you believe in DIRECT?  (Read 70524 times)

Offline CFE

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Re: Do you believe in DIRECT?
« Reply #100 on: 01/13/2008 06:08 am »
I think NASA would save a lot of face if they went back to the 8.4 m core but still called their heavy-lift rocket "Ares V."  I guess it would really be an "Ares IV" if you can only fit four RS-68's on the 8.4m core.  I'd like for NASA to adopt the basic concepts behind DIRECT, even if they don't overly admit it.

At this point, it looks like Ares I is invulnerable to cancellation (unless a major technical issue derails it.)  But DIRECT can be tapped in the event that Ares I experiences a show-stopping technical problem (J-120 can be rebranded "Ares II" and developed as a quick replacement,) and to reduce the cost of heavy-lift infrastructure if "Ares III/IV" is developed in place of Ares V.
"Black Zones" never stopped NASA from flying the shuttle.

Offline MATTBLAK

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Re: Do you believe in DIRECT?
« Reply #101 on: 01/13/2008 07:50 am »

You could fit 5x RS-68s on an 8.4m corestage. But; I'd worry about their exhaust impinging on the SRB plumes and the outer four impinging on the center engine's output and efficiency, which reportedly did happen to an extent to the 10-meter diameter Saturn V. In relation to this, NASA's Ares V team has reportedly changed the engine layout to a "ring" configuration (see attached) to minimise this prospect. Not to mention that 5x RS-68s would drain an 8.4m stage's propellants pretty damn quickly. Would an 8.4m, 5-engine corestage have to be stretched ridiculously to get a decent propellant burntime? Or could you get around that by having a more powerful, capacious upper stage and/or third stage?

I'd think having 4x RS-68s with the maximum, practical stretched corestage might be a good compromise, along with the standard 4-segment SRBs. To get closer to their original payload requirement NASA would likely then need the lately-discussed, second upperstage with its 3x or even 4x J-2X. Would this second, upper stage have a short burntime, because of the need to restrict it's height for the VAB limitations, with the final, 1x J-2X EDS on top?

Incidentally, I still think the 3x RS-68 Jupiter 232 is the best compromise, particularly if those RS-68s become optimised, regeneratively-cooled versions.

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Offline Trever

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Re: Do you believe in DIRECT?
« Reply #102 on: 01/13/2008 02:11 pm »
Let me start by saying that I believe the J-232 to be superior to development of Ares 1 & V.  However, some of the hype and free descriptions some Direct supporters are stating are IMHO over the top.  I would like to specifically comment on comparisons of the J-232 upper stage to Atlas’s Wide Body Centaur (WBC) concept.  These comments were made in the 25 T vs 100 T thread, but I believe are more on topic in this thread:


Quote
Yinzer,
Don't forget that we've been proposing to use a "Wide Body Centaur" for the Upper Stage of Jupiter-232 anyway. So such a development investment is broadly "equal" for either program. The physical size of a new stage makes almost no difference in terms of development cost.

That decision would mean the only major development cost delta between Atlas and DIRECT would be the re-development of the External Tank into the Core for Jupiter and the development of the J-2X which is already well underway.

Ross.

Edited by kraisee 7/1/2008 1:33 AM


Quote
Quote
yinzer - 7/1/2008 3:23 AM

Referring to the Jupiter Upper Stage as a "Wide Body Centaur" is a bit of a stretch, don't you think? It's three times the diameter of the existing Centaur and twice that of the Lockheed-proposed WBC. This will make it harder to have the stage be structurally stable when sitting on the launch pad like the Lockheed one is supposed to be. It's also going to have something like five times the installed thrust. New engines. More extensive pad modifications (an Atlas WBC can use the same launch pad as the Common Centaur), etc.

We sourced numbers and details directly from Lockheed's Centaur Development Team for it.

Jupiter's U/S is an 8.41m diameter version of Lockheed's Wide Body Centaur, with J-2X engines instead of RL-10's. Lockheed provided us with details and confirmed that the design is quite viable.
(EDIT: and masses an awful lot less than what we are actually claiming too!)

We have been planning an ICES variant of the WBC ever since we started work on v2.0 of the DIRECT proposal because it offers the best boiloff characteristics of any stage and boiloff was a very high priority for us.

Though, at 8.41m diameter, our U/S will not fly on any existing Atlas.

Ross.

Edited by kraisee 7/1/2008 6:32 AM


One of the intriguing aspects of WBC was its straight forward development.  It was a new tank integrated with existing subsystems on the existing Atlas booster.  I’m talking about almost all subsystems being identical to today’s flight certified Centaur subsystems:
Avionics: FTINU, remote data unit, batteries, telemetry, etc
Pneumatics: pressurization valves, vent valves, regulator, tank pressure transducer, PU delta pressure transducer, helium bottlesetc
Propulsion: RL10A-4-2, Inlet valves, EMA’s, gimbals, hydrazine bottles, RCS thrusters, etc.
Flight software

These systems are in production today, for the most part were updated with the development of Atlas III or V and the engineers who own and understand these systems today would own these systems on WBC.  WBC, flying on the existing Atlas booster, provides environments very similar to today’s environments, keeping environments and component usage within existing qual limits.


The same can not be said for J-232.  Ascent environments, driven by the 5 SRB’s, drive qualification requirements for Atlas.  J-232’s two SRB’s produce 5.2m lb of thrust, more than triple Atlas’s 5 SRB’s with 1.5m lb of thrust.  Then on-orbit, the RL10 provides a very benign vibe environment.  Two J2-S’s, each with 10 times the RL10 thrust, are likely to provide vibes that are well above existing Centaur.  These extreme environments are incompatible with existing hardware qual levels, implying significant redesign and requal.  Also the scale of the J-232 upper stage and its two J2-S’s imply the need for larger flow areas than could be provided by Centaur hardware.

As far as I’m aware, the Atlas program has never taken a serious look at the implications of flying a WBC on an in-line SDV such as J-232 and thus I have no idea where the Direct team would have gotten good cost estimates.

One can say similar things about a lot of the rest of the J-232 concept.  For example, the RS68 is an engine designed to fly with the environments of up to 3 side by side engines, or a single engine surrounded by 4 small SRB’s.  It is likely to require significant redesign and certainly requalification to fly 3 RS68’s near two 2.5m lb SRB’s.  This is not today’s RS68 or even the RS68A or even a human rated RS68 flying on Delta.


The above is not intended to mean that the J-232 can’t be developed, just that there are significant technical hurdles to its development.

Offline clongton

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Re: Do you believe in DIRECT?
« Reply #103 on: 01/13/2008 02:54 pm »
Quote
Trever - 13/1/2008  10:11 AM

As far as I’m aware, the Atlas program has never taken a serious look at the implications of flying a WBC on an in-line SDV such as J-232 and thus I have no idea where the Direct team would have gotten good cost estimates.

Thank you for sharing your concerns.

The upper stage of the J-232 is not only based on a variation of the WBC/ICES, it was designed in conjunction with efforts of members of the Atlas Advanced Systems Development team at LM. We contacted them and asked for their participation in the design effort. They agreed and looked very carefully at it, making suggestions, asking questions, offering alternatives, adjudicated discrepancies, ran analysis after analysis, etc, etc; everything you would expect design team participants to do. In the end, it was they who judged the design to be a workable variant to the WBC/ICES. It was they who provided us with the performance numbers, anticipated costs and masses, and it was they who did the analysis to provide the pmf. Note please that the assistance we received was not an official LM effort and the ones that helped did so on their own time in a completely unofficial manner.

Quote
One can say similar things about a lot of the rest of the J-232 concept.  For example, the RS68 is an engine designed to fly with the environments of up to 3 side by side engines, or a single engine surrounded by 4 small SRB’s.  It is likely to require significant redesign and certainly requalification to fly 3 RS68’s near two 2.5m lb SRB’s.  This is not today’s RS68 or even the RS68A or even a human rated RS68 flying on Delta.
We were in constant communication with P&WR personnel as we went forward with this design effort. The flight environment was carefully analyzed and it was their determination that in the environment of the Jupiter-232, the engine would function as designed with no changes needed excepting those that would be expected for man-rating.

Quote
The above is not intended to mean that the J-232 can’t be developed, just that there are significant technical hurdles to its development.
I hope I have answered your concerns to a reasonable level of satisfaction about those 2 cited areas, but your statement seems to indicates that there are others. Would you mind detailing them for us?

Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Jim

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Re: Do you believe in DIRECT?
« Reply #104 on: 01/13/2008 03:18 pm »
Quote
Trever - 13/1/2008  10:11 AM

 I’m talking about almost all subsystems being identical to today’s flight certified Centaur subsystems:
Avionics: FTINU, remote data unit,
snip  
Flight software


This may cause issues.  These components, on an Atlas, control the whole vehicle, booster and upperstage.  They are not upperstage specific.  

I believe Direct uses an Instrument Unit type avionics system.  It flies on the last stage of the vehicle whether it is the core or upperstage.

Adding another avionics system increases cost and complexity

Offline Trever

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Re: Do you believe in DIRECT?
« Reply #105 on: 01/13/2008 04:56 pm »
Quote
clongton - 13/1/2008  9:54 AM
The upper stage of the J-232 is not only based on a variation of the WBC/ICES, it was designed in conjunction with efforts of members of the Atlas Advanced Systems Development team at LM. We contacted them and asked for their participation in the design effort. They agreed and looked very carefully at it, making suggestions, asking questions, offering alternatives, adjudicated discrepancies, ran analysis after analysis, etc, etc; everything you would expect design team participants to do. In the end, it was they who judged the design to be a workable variant to the WBC/ICES. It was they who provided us with the performance numbers, anticipated costs and masses, and it was they who did the analysis to provide the pmf.

Chuck, I've asked the folks that led the WBC development what they provided to the direct team.  They agreed that they had provided Ross some very basic info regarding WBC.  They never did any specific anaylsis of an in-line SDLV, other than a simple mass estimate using simple scaling equations.  They were never provided environmental data to look at existing component qual levels.  They never looked at the implications of the larger out flow rates associated with the J2-S. They never did a cost estimate of a WBC not flying on an Atlas or Atlas derived LV.

With regard to the RS68 I hope you are correct.  Engines do not tend to operate well in conditions for which they weren't designed and changes, even minor ones tend to be very expensive.  An error on this could mean the difference in billion of dollars non-recurring.

Offline meiza

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Re: Do you believe in DIRECT?
« Reply #106 on: 01/13/2008 05:02 pm »
A problem with Direct is that the proponents can claim almost anything since they can say work and data is secret and thus inscrutable.

Offline HIP2BSQRE

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RE: Do you believe in DIRECT?
« Reply #107 on: 01/13/2008 05:31 pm »
A problem with Direct is that the proponents can claim almost anything since they can say work and data is secret and thus inscrutable.

I belive that Direct has been very open with thier numbers and data.  If you want thier numbers just ask them.  Just remembert that they cannot give you thier contacts.  Now--looking at NASA---have they given thier numbers for Ares I and Ares V?  Nope.   :angry:  I did a Freedom of Information Request for the Appendixs that came from the ESAS Study--No response.  You can do one yourself and see what you get?  Ask NASA for their currant numbers on Ares I, and tell us your response.  

I believe NASA engineers are the best out there.  They have been told to make a PIG fly and they will make it fly.  Is it the best solution?  I don't think so!

Ten years from now when people look at Ares I, what do they think they will say? They will say how did NASA commit $10B+ and to a vicheal that may be flying for 10+ years in that 6 month study?  And even when they relized that the study had got things wrong, why did they not go and re-evaluate the program?  

Ares I might be a classical study why big engineering and IT projects fail---not willing to re-evaluate you assumptions and the choices that you have made, when you relize early that you have major problems.

Offline Scotty

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Re: Do you believe in DIRECT?
« Reply #108 on: 01/13/2008 05:44 pm »
Meiza, I beg to differ with that statement.
The Direct Team has been far more open with their data than NASA has been with its data.
Direct has admitted errors, and corrected them (even after proving many times the the preceived errors were not errors in the first place, as example the 430 to 435 isp RS68).
Modern times with the availability of the internet, and the wide spread ownership of computers, has made doing anything and keeping it secret very difficult.
NASA has discovered this basic truth the hard way.
Still, the Direct Team is obligated to protect its information sources, as many people have placed their jobs and careers at risk by feeding data to the Direct Team.
It is very easy for someone who is not risking anything, to demand to know the exact source of the data.
Like it or not, that will just not happen.

Offline Trever

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Re: Do you believe in DIRECT?
« Reply #109 on: 01/13/2008 06:04 pm »
I agree that the Direct people have been extremely open with their data and do have a good idea.  I also truly appreciate the need to protect data sources and thank the Direct folks for doing that.  

The NASA Ares team constantly is asking for data, but very rarely are they willing to share data.  The majority of formal data leaving NASA is scrubbed for political correctness first.

I think Direct is a good enough idea that it doesn't need to be over sold.  I don't think that anyone believes that Directs environments will be similar to Atlas or Delta.  These high environments increase development costs and risk.  Have the Direct folks adequately covered this development?  They might have.  They are assuming development costs 2 to 3 times higher than Atlas or Delta, and on par with what it took to develop Ariane.  My qualm was claiming development of a WBC for Direct would be of the same cost as for Atlas.  

I do wish the Direct team well in their efforts to get NASA to change course.  I really hope that it doesn't take waiting for a new president and NASA administrater before NASA is willing to admit that a change of direction is required.

Offline meiza

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Re: Do you believe in DIRECT?
« Reply #110 on: 01/13/2008 06:17 pm »
Huh, of course they have to keep some things secret.
There are other things too that have gotten people into uneasy situations. I'm NOT demanding they should reveal their sources. The politics and shoot the messenger culture is as bad as it is.

And still, this doesn't conflict with anything I've said. It continues to stay being a problem and I have simply noted its existence.

Offline Norm Hartnett

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RE: Do you believe in DIRECT?
« Reply #111 on: 01/13/2008 06:23 pm »
Trever could you clarify a couple of points for me?

Your concern about the environment that the RS68s would be operating in would seem to apply to both the DIRECT and Constellation program wouldn’t it? The environment that the Jupiter 120 and 232 would be operating in would seem to be, if anything, somewhat more benign that that of the Ares V. While the DIRECT Team is claiming that they can operate with the existing RS68 and accelerate the fielding of the Jupiter 120, even if they are incorrect wouldn’t the delay and additional cost of developing the enhanced RS68 still be less than the current Constellation program?

Your concerns about the claims of the DIRECT Team’s EDS may be valid, but even if they need to return to a clean sheet design they are in no worse a situation than NASA is with their Ares EDS development. If the claims can be taken as accurate for the performance of the Jupiter 230 and for the overall cost savings of the program wouldn’t DIRECT actually leave NASA with sufficient margin in lift, time, and cost to address these EDS concerns?
“You can’t take a traditional approach and expect anything but the traditional results, which has been broken budgets and not fielding any flight hardware.” Mike Gold - Apollo, STS, CxP; those that don't learn from history are condemned to repeat it: SLS.

Offline Smatcha

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Re: Do you believe in DIRECT?
« Reply #112 on: 01/13/2008 06:28 pm »
For those who selected;
“If accepted the DIRECT would require major overhaul.”

…. could you elaborate on the areas in the DIRECT v2 proposal that would require a ‘major overhaul’.  Unlike what happened to Skip recently we believe that informed disagreement makes a concept stronger not weaker.  It’s our secret weapon don’t tell NASA upper management.


For those who selected;
“NASA Politics Will Not Allow It.”

….. could you elaborate as well?  While I agree it would be mighty plate of crow at this point what about the context of those appointed to fix the current mess.  How married would they really be to the current approach?


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Question posed in Letter to Dr. Robert C. Seamans Jr, NASA Associate Administrator

Ralph Ellison “I was never more hated than when I tried to be honest”




Offline Smatcha

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RE: Do you believe in DIRECT?
« Reply #113 on: 01/13/2008 06:46 pm »
Quote
HIP2BSQRE - 13/1/2008  10:31 AM

A problem with Direct is that the proponents can claim almost anything since they can say work and data is secret and thus inscrutable.

I belive that Direct has been very open with thier numbers and data.  If you want thier numbers just ask them.  Just remembert that they cannot give you thier contacts.  Now--looking at NASA---have they given thier numbers for Ares I and Ares V?  Nope.   :angry:  I did a Freedom of Information Request for the Appendixs that came from the ESAS Study--No response.  You can do one yourself and see what you get?  Ask NASA for their currant numbers on Ares I, and tell us your response.  

I believe NASA engineers are the best out there.  They have been told to make a PIG fly and they will make it fly.  Is it the best solution?  I don't think so!

Ten years from now when people look at Ares I, what do they think they will say? They will say how did NASA commit $10B+ and to a vicheal that may be flying for 10+ years in that 6 month study?  And even when they relized that the study had got things wrong, why did they not go and re-evaluate the program?  

Ares I might be a classical study why big engineering and IT projects fail---not willing to re-evaluate you assumptions and the choices that you have made, when you relize early that you have major problems.

The reason NASA won’t release the appendix is because among the 40,000 configurations run something nearly identical to the Jupiter-120/232 approach is in there.  NASA upper management only publicly showed strawman configurations in the public ESAS report to support the conclusion they already had before the ESAS study was even started.

Maybe Congress should request the appendix?

“Do we want to go to the moon or not?”
John C. Houbolt - November 15, 1961
Question posed in Letter to Dr. Robert C. Seamans Jr, NASA Associate Administrator

Ralph Ellison “I was never more hated than when I tried to be honest”




Offline Trever

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RE: Do you believe in DIRECT?
« Reply #114 on: 01/13/2008 06:55 pm »
Quote
Norm Hartnett - 13/1/2008  1:23 PM

Trever could you clarify a couple of points for me?

Your concern about the environment that the RS68s would be operating in would seem to apply to both the DIRECT and Constellation program wouldn’t it? The environment that the Jupiter 120 and 232 would be operating in would seem to be, if anything, somewhat more benign that that of the Ares V. While the DIRECT Team is claiming that they can operate with the existing RS68 and accelerate the fielding of the Jupiter 120, even if they are incorrect wouldn’t the delay and additional cost of developing the enhanced RS68 still be less than the current Constellation program?

Your concerns about the claims of the DIRECT Team’s EDS may be valid, but even if they need to return to a clean sheet design they are in no worse a situation than NASA is with their Ares EDS development. If the claims can be taken as accurate for the performance of the Jupiter 230 and for the overall cost savings of the program wouldn’t DIRECT actually leave NASA with sufficient margin in lift, time, and cost to address these EDS concerns?

I fully agree with you Norm that Direct is better off in these regards than Ares V.  I concur that direct makes more sense than the current course.

Offline A_M_Swallow

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Re: Do you believe in DIRECT?
« Reply #115 on: 01/14/2008 12:50 am »
Quote
SMetch - 13/1/2008  7:28 PM

For those who selected;
“If accepted the DIRECT would require major overhaul.”

…. could you elaborate on the areas in the DIRECT v2 proposal that would require a ‘major overhaul’.  Unlike what happened to Skip recently we believe that informed disagreement makes a concept stronger not weaker.  It’s our secret weapon don’t tell NASA upper management.

If starting Direct is delayed until the Shuttles are decommissioned then the people available in NASA and its contractors will rather different this will result in big changes to the programme and hardware available.  The next president could also mess up the aims.

Offline Yegor

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Re: Do you believe in DIRECT?
« Reply #116 on: 01/14/2008 02:34 am »
Quote
JonSBerndt - 12/1/2008  11:55 AM

Quote
clongton - 12/1/2008  10:21 AM

Quote
Yegor - 12/1/2008  11:00 AM

Hmm… All of sudden the number of people voted “If accepted the DIRECT would require major overhaul” doubled overnight (somewhere from midnight – in a very short time) from 19 to 38.
When “If accepted the DIRECT would require only sensible, peer-studied changes” gain only 10% - 11 more votes at the same time.
IMHO there is something fishy in this.
Why would you say that? It's pretty standard that when it comes to polling, a lot of people don't make up their minds until they see some of the early responses. There is something to be said for listening a LOT before you open your mouth. In actual matter of fact, DIRECT actually got its start that way. There was a WHOLE LOT of listening to people who know what they're talking about before the design even began to gel.
It does sort of seem strange. Particularly if no other votes were cast for the other items in the same overnight period - especially considering this poll has already been out there for a while.
Jon
The majority of people voted in the first couple of days. Then there was something like 7 votes a day. “If accepted the DIRECT would require major overhaul” was getting steady 10% of votes all that time.
Then all of sudden 30 new people voted overnight where “If accepted the DIRECT would require major overhaul” got 65% of votes. In that “If accepted the DIRECT would require major overhaul” number doubled. Then again there were 7 votes a day with the old distribution.
1. Unusually high activity in a short time period.
2. Totally different distribution.
3. Out of 19 peoples voted “If accepted the DIRECT would require major overhaul” just one voiced his opinion.
IMHO with the probability of 99% these votes were fabricated – someone just created many user profiles and voted.


Offline clongton

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Re: Do you believe in DIRECT?
« Reply #117 on: 01/14/2008 02:41 am »
Quote
Yegor - 13/1/2008  10:34 PM

Quote
JonSBerndt - 12/1/2008  11:55 AM

Quote
clongton - 12/1/2008  10:21 AM

Quote
Yegor - 12/1/2008  11:00 AM

Hmm… All of sudden the number of people voted “If accepted the DIRECT would require major overhaul” doubled overnight (somewhere from midnight – in a very short time) from 19 to 38.
When “If accepted the DIRECT would require only sensible, peer-studied changes” gain only 10% - 11 more votes at the same time.
IMHO there is something fishy in this.
Why would you say that? It's pretty standard that when it comes to polling, a lot of people don't make up their minds until they see some of the early responses. There is something to be said for listening a LOT before you open your mouth. In actual matter of fact, DIRECT actually got its start that way. There was a WHOLE LOT of listening to people who know what they're talking about before the design even began to gel.
It does sort of seem strange. Particularly if no other votes were cast for the other items in the same overnight period - especially considering this poll has already been out there for a while.
Jon
The majority of people voted in the first couple of days. Then there was something like 7 votes a day. “If accepted the DIRECT would require major overhaul” was getting steady 10% of votes all that time.
Then all of sudden 30 new people voted overnight where “If accepted the DIRECT would require major overhaul” got 65% of votes. In that “If accepted the DIRECT would require major overhaul” number doubled. Then again there were 7 votes a day with the old distribution.
1. Unusually high activity in a short time period.
2. Totally different distribution.
3. Out of 19 peoples voted “If accepted the DIRECT would require major overhaul” just one voiced his opinion.
IMHO with the probability of 99% these votes were fabricated – someone just created many user profiles and voted.
Hmmm. That's possible.
Chris. Is there any way to check the validity of this suggestion? Put this way it sort of does sound a little odd.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Lee Jay

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Re: Do you believe in DIRECT?
« Reply #118 on: 01/14/2008 03:32 am »
The disease:  STS is expensive, unreliable, and unsafe, by inherent design.

The patient:  NASA's human spaceflight program.

The cure:  Ares I and Ares V.

The result:  Known:  The patient will be "laid up" for at least 5 years.  Even then, only partial health will be restored.  Speculation:  The long down time will cause the General Manager to fire the sick quarterback, relegating the team (patient) to years or decades of "rebuilding" (also known as failure).

Since a successful completion of "the cure" will seriously cripple the patient *for sure* and possibly kill the patient as well, I deem the cure to be a failure even if it's successful, and chose an alternative treatment.

Option 4 for me.  No trade study is perfect, even if it includes significant engineering effort.  Even the very best will require sensible revisions during implementation.

Offline Yegor

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Re: Do you believe in DIRECT?
« Reply #119 on: 01/14/2008 04:24 am »
I voted option 4 – “If accepted the DIRECT would require only sensible, peer-studied changes”.


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