Author Topic: DIRECT v3.0 - Thread 1  (Read 1176369 times)

Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #180 on: 06/03/2009 06:29 am »
As a side note (and I am going to shut up past this), please tone down on the 'Ares&NASA'   You want to win hearts and minds who have invested and are indeed investing *their hearts and minds*, and folks who *will have to implement yours* if they are asked to.  And some posts here have spoken to this effect.  Ares goes on because folks carry on -- it is not helpful to tell them "RESET what you are doing and do a different thing, ' cause it's better".

That's an incredibly fine line to tread.   And yes, I know we've stepped over it a few more times than we would have liked.   But I would venture to say that it has been much harder to avoid offending *anyone* than it is to design the darn rocket! :)

Seriously though, you're right to point that out.

We do try to minimize it as much as possible, but sometimes there is no real alternative to get the message clearly across except to draw comparisons and point out certain flaws -- and that's a process which will *always* make some folk very uncomfortable.   Its unavoidable in the situation we're in.


But that isn't what stops me sleeping.   For over two years now, we keep having discussions about "how to let NASA take ownership" and how to "save face" for the agency.   I believe that the time is almost upon us for that to happen.

I think those two, more political, issues have actually grown to be even bigger sticking points than any of the technical issues.   But we have some surprisingly simple solutions which we can put-forward to resolve all those issues.

For a start, it sure helps that NASA already did NLS.   That proves that this approach was born -- 100% -- within NASA.   NASA already invented this.   We just dusted it off, tweaked it a little and gave it a new face.

For seconds, its not NASA's fault that the economy has gone to pot and that discretionary funding is being reduced all-across Federal government.   The agency was promised a certain amount of additional money four years ago and now they aren't getting any of it, in fact their budget is about to be reduced for the third time since then.   That seems like a damn good argument to use to explain why they need to start considering an architecture change now, wouldn't you agree?

Ross.
« Last Edit: 06/03/2009 06:33 am by kraisee »
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Offline DustinD

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Re: DIRECT v3.0 - Thread 1
« Reply #181 on: 06/03/2009 07:26 am »
Thank you for the preview kraisee.

Edit - I found the answer to my question.
« Last Edit: 06/03/2009 02:42 pm by DustinD »

Offline Magnus_Redin

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Re: DIRECT v3.0 - Thread 1
« Reply #182 on: 06/03/2009 08:45 am »
And it isn't quite so straight-forward either.   The SRB Aft supports would then be located on the LH2 tank wall, no longer where the lower ring-frame is situated.   To implement the stretch you either have to relocate the SRB attachments lower on the SRB's (requiring re-qual) of you would have to strengthen that region of the tank with an extra ringframe inside the LH2 tank.   

Ok!

Offline joncz

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Re: DIRECT v3.0 - Thread 1
« Reply #183 on: 06/03/2009 10:14 am »

Offline William Barton

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Re: DIRECT v3.0 - Thread 1
« Reply #184 on: 06/03/2009 10:30 am »
Here's a probably dumb question that pertains equally to Shuttle and all SDVs:

If you add segements to the SRBs or stretch the core/ET tank, is it absolutely necessary to move the core/SRB attach points on either the tank or the SRBs? Particularly for the SRBs, are the attach points located where they are relative to overall SRB length, or could you add segments above the existing attach points?

Offline marsavian

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Re: DIRECT v3.0 - Thread 1
« Reply #185 on: 06/03/2009 10:33 am »
As a side note (and I am going to shut up past this), please tone down on the 'Ares&NASA'   You want to win hearts and minds who have invested and are indeed investing *their hearts and minds*, and folks who *will have to implement yours* if they are asked to.  And some posts here have spoken to this effect.  Ares goes on because folks carry on -- it is not helpful to tell them "RESET what you are doing and do a different thing, ' cause it's better".

But that isn't what stops me sleeping.   For over two years now, we keep having discussions about "how to let NASA take ownership" and how to "save face" for the agency.   I believe that the time is almost upon us for that to happen.

I think those two, more political, issues have actually grown to be even bigger sticking points than any of the technical issues.   But we have some surprisingly simple solutions which we can put-forward to resolve all those issues.

For a start, it sure helps that NASA already did NLS.   That proves that this approach was born -- 100% -- within NASA.   NASA already invented this.   We just dusted it off, tweaked it a little and gave it a new face.

For seconds, its not NASA's fault that the economy has gone to pot and that discretionary funding is being reduced all-across Federal government.   The agency was promised a certain amount of additional money four years ago and now they aren't getting any of it, in fact their budget is about to be reduced for the third time since then.   That seems like a damn good argument to use to explain why they need to start considering an architecture change now, wouldn't you agree?

Ross.

and thirdly the architecture you have specifically chosen (SSME J-246) allows NASA to do a variant of it and still claim it is an Ares variant by starting with the 8.4m SSME Ares V classic as the CaLV end point and just making an Ares III CLV(+) out of it with 3 SSMEs. The CLV would obviously have to lift the LSAM as well as Orion. They still get an Ares V, 5-segs and the J-2X but the CLV is basically the same launcher without 2 SSMEs and an upper stage and is truly safe, simple, soon ;). Many ways to skin this cat if there is the will ;).
« Last Edit: 06/03/2009 10:35 am by marsavian »

Offline Ben the Space Brit

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Re: DIRECT v3.0 - Thread 1
« Reply #186 on: 06/03/2009 10:34 am »
If you add segements to the SRBs or stretch the core/ET tank, is it absolutely necessary to move the core/SRB attach points on either the tank or the SRBs?

The point to remember is that the main (upper) attach points are attached to a spar that runs through the LH2/LOX intertank on the ET.  Changing the size of the tanks logically changes the location of the intertank.  Either you move the attachment point or you redesign it (a ring rather than a spar, for example).
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Offline Mark S

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Re: DIRECT v3.0 - Thread 1
« Reply #187 on: 06/03/2009 11:05 am »
Wasn't someone from DIRECT supposed to be on one of the "Space" TV shows tonight?  Or do I have the wrong day?

Anyone rember which show?  Any comments from someone that watched it?

Ross should be on right now. Started at 10:00 pm Eastern

Ahhh, two hours of non-stop talking on The Space Show!

Given that I'm normally quite terrified at the prospect of all such public 'appearances', I think that went pretty well and my "stage terror" didn't really come out, whew! :)

I'll be around to answer questions for a while still.

Ross.

Ross,

Luckily I knew the venue was "The Space Show" and was able to Google for it.

I caught the last half of the show, and you were very eloquent and handled skeptical questioners with aplomb.  Practice makes perfect!

Since I missed the first half of the show, I don't know if you covered the following point.  Many of the callers were challenging you about how DIRECT could possibly be so much more affordable and capable than ARES.  I didn't hear you put forward my favorite aspect of DIRECT: that you are replacing two separate, duplicative, and entirely new development efforts (Ares-I and Ares-V) with the evolution of an existing launcher (Shuttle) into a new inline configuration (Jupiter-130).

I think DIRECT would be entirely justified in calling Jupiter an evolution or adaptation of existing Shuttle technology, rather than a new development effort, much more so than Ares can claim.  Ares is designed to look like it is Shuttle derived, but there really is very very little carried over.  On the other hand, DIRECT uses the same boosters, the same main engines, as much of the same ET as possible, and almost all of the existing tooling and infrastructure.  Ares can't claim any of those commonalities, and they're doing it twice!

Mark S.

Offline engstudent

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Re: DIRECT v3.0 - Thread 1
« Reply #188 on: 06/03/2009 12:19 pm »
PRESENTATION TIME!

Okay, ahead of placing this up on the website (hopefully Wednesday!) I wanted to deliver a "Preview" copy of the ISDC Presentation here first.

Be aware that this copy HAS NOT GOT A FINISHED APPENDIX YET!!!   That's still "in work" right now.   We also plan to add a series of "comments" throughout the presentation to make up for the fact that we don't have someone actually talking you through the various slides -- as the Presentation is really designed to be presented.

So here is a "not-quite-finished writing the Appendix" version of the Presentation specifically for NSF readers to enjoy:-

http://www.directlauncher.com/documents/DIRECT_ISDC_2009_NSF_Preview.pps


To make the animation sequence work you will need the .wmv video and will need to place it in the same folder as the .pps file.   You can get the .wmv version here:-

http://www.directlauncher.com/media/video/STS_to_Jupiter-246.wmv

Enjoy!   And feedback is welcome.

Ross.

[EDIT:   If you have problems accessing those, try replacing 'directlauncher.com' with 'launchcomplexmodels.com/Direct']

NICE
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Offline TrueBlueWitt

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Re: DIRECT v3.0 - Thread 1
« Reply #189 on: 06/03/2009 12:36 pm »
Very impressed with the presentation. GREAT JOB!


BTW: Appendix Slide 77 still references J-120 and J-232..

Offline engstudent

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Re: DIRECT v3.0 - Thread 1
« Reply #190 on: 06/03/2009 01:00 pm »
Very impressed with the presentation. GREAT JOB!


BTW: Appendix Slide 77 still references J-120 and J-232..

I saw a J-120 using 2 SSMEs with an LEO capability of 39mT +10% fuel reserve.
Would this be more economical at servicing crew and supplies than the J-130 until advancedEELVs and COTS-D?


” …All of this. All of this was for nothing – unless we go to the stars.” - Sinclair

Offline mnewcomb

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Re: DIRECT v3.0 - Thread 1
« Reply #191 on: 06/03/2009 02:13 pm »
Guys, this is just an incredible piece of work. The presentation is put together extremely well and is very clear with regard to what can be achieved.

I especially love how the SSMEs pop right out of the shuttle and get placed on the bottom the external tank.

Offline BogoMIPS

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Re: DIRECT v3.0 - Thread 1
« Reply #192 on: 06/03/2009 02:14 pm »
I saw a J-120 using 2 SSMEs with an LEO capability of 39mT +10% fuel reserve.
Would this be more economical at servicing crew and supplies than the J-130 until advancedEELVs and COTS-D?

Two reasons;

1. Avoid competing directly with the same lift-class as the EELVs.  Jupiter doesn't want to be the full-time LEO ferry rocket for ISS missions.  It wants to "aim higher".

2. 2-engine SSME variant does not have very robust engine-out capabilities.  That extra engine gets you more contingency options and safety.

Edit: Typo.
« Last Edit: 06/03/2009 02:18 pm by BogoMIPS »

Offline usn_skwerl

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Re: DIRECT v3.0 - Thread 1
« Reply #193 on: 06/03/2009 02:25 pm »
Excellent presentation, guys! That really does put things into perspective. Save me a seat on Orion would ya? I don't want to fly on Ares.
If we do not destroy ourselves, we will one day venture to the stars.

Offline cixelsyD

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Re: DIRECT v3.0 - Thread 1
« Reply #194 on: 06/03/2009 02:31 pm »
Awesome presentation! That timeline gives me goosebumps. The idea of getting a replacement for the shuttle on the pad by 2012 is exciting. I hope the Augustine Commission and you guys can make it a reality! I can't see how you wouldn't support direct if you showed them the timeline (not to mention the costs).

Online ehb

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Re: DIRECT v3.0 - Thread 1
« Reply #195 on: 06/03/2009 05:58 pm »
The MP3 of Ross Tierney's Space Show presentation is now available at http://www.thespaceshow.com/detail.asp?q=1167

Offline MP99

Re: DIRECT v3.0 - Thread 1
« Reply #196 on: 06/03/2009 08:19 pm »
If you add segements to the SRBs or stretch the core/ET tank, is it absolutely necessary to move the core/SRB attach points on either the tank or the SRBs?

The point to remember is that the main (upper) attach points are attached to a spar that runs through the LH2/LOX intertank on the ET.  Changing the size of the tanks logically changes the location of the intertank.  Either you move the attachment point or you redesign it (a ring rather than a spar, for example).

If the SRB is stretched (eg 4-seg to 5-seg) without core stretch, the casing has the strength to easily re-locate the attach point so that it still goes to the thrust beam. 5-seg will be re-qualified anyway, so this isn't a huge issue. I believe this is the scheme that was intended if the Shuttle was to be upgraded to 5-segs. (Simplifying, just add another segment above the existing attach point).

The thrust beam is very important for ameliorating Thrust Oscillation (ref Ares I issues).

If the core is stretched without an SRB stretch, it's hard to see how the SRB could attach to a new, higher thrust beam point.

A 4-seg design could be upgraded with 5-segs as a future upgrade, but none of the 5-seg optimized configurations could be used with 4-segs unless they included a 'spacer' to artificially lengthen them.

5-seg SRB's don't add a huge amount of payload (~7mT, I think [that may be for RS-68 vehicle]), but they then enable a core stretch, which adds ~25mT (again, IIRC, and that may be for RS-68 vehicle). Also found this:-

Quote

Quote from: kraisee on 09-03-2009, 11:28:41

    Now, if we were to propose a Stretched Core to work optimally with a set of 5-segs, then the 5-engine arrangement would be better suited than the 4-engine.   But that would add significant additional development costs and stretch out the schedule for IOC of the initial J-130's too -- so we don't really like that option.

    Ross.


Of course, if the 5-segment SRB actually becomes a reality, that stretched, 5-engine configuration might make sense. But that's for FUTURE planners


I must admit, I'm fascinated whether a core stretch with 4-seg SRB's would even lift off the ground / perform as well as a non-stretched vehicle. It seems as if the larger fuel load should override the hit during the SRB phase (more mass, no / little extra thrust), but...

cheers, Martin
« Last Edit: 06/03/2009 08:22 pm by MP99 »

Offline MP99

Re: DIRECT v3.0 - Thread 1
« Reply #197 on: 06/03/2009 08:22 pm »
Ross also recently posted about moving the lower attach point (in the event of a 7-9% downwards stretch of the core):-

And it isn't quite so straight-forward either.   The SRB Aft supports would then be located on the LH2 tank wall, no longer where the lower ring-frame is situated.   To implement the stretch you either have to relocate the SRB attachments lower on the SRB's (requiring re-qual) of you would have to strengthen that region of the tank with an extra ringframe inside the LH2 tank.   While both are possible, neither is a trivial change and both add $$$ and time to the development -- and delays = job losses.

Given that we already comfortably exceed all of the performance requirements, we don't see this as a worthy trade in Phase 1 of our proposal.

Ross.

Basically, the current lower SRB attach point is a strong point on the tank - where the barrel section joins to the dome.

cheers, Martin

Offline Cale

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Re: DIRECT v3.0 - Thread 1
« Reply #198 on: 06/03/2009 08:41 pm »
Just looked at the PowerPoint presentation, Ross.

Outstanding job as always :)

Best,

Cale

Offline William Barton

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Re: DIRECT v3.0 - Thread 1
« Reply #199 on: 06/03/2009 09:08 pm »
As a side note (and I am going to shut up past this), please tone down on the 'Ares&NASA'   You want to win hearts and minds who have invested and are indeed investing *their hearts and minds*, and folks who *will have to implement yours* if they are asked to.  And some posts here have spoken to this effect.  Ares goes on because folks carry on -- it is not helpful to tell them "RESET what you are doing and do a different thing, ' cause it's better".

But that isn't what stops me sleeping.   For over two years now, we keep having discussions about "how to let NASA take ownership" and how to "save face" for the agency.   I believe that the time is almost upon us for that to happen.

I think those two, more political, issues have actually grown to be even bigger sticking points than any of the technical issues.   But we have some surprisingly simple solutions which we can put-forward to resolve all those issues.

For a start, it sure helps that NASA already did NLS.   That proves that this approach was born -- 100% -- within NASA.   NASA already invented this.   We just dusted it off, tweaked it a little and gave it a new face.

For seconds, its not NASA's fault that the economy has gone to pot and that discretionary funding is being reduced all-across Federal government.   The agency was promised a certain amount of additional money four years ago and now they aren't getting any of it, in fact their budget is about to be reduced for the third time since then.   That seems like a damn good argument to use to explain why they need to start considering an architecture change now, wouldn't you agree?

Ross.

and thirdly the architecture you have specifically chosen (SSME J-246) allows NASA to do a variant of it and still claim it is an Ares variant by starting with the 8.4m SSME Ares V classic as the CaLV end point and just making an Ares III CLV(+) out of it with 3 SSMEs. The CLV would obviously have to lift the LSAM as well as Orion. They still get an Ares V, 5-segs and the J-2X but the CLV is basically the same launcher without 2 SSMEs and an upper stage and is truly safe, simple, soon ;). Many ways to skin this cat if there is the will ;).

What would we call an Ares III CLV + Ares IV CaLV archticture? 1.75 launch?

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