Author Topic: Commercial Crew - Discussion Thread 1  (Read 640973 times)

Offline SWGlassPit

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #400 on: 10/17/2014 04:01 pm »
As has been said multiple times on here, dismissing CDR as "just a powerpoint" shows a complete lack of knowledge of how engineering design works.

To dumb it down somewhat, CDR is when the blueprints get approved.  Here are just a few examples of tricky design issues that have to be tackled to pass CDR:

- Cable routing: minimizing noise and crosstalk, ensuring there is room for every cable, ensuring that routing does not interfere with other "behind the panel" issues like life support hardware and plumbing.  Minimizing the mass contribution of the cables while retaining robustness and redundancy where necessary.  Ever try to neatly manage cables for a home entertainment system when you have a satellite box, a Blu-Ray player, three game systems, and a surround sound system?  Go visit the SAIL in Building 16 at JSC to see just how big a deal cable routing is.

- Plumbing and ventilation: ensure lines are wide enough to avoid large pressure drops (including cavitation for liquids) while yet keeping them within mass limits and making sure they fit within the outer mold line.  Just within the pressurized volume, you need to handle: oxygen, nitrogen, water, CO2 removal, refrigerant (or other heat transfer fluid).  Between the pressure shell and the outer mold line, you need: all of the above, plus RCS/OMS (or equivalent) fuel and oxidizer, and pressurant for those two.  Routing for these is not trivial -- if water lines are too close to refrigerant lines for the avionics, you risk freezing the water lines.  Do you mix the nitrogen and oxygen in a manifold or a plenum before delivering it to the crew space to avoid problems with high/low oxygen concentrations?  How do you get fluids and electrical power / signals between the crew module and the service module?  Do you go through the heat shield?  If so, how do you ensure reentry survivability?  If not, you have to change the outer mold line.

- Structures: As strong as possible, and as light as possible, but even then, it's not that simple.  You need to provide attach points for every cable, fluid line, and tank.  If the routing changes, your design changes.  Oh, and by the way, it's your job to ensure there are no bizarre modal resonances that could shake the spacecraft apart during launch.  To do that correctly, you need to know the mass of every component in the craft and where it will be. 

- Aerodynamics: Your vehicle needs to perform in all flow regimes -- subsonic, transonic, supersonic, and hypersonic.  Even after years of Shuttle, hypersonic flight is still not well-understood, (see issues with the X-51 and differences in aerothermal heating on Shuttle between prediction and reality).  For a capsule, this isn't so bad, but for a winged vehicle or a lifting body, well, there's a reason pretty much all winged hypersonic craft (including spacecraft other than Shuttle) are X-vehicles.

Ensuring you pass CDR before you get serious with "bending metal" is the epitome of the "measure twice, cut once" philosophy.  Fabrication of space hardware is extremely expensive.  It pays to make sure your design makes sense before you fire up the CNC machines.

You wouldn't build a skyscraper without detailed blueprints.  Why would you assume CDR for a spacecraft is anything less than what it is -- an evaluation of the design's maturity and readiness for manufacture?

Offline Brovane

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #401 on: 10/17/2014 04:07 pm »
So, we again come back to the fact that everyone who is claiming Boeing has done more work than the other competitors has no way to prove their claims. As long as everyone agrees to this, I think we know how we should treat these claims.

As long as we can also agree that Boeing received higher marks than either SpaceX or SNC by the the NASA review panel for the Commercial Crew Contract proposals, in areas of technical maturity, management competence, program management and past performance. 
"Look at that! If anybody ever said, "you'll be sitting in a spacecraft naked with a 134-pound backpack on your knees charging it", I'd have said "Aw, get serious". - John Young - Apollo-16

Offline YesRushGen

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #402 on: 10/17/2014 04:10 pm »
As has been said multiple times on here, dismissing CDR as "just a powerpoint" shows a complete lack of knowledge of how engineering design works.

To dumb it down somewhat, CDR is when the blueprints get approved.  Here are just a few examples of tricky design issues that have to be tackled to pass CDR:
snip...

<DE-LURK>Thanks so much for succinctly describing everything that goes into these designs. Very informative post!</DE-LURK>

Offline Roy_H

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #403 on: 10/17/2014 04:17 pm »
As several have pointed out CDRs are a big deal. Anyone who thinks NASA is willing to pay $17.9M for someone to throw together a PowerPoint presentation is off their nut.

I only know what I have read on this forum, not an expert, but I get the distinct impression that there is a big difference between a Critical Design Review and an Integrated Critical Design Review. IIRC SpaceX went through a CDR with COTS and that may have been relevant for CCiCAP
According to: http://www.nasa.gov/sites/default/files/files/NASA_ROI_Report_Feb_2014.pdf
Boeing was paid $17.9M for their CDR.
SpaceX is being paid $40M for their ICDR.
I believe that Boeing has yet to do their ICDR.
« Last Edit: 10/17/2014 04:52 pm by Chris Bergin »
"If we don't achieve re-usability, I will consider SpaceX to be a failure." - Elon Musk
Spacestation proposal: https://politicalsolutions.ca/forum/index.php?topic=3.0

Offline joek

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #404 on: 10/17/2014 04:57 pm »
SpaceX is being paid $40M for their ICDR.
I believe that Boeing has yet to do their ICDR.

Both are integrated CDR's ...

Quote from: CCiCap SAA
Boeing
Critical Design Review (CDR) Board

Completion of critical baseline design of the CCTS integrated system and operations that confirms that the requirements, detailed designs, and plans for test and evaluation form a satisfactory basis for production and integration ... Boeing shall establish and demonstrate a critical baseline design of the CCTS that meets system requirements. CDR confirms that the requirements, detailed designs, and plans for test and evaluation form a satisfactory basis for production and integration. ... The CDR demonstrates that the maturity of the design is appropriate to support proceeding with full-scale fabrication, assembly, integration and test. CDR determines that the technical effort is on track to complete the flight and ground system development and mission operations, meeting mission performance requirements within cost and schedule constraints.


SpaceX
Integrated Critical Design Review (CDR)

Scope: SpaceX will hold an Integrated Critical Design Review (CDR) at the SpaceX headquarters in Hawthorne, CA, or a nearby facility to demonstrate that the maturity of the CTS design is appropriate to support proceeding with full-scale fabrication, assembly, integration and test. This integrated CDR will determine that the technical effort is on track to complete the flight and ground system development and mission operations in order to meet mission performance requirements and schedule. NASA and relevant industry teammates will be invited to attend and to provide comments and feedback. This integrated CDR will cover spacecraft, launch vehicle, and ground and mission operations systems.

Online abaddon

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #405 on: 10/17/2014 05:14 pm »
From the Sierra Nevada thread, but relevant here, and similar to recent discussion in this thread:

Lack of progress???  Boeing completed CDR, something neither SpaceX nor Sierra Nevada have done!  Their design is further along than either of their competitors -- SpaceX by a few months but Sierra Nevada by a few years.

So, Boeing is ahead of SpaceX in terms of having their design reviewed and approved by NASA (they are done), but behind in building and integrating the hardware.  SpaceX is ahead of Boeing in terms of actually building their design, but behind in terms of having it reviewed and approved by NASA.

SpaceX is therefore ahead of Boeing in terms of the goal of getting their hardware into space on a test flight first, with the notable caveat that if NASA finds something in CDR that they don't like, it could potentially cause rework of already completed hardware that could set SpaceX back as compared to Boeing.

SpaceX is choosing the riskier approach of proceeding further with hardware implementation before CDR is complete.  It will pay off if they come out of CDR relatively clean.

Please correct me (anyone) if I am wrong here.  I think this is why we keep having the "Boeing is ahead" vs. "SpaceX is ahead" debate; because both are right and wrong.

Offline joek

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #406 on: 10/17/2014 05:38 pm »
SpaceX is choosing the riskier approach of proceeding further with hardware implementation before CDR is complete.  It will pay off if they come out of CDR relatively clean.

I wouldn't necessarily classify SpaceX's approach as riskier, just a different path than Boeing has taken getting to CDR:
Quote from: SpaceX CCiCap SAA
The proposed hardware development testing will expedite design maturity, leading to an integrated critical design review (CDR) in March 2014.

Offline Space Ghost 1962

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #407 on: 10/17/2014 05:57 pm »
Yeah they have both done CDR of integrated systems - can we table this finally?

As I said earlier, Boeing wishes to use its immense advantage of overlapping execution of an actual build with the considerable portions of working with NASA for what its processes need as well. And the reason you don't do early integration work, among others, is to have a better integration in the second now first pass.

This necessarily "rear loads" the program execution heavily. Why large firms can do this, they pay a penalty in having heavy corporate loading - the two go hand in hand. Unlike what happened with COTS, which use less loading through different approaches. Reflecting concern, not badmouthing any here.

Here's the risks with both:
1) In the large corporation, often miscommunication gets picked up late, requires redo's. These can have significant impact because the leverage advantage works backwards for obvious reasons. On commonly issued projects, its less of a deal because the repeats don't have obvious big redo's. In this case, the leveraged commonality is from ISS related recent history for the most part. I buy off on that for in space systems. The rest is where my concern for FFP comes from. Look to Orion for its learning curve on capsules for more specifics. As I said, I'd have been happier if the pressure vessel in the drops was representative high fidelity. Net effect is that this way of getting things done uses overruns/take-backs through management buffering as its recovery means.

2) In the smaller ones, the issues involve overtaxed multiple use people waiting too long to revise a key component/process/issue/"long pole", and no bandwidth to do the "get ahead" tasks - they bite off more than they can chew. This also may be complicated by things like working NASA's processes, which are feared might slip. None of them ever are prepared for what this takes. However, there is much less of the "organizational leverage" effect mentioned in the prior, and often how these things are addressed is a spontaneous change in design (but not scope) to subsume the vexing item differently than expected - this almost never occurs in the prior case. Part of the necessary incrementalism from start to finish, with start at the start unlike the prior case. Which may(always) cause NASA unexpected disruption in processes. A side effect may be things get improved beyond expectation (although that may be seen in hindsight further on). The lack of the "organizational leverage" means the costing tends to go less out of control, because they are always smaller, tighter groups who find ways to take in the schedule for recovery, depending on management more in continuity.

This is an extreme simplification of course. But it explains why COTS like programs can be successful. CC was supposed to be like COTS.

Nothing would make me happier than to see Boeing do a FFP CC entry that preserved those NASA advantages come in on schedule/price. But for that to happen, they have to selectively use the above mentioned advantage for CCtCAP. The way it would seem they did CCiCAP does not suggest that this is likely.

Did I do that respectfully enough, preserving professional appreciation of heritage contractors?

Back to your regularly scheduled "food fight".

Offline TomH

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #408 on: 10/17/2014 06:08 pm »
Who said it was a cake walk?

Chris, respectfully, you have said that all Boeing had produced was some Power Points and Word documents. Though you did not use the term specific term cake walk, what you did say implied that Boeing had not done serious or scholarly work.

Offline TomH

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #409 on: 10/17/2014 06:13 pm »
So, Boeing is ahead of SpaceX in terms of having their design reviewed and approved by NASA (they are done), but behind in building and integrating the hardware.  SpaceX is ahead of Boeing in terms of actually building their design, but behind in terms of having it reviewed and approved by NASA.

Please correct me (anyone) if I am wrong here.  I think this is why we keep having the "Boeing is ahead" vs. "SpaceX is ahead" debate; because both are right and wrong.

Not really, because what NASA has required to this point is design, not fabrication. So from the specific technical and legal definitions, Boeing is ahead. Period. Not that Boeing was my choice, but from a technical standpoint, this is what is clear.

Offline baldusi

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #410 on: 10/17/2014 06:26 pm »
Nothing would make me happier than to see Boeing do a FFP CC entry that preserved those NASA advantages come in on schedule/price. But for that to happen, they have to selectively use the above mentioned advantage for CCtCAP. The way it would seem they did CCiCAP does not suggest that this is likely.
I believe that you are worrying about something that's not the core issue (for NASA/Boeing). They are worried about schedule, not cost, since this is a FFP contract. NASA is not worried that Boeing will default on the contract, either (if there's one company that has almost infinite financial resources for NASA is Boeing).
And from Boeing side, they probably calculated a 3.2B of expected cost and added a 30% margin on top of that. So if they execute well, they get a ridiculous profit. If they don't, they get normal profits. Thus, they are betting on keeping costs low and if they get behind, then let's tap the reserves. But this can only happen iff Congress funds this program. Again, this goes into the margin.

Offline raketa

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #411 on: 10/17/2014 07:30 pm »
>
I'm confident that SpaceX will be able to design and install the needed systems, but it's not a given that it will be easy.  Learning from history, some of them may require some redesign along the way and become real pacing items for a 2017 launch.  And as with most things, the items that will rear up and bite them in the butt aren't necessarily on their (or our) radar at the moment.

-Doug

SpaceX is using an ECLSS made by Paragon SDC, and developed during COTS-1 for commercial spacecraft. IIRC they're also providing systems for Orion.

Good, and I hope their products work well and need very little tweaking.  I wasn't trying to forecast doom for the ECS (or whatever acronym you wish to use for it, I tend to use the Apollo acronyms out of habit).  I was just coming up with the first example that came to mind.

There are, of course, a lot of other systems that SpaceX will have to add to their cargo version of the spacecraft to make it a manned spacecraft -- just as Boeing has to develop the same kinds of systems for their spacecraft.  It doesn't surprise me that they might be using the same contractors for some systems, either.  But every manned space vehicle America has produced to date has dealt with major rework issues in critical systems late in their development cycles, most of which have caused delays in the flight schedules.  As I said, I'd bet you any money that the things that pop up as critical, last-minute reworks are probably not even on their radar right now.

It's just hard to plan for that kind of thing, ya know?  If you knew what was going to become your major pain-in-the-ass beforehand, you would know to fix it earlier and then something else would come to the forefront as the pacing item.  You can try to leave room in the schedules for this kind of thing, but you really can only let it play itself out the best you can.

-Doug

With my shield, not yet upon it
It is better to build test modify and test again. If NASA prefer paper work , she is guilty by driving development the way that is more in  risk of delay and cost overrun. When I develop my program, it is good to know what I am building, but it is better to develop basic program structure, that is flexible to change and then I test and modify and test until I am happy with result. With rise of 3D printing I think it is moment to use same method in physical product development.

Offline SWGlassPit

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #412 on: 10/17/2014 07:45 pm »
It is better to build test modify and test again.

That is opinion, not fact, and while it is applicable in some cases, it certainly isn't appropriate for all.

Offline raketa

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #413 on: 10/17/2014 07:48 pm »
A CDR is a powerpoint, nothing more. You don't have to (necessarily) do dev testing, and you certainly don't QTP or ATP anything. QuantumG is totally right here.

You cannot state that CDR involves only "a powerpoint, nothing more";. What is required for CDR is program-specific.  All we know is that Boeing passed CDR--as defined by NASA as part of the CCiCap milestones and schedule--and that others did not.
OK  and MS project plan :)

Offline raketa

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #414 on: 10/17/2014 07:54 pm »
I'm a bit dismayed that a lot of people here haven't bothered to learn much about NASA program management.  Here's a short overview: (Please shorten the link, breaks site format - Chris).

A critical design review is a lot more than a Powerpoint presentation.  It's a review that you do when the design is substantially done.  The reason for the review is that it's a lot more expensive and difficult to fix problems after you've started fabricating hardware.  These processes seem burdensome, but they were developed from painful, expensive experience on the part of the military and NASA when developing high technology projects. 

It's true that we don't know the exact content of Boeing's CDR.  We do know that SpaceX and SNC have not completed their CDRs.  If the CDR is a cakewalk with no real content, it does not reflect well on those companies to not have completed it yet.
If NASA has to pay for modification and mistake that company did during development, I see point to have CDR. But in this program all development issue are solo provider responsibility. NASA just state which type of service and detail of this service is required.

Offline joek

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #415 on: 10/17/2014 07:57 pm »
When I develop my program, it is good to know what I am building, but it is better to develop basic program structure, that is flexible to change and then I test and modify and test until I am happy with result.

Then you should stay away from safety- or life-critical systems.  That is a very different world, where opportunities to iterate in the real world are limited, testing is not a sufficient defense, and mistakes can cause death, dismemberment and destruction.

Offline raketa

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #416 on: 10/17/2014 08:01 pm »
A critical design review is a lot more than a Powerpoint presentation.  It's a review that you do when the design is substantially done.  The reason for the review is that it's a lot more expensive and difficult to fix problems after you've started fabricating hardware. 

Correct. But it's even more expensive and more difficult to fix problems, resulting from the CDR, after you've begun INTEGRATING your hardware components into an integrated spacecraft.
And that's why Boeing had done only marginal integration activities (at best) before completion of their CDR.
Meaning that as of the end of august (this year) Boeing had no integrated CST-100 spacecraft (not even a partially integrated one) to show off, unlike SpaceX at their Dragon 2 presentation. Hence the mock-up only display when Boeing officially presented the CST-100 in last June, two months before completion of their CDR.
'
This is reason it is necessary to have it for Boeing, because outsourcing, not for Spacex where outsourcing is minimal.

Offline raketa

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #417 on: 10/17/2014 08:10 pm »
From the Sierra Nevada thread, but relevant here, and similar to recent discussion in this thread:

Lack of progress???  Boeing completed CDR, something neither SpaceX nor Sierra Nevada have done!  Their design is further along than either of their competitors -- SpaceX by a few months but Sierra Nevada by a few years.

So, Boeing is ahead of SpaceX in terms of having their design reviewed and approved by NASA (they are done), but behind in building and integrating the hardware.  SpaceX is ahead of Boeing in terms of actually building their design, but behind in terms of having it reviewed and approved by NASA.

SpaceX is therefore ahead of Boeing in terms of the goal of getting their hardware into space on a test flight first, with the notable caveat that if NASA finds something in CDR that they don't like, it could potentially cause rework of already completed hardware that could set SpaceX back as compared to Boeing.

SpaceX is choosing the riskier approach of proceeding further with hardware implementation before CDR is complete.  It will pay off if they come out of CDR relatively clean.

Please correct me (anyone) if I am wrong here.  I think this is why we keep having the "Boeing is ahead" vs. "SpaceX is ahead" debate; because both are right and wrong.
yes I think you clarify it

Offline raketa

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #418 on: 10/17/2014 08:18 pm »
It is better to build test modify and test again.

That is opinion, not fact, and while it is applicable in some cases, it certainly isn't appropriate for all.
In my world of IT, CDR approach in complicated project took at least 3 times more time and resources(In simple one 10 times and more). It is important that your initial design is flexible. By testing and modifying to you can achieve result in surprisingly short time. Because real  test is best CDR.

Offline SWGlassPit

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Re: Commercial Crew (CCtCAP) - Discussion Thread
« Reply #419 on: 10/17/2014 08:26 pm »
In my world of IT, CDR approach in complicated project took at least 3 times more time and resources(In simple one 10 times and more). It is important that your initial design is flexible. By testing and modifying to you can achieve result in surprisingly short time. Because real  test is best CDR.

This isn't IT.  Not even close.  Don't even *try* to compare the two.

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