Commercial Crew - Discussion Thread 1

[gongora]

New more detailed milestone summery and timeline found on the last page in this pdf from the July NAC meeting https://www.nasa.gov/sites/default/files/atoms/files/9-mcalister_status_of_ccp.pdf

No "Inflight Abort Test" ?

It's not a CCTCap milestone.  It was still listed on this recent SpaceX presentation.

[oiorionsbelt]

https://www.nasa.gov/sites/default/files/atoms/files/9-mcalister_status_of_ccp.pdf



From page 12 "Completed all three demonstration flights needed for Range approval to use automated flight termination system."
 Does anyone have more insight into this? How does the automated system work, unzipping the tanks, engine shut down or something else. What was done in the three demonstration flights to get Range approval?

SpaceX spacesuit is in fabrication....can't wait to see that.

[docmordrid]

https://www.nasa.gov/sites/default/files/atoms/files/9-mcalister_status_of_ccp.pdf

From page 12 "Completed all three demonstration flights needed for Range approval to use automated flight termination system."

Does anyone have more insight into this? How does the automated system work, unzipping the tanks, engine shut down or something else. What was done in the three demonstration flights to get Range approval?
>

Tech Briefs...

>
The AFTS can augment or replace the functions of the traditional humanin- the-loop system. Redundant AFTS processors evaluate data from onboard Global Positioning System (GPS) and inertial measurement unit (IMU) navigation sensors. Configurable rulebased algorithms are used to make flight termination decisions. The mission rules are developed by the local Range Safety Authorities using the inventory of rule types taken from current human-in-the-loop operational flight safety practices. The main benefit of the AFTS is to decrease the need for permanent ground-based range safety assets with a corresponding savings in operational costs, and to increase the number of potential launch sites and corridors. The ultimate goal of this project is to produce an autonomous flight safety reference design that may be commercialized for industry use.
>

[Kabloona]

https://www.nasa.gov/sites/default/files/atoms/files/9-mcalister_status_of_ccp.pdf



From page 12 "Completed all three demonstration flights needed for Range approval to use automated flight termination system."
 Does anyone have more insight into this? How does the automated system work, unzipping the tanks, engine shut down or something else. What was done in the three demonstration flights to get Range approval?

SpaceX spacesuit is in fabrication....can't wait to see that.

Here's a graphic from a 2012 Air Force paper showing how it would work. "AFSS" is Automated Flight Safety System, aka Automated Flight Termination System (AFTS). Note that the "ROCC Lite" has no MFCO (missile flight  control officer) console, so there is no human in the loop sending a destruct command.

https://www.aiaa.org/WorkArea/DownloadAsset.aspx?id=7550

I'd expect the F9 AFSS will function the same as now, ie shutting down the engines and unzipping the tanks. No reason to change that. The only difference is probably how the destruct signal is generated, ie onboard based on GPS and IMU inputs vs sent by the MFCO on ground.

Maybe the demo flights carried an avionics box that would generate the destruct signal and proved that the GPS and IMU inputs to it during ascent were correct.

[whitelancer64]

That's where the commercial habitat attached to a commercial docking port fits in. For example, a B330 could be attached to a commercial port (where BEAM currently is).

I don't think there's room anywhere on the ISS for a BA330. Where BEAM currently is has clearance issues with the partially-retracted solar arrays on Zarya and the Japanese Kibo module.

[yg1968]

Here is an article on this topic:
http://spacenews.com/commercial-crew-delays-could-lead-to-gap-in-iss-access-nasa-advisors-warn/

[SWGlassPit]

That's where the commercial habitat attached to a commercial docking port fits in. For example, a B330 could be attached to a commercial port (where BEAM currently is).

I don't think there's room anywhere on the ISS for a BA330. Where BEAM currently is has clearance issues with the partially-retracted solar arrays on Zarya and the Japanese Kibo module.

About the only place you could fit one would be Node 2 Forward.  Current beam location would not fit with the radiators and with the FGB solar arrays.  Node 1 nadir would probably interfere with Russian docking.  Node 2 nadir... maybe.  It would interfere with any external earth observation payloads mounted on Columbus.  Node 2 zenith would interfere with the SGANT sight lines.

Furthermore, any of the currently open ports would violate the requirement to have redundant docking and berthing locations for cargo and crew vehicles.

[A_M_Swallow]

{snip}
Furthermore, any of the currently open ports would violate the requirement to have redundant docking and berthing locations for cargo and crew vehicles.

We have not tested it but the B330 has a docking/berthing port at both ends.

[joek]

The docking system qualification is shown as a completed milestone on the more detailed chart.

Thanks; good catch.  Looks like they added another interim milestone to show progress or maybe they negotiated an additional payment milestone; impossible to tell.   In any case, was not explicitly stated in the original CCtCap milestones/contracts .  Trying to keep up with the changes is maddening,.  But likely we will see more of them as NASA and contractors tryi to demonstrate more granular progress by inserting additional milestones.

[Space Ghost 1962]

Here is an article on this topic:
http://spacenews.com/commercial-crew-delays-could-lead-to-gap-in-iss-access-nasa-advisors-warn/

Notable:

One example is Boeing, who earlier this year delayed its two test flights by several months because of technical problems, including acoustic loads on its spacecraft and Atlas 5 rocket during launch that McAlister said the company has largely resolved.

“They’re in the final stages of some wind tunnel testing. They think they have a good solution,” he said, which involves installing an extended skirt behind the capsule. “We think that’s a pretty good solution too, but we really want to see some of that final wind tunnel test data come through.”

It'll lower their payload but get them out of a bind. Smart.

[yg1968]

Here is an article on this topic:
http://spacenews.com/commercial-crew-delays-could-lead-to-gap-in-iss-access-nasa-advisors-warn/

Notable:

One example is Boeing, who earlier this year delayed its two test flights by several months because of technical problems, including acoustic loads on its spacecraft and Atlas 5 rocket during launch that McAlister said the company has largely resolved.

“They’re in the final stages of some wind tunnel testing. They think they have a good solution,” he said, which involves installing an extended skirt behind the capsule. “We think that’s a pretty good solution too, but we really want to see some of that final wind tunnel test data come through.”

It'll lower their payload but get them out of a bind. Smart.

I agree that it's a smart move. But one of the reasons that Boeing won an award under CCtCap was because it could carry more cargo (in addition to crew) than other spacecrafts. Well, so much for that...

[Space Ghost 1962]

But one of the reasons that Boeing won an award under CCtCap was because it could carry more cargo (in addition to crew) than other spacecrafts. Well, so much for that...

Was skeptical of that claim given the 2x SRB, now possibly 3x. Not just the direct cost but the operations cost in mounting them. At some point "dial a rocket" economics concerns against a rival who can do 0 SRBs and greater flight frequency/history.

[arachnitect]

Here is an article on this topic:
http://spacenews.com/commercial-crew-delays-could-lead-to-gap-in-iss-access-nasa-advisors-warn/

Notable:

One example is Boeing, who earlier this year delayed its two test flights by several months because of technical problems, including acoustic loads on its spacecraft and Atlas 5 rocket during launch that McAlister said the company has largely resolved.

“They’re in the final stages of some wind tunnel testing. They think they have a good solution,” he said, which involves installing an extended skirt behind the capsule. “We think that’s a pretty good solution too, but we really want to see some of that final wind tunnel test data come through.”

It'll lower their payload but get them out of a bind. Smart.

I agree that it's a smart move. But one of the reasons that Boeing won an award under CCtCap was because it could carry more cargo (in addition to crew) than other spacecrafts. Well, so much for that...

Well if CST is struggling on Atlas 422, we can only imagine how bad of a bind DC would have been in.

In any case, I interpreted the cargo capacity comments as more about Boeing having a well developed stowage plan, not necessarily about raw mass numbers.

[yg1968]

I am not aware of any DC weight issue. I was under the impression that crewed DC would have used a 412.

[SWGlassPit]

I am not aware of any DC weight issue. I was under the impression that crewed DC would have used a 412.

Mass issues often don't show up until you get deep into detailed design.  Every fastener, every clip, every inch of wire, every drop of fluid in your propellant and cooling systems, every thousandth of an inch of wall thickness -- it all adds up.  When developing new projects, you try to project as well as you can, and you leave margin to account for design decisions that haven't been made, but there's always the risk that you end up with a surprise late in the design as each decision cascades into other decisions.

When you're in the early stages, how do you decide between one option and an alternative that, say, weighs thirty percent less than the other but costs a hundred times as much?  The info you have to drive mass/cost trades early in the design cycle isn't necessarily the info you have late in the design cycle, and the resulting decisions may be different.

[ChrisWilson68]

I am not aware of any DC weight issue. I was under the impression that crewed DC would have used a 412.

Mass issues often don't show up until you get deep into detailed design.  Every fastener, every clip, every inch of wire, every drop of fluid in your propellant and cooling systems, every thousandth of an inch of wall thickness -- it all adds up.  When developing new projects, you try to project as well as you can, and you leave margin to account for design decisions that haven't been made, but there's always the risk that you end up with a surprise late in the design as each decision cascades into other decisions.

When you're in the early stages, how do you decide between one option and an alternative that, say, weighs thirty percent less than the other but costs a hundred times as much?  The info you have to drive mass/cost trades early in the design cycle isn't necessarily the info you have late in the design cycle, and the resulting decisions may be different.

I agree.  And there's another point: SNC had very strong pressure to make the numbers they were quoting as optimistic as possible, and SNC has more of a history than any of the other CCtCap competitors of misleading hype.  SNC also has less experience building spacecraft than the other CCtCap competitors.

If they had won a CCtCap award and then the numbers turned out to be worse than anticipated, it's unlikely NASA would have cancelled the contract after most of the money was spent, and SNC knew that.  So, the incentives were set up to encourage them to be optimistic in their proposal even if it meant worse performance than projected in the end.

Whether consciously or unconsciously, it seems likely to me that the numbers they quoted were at the optimistic end of the range of the possible final numbers, and the range was wider than for other CCtCap competitors, due both to SNC's lack of experience and the fact that capsules have more heritage from which to extrapolate.

[yg1968]

I agree.  And there's another point: SNC had very strong pressure to make the numbers they were quoting as optimistic as possible, and SNC has more of a history than any of the other CCtCap competitors of misleading hype. 

It's not misleading hype, it's meaningless hype. SNC's MOUs are meaningless. The persons that are involved in the CCtCap selection already know this and aren't swayed by these agreements.

Edited to take into account woods170's comments.

[woods170]

I agree.  And there's another point: SNC had very strong pressure to make the numbers they were quoting as optimistic as possible, and SNC has more of a history than any of the other CCtCap competitors of misleading hype. 

It's not misleading hype, it's meaningless hype. MOUs are meaningless. The persons that are involved in the CCtCap selection already know this and aren't swayed by these type of agreements.

Emphasis mine.
Having witnessed great results of several space-related MOUs I take issue with your general statement regarding MOUs.

[yg1968]

I agree.  And there's another point: SNC had very strong pressure to make the numbers they were quoting as optimistic as possible, and SNC has more of a history than any of the other CCtCap competitors of misleading hype. 

It's not misleading hype, it's meaningless hype. MOUs are meaningless. The persons that are involved in the CCtCap selection already know this and aren't swayed by these type of agreements.

Emphasis mine.
Having witnessed great results of several space-related MOUs I take issue with your general statement regarding MOUs.

You are right. It is too broad a statement. I should have phrased it differently. I am skeptical about SNC's MOUs (and for that matter, those signed by Bigelow).

[catdlr]

Closer to a New Way Every Day

 
NASAKennedy

Published on Sep 16, 2016
Two years after selecting the next generation of American spacecraft and rockets that will launch astronauts to the International Space Station, engineers and spaceflight specialists across NASA’s Commercial Crew Program, Boeing and SpaceX are putting in place the elements required for successful missions.