Commercial Crew - Discussion Thread 1

[mn]

There have been unspecified anomalies observed with parachute testing and CRS parachutes.

I have no idea what anomalies they are referring to, but if the parachutes behaved in an unexpected way I would agree with the ASAP that it should be investigated until the behavior is understood. Only after you understand why the parachute behaved the way they did can you determine if that is safe or not.

The fact that despite the anomaly it still remained within prescribed bounds should not be satisfactory if it behaved in an unexpected way.

[WindnWar]

There have been unspecified anomalies observed with parachute testing and CRS parachutes.

I have no idea what anomalies they are referring to, but if the parachutes behaved in an unexpected way I would agree with the ASAP that it should be investigated until the behavior is understood. Only after you understand why the parachute behaved the way they did can you determine if that is safe or not.

The fact that despite the anomaly it still remained within prescribed bounds should not be satisfactory if it behaved in an unexpected way.

You've missed the point that parachute systems often experience anomalies but good design takes that into account. So long as it doesn't point to a larger problem that would cause a failure, your simply not going to be able to design out every possible variable in performance. It's how the entire system operates that is important. More concerning is the possibility of Starliners chutes being damaged by the door that must deploy for them to be released. That's an issue they will have to prove is not possible, as that's a much different risk.

[envy887]

There have been unspecified anomalies observed with parachute testing and CRS parachutes.

I have no idea what anomalies they are referring to, but if the parachutes behaved in an unexpected way I would agree with the ASAP that it should be investigated until the behavior is understood. Only after you understand why the parachute behaved the way they did can you determine if that is safe or not.

The fact that despite the anomaly it still remained within prescribed bounds should not be satisfactory if it behaved in an unexpected way.

The individual parachutes have margin to cover unexpected anomalies (within a certain range). The parachute system as a whole also has additional margin to cover catastrophic failure of a entire parachute. In the case of Crew Dragon, I believe the system has margin to cover catastrophic failure of two out of four parachutes and still land safely.

As long as SpaceX can show that the unspecified anomalous behavior is not likely (for some numeric level of "likely") to exceed the margin of an individual parachute, they should't have any problem getting sign-off on the design.

Each chute is not a potential criticality-1 failure because they are multi-fault tolerant.

[Joffan]

The SpaceX IFA was moved to be after DM-1.  Probable reason was to make sure it used 100% final configuration.

To make things more interesting, they are also planning to reuse the Dragon 2 from DM-1 with only a few months turnaround. This despite landing in the water, and NASA not certifying (yet) reuse of Dragon 2 for crew missions.

The Crew Dragon vehicle from DM-1 (which is an unmanned mission) will be reused for the (unmanned) ascent abort test (IFA). There is no need for NASA to certify reuse of Crew Dragon for crew missions because neither mission (DM-1 and IFA) is a crew mission. Certification of Crew Dragon reuse for uncrewed (demo) missions is outside of the scope of the CCP contract.

Well... while both DM-1 and IFA are unmanned, they are more useful as tests if they are flown as if manned. But the fact of reuse doesn't need to interfere with that; in fact it may help the case of reusing water-landed Crew Dragons.

What seems very likely to me is that refurbishing the DM-1 capsule for use on IFA will involve making sure it could in principle support a crew through its entire flight profile, since no doubt the instrumentation will be recording exactly how well it does that. So anything "broken" (or otherwise stressed) by the water landing would need to be fixed to a standard where its performance in IFA could be accurately evaluated.

[vt_hokie]

I still wonder if propulsive landing using the Super Dracos is a feasible backup mode.  If it's remotely feasible, it seems like something worth pursuing to help make Crew Dragon the American Soyuz that we need - i.e. a robust and reliable crew transport system.  However, SpaceX seems to view it as a dead end as it shifts focus to BFR/BFS.

[Tulse]

If NASA isn't requiring it, I can't see SpaceX spending any time or money on it.

[Lemurion]

My question is why is ASAP talking about SpaceX "closing the case" on COPVs instead of simply mentioning that the company has not yet completed the required test flights with the new design?

[gongora]

My question is why is ASAP talking about SpaceX "closing the case" on COPVs instead of simply mentioning that the company has not yet completed the required test flights with the new design?

Simply doing the test flights isn't enough.  All of the parts of the system still need to be approved.

[Jcc]

The SpaceX IFA was moved to be after DM-1.  Probable reason was to make sure it used 100% final configuration.

To make things more interesting, they are also planning to reuse the Dragon 2 from DM-1 with only a few months turnaround. This despite landing in the water, and NASA not certifying (yet) reuse of Dragon 2 for crew missions.

The Crew Dragon vehicle from DM-1 (which is an unmanned mission) will be reused for the (unmanned) ascent abort test (IFA). There is no need for NASA to certify reuse of Crew Dragon for crew missions because neither mission (DM-1 and IFA) is a crew mission. Certification of Crew Dragon reuse for uncrewed (demo) missions is outside of the scope of the CCP contract.

Well... while both DM-1 and IFA are unmanned, they are more useful as tests if they are flown as if manned. But the fact of reuse doesn't need to interfere with that; in fact it may help the case of reusing water-landed Crew Dragons.

What seems very likely to me is that refurbishing the DM-1 capsule for use on IFA will involve making sure it could in principle support a crew through its entire flight profile, since no doubt the instrumentation will be recording exactly how well it does that. So anything "broken" (or otherwise stressed) by the water landing would need to be fixed to a standard where its performance in IFA could be accurately evaluated.

My only concern with the plan is risk to schedule, it's quite a bold move on SpaceX part, and shows confidence in their ability to refurbish Dragon-1 despite the generally accepted impossibility to reuse a capsule that landed in salt water. They have done it several times now for cargo. They might well convert reused crew Dragon-2 into cargo Dragon-2, or use them for private crew, or convince NASA to use them for Commercial Crew. But committing to fly one in less than 6 months from first flight is bold to say the least.

[woods170]

The SpaceX IFA was moved to be after DM-1.  Probable reason was to make sure it used 100% final configuration.

To make things more interesting, they are also planning to reuse the Dragon 2 from DM-1 with only a few months turnaround. This despite landing in the water, and NASA not certifying (yet) reuse of Dragon 2 for crew missions.

The Crew Dragon vehicle from DM-1 (which is an unmanned mission) will be reused for the (unmanned) ascent abort test (IFA). There is no need for NASA to certify reuse of Crew Dragon for crew missions because neither mission (DM-1 and IFA) is a crew mission. Certification of Crew Dragon reuse for uncrewed (demo) missions is outside of the scope of the CCP contract.

Well... while both DM-1 and IFA are unmanned, they are more useful as tests if they are flown as if manned. But the fact of reuse doesn't need to interfere with that; in fact it may help the case of reusing water-landed Crew Dragons.

What seems very likely to me is that refurbishing the DM-1 capsule for use on IFA will involve making sure it could in principle support a crew through its entire flight profile, since no doubt the instrumentation will be recording exactly how well it does that. So anything "broken" (or otherwise stressed) by the water landing would need to be fixed to a standard where its performance in IFA could be accurately evaluated.

My only concern with the plan is risk to schedule, it's quite a bold move on SpaceX part, and shows confidence in their ability to refurbish Dragon-1 despite the generally accepted impossibility to reuse a capsule that landed in salt water. They have done it several times now for cargo. They might well convert reused crew Dragon-2 into cargo Dragon-2, or use them for private crew, or convince NASA to use them for Commercial Crew. But committing to fly one in less than 6 months from first flight is bold to say the least.

Emphasis mine.

That is exactly the plan.
Reusing the DM-1 Crew Dragon for the IFA is a direct result of NASA having vetoed propulsive landing.
The result of that decision was that Crew Dragon landing in the ocean became the prime landing method. As such, SpaceX had to invest a lot of time (a full year) and money on improving the "seaworthyness" of Crew Dragon.
The side effect of that effort is that Crew Dragon is much more resistant to the effects of salt-water immersion than Cargo Dragon. And that in turn makes it a lot easier to refurbish an ocean-landed Crew Dragon for a next (unmanned) mission.

[JonathanD]

If NASA isn't requiring it, I can't see SpaceX spending any time or money on it.

If it could save the lives of the crew, I could see them doing it.  You have the systems, you have the thrusters, you have the fuel.  It would be crazy to not have it as a "worst case scenario" option that could potentially prevent what would be a horrible tragedy for the country, the space program, and the company.  How foolish would one feel to have that capability but not use it in that terrible situation.

[Tulse]

If it could save the lives of the crew, I could see them doing it.  You have the systems, you have the thrusters, you have the fuel.

Parachutes have been used with capsule landings successfully for quite a while, and it is not at all clear that qualifying the SuperDracos for propulsive landing would significantly reduce crew risk.

[tdperk]

If it could save the lives of the crew, I could see them doing it.  You have the systems, you have the thrusters, you have the fuel.

Parachutes have been used with capsule landings successfully for quite a while, and it is not at all clear that qualifying the SuperDracos for propulsive landing would significantly reduce crew risk.

Either they will be loaded with safe inert fluids instead of fuel, or, being able to run them in such an emergency reduces risk.

[speedevil]

If it could save the lives of the crew, I could see them doing it.  You have the systems, you have the thrusters, you have the fuel.

Parachutes have been used with capsule landings successfully for quite a while, and it is not at all clear that qualifying the SuperDracos for propulsive landing would significantly reduce crew risk.

Either they will be loaded with safe inert fluids instead of fuel, or, being able to run them in such an emergency reduces risk.

They can't be.
The fuel is used (or not) in the event of a launch emergency (and for orbital manoevering, I am unclear if there are separate tanks).

They can in principle nonpropulsively burn off the propellant before entry.

[edkyle99]

The cause wasn't rush. The cause was using pure oxygen in the cabin and we were lucky it had not killed any crews beforehand. The solution was to use oxygen/nitrogen during the launch phase and to design the craft for emergency escape on the pad if need be. Also they never did find what started the fire but simply redesigned the electoral system to get rid of probable causes.

One of the guys who crawled in and out of 204 thought it was rush.

Johnson Space Center Oral History Project Walter M. Schirra, Jr.
1 December 1998

"SCHIRRA: I was annoyed at the way what became Apollo 1 came out of the plant at [North American Aviation’s plant in] Downey [California].  It was not finished.  It was what they called a lot of uncompleted work or incomplete tests and work done on it.  So it was shipped to the Cape with a bunch of spare parts and things to finish it out.  And that, of course, caused this whole atmosphere of developing where I would almost call it a first case of bad “go” fever.  “Go” fever meaning that we’ve got to keep going, got to keep going, got to keep going!"

 - Ed Kyle

[woods170]

The cause wasn't rush. The cause was using pure oxygen in the cabin and we were lucky it had not killed any crews beforehand. The solution was to use oxygen/nitrogen during the launch phase and to design the craft for emergency escape on the pad if need be. Also they never did find what started the fire but simply redesigned the electoral system to get rid of probable causes.

One of the guys who crawled in and out of 204 thought it was rush.

Johnson Space Center Oral History Project Walter M. Schirra, Jr.
1 December 1998

"SCHIRRA: I was annoyed at the way what became Apollo 1 came out of the plant at [North American Aviation’s plant in] Downey [California].  It was not finished.  It was what they called a lot of uncompleted work or incomplete tests and work done on it.  So it was shipped to the Cape with a bunch of spare parts and things to finish it out.  And that, of course, caused this whole atmosphere of developing where I would almost call it a first case of bad “go” fever.  “Go” fever meaning that we’ve got to keep going, got to keep going, got to keep going!"

 - Ed Kyle

Ed is correct on this one. It has been established officially (via testitmony given to the investigation Board and recognized as such in the official investigation report) and historically that NASA was in a rush to get Apollo into orbit. And although safety was never intentionally compromised, it was very clearly unintentionally compromised in the rush to get things done.

NASA was in a hurry to get to the Moon.

[Hog]

The cause wasn't rush. The cause was using pure oxygen in the cabin and we were lucky it had not killed any crews beforehand. The solution was to use oxygen/nitrogen during the launch phase and to design the craft for emergency escape on the pad if need be. Also they never did find what started the fire but simply redesigned the electoral system to get rid of probable causes.

One of the guys who crawled in and out of 204 thought it was rush.

Johnson Space Center Oral History Project Walter M. Schirra, Jr.
1 December 1998

"SCHIRRA: I was annoyed at the way what became Apollo 1 came out of the plant at [North American Aviation’s plant in] Downey [California].  It was not finished.  It was what they called a lot of uncompleted work or incomplete tests and work done on it.  So it was shipped to the Cape with a bunch of spare parts and things to finish it out.  And that, of course, caused this whole atmosphere of developing where I would almost call it a first case of bad “go” fever.  “Go” fever meaning that we’ve got to keep going, got to keep going, got to keep going!"

 - Ed Kyle

I could be said that OV-101 Columbia was "airmailed" to the Cape on March 24, 1979 under similar conditions.

Pics of STS-102 during takeoff from Edwards AFB.

[alang]

A number of negative comments about the Aerospace Safety Advisory Panel (ASAP) on this forum.
I believe thst audio recording starts with a comment that statements from the public are invited but that none were received.
How does that work in the U.S. ? Can people without accreditation really take up time in that way or is that statement shorthand for something else?
I know that I don't know what I'm talking about in Engineering terms so I'd respect some of these comments more if I heard them made formally.

[docmordrid]

A number of negative comments about the Aerospace Safety Advisory Panel (ASAP) on this forum.

Most would say they've earned it.

I believe thst audio recording starts with a comment that statements from the public are invited but that none were received.

How does that work in the U.S. ? Can people without accreditation really take up time in that way or is that statement shorthand for something else?
>

Public comment periods are very common at almost all levels of government and rule making. They can be in person at a public meeting or in writing, but in general everyone can have a say. Vox populi.

Examples: letters to members of Congress, which can literally kill legislation, or dozens of people  showing up at a public regulatory meeting and lining up at a microphone.

[Rondaz]

Astronauts Practice Spacewalks Virtually

Marie Lewis Posted on October 23, 2018

Commercial crew astronauts are rehearsing their movements in space for when they launch on Boeing and SpaceX missions to the International Space Station. Astronauts Suni Williams (above) and Mike Hopkins (below left) recently practiced spacewalking in the Virtual Reality Lab at Johnson Space Center in Houston. The training is designed to be as realistic as possible, with real time graphics and motion simulators to replicate the space environment.

NASA uses virtual reality for spacewalk training. The astronauts see a virtual representation of the space station through their goggles and are able to practice moving around on its exterior, without the drag that they would experience from the water in the Neutral Buoyancy Lab, NASA’s enormous swimming pool where astronauts practice spacewalking underwater. They can practice maneuvering safely back to the space station as well as plotting paths from worksite to worksite.

NASA’s Commercial Crew Program is working with Boeing and SpaceX to return human spaceflight launches to the United States in 2019. Williams is assigned to Boeing’s first operational mission after the company’s test flight with crew. Hopkins is assigned to SpaceX’s first operational mission after the company’s test flight with crew.