SpaceX F9 : Crew Dragon In-Flight Abort Test : Jan. 19, 2020 : Discussion

[Patchouli]

SpaceX would only refly the uncrewed test flight if there is significant redesign of the capsule (e.g. abandoning the superdracos for a traditional solid launch abort tower). It is too early to tell if that will be needed.

If they were to fit solids as a stop gap measure for a LAS I figure they'd put them on or in the trunk.
Could also ripple fire them for part of the orbital insertion like the Russian Kliper vehicle.

Of course this would likely be just as much work as fixing the issues with the Super Dracos and Spacex generally does not like dealing with solids.
As seen they didn't consider using something like a Star-37 to compensate for the lack of a high energy upper stage and decided to just fly some missions with drone ship recovery or completely expendable.

[gongora]

There is a thread dealing with the test failure.  Speculation about random ideas to redesign the capsule don't belong in this thread.

[lrk]

Could also ripple fire them for part of the orbital insertion like the Russian Kliper vehicle.

Do you have anymore information about the LAS for this vehicle?  Seems like an interesting concept, but a quick online search for more info was rather sparse. 

[Patchouli]

Do you have anymore information about the LAS for this vehicle?  Seems like an interesting concept, but a quick online search for more info was rather sparse. 

There's information and an animation on this site.
http://www.russianspaceweb.com/kliper_history.html
The MLAS in the tested configuration was similar

If Spacex decided to redo the abort system with SRBs I could see them adding rockets to trunk.
Though this would be very unlikely unless issues with the present abort system were deemed unsolvable as it would be a new engineering project and have a high mass penalty.

[Comga]

Test like you fly.  Use the DM2 spacecraft for abort test, then fly DM3 to orbit, and think hard before crewing same.  There's going to be a schedule hit here regardless - and there should.

 - Ed Kyle

DM3?

You know what he meant.
With the DM1 capsule destroyed, they fly the second Dragon 2 capsule that was meant for DM2 on the IFA
Then the third Dragon 2 capsule would be used in an added demo mission.
Ed is suggesting that it be unmanned. 
(I don't necessarily agree.  If they can't run the failure to ground, the success of a flight that doesn't use the SuperDracos won't prove or improve the reliability.  If they can, and they would have to, then they fly "DM3" as they would have DM2.)

[Tomness]

Test like you fly.  Use the DM2 spacecraft for abort test, then fly DM3 to orbit, and think hard before crewing same.  There's going to be a schedule hit here regardless - and there should.

 - Ed Kyle

DM3?

You know what he meant.
With the DM1 capsule destroyed, they fly the second Dragon 2 capsule that was meant for DM2 on the IFA
Then the third Dragon 2 capsule would be used in an added demo mission.
Ed is suggesting that it be unmanned. 
(I don't necessarily agree.  If they can't run the failure to ground, the success of a flight that doesn't use the SuperDracos won't prove or improve the reliability.  If they can, and they would have to, then they fly "DM3" as they would have DM2.)

Actually use Spx Crew 1 for in-flight abort. it doesn't have to be finished for the test. Any adjustments fix DM-2. Keep the schedule

[Roy_H]

Actually use Spx Crew 1 for in-flight abort. it doesn't have to be finished for the test. Any adjustments fix DM-2. Keep the schedule

Wishful thinking. Probably the better part of a year before this issue is cleared up and the IFA takes place. Work on Crew Dragon will probably cease until a fix is decided on.

[woods170]

Actually use Spx Crew 1 for in-flight abort. it doesn't have to be finished for the test. Any adjustments fix DM-2. Keep the schedule

Wishful thinking. Probably the better part of a year before this issue is cleared up and the IFA takes place. Work on Crew Dragon will probably cease until a fix is decided on.

Actually no. Work not related to the propulsive systems is continuing.

[cuddihy]

Test like you fly.  Use the DM2 spacecraft for abort test, then fly DM3 to orbit, and think hard before crewing same.  There's going to be a schedule hit here regardless - and there should.

 - Ed Kyle

DM3?

You know what he meant.
With the DM1 capsule destroyed, they fly the second Dragon 2 capsule that was meant for DM2 on the IFA
Then the third Dragon 2 capsule would be used in an added demo mission.
Ed is suggesting that it be unmanned. 
(I don't necessarily agree.  If they can't run the failure to ground, the success of a flight that doesn't use the SuperDracos won't prove or improve the reliability.  If they can, and they would have to, then they fly "DM3" as they would have DM2.)

Actually use Spx Crew 1 for in-flight abort. it doesn't have to be finished for the test. Any adjustments fix DM-2. Keep the schedule

I think you mean if the cause is revealed not to require radical changes to the Dragon 2 propulsion system, use the DM-2 vehicle to do the IFA, right?

If cause is understood & mitigated & all went well, *theoretically* IFA could still be launched by fall this year using the DM-2 vehicle with fixes applied...then the  vehicle, if IFA is successful, could be recovered, any additional testing be performed (including additional static firings) & either it post-refurbishment or the next Dragon 2 hull could be used for DM-2 mission.

Of course that's the best case in which failure mode is understood, replicatable, & proved preventable in just the next few months...

More likely scenario is SpaceX having to build some test systems, up to possibly an entire Dragon 2 propulsive stack, to fully prove /disprove failure modes. That pushes it likely many months before confidence in Dragon 2 could be restored to enable IFA /  DM-2 to move forward.

But here's hopin!

[Joffan]

Update on @SpaceX anomaly

Of relevance:

- Schedule replanning is underway for IFA, Demo-2 and Crew-1 schedule
- SpaceX has multiple capsules in build for the Dragon fleet and will advance assignments of capsules to specific missions.
- Capsule previously intended for Demo-2 (SN 205) will be used for IFA

https://twitter.com/NASAWatch/status/1133441235144847360

[scr00chy]

https://twitter.com/thesheetztweetz/status/1141735154374893568

GAO says SpaceX plans to put together the crew and support modules for the inflight abort test Crew Dragon "in summer 2019 and integrate them with the launch vehicle in fall 2019."

[aviators99]

I'm trying to figure out for viewing purposes if it might be more interesting to focus on the abort part of this test.  I wonder if someplace with an unubstructed view of the Atlantic might be preferred, in order to see the abort (if possible), as opposed to focusing on the launch complex.  Some of this may depend on the ongoing debate as to whether the 1st stage will "suffer an anomoly" or not.  Thoughts?

[whitelancer64]

I'm trying to figure out for viewing purposes if it might be more interesting to focus on the abort part of this test.  I wonder if someplace with an unubstructed view of the Atlantic might be preferred, in order to see the abort (if possible), as opposed to focusing on the launch complex.  Some of this may depend on the ongoing debate as to whether the 1st stage will "suffer an anomoly" or not.  Thoughts?

There won't be an "anomaly," the 1st stage will be commanded to shut down its engines.

The abort is going to happen about 1 minute or so into the launch, any place with a good view of a normal launch trajectory will have a good view of the abort.

[aviators99]

I'm trying to figure out for viewing purposes if it might be more interesting to focus on the abort part of this test.  I wonder if someplace with an unubstructed view of the Atlantic might be preferred, in order to see the abort (if possible), as opposed to focusing on the launch complex.  Some of this may depend on the ongoing debate as to whether the 1st stage will "suffer an anomoly" or not.  Thoughts?

There won't be an "anomaly," the 1st stage will be commanded to shut down its engines.

The abort is going to happen about 1 minute or so into the launch, any place with a good view of a normal launch trajectory will have a good view of the abort.

I know there were *some* docs that showed that the shutdown might cause break-up due to stresses, but I don't want to start that debate again :-)

[gongora]

I'm trying to figure out for viewing purposes if it might be more interesting to focus on the abort part of this test.  I wonder if someplace with an unubstructed view of the Atlantic might be preferred, in order to see the abort (if possible), as opposed to focusing on the launch complex.  Some of this may depend on the ongoing debate as to whether the 1st stage will "suffer an anomoly" or not.  Thoughts?

The offshore landing distance for Dragon has a large range in the environmental docs (6-42 miles?), but since there is a possibility of it being not too far from shore you probably want a clear view of the horizon.  Max Q on the last CRS flight was between 40,000 and 50,000 feet altitude, it's not that high.  Bring your binoculars and you should get a good show.  Playalinda would probably be ideal but as long as you can see what's happening a few miles offshore 40,000 feet in the air you should be fine.

[mn]

Is it a given that the IFA needs to wait for the conclusion of the investigation?

I've been thinking both ways.

You could argue that the investigation will possibly result in changes to the SuperDraco system which would invalidate a test done on the current design.

But you could counter argue that the test proves that you can safely abort given x thrust, and as long as the design changes retain that level of thrust the test is still valid. (Of course the design changes would need plenty of testing, but not necessarily another IFA)

[CorvusCorax]

Is it a given that the IFA needs to wait for the conclusion of the investigation?

I've been thinking both ways.

You could argue that the investigation will possibly result in changes to the SuperDraco system which would invalidate a test done on the current design.

But you could counter argue that the test proves that you can safely abort given x thrust, and as long as the design changes retain that level of thrust the test is still valid. (Of course the design changes would need plenty of testing, but not necessarily another IFA)

Thrust level is only half the equation, weight distribution and aerodynamics play a role, too.
So for the IFA to remain valid, any modification would have to

- make no changes to outer mold line
- keep the weight distribution identical (within margins)
- keep both max thrust and transient characteristics identical ( considering dragon steers during abort using differential thrust, thrust level delaxs could affect stability )

on the other hand, if the test verifies SpaceX models and fits expected results closely, they can use the models to characterise the behaviour even with future mods and trust those.

Lets hope no significant mods are necessary, than this all becomes a mute point :-)

[cppetrie]

Cross posting

Did I miss this being posted somewhere else already?

https://www.spacex.com/news/2019/07/15/update-flight-abort-static-fire-anomaly-investigation

[Roy_H]

Is it a given that the IFA needs to wait for the conclusion of the investigation? ...

Absolutely, yes. Any changes as a result of the investigation, i.e. installing burst disks to replace valves, have to be implemented and tested on the IFA.

[mn]

Is it a given that the IFA needs to wait for the conclusion of the investigation? ...

Absolutely, yes. Any changes as a result of the investigation, i.e. installing burst disks to replace valves, have to be implemented and tested on the IFA.

I'm not convinced? Explain why?