SpaceX F9 - Comm Crew In Flight Abort - LC-39A

[ecarfan]

Launch Date: Jan 19 2020
Launch Window: 0800 EST
Launch site: LC-39A, Cape Canaveral, Florida
Booster Recovery: No Chance
Booster Type: B1046.4
Mass: 6,350 kg (14,000 lbs) - DM-2 Capsule
Orbit: suborbital mission profile - Abort at Max-Q (88 seconds)

Apologies if I did not format the thread title correctly - @Grendal please correct and add any necessary mission info to the top of this post - but I just thought of a question about about Crew Dragon that relates to the Super Draco thruster abort system that I want to ask and don’t see a thread about this mission yet.

I believe it is well known that originally Elon wanted to land the Crew Dragon retropropulsively using Super Draco thrusters but NASA insisted on using a traditional triple-canopy parachute system. The Super Dracos remained part of the Crew Dragon design because they were the inflight abort system.

What I’m wondering is this; if the parachute system fails for some reason, has SpaceX implemented the firmware to detect a chute failure and then fire up the Super Dracos to land the capsule safely?

It seems like that would be worth doing, as a failsafe backup for the parachutes.

The IFA will take place at the 88 second mark.

 

[Lift]

What I’m wondering is this; if the parachute system fails for some reason, has SpaceX implemented the firmware to detect a chute failure and then fire up the Super Dracos to land the capsule safely?

It seems like that would be worth doing, as a failsafe backup for the parachutes.

As far as I know NASA never actually certified SuperDracos to be used as a landing option (and I would imagine NASA wasn't very keen on the idea of having Hydrazine around the astronauts after splash/touchdown). Now that Dragon has 4 parachutes, I would imagine it's highly unlikely that all 4 would fail to deploy. Dragon would still be able to land safely under 3 parachutes, 2 or 1 would probably make for a hard landing that could cause minor injuries.

 

[Grendal]

I agree with Lift. NASA has pushed for four parachutes and it is extremely unlikely that there would be multiple catastrophic failures to eliminate the chute system. If I were SpaceX, I would still have the programming in place as an emergency fallback in case of parachute failure though. I would hope that SpaceX would consider such a thing since the emergency fallback programming was not in place for CRS-7 to have the parachutes deploy for that capsule. It doesn't have to be elegant since it is only a .001% emergency situation. But not having the programming in place for such a situation and it manages to come about seems reckless.

 

[Doug_G]

Adding safety systems that are of marginal utility can actually degrade safety, because safety systems themselves can fail.

Classic case in point: a twin turboprop aircraft crashed on takeoff because one engine failed, and the pilot followed the procedure to feather the prop... but feathered the wrong one. No working propellers... and crash. So the manufacturer added an auto-feather system to prevent that from happening again. A few years later one of the planes had an auto-feather system failure. It feathered the prop on a perfectly working engine. The pilot, remembering his original training, went ahead and made the same mistake... and feathered the wrong prop manually. No working propellers... and crash.

 

[ecarfan]

As far as I know NASA never actually certified SuperDracos to be used as a landing option

I understand, and I acknowledged that in my post.

If I were SpaceX, I would still have the programming in place as an emergency fallback in case of parachute failure though.

That’s what I was thinking.

Classic case in point: a twin turboprop aircraft crashed on takeoff because one engine failed, and the pilot followed the procedure to feather the prop... but feathered the wrong one. No working propellers... and crash. So the manufacturer added an auto-feather system to prevent that from happening again. A few years later one of the planes had an auto-feather system failure. It feathered the prop on a perfectly working engine. The pilot, remembering remembering his original training, went ahead and made the same mistake... and feathered the wrong prop manually. No working propellers... and crash.

Fair point, though that example involved human error, not a software malfunction. So your concern would be that if there was a program to fire the Super Dracos in case of chute failure, there is also the possibility that they could be fired when there was no chute failure and turn a safe landing into a problem landing.

 

[Doug_G]

Fair point, though that example involved human error, not a software malfunction.

It was indeed a hardware or software error, in a "safety system", that caused the initial "engine failure". That, in turn, prompted the very human error the system was intended to prevent!

Crashes in aviation rarely involve just one factor.

So your concern would be that if there was a program to fire the Super Dracos in case of chute failure, there is also the possibility that they could be fired when there was no chute failure and turn a safe landing into a problem landing.

Yes, exactly.

Software that isn't tested doesn't work. That's pretty much a 100% guarantee. The more functionality you add to software the less reliable it is.

 

[ecarfan]

Now that Dragon has 4 parachutes, I would imagine it's highly unlikely that all 4 would fail to deploy. Dragon would still be able to land safely under 3 parachutes, 2 or 1 would probably make for a hard landing that could cause minor injuries.

Sorry, I didn’t realize that Dragon had a 4 chute systems.

Capsule parachute systems have been very reliable, but not perfect. Apollo 15 had one of three chutes fail, but the astronauts were unharmed.
Return of Apollo 15 to Earth - Wikipedia

And the Soyuz-1 mission ended catastrophically when the chute system failed.
The Soyuz-1 Parachute Failure

 

[mongo]

Update: NASA briefly updates status of Crew Dragon anomaly, SpaceX test schedule – NASASpaceFlight.com

According to Ms. Lueders, SpaceX will have the Falcon 9 rocket and Crew Dragon capsule hardware ready for the In Flight Abort test by the end of July, just two months from now.

 

[ecarfan]

According to Ms. Lueders, SpaceX will have the Falcon 9 rocket and Crew Dragon capsule hardware ready for the In Flight Abort test by the end of July, just two months from now.
—————————————————

That would be terrific if that happens, but isn’t the In Flight Abort Test mission dependent on resolving the recent Dragon test stand anomaly?

 

[mongo]

According to Ms. Lueders, SpaceX will have the Falcon 9 rocket and Crew Dragon capsule hardware ready for the In Flight Abort test by the end of July, just two months from now.
—————————————————

That would be terrific if that happens, but isn’t the In Flight Abort Test mission dependent on resolving the recent Dragon test stand anomaly?

Not necessarily, I recommend reading the full article, but it sounds like the issue may be a result of having gone to space or landing in the ocean. So nothing that impacts the SuperDraco's purpose.
A snippet:

The second option is that the investigation has revealed a specific cause for the anomaly and that the cause has been traced to something that occurred after Crew Dragon splashed down in the Atlantic Ocean after its mission.

 

[ecarfan]

I recommend reading the full article, but it sounds like the issue may be a result of having gone to space or landing in the ocean

I read the full article and my impression was that was speculation on the part of the author, not a clear statement from NASA.

 

[mongo]

I read the full article and my impression was that was speculation on the part of the author, not a clear statement from NASA.

Sure, but all the maybes and mights regarding changes are from NASA. So NASA is saying they are fairly okay with an abort test in July even though no changes have been made yet. That seems to me to indicate that no changes are expected.

 

[ecarfan]

Sure, but all the maybes and mights regarding changes are from NASA. So NASA is saying they are fairly okay with an abort test in July even though no changes have been made yet. That seems to me to indicate that no changes are expected.

Seems to me that drawing a conclusion from the vague language used by Ms Leuders is ill-advised.

Quote from article:
——————————————-
During this part of the presentation, Ms. Lueders repeatedly used the phrases “may need” and “might” to refer to potential changes in the SuperDraco propulsion system.

This language is admittedly not common in the aftermath of anomalies of this kind that have historically in the U.S. human spaceflight arena always led to some kind of significant change to the vehicle.

To this end, Ms. Lueders’ language could be read one of two ways: the first being that she was simply hedging her language as the investigation has not revealed the root cause of the anomaly at this time and therefore changes “might be” coming via information revealed at a later date.

The second option is that the investigation has revealed a specific cause for the anomaly and that the cause has been traced to something that occurred after Crew Dragon splashed down in the Atlantic Ocean after its mission.
———————————————-

 

[mongo]

Seems to me that drawing a conclusion from the vague language used by Ms Leuders is ill-advised.

Quote from article:
——————————————-
During this part of the presentation, Ms. Lueders repeatedly used the phrases “may need” and “might” to refer to potential changes in the SuperDraco propulsion system.

This language is admittedly not common in the aftermath of anomalies of this kind that have historically in the U.S. human spaceflight arena always led to some kind of significant change to the vehicle.

To this end, Ms. Lueders’ language could be read one of two ways: the first being that she was simply hedging her language as the investigation has not revealed the root cause of the anomaly at this time and therefore changes “might be” coming via information revealed at a later date.

The second option is that the investigation has revealed a specific cause for the anomaly and that the cause has been traced to something that occurred after Crew Dragon splashed down in the Atlantic Ocean after its mission.
———————————————-

Perhaps, but it seems odd that, if NASA were really concerned with the test failure, they would be setting scheduled event for a couple months out.
Contrast with: 'Until we know what caused this, testing is on hold'. Especially since the abort test relies on SuperDracos working correctly. If SpaceX were not comfortable with the status of the investigation, they would not be running the test.

 

[Grendal]

I thought I'd give this a bump since the DM-2 Super Draco test will be happening this week. Once that is successful, then the In Flight Abort test will get scheduled very soon after that. So a six month delay caused by the DM-1 capsule anomaly.

 

[e-FTW]

Gwynne even saying “November” for this. And I have not heard or “Gwynne-time” before...
We shall see.

 

[Pricee2]

On the launch coverage today, at about 8 minutes and 50 seconds, one of the announcers said the in-flight abort test is scheduled for Feb.

 

[FoverM]

On the launch coverage today, at about 8 minutes and 50 seconds, one of the announcers said the in-flight abort test is scheduled for Feb.

The commentator in the launch video made a mistake. He mixed up the IFA test and first manned Dragon mission. SpaceX is still targeting later this month (December) for the IFA. The first manned Dragon mission is Feb 2020.

Of course, being space-related, things will probably be delayed ...

 

[mongo]

"Hello from Hawthorne. Got to see the Dragon for the Demo-2 crewed mission. SpaceX aims to ship it out of factory by the end of year for thermal vacuum testing. Gwynne Shotwell says the target date for the in-flight abort test is Jan. 4. She says Demo-2 as soon as February."
Twitter

 

[FoverM]

"Hello from Hawthorne. Got to see the Dragon for the Demo-2 crewed mission. SpaceX aims to ship it out of factory by the end of year for thermal vacuum testing. Gwynne Shotwell says the target date for the in-flight abort test is Jan. 4. She says Demo-2 as soon as February."
Twitter

Yep, here's the official word:

SpaceX In-Flight Abort Test Launch Date Update – Commercial Crew Program

IFA is NET 2020/01/04. That'll probably push the crewed DM-2 out to March, too.