[dabeeeenster]

"Preliminary analysis suggests the vehicle experienced an overpressure event in the upper stage liquid oxygen tank approximately 139 seconds into flight. Telemetry indicates first stage flight was nominal and that Dragon remained healthy for some period of time following separation."

Sounds like they are trying to suggest that if there had been people in the capsule they would have survived...

[dlgeek]

The manned capsule has a powered abort system, and this one doesn't, so they really don't need to suggest anything (since a failure here would not be reflective of the surviviability of Dragon2).

They intentionally disable ("safe") the parachute system during the launch phase, but from the rumors I'm hearing coming out of SpaceX, if they had been enabled, this capsule would have survived.

[imglorp]

Maybe all the cargo shots should have these systems enabled to further exercise them. It would have been nice to demonstrate capsule survival in yesterday's event.

[mikeash]

It's not something you merely "enable." These cargo missions are using Dragon 1 capsules, whereas the manned system is Dragon 2. The abort system in Dragon 2 is integral to the capsule (it doubles as the landing system used after a normal flight) and isn't something you can just retrofit to a different vehicle.

[grecy]

Can Dragon 1 have parachutes?

[mikeash]

Yes, and it does on every flight since it's used to return things from the space station back to Earth. However an abort system also needs something to move the capsule away from the (probably exploding) rocket when something goes wrong, which is typically a strong and short-firing rocket on the capsule itself.

In this particular case, it sounds like Dragon survived and probably could have been recovered using the parachutes, but they weren't armed since survival without an abort system isn't something they really try for. It would be interesting to make the attempt, but not informative for manned flights since those will have a proper abort system.

[grecy]

Interesting, thanks.

It would be interesting to know if they can remotely trigger the parachutes - i.e. in this case after it had fallen a ways they could have triggered them - even just to see what would happen.

[dlgeek]

Sorry (there was some confusion below):

Dragon 2 has a powered escape system. Dragon 1 just has parachutes for the recovery phase.

You safe the parachutes for the ascent phase because they're dangerous. If they accidentally trigger, you lose the whole rocket due to structural failure from the sudden forces. You'd most likely lose the capsule/chute at this point too.

A chance of recovering the cargo in the event of an incident like this just isn't considered worth it.

[mrfusion]

Also the first stage might have survived and returned to landing if it had known about the trouble and detached earlier? Or am I misunderstanding?

[lmm]

If the second stage just hadn't been there then the first stage might have survived and landed. But I'm not sure there is any way to "detach early", and you'd have the problem of having too much fuel left over in the first stage. I doubt it's designed to land in those circumstances (why would it be?), so it probably couldn't.

[dabeeeenster]

I think that might be a stretch but I don't think they care about that half as much.