SpaceX Crew Dragon Escape Demonstration Was Successful

SpaceX tested the escape of the crew dragon. They also purposely blew up the Falcon 9.

Retrothrusters were used to re-orient the capsule. Four parachutes deployed and the capsule had a successful splashdown.

19 thoughts on “SpaceX Crew Dragon Escape Demonstration Was Successful”

  1. “I’m guessing NASA wasn’t up for it. Shame, really.”

    NASA paid to blow this booster up as part of the ISS commercial crew program.

  2. You’re right that the abort system commanded the shutdown and then proceeded immediately to the rest of the abort sequence. I’d expected that the shutdown command would be sandboxed from the rest of the abort code, so that the indication of shutdown would actually trigger the abort, but that’s not correct. Looks like they added a dummy abort criterion, so the shutdown is part of the actual abort sequence.

    But the explosion wasn’t commanded.

  3. Didn’t anyone here watch the press conference a few hours following the test?

    In that, Elon explained that the computer in the Dragon that has responsibility for monitoring the action was set to trigger the escape system at a particular capsule speed for this test. Once that computer decides that the escape is to be done, it sends a command to the Falcon 9 to shut down the engines, and in parallel with that, pressurizes the Super Draco thrusters and fires them when they are ready. This occurs over a time span of about 700 ms.

    The events on the Falcon 9 following that were due purely to the aerodynamic forces acting on it, which had no thrust and a big, gaping hole in the front where the Dragon had been.

  4. It was supersonic, lost thrust control, and had its aerodynamic first stage depart. It was going to come apart. Simple physics.

  5. The engine shutdown was commanded, which in turn triggered the abort. Once the D2 is gone and there’s effectively no thrust, the core/S2 stack with no D2 starts to pitch and yaw, increasing the angle of attack until something bad happens.

    If you look closely, the S2 starts venting something within a couple of seconds of the D2 departing. Shortly after, the core also starts venting something–a lot of something. Then the something(s) ignite in the slipstream, and then about 30 ms later, the big explosion occurs somewhere inside the core.

    My guess is that the slipstream explosion caused a big enough overpressure on the core LOX tank to drive LOX through the bulkhead between the LOX and RP-1 tanks, which caused a nice aerosol to mix in the tank, with predictable results.

  6. I think this booster was used on 4 other occasions, doesn’t seem like end of life to me… I’d read they built these for 10 flights before refurbishment.
    Would have been way cooler if they hadn’t stripped it and had re-throttled after abort, dropped the 2nd stage and had the booster land back at the Cape for processing and use on another flight.
    I’m guessing NASA wasn’t up for it. Shame, really.

  7. Couple reasons for this. The shuttle has a lot more mass off the axis of acceleration so the dispersal plume is going to be more asymmetric. Falcon 9 is a smooth axisymmetric rocket stack and the FTS system symmetrically terminates thrust by design. The shuttle losses were not single point detonations, they basically broke apart and then the fuel exploded, so it became a big messy plume where thrust termination didn’t really occur right away and it got all spread out.

  8. That’s correct.

    If you look at the video carefully, you’ll see that the second stage starts to vent something within a second or two of D2 separation. Then the core stage begins to vent something. Then there’s a small fireball that originates in the slipstream, which the leads to the big fireball.

    My guess is that the slipstream explosion was just enough to drive LOX in the core tanks through the bulkhead dome into the RP-1 tanks, with the big boom following.

  9. The consensus seems to be that the explosion was a result of the tanks rupturing as the angle of attack got too steep, not from a commanded event, or even from AFTS. If it had been a flight termination command, either manual or automated, the second stage wouldn’t have survived intact to blow up when it hit the ocean.

  10. I truly was a deliberate action. Elon said previously that he had his engineers try to figure out how to bring back the booster and land it but it “was impossible”. When the parts separate at that maximum thrust and altitude, the effects of the air rushing into the open ended cylinder would tear the booster apart. Blowing it up also burns the excess fuel to reduce the toxic waste into the ocean. The second stage was left without fuel but had weight added to match a true liftoff.

  11. Wasn’t quite as dramatic as the space shuttle blowing up…. I suppose that means it’s less complicated then the space shuttle…. thus more reliable… only one small debri cloud vs debri everywhere for space shuttle…. From the dragon camera it looked like it was already suborbital when it blew up…. Maybe they should blow up a falcon heavy instead for full debri cloud effect….

  12. They did the test with an end of life booster, which was going to be ripped up by aerodynamic forces anyway. Why NOT have some fun and blow it up?

    I bet you’re pissed that Musk sent that car into space in a test, instead of a block of concrete, too.

  13. The upper stage would have been fully fueled to make orbit with a crew aboard, thus a more realistic simulation of an emergency escape. Perhaps operations also provided for proper weighting of the capsule to reflect a maximal loading

  14. So you’re saying they didn’t really “deliberately blow it up”? That it was just an unavoidable side effect from having the nose separate from the rest of the vehicle?

  15. So you have to blow it up to make the test more convincing? That is stupid. Probably something NASA insisted on.

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