SpaceX Launch Abort Test Successful

An anonymous reader writes: As we discussed yesterday, SpaceX launched a prototype this morning to test its Dragon passenger capsule in an aborted launch. The test was a success — the capsule separated cleanly, propelled itself to a safe distance, deployed its parachutes, and lowered gently down to a water landing, where it remained floating. You can watch video of the test on SpaceX's website — skip to 15:40 to get right to it. Externally, everything seems to have gone fine. I'm sure we'll hear in the coming weeks whether the downrange distance was ideal, whether they hit their splashdown target, and how the crash test dummy inside the capsule weathered the abort!

Comments

Re:I just tested a launch abort too.

[TWX]

Please, no need to share your bathroom details with the rest of us...

Saw it in person

[trout007]

It was like a big model rocket launch. Quick burn, coast to apogee, chutes deploy, and landed in neighbors yard.

It was neat the engines shut off before I heard them start.

Re:Saw it in person

[TWX]

My wife worked on the spin-motors for the NASA LDSD test platform. Lots and lots and lots of rocket engines do this. Ejector seat motors come to mind- they want the pilot up and out quickly and without burning him up inside of the cockpit. Quick puff and the chair is out. Admittedly the pilot is now almost three inches shorter from spinal compression, but he should recover at least half of that.

Sort-of-worked.

[queazocotal]

Close examination of the video shows that one of the near thrusters shut off. Look carefully and you see a puff of smoke, and one of the thruster clusters dims as one of the two superdracos has stopped thrusting.
At the same moment, the vehicle begins to pitch.
The thrust was perhaps then terminated early - the vehicle did not quite get nominal total velocity.

Re:Sort-of-worked.

[bareman]

Pitch is part of the plan. Escape systems need to move the capsule out of the path of the rocket below it.

"T+.5s: After half a second of vertical flight, Crew Dragon pitches toward the ocean and continues its controlled burn. The SuperDraco engines throttle to control the trajectory based on real-time measurements from the vehicle’s sensors."

Re:Sort-of-worked.

[Bugler412]

thus the redundancy of the thruster arrangement, call it an additional successful test of a feature

Re:Sort-of-worked.

[photonic]

No, OP's remark was correct, he is not discussing the planned pitch over towards the sea after half a second, but a visible puff of smoke around the 4 second mark and some subsequent 'wobble', as if one of the 8 thrusters is switched of. See the zoomed video here. This proves the effectiveness of having 8 redundant thrusters, instead of having only 4. It is still not clear if this was a real engine failure (which might be verified via post-mortem examination of the motor), or if this was a deliberate, unannounced test of the 'engine out' capability. Credit: the discussion in the forum over at nasaspaceflight.com.

Re:Sort-of-worked.

[bondsbw]

Just throwing out a guess, but perhaps that was part of the test? A mechanical flaw may have been introduced into the engine in order to test that the rocket can appropriately decide when to abort, and also how to recover.

Re:Sort-of-worked.

[Bruce Perens]

What I am getting from the videos is that this test was a success but that there was indeed an engine failure and the system recovered from it successfully by throttling off the opposing engine. There was less Delta-V than expected, max altitude was lower than expected, downrange was lower than expected, and that tumble after trunk jettison and during drogue deploy looked like it would have been uncomfortable for crew.

This is the second time that SpaceX has had an engine failure and recovered from it. They get points for not killing the theoretical crew either time. There will be work to do. It's to be expected, this is rocket science.

It sounds to me like the launch engineers were rattled by the short downrange and the launch director had to rein them in.

Re:Sort-of-worked.

[cjameshuff]

Musk mentioned something about a thruster underperforming due to a poor propellant mixture ratio, but the Dragon was also controlling its thrust to direct its trajectory out to sea, so either could be the cause of the "puffs".

It came in surprisingly close to shore, but was also being dragged quite quickly by the wind before the parachutes finally collapsed. The altitude/speed reached are probably better indications of the actual performance.

Good, but close to shore!

[mlosh]

The landing was a bit closer to shore than expected, but probably due to high on-shore winds, and splashdown was 8 or 9 seconds early. Video seems to show one of the "SuperDraco" engines shutting down a bit earlier than the others. Still, very successful overall!

Very similar to the Mercury tests

[Anonymous Coward]

From space-x sub-reddit:

https://www.reddit.com/r/spacex/comments/34yote/rspacex_dragon_2_pad_abort_live_discussion/cr073cj

Looks like it landed just a bit further off-shore than the unmanned Mercury capsule from an Atlas 3 failure April 25, 1961: https://youtu.be/Vp9BnBDKa0s?t=5m55s Flight terminated after 43 seconds, LES tower ignited, pulling capsule free. Apogee of 7.2km, downrange only 1.8km. Capsule recovered and used again.

Re:Orion tower concept superior

[Strider-]

Watching the stream this morning, I couldn't help but feel sorry for any crew who were in the capsule as it tumbled over after separation. That looks like a really uncomfortable ride, but better than exploding on the pad.

I guess they forgot to hit T to enable SAS... ;)

...only a dummy...

[SylvesterTheCat]

>> Wednesday's test was conducted at Cape Canaveral in Florida, and saw a test vehicle - carrying no humans, only a dummy - hurled skywards by a set of powerful in-built thrusters.

Strange. I don't remember reading anything about there being a member of Congress on board..

Headline is screwing with my head

[glwtta]

If you fail a launch abort test, does that mean you had a successful launch?

Re:Yikes

[0123456]

The Apollo Command Module was designed to cave in if it came down on land instead of water (which could happen if it aborted very early in the launch). If I remember correctly, the helium tanks used to pressurize the RCS would crush and absorb the impact.

Re:I just tested a launch abort too.

[hey!]

Mine failed and I ended up in orbit.

Re:Orion tower concept superior

[DMUTPeregrine]

Not during an abort, only during a normal landing. During an abort the landing fuel is used to get the capsule away from the (shortly exploding) rocket as fast and as far as possible.

Re:Super Draco

[cbhacking]

They are, in fact, the engines the Musk said were fully 3D printed. Good point about the first flight thing.

Re:Orion tower concept superior

[Anonymous Coward]

In today's test it pushed between 4 and 5Gs. I don't believe the Falcon-9 first stage can do that at any point with a second stage on top. (IANARS, though, so I could totally be wrong.) That gives it a great shot at being able to clear an accelerating rocket in an early phase of the launch. (I have a lot less confidence in my guesses about the second stage performance. I guess I know it has 1/9th the maximum thrust...)