SpaceX reviewing mountains of data to figure out why its rocket exploded

L A Times ^ | Christine Mai-Duc

[cicero2k]

My guess, it was easily avoidable and heads will roll.

Perhaps as simple as incorrect units of measure conversion, again. How many KM in a mile is that?

[minnesota_bound]

I think that the fuse burned down to the back of the rocket and it went KABOOM!

[Ozark Tom]

Telemetry continued through the event showing LOX overpressure spike on 2nd stage tank. Massive venting of lox captured on ground tracking video coming from just below the trunk adapter and second stage join point. Tracking video shows Dragon capsule on parallel track prior to final launcher disintegration.

Vehicle is traveling close to Mach 3 and well past the highest loading from punching a hole through the atmosphere. Was approaching the maximum G-loading as first stage runs empty close to 30 miles altitude.

Second stage engine was receiving cryogenic oxygen component-cooling per imminent staging procedure. Engine did “not” start causing loss of vehicle. A massive leak from the LOX tank of the second stage is evident.

Tank pressure is essential for structural strength of the vehicle body. Loss of pressure allows crumpling, like standing on an empty aluminum soda can. The capsule separated intact due to supporting structure failure. The atmospheric shock-wave loading, absent the capsule and fairing, collapsed and blasted apart the remaining vehicle structure.

[wastoute]

Maybe if it was his money he would be more careful.

[Jeff F]

Very nice summary. The G loading would have gone up even further with the rapid loss of mass from venting the LOX while the first stage still powered on for another eight seconds. The supersonic airstream would likely have been powerful enough to shred the open second stage once the capsule broke free. Capsule separation seemed to happen within a second or two of the tank rupture. The same shredding would then happen to the first stage along with the flash burning of what fuel remained leaving only the Dragon capsule intact.

I haven't seen a good description yet of the tank overpressure event. If it was gradual, then the stuck relief value idea seems to make sense to me. If it was very sudden (you mentioned a spike), then there may have been an internal combustion event as with the Apollo 13 command module's LOX tank. Or perhaps the tank was suddenly deformed or crushed from some external force such as a structural failure of the upper stage body.

[Jeff F]

Mr. Jeff F yesterday guessed LOX tank rupture due to failed relief valve.

You are kind to remember and credit me. And, no, sadly I am neither as funny as Jeff Foxworthy nor as smart as a rocket scientist.

[Jeff F]

I also see you are a fellow veteran member here with a full 7 days of seniority over me. Dang!

[Moonman62]

overpressure event

Yeah. It blew up. We know that.

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I think there is a significant difference between the tank rupturing due to overpressure versus the tank exploding due to ignition of the fuel.

[Moonman62]

Insufficient gubermint subsidies....

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SpaceX has contracts with the government for launch services and achieving milestones. They aren’t subsidies.

[Moonman62]

Maybe if it was his money he would be more careful.

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Musk has invested a significant amount of his own money in the three companies where he’s either CEO or Chairman. Almost all of SpaceX’s money either comes from services rendered according to contract (not subsidies), or from investors.

[Jack Hydrazine]

Explaining the Space X CRS7 Launch Failure
21JUL2015
https://www.youtube.com/watch?v=1i8hfpLNAIo

[Jack Hydrazine]

SpaceX Falcon 9 failure investigation focuses on COPV struts
http://www.nasaspaceflight.com/2015/07/spacex-falcon-9-failure-investigation-focuses-update/