SpaceX Launch Not So Perfect After All

First time accepted submitter drichan writes "Those of us who watched the live feed of last night's Falcon 9 launch could be forgiven for assuming that everything went according to plan. All the reports that came through over the audio were heavy on the word "nominal," and the craft successfully entered an orbit that has it on schedule to dock with the International Space Station on Wednesday. But over night, SpaceX released a slow-motion video of what they're calling an 'anomaly.'"

Comments

Whats the problem?

[ZiakII]

The Falcon 9, as its name implies, has nine engines, and is designed to go to orbit if one of them fails. On-board computers will detect engine failure, cut the fuel supply, and then distribute the unused propellant to the remaining engines, allowing them to burn longer. This seems to be the case where that was required, and the computers came through. The engines are also built with protection to limit the damage in cases where a neighboring engine explodes, which appears to be the case here.

Sounds like it did exactly what it was supposed to do.

Re:Whats the problem?

[afidel]

It wasn't an engine explosion, the protective fairing around the engine shattered when the engine cutoff caused a major change in pressure. SpaceX said that they continued to receive telemetry data from the engine which means it did not explode, and in fact was physically intact though not functioning correctly.

Re:Whats the problem?

[jamstar7]

As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragon’s entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.

IIRC, there was no way to recompute a Saturn 5 flight profile on the fly. Remember, kids, that was back in the days when we hunted dinosaurs from the backs of our '57 Chevys. Kudos to SpaceX for having enough out of the box thinking to have the needed software routines in the can already and ready to go. Falcon 9 is more than just another Big Dumb Booster, AAMOF, from everything I'm reading and seeing of its operation, it's pretty goddamned smart. Remember the test flight to the ISS? The first launch attempt, the onboard computers detected a glitch that might have taken out the bird and shut down and aborted the launch right at T -0, even after the humans tapped the buttons authorising the computers to do the launch. Like I say, some serious onboard smarts programmed by some seriously smart people.

Re:Whats the problem?

[fyngyrz]

No, the engine did not explode. The fairing around the nozzle was crush by the sudden loss of interior pressure when the engine shut down -- the external pressure was then much higher than the nozzle's interior pressure (no more rocket exhaust) and it got crushed and fell away, harming nothing. The engine is still there, intact, and it did, in fact, just turn off.

Re:Whats the problem?

[johnny cashed]

None of the Saturn series rockets were "dumb". The booster had its own guidance system independent of the spacecraft's guidance system.

For further reading: http://en.wikipedia.org/wiki/Saturn_Launch_Vehicle_Digital_Computer

Not all the info

[Antipater]

TFA only tells half the story. MSNBC has more. Dragon is fine, but it's possible that the launch's secondary objective, which was to put the first of an 18-satellite telecom array into a tricky high-inclination orbit, went a little screwy as well, and the sat isn't in the proper orbit at the moment. Details are still being dug out.

Re:not really a bad thing

[wierd_w]

This is very true, but if you've ever worked in aerospace, you surely know about "tribal knowledge."

SpaceX would have started with a clean slate in that department, and without NASA's tribal knowledge... let's just say that I am very pleased with their performance.

Re:An

[guruevi]

I don't think you know how these so-called fixed-price bids work for governments. They're not fixed at all as the contract or language implies. They are just starting points for negotiations on more contracts as the scopes and costs change on both ends of the contract.

Basically a government fixed-price request is a very vague description of an idea. The fixed-price bid is a very vague description of a project and associated budget. Whether or not the budget then balloons to eclipse the specified price is irrelevant to the bureaucracy on either side.