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Satellite burns up following SpaceX rocket glitch

reuters.com

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Re: Satellite burns up following SpaceX rocket glitch

#61

Post by zachalexander »

nkurz wrote: post #55

Due to the engine shutdown, the Falcon 9 used slightly more fuel and oxygen to reach Dragon's intended 202 mile- (325-km) high orbit. For the ride up, SpaceX stashed chocolate-vanilla swirl ice cream inside. the amount of liquid oxygen "was only enough to achieve a roughly 95 percent likelihood of completing the second burn..." 882 pounds (400 kg) of cargo aboard the Dragon capsule The cynic in my wonders: would they…

Falcon 9: 333,450 kg

Dragon: 4,200 kg

Cargo: 905 kg

Ice cream: Skipping the ice cream would've reduced their total mass by <0.001% or so, at least at launchtime.

Re: Satellite burns up following SpaceX rocket glitch

#62

Post by confluence »

mturmon wrote: post #48
graupel wrote: post #45

Earlier quoted context omitted.

Yes, because guess what? I think the premiums just went up a bit!

Yes, the actuarial problem here is actually quite interesting, because one question it must address is the probability of failure. I wonder how much insight the insurers were given into safety margins on the spacecraft? [Edit: OK, a link on spacecraft actuarial methods: http://www.casact.org/pubs/forum/00fforum/00ff047.pdf ]

Thanks for that.

I don't suppose you have other links to catastrophic risk insurance papers that are relatively interesting. I've always been interested in the industry from a far.

Re: Satellite burns up following SpaceX rocket glitch

#64

Post by jlgreco »

tarice wrote: post #6

So, essentially, a company sends a satellite into space, tests it a lot, and then charges an insurance company $10 million because they expected it to fall into the atmosphere? What insurance company lets a company take out a plan with that kind of risk? Seems like NASA should've been getting insurance plans for the shuttle's External Tank all these years.

I think you will find that very few people in this world understand risk better than insurance companies. They were not victimized here.

Re: Satellite burns up following SpaceX rocket glitch

#65

Post by danielweber »

alanh wrote: post #3

Wow, I hope everyone reads the article before commenting. It’s still amazingly successful. There was a 95% chance the satellite would have made it if they tried, but they were obligated not to try if there were less than a 99% chance of success. (The reduced chance was due to the loss of one of the 9 engines.) And, of course, the primary mission to the space station was fully successful (the engine glitch notwithstan…

It wasn't a 95%/99% of the satellite making it; those were the chances that there wouldn't be an incident with the ISS if the upper stage activated.

The Falcon 9 ended up in a slightly different position/velocity than was expected, and the primary mission (deliver to the ISS and don't dare run anything into it) took complete priority over the secondary mission of launching the other satellite into a high orbit.

Re: Satellite burns up following SpaceX rocket glitch

#66

Post by codex »

martinkallstrom wrote: post #5

It is perfectly clear that this is a story of safety margines adhered to in an admirably strict fashion; not allowing short term thinking rule over long term; and certainly not allowing marketing rule over engineering. This is how you move mountains.

It should; all of the material quotes in this article came from a SpaceX public relations agent and not from independent space analysts. Not exactly objective. The only quote from Orbicomm is practically a tautology.

Re: Satellite burns up following SpaceX rocket glitch

#67

Post by danielweber »

ramidarigaz wrote: post #46
mikeash wrote: post #38

Earlier quoted context omitted.

No, the risky part was trying to raise the orbit using the F9 upper stage after it had burned more fuel than expected due to the failed engine. Quoth the article: > Falcon 9 had enough kerosene fuel left over to relight the engine, but the amount of liquid oxygen "was only enough to achieve a roughly 95 percent likelihood of completing the second burn, so Falcon 9 did not attempt a restart," I doubt many satellites h…

You're right. I remember them discussing attempting to raise the orbit with onboard fuel, but I doubt that was possible. My point was more that, prior to the engine failure, raising the orbit with the second stage was considered non-risky. You're correct that after the failure, raising the orbit with the second stage was risky.

From what I recall, the Orbcomm satellite was supposed to be left in a 350km x 750km orbit by the Falcon 9, and would then use its own reserves to achieve a basically circular orbit, 750km x 750km.

Re: Satellite burns up following SpaceX rocket glitch

#68

Post by danielweber »

confluence wrote: post #36

> Among the Dragon's cargo was a freezer that will be used to store scientific samples. For the ride up, SpaceX stashed chocolate-vanilla swirl ice cream inside. Just awesome. The mission was a success. The satellite maker's loss was covered with insurance money, the ISS stays up in the sky, engine-out capability proven, subsequent launch contracts remain in place from both NASA/the satellite maker - and the ISS astr…

The primary mission was a success. The secondary mission was a failure. $10 million probably covers Orbcomm's launch costs.

SpaceX is awesome, but this isn't an unqualified win. There are groups out for SpaceX's head and they will try (unsuccessfully, I hope) to use this "engine incident" against them. SpaceX did not want this to happen at all.

Re: Satellite burns up following SpaceX rocket glitch

#69

Post by [deleted] »

codex wrote: post #66
martinkallstrom wrote: post #5

It is perfectly clear that this is a story of safety margines adhered to in an admirably strict fashion; not allowing short term thinking rule over long term; and certainly not allowing marketing rule over engineering. This is how you move mountains.

It should; all of the material quotes in this article came from a SpaceX public relations agent and not from independent space analysts. Not exactly objective. The only quote from Orbicomm is practically a tautology.

[deleted]

Re: Satellite burns up following SpaceX rocket glitch

#70

Post by Dylan16807 »

martinkallstrom wrote: post #5

It is perfectly clear that this is a story of safety margines adhered to in an admirably strict fashion; not allowing short term thinking rule over long term; and certainly not allowing marketing rule over engineering. This is how you move mountains.

On the other hand it doesn't explain why they didn't look at another orbit that they did have enough fuel for. Was this a decision that had to be made immediately?
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