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SpaceX – Launch Vehicle Failure

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Re: SpaceX – Launch Vehicle Failure

#331

Post by MPSimmons »

GreenPlastic wrote: post #311
demachina wrote: post #305

Earlier quoted context omitted.

The SpaceX design should be dramatically suprior to the aging Atlas and Delta designs because they are designed to be cheaper to build in the first place and they will be game changing if they manage to land the first stage and immediately turn it around for multiple launches. Atlas and Delta are certainly good platforms for high reliability but they are expensive and they aren't making much effort to bring the costs…

ULA is already dead in the water. The only reason why they're around is because of the monopoly they have with US military launches.

With the sheer amount of money backing ULA, there's no way they can be considered dead in the water. Their launch vessels are incredibly reliable, as mentioned elsewhere in this thread.

They're not just viable competitors, they're the current market leader. SpaceX is the peppy young upstart here (and still, failures like this are stepping stones to future reliability, if they're spending the time learning from their mistakes like they should be).

At least it was unmanned.

Re: SpaceX – Launch Vehicle Failure

#332

Post by greglindahl »

MPSimmons wrote: post #331
GreenPlastic wrote: post #311

Earlier quoted context omitted.

ULA is already dead in the water. The only reason why they're around is because of the monopoly they have with US military launches.

With the sheer amount of money backing ULA, there's no way they can be considered dead in the water. Their launch vessels are incredibly reliable, as mentioned elsewhere in this thread. They're not just viable competitors, they're the current market leader. SpaceX is the peppy young upstart here (and still, failures like this are stepping stones to future reliability, if they're spending the time learning from their…

ULA wins very little commercial business. So yes, they're the market leader for US government launches of extremely expensive satellites. The rest of the market, commercial and US government launches of less expensive stuff, is where SpaceX is way ahead of ULA.

Re: SpaceX – Launch Vehicle Failure

#333

Post by nhstanley »

Edmeral wrote: post #297
dcposch wrote: post #290

I watched the launch live this morning. It reminded me of one of the best interviews ever. Elon Musk after SpaceX's first three launches all exploded: http://archive.wired.com/science/space/news/2008/08/musk_qa I read that in high school, and it's part of the reason I became an engineer. "Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure... than to rank with those poor…

"Optimism, pessimism, fuck that; we're going to make it happen. As God is my bloody witness, I'm hell-bent on making it work." I got goose bumps reading Elon's response at the end of the article.

"Why did you want to climb Mount Everest?"

"Because it's there. Everest is the highest mountain in the world, and no man has reached its summit. Its existence is a challenge. The answer is instinctive, a part, I suppose, of man's desire to conquer the universe." - George Mallory

Re: SpaceX – Launch Vehicle Failure

#334

Post by Retric »

nhstanley wrote: post #333
Edmeral wrote: post #297

Earlier quoted context omitted.

"Optimism, pessimism, fuck that; we're going to make it happen. As God is my bloody witness, I'm hell-bent on making it work." I got goose bumps reading Elon's response at the end of the article.

"Why did you want to climb Mount Everest?" "Because it's there. Everest is the highest mountain in the world, and no man has reached its summit. Its existence is a challenge. The answer is instinctive, a part, I suppose, of man's desire to conquer the universe." - George Mallory

That's a great reason to be the first to climb Everest, but it seems lacking to be the 4,000th.

Re: SpaceX – Launch Vehicle Failure

#335

Post by Retric »

lutorm wrote: post #265
spdionis wrote: post #263

Earlier quoted context omitted.

Also what does "no outright failures" mean?

I assume they mean "failure to accomplish mission", as opposed to "things didn't work correctly but the outcome was still successful."

There is some wiggle room, payload achieved orbit, but not nessisarily the desired orbit.

Re: SpaceX – Launch Vehicle Failure

#336

Post by kalleboo »

Retric wrote: post #334
nhstanley wrote: post #333

Earlier quoted context omitted.

"Why did you want to climb Mount Everest?" "Because it's there. Everest is the highest mountain in the world, and no man has reached its summit. Its existence is a challenge. The answer is instinctive, a part, I suppose, of man's desire to conquer the universe." - George Mallory

That's a great reason to be the first to climb Everest, but it seems lacking to be the 4,000th.

"Why do I climb the mountain? Because I'm in love" - William Shatner

https://www.youtube.com/watch?v=Kestt5BI3eg

Re: SpaceX – Launch Vehicle Failure

#337

Post by bluehawk »

vlasev wrote: post #284
FiatLuxDave wrote: post #204

Earlier quoted context omitted.

Aye, it's a good thing no one was aboard. On my 12th birthday, I watched the Challenger explosion happen right in front of my eyes. Me and the rest of the kids from Indian Harbour Beach watched the pieces of the shuttle slowly fall out of the sky. Some speculated that one of the pieces was an escape pod, but one of the kids whose dad worked on the shuttle said there wasn't an escape pod. We just couldn't believe it.…

Did you know that the shuttle was mostly intact after the disintegration [1]? "The crew cabin, made of reinforced aluminum, was a particularly robust section of the shuttle. During vehicle breakup, it detached in one piece and slowly tumbled into a ballistic arc. NASA estimated the load factor at separation to be between 12 and 20 g; within two seconds it had already dropped to below 4 g and within ten seconds the ca…

> Did you know that the shuttle was mostly intact

The shuttle wasn't intact, just the crew cabin, or the very front part.

Re: SpaceX – Launch Vehicle Failure

#338

Post by fian »

robzyb wrote: post #321
HeyLaughingBoy wrote: post #320

Earlier quoted context omitted.

I'm no Risk expert, but going from memory, you hypothesize potential failures based on experience and knowledge of the module. Then you use the FTA to understand what faults may result in the failures under examination. FTA can be used either pre- or post- event.

> FTA can be used either pre- or post- event. Fair point. OP's objection to a post-event FTA still makes no sense, though.

Generally you do a Root Cause Analysis post-event, not a Fault Tree Analysis.

Fault Trees are typically used to determine the probability of a bad thing (fault) occurring. This probability is used to populate a Risk Matrix (Probability vs Consequence). The Risk Matrix is used to decide whether the risk is low enough vs the consequence within a design. It the risk is too high, then more redundancy or layers of protection are likely to be needed.

Root Cause Analysis builds a tree of possible causes that will look much like the Fault Tree diagram but may include more human factors (was the part inspected before use, was the equipment maintained etc).

There is a lot of overlap of techniques within the Risk Engineering discipline. Fault Trees can be mapped to Reliability Block Diagrams (AND gates are equivalent to Parallel pathways, OR gates are equivalent to Series pathways for example).

The mention of Fault Tree Analysis being required post event seems a bit odd. It may just have been a confusion of terms in the heat of the moment.

Re: SpaceX – Launch Vehicle Failure

#339

Post by flashman »

dewarrn1 wrote: post #232
engi_nerd wrote: post #140

Earlier quoted context omitted.

There is a lot of money thrown around in commercial space, but it is not a particularly high-margin business. http://spacenews.com/39492orbital-eyes-broader-antares-busin... This cites Orbital Sciences (now Orbital ATK) CEO David Thompson as saying that the profit margin on CRS was about 5.5% and they hoped to reach 6% with CRS-3.

So with a 5.5% margin the $1.6 billion contract would be expected to yield $88 million in profit? Given what I'm assuming are large R&D expenditures on top of launch-related costs, I wonder whether the business is sustainable.

"We're not losing money AND we get to shoot things into space" sounds like a winning business model to me.

Re: SpaceX – Launch Vehicle Failure

#340

Post by flashman »

damoncali wrote: post #236
TrevorJ wrote: post #226

Earlier quoted context omitted.

Interesting - what were the differences between the orbiters that you had to account for?

The cargo bays are laid out a little differently - If I recall correctly, it was mostly due to different styles of airlock between different orbiters. And since the loading on the cargo is highly dependent on where it sits in the bay, you can't just move stuff around willy nilly. There are probably other minor differences (I want to say there were some electrical interface issues), but that was the part that impacted…

Let me guess, your mission went up on Atlantis instead? Being the newest in the fleet I'd expect it to have a different layout from Columbia. Also from your other comments in the thread, sounds like you worked on a Hubble servicing mission, which only Atlantis did after the Columbia accident.
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