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SpaceX's Starship Mk1 just blew off its bulkhead in a pressurization accident

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Re: SpaceX's Starship Mk1 just blew off its bulkhead in a pressurization accident

#91

Post by d-sc »

taneq wrote: post #80
NamTaf wrote: post #71

Oh dear! It looks like someone accidentally divided by 2 for the cylindrical hoop stresses, forgetting that they're not the same equation as for spherical stresses. :) Less facetiously, a thin-walled cylinder's stress is a function of pressure, radius and thickness with the equation: sigma = P*r/t whereas for a sphere (including the spherical end caps on a cylindrical pressure vessel), it follows the equation: sigma…

That's why you take your maximum design stress and double it, right? /s

Typically the factor of safety is not that high in the aerospace industry.

Re: SpaceX's Starship Mk1 just blew off its bulkhead in a pressurization accident

#92

Post by kev009 »

newnewpdro wrote: post #63
kev009 wrote: post #34

I had an unpopular opinion amongst friends that this thing looked like a total piece of shit, like a movie prop. They were using rented lifts and cranes to assemble it in the field. Clock right twice a day or maybe there's a reason everything about Apollo spacecraft was meticulously assembled.

It looking like a piece of shit is an unpopular opinion? I assumed that was a consensus. The thing isn't trying to win any beauty contests, it's covered in ugly seam welds. And none of that matters, not one bit.

It's not cosmetics. What kind of tolerances can you get dangling a massive assembly from a crane in the wind? How many people are cross checking the work? What kind of instrumentation are you using to check joint quality and integrity at these heights from a genie lift? It’s hard to shoot a stucco roof from a genie lift, I can’t help but laugh out loud at the assertion this is sane. Astronomically stupid.

Re: SpaceX's Starship Mk1 just blew off its bulkhead in a pressurization accident

#93

Post by craftinator »

adventured wrote: post #68
vkou wrote: post #52

Earlier quoted context omitted.

When their entire business depends on very carefully managing their PR, you're not going to get a public post-mortem without spin. If a government regulator runs the investigation, you might. I don't know if a regulator's going to get involved in this, though.

These are the guys that give us amusing compilations of some of their more explosive mistakes: https://www.youtube.com/watch?v=bvim4rsNHkQ So much for very carefully managing PR.

Thank you so much for sharing this!

Re: SpaceX's Starship Mk1 just blew off its bulkhead in a pressurization accident

#94

Post by kev009 »

cududa wrote: post #50
cyrux004 wrote: post #40

Earlier quoted context omitted.

I wish more smart people like you worked there.

Yes because without this dude they would’ve never invented self landing reusable rockets

The guy was clearly being sarcastic. Woosh. I am as unqualified as Elon to strap humans to an explosion.

Re: SpaceX's Starship Mk1 just blew off its bulkhead in a pressurization accident

#95

Post by gaius_baltar »

DennisP wrote: post #28
lmilcin wrote: post #26

Earlier quoted context omitted.

Depends on what kind of test that was supposed to be. If they pumped it until it explodes it would be a kind of test (also called experiment) where it makes sense. If you design something with a margin of safety, then pump it to working pressure and it blows, then it means you made a mistake. If you made a mistake it shows you don't know what is necessary to design a rocket (yet). Seriously, they don't build skyscrap…

I think SpaceX has proven they know how to design rockets. But they are newcomers to building rockets from welded steel.

> But they are newcomers to building rockets from welded steel.

AFAIK everybody is.

Re: SpaceX's Starship Mk1 just blew off its bulkhead in a pressurization accident

#98

Post by Klathmon »

kev009 wrote: post #87
Klathmon wrote: post #46

Earlier quoted context omitted.

I have a feeling that they could blow up another dozen of these and still be spending less than doing it the "traditional" way of in cleanrooms and the VFAB building. This was a prototype that they've publicly said was most likely never to reach orbit, they are building this stuff right now to learn, test, and prove that their design works and find improvements that can be made.

Any elementary student of history can tell you how bad an idea this is. Apollo 1 almost ended the program. A backlash in public opinion will crater SpaceX in the market and legislature. There is no space mission in the near decades worth the loss of human life. Economy in terms of money is no priority if you are to undertake human space flight. Move fast and break things is cute for a global search index or regressin…

They aren't using any tax dollars for Starship. It's entirely funded by their profits (at least as far as I know).

And this Starship MK1 is/was a prototype designed to test some aspects of their design in the real world. It was never going to be anywhere close to taking people onboard. Even this incident had all people far away before they started doing anything like pressurising.

This is active development, every single rocket company or program in existence has had explosions and test failures, and they will continue to have them. The important part is that they are doing this safely and nobody is getting hurt, these are controlled tests.

It may not be the way you think rockets should be designed and built (I'm personally kinda skeptical that they will actually build the full prototypes/rockets outside like this), but it's not more dangerous than any other rocket company.

Re: SpaceX's Starship Mk1 just blew off its bulkhead in a pressurization accident

#99

Post by JshWright »

taneq wrote: post #89
londons_explore wrote: post #72

Aren't pressure tests done with water? That way, since water is non-compressible, if it fails, you just get a small hole or buldge somewhere rather than the catastrophic damage seen here. Perhaps they already tested with water and now needed to test with the real fuel/oxygen to get the temperature correct?

Is it strong enough to take a full tank of water? Liquid methane weighs less than half what water weighs.

Liquid oxygen weighs more than water though...

Re: SpaceX's Starship Mk1 just blew off its bulkhead in a pressurization accident

#100

Post by ceejayoz »

kev009 wrote: post #87
Klathmon wrote: post #46

Earlier quoted context omitted.

I have a feeling that they could blow up another dozen of these and still be spending less than doing it the "traditional" way of in cleanrooms and the VFAB building. This was a prototype that they've publicly said was most likely never to reach orbit, they are building this stuff right now to learn, test, and prove that their design works and find improvements that can be made.

Any elementary student of history can tell you how bad an idea this is. Apollo 1 almost ended the program. A backlash in public opinion will crater SpaceX in the market and legislature. There is no space mission in the near decades worth the loss of human life. Economy in terms of money is no priority if you are to undertake human space flight. Move fast and break things is cute for a global search index or regressin…

> There is no space mission in the near decades worth the loss of human life.

This is a weird assertion. Tens of thousands of people die in car accidents each year, but no one proclaims that going to the grocery store isn't worth the risk to human life.

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