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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

#21

Is the Starship Mk1 more structurally sound than it looks? From a first glance and having no knowledge of its design, it looks like an empty soda can that would deform at the slightest disturbance. And the way it crumpled in the video doesn't seem far off from what I would expect.

Soda cans are actually incredibly strong for their weight.

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

#22

Is the Starship Mk1 more structurally sound than it looks? From a first glance and having no knowledge of its design, it looks like an empty soda can that would deform at the slightest disturbance. And the way it crumpled in the video doesn't seem far off from what I would expect.

Rockets are actually pretty easy to poke holes in. They're meant to keep stuff in, not out. A dropped torque wrench blew up a Titan. https://en.m.wikipedia.org/wiki/1980_Damascus_Titan_missile_...

An 8lb socket dropped 80 feet. That's going to put a heck of a dent in almost anything.

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

#23

Earlier quoted context omitted.

This twitter reply sums it up well: “SUCCESS! We now now max pressure the tank can hold and the damage a rupture might do.”

Ah so this wasn't an accident? They needed to know the pressure limits so they purposely blew the bulkhead?

[deleted]

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

#24

Is the Starship Mk1 more structurally sound than it looks? From a first glance and having no knowledge of its design, it looks like an empty soda can that would deform at the slightest disturbance. And the way it crumpled in the video doesn't seem far off from what I would expect.

Rockets are actually pretty easy to poke holes in. They're meant to keep stuff in, not out. A dropped torque wrench blew up a Titan. https://en.m.wikipedia.org/wiki/1980_Damascus_Titan_missile_...

There's also a fantastic This American Life about the incident: https://www.thisamericanlife.org/634/human-error-in-volatile...

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

#25

Is the Starship Mk1 more structurally sound than it looks? From a first glance and having no knowledge of its design, it looks like an empty soda can that would deform at the slightest disturbance. And the way it crumpled in the video doesn't seem far off from what I would expect.

You don't want your rocket to be heavier than necessary. They're usually dead weight once in orbit. So yes, they're a bit like a soda can. Just as strong as necessary.

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

#26
post #6

And that's why they are testing it.

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 skyscrapers or bridges and leave for 5 days to see if they topple to prove the design was correct.

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

#27

I don’t know the specifics of this particular setup, but aren’t pressure vessels usually tested hydrostatically. Water, for example, can be pressurised without actually compressing, and therefore doesn’t undergo rapid expansion when a failure occurs. There may be reason that precluded pressure testing with a fluid tough.

Maybe weight? Filling something that big with water would be very heavy; maybe it's not strong enough in all the right places to support that much mass.

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

#28
post #26
post #6

And that's why they are testing it.

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.

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

#29
post #26
post #6

And that's why they are testing it.

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…

Rockets are designed to have a vastly lower margin of safety. If they never fail in testing that’s a sign you’re over engineering it and sacrificing cargo capacity, which is a bad thing. That said, these failures should be uncommon.

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

#30
post #6

And that's why they are testing it.

Yea, there is something about all the attention on this thing that stresses me out. Its a prototype, right? There is going to be things that appear bad, but its really just a treasure chest of data.
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