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Starship survives reentry during fourth test flight

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Re: Starship survives reentry during fourth test flight

#31
post #7

Earlier quoted context omitted.

The engine failure was minor, true. That's the design point: if engines have a firm ceiling to reliability it's better to design so that one or two can fail than to put all the eggs in a basket. And indeed, the 32/33 engine set was enough to hit the trajectory targets, so that worked great. But I don't think you can characterize a burned-through flap as minor. Once there's a hole in something like that, the fact that…

> But I don't think you can characterize a burned-through flap as minor... In prod, a localized flap burn-through would be a Major Incident. Vs. in dev...what competent manager would be bothered if the some bleeding-edge beta code dropped 10% of packets the first time that it faced a full-load test?

That sort of depends on context. If the failure was reasonably expected, like for example your router is running on prototype underclocked hardware or is a debug build that is known not to have the final performance characteristics, sure. But if it fails and you don't immediately suspect why it failed, then that's a sign of a genuine design flaw.

And sure, it's good to find the design flaws in "dev" vs. "prod", but it's still bad to have them.

In this case, we don't really know what the expected performance of that flap shielding was. Maybe it was a kludge and they were just hoping the glue held together, maybe it was a finished design they just thought they were validating. The latter is a much (!) bigger problem than the former.

Re: Starship survives reentry during fourth test flight

#32
post #31

Earlier quoted context omitted.

> But I don't think you can characterize a burned-through flap as minor... In prod, a localized flap burn-through would be a Major Incident. Vs. in dev...what competent manager would be bothered if the some bleeding-edge beta code dropped 10% of packets the first time that it faced a full-load test?

That sort of depends on context. If the failure was reasonably expected, like for example your router is running on prototype underclocked hardware or is a debug build that is known not to have the final performance characteristics, sure. But if it fails and you don't immediately suspect why it failed, then that's a sign of a genuine design flaw. And sure, it's good to find the design flaws in "dev" vs. "prod", but i…

Per Wikipedia, SpaceX's 3 "Get out of Mishap Investigation, Free" cards from the FAA for this test flight were -

Starship burns up during reentry

Flaps lack sufficient control authority

Raptor engines fail to relight

- suggesting that both the flaps and heat shielding were regarded as highly experimental, and failure(s) in them very likely to occur.

Re: Starship survives reentry during fourth test flight

#33
post #21

Earlier quoted context omitted.

It's almost expected with Elon owning X. The platform may really have the ability to challenge Youtube for live video things. The infrastructure and dev capability is there. It may well reach the value that he paid for it....

It seems to work great for live content, but doesn't seem to allow for rewatching. Hence people here in the comments linking to YouTube videos.

It does support re-watching:

https://twitter.com/i/broadcasts/1OwxWYzDXjWGQ

You can also watch it - the same video stream - on SpaceX' site:

https://www.spacex.com/launches/mission/?missionId=starship-...

Re: Starship survives reentry during fourth test flight

#34

The internet is weirdly quiet about this achievement

Yet one flap is going to be eternal in human memory

One flap we know of, it is quite possible its counterpart suffered the same fate. No matter, the ship remained manoeuvrable and performed the landing flip even with half a flap - or half of two flaps - missing. That is valuable data which shows the thing can survive such damage without losing control. Now they'll need to find some way to better seal those hinge areas from the 20 minute plasma torch it is subjected to during re-entry.
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