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Starship Flight 7

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Re: Starship Flight 7

#621

Post by zardo »

mrandish wrote: post #396
logifail wrote: post #390

Earlier quoted context omitted.

> the debris was likely closer to around ~100km in altitude. Commercial airliners fly around ~10km in altitude (Not wishing to ask the obvious, and depending on the size of the pieces) debris at 100km altitude pretty much always ends up being debris falling through 10km ... right?

At the incredible speeds Starship was moving (>13,000 mph) by the time it was over the Caribbean, debris from a Starship is expected to burn up by the time it reaches the surface. But you said "depending on the size", so let's imagine it's a different spacecraft carrying something that won't entirely burn up, like the Mir space station from several years back. In that scenario, debris from 100km will survive to pass…

> At the incredible speeds Starship was moving (>13,000 mph) by the time it was over the Caribbean, debris from a Starship is expected to burn up by the time it reaches the surface.

Don't the heat tiles at least make it through? And possibly large hunks of metal like the thrust frame and engines.

Re: Starship Flight 7

#622

Post by cbracketdash »

drillsteps5 wrote: post #601

Can someone please please PLEASE tell SpaceX PR/Streaming team that the speed (per SI system) is measured in meters per second, not kilometers per hour? The speed of sound is approx 300 m/s, orbital velocity is approx 8,0000 m/s (depending on altitude), free fall acceleration on Earth is 9.81m/s, 1.63m/s on the Moon, the speed of light is apporx 300,000,000 m/s, people learn these numbers in middle school. It's not 1…

They are likely appealing to the common population who mostly think of speed in mi/h or km/h due to car speeds

Re: Starship Flight 7

#623

Post by notorandit »

TypingOutBugs wrote: post #480
notorandit wrote: post #440

Earlier quoted context omitted.

Running a code test doesn't require firing a rocket. How would you test a rocket?

You test components in isolation, you test integration of components, you run simulations of the entire rocket, and finally you test the rocket launch. You’ll catch issues along the way, but you can’t catch all of them before a full launch test. That’s why there are launch tests.

This can get as far as the test plan is complete, multiply iterated under different interface conditions and thorough. And you are still relying upon the adherence of the simulated models to the physical reality.

Real tests do all of this at once with no option to escape reality.

Again, one thing is automating thorough software tests, another one is testing physical stuff.

Re: Starship Flight 7

#624

Post by EncomLab »

saberience wrote: post #605
cma wrote: post #524

Earlier quoted context omitted.

> They have the first rocket ever made which can take payloads to orbit and then be reused. The space shuttle did this over 40 years ago. You can argue SpaceX have the first economical one 40 years later, but the second stage isn't reusable. Once they get starship working they might have it. Their finances aren't public but there is some stuff to go on where we can say Falcon is probably economical despite not recove…

The space shuttle lol? Are you not considering the fact that the huge external tank and the two SRBs were destroyed every time? Not to mention the insane costs of refurbishing each space shuttle, not the mention the insanely bad safety of the shuttle and the 14 astronauts who died in it! Space shuttle, while cool, was really, really bad design, bad safety, and totally uneconomical. It was definitely cooler than Soyuz…

The Shuttle program only failed to recover 4 SRB's out of 270 launched - and 2 of those were on Challenger.

Why should we care what you think if you can't get something that basic right?

Re: Starship Flight 7

#625

Post by Albatross9237 »

me_me_me wrote: post #522
jve wrote: post #513

Earlier quoted context omitted.

Maybe this will help you see it: https://x.com/dpoddolphinpro/status/1874191808751972447 The whole world combined VS SpaceX has less mass to orbit. Either whole nations are not interested in that much mass to orbit or they don't have the capability. Or financial means/incentive to compete against that commercial entity. But they do and at least in China they start to work on reusable rockets and ULA is for sale becau…

I guess that's an 'achievement'?

What would you consider an achievement then? The point of a rocket is to deliver mass to space.

Re: Starship Flight 7

#626

Post by varjag »

littlestymaar wrote: post #547
shellfishgene wrote: post #533

Earlier quoted context omitted.

If it was really an oxygen/fuel mix burning I don't think you can do much of anything to stop that.

If you cooled the mixture at low enough temperature, you'd stop it from burning (like when you pour water on top of a camp fire), but it's not clear how you're supposed to do that in a spaceship where you can't carry a few tons of water for your sprinklers.

There are other methods too, e.g. fire inhibitors (like Halon or whatever is allowed now) or shockwave to disrupt fire boundary. But I doubt they are very practical on a spaceship.

Re: Starship Flight 7

#627

Post by mr_toad »

hinkley wrote: post #388
Galxeagle wrote: post #359

Earlier quoted context omitted.

Any extra time spent during a burn is wasted fuel. Intuitively, any time before the rocket is in orbit, some part of the rocket thrust is resisting the force of gravity or else it would fall back down to earth. The longer that time is, the more thrust (and thus fuel) was spent negating that force. It's the main reason why the Falcon 9 boosters do a 'hoverslam' on return and land at close to full throttle - any extra…

Designing a rocket that's strong enough to survive 100% thrust at maxQ also wastes fuel, because you've overbuilt.

The rocket is well beyond max Q by the time the second stage engines ignite. There’s no reason not to run them at full throttle at that point.

Re: Starship Flight 7

#628

Post by yuliyp »

dmurray wrote: post #200
Retric wrote: post #155

Earlier quoted context omitted.

Arlines are extremely cautious around these kinds of one off events. It’s not about the calculated risks, but the uncertainty around if they have the right information in the first place. Sure it may have broken up at 145km miles, but what if someone messed up and it actually was 14.5km etc.

No, airlines do not build in a safety factor sufficient to cover an important measurement being off by a factor of 10. They don't ground flights because the pilot might load 2,000 litres of fuel instead of 20,000 litres. They don't take evasive action in case the other plane is travelling at 5,000 knots instead of 500 knots. They don't insist on a 30-km runway because the runway published as 3 km might only be 300 me…

Unlike fuel gauges, land surveys, and radar, fast-breaking news of explosions carries a significant risk of mistransmission or inaccuracy. They might know when/where the explosion occurred, but not necessarily have much confidence on how fast debris might have been ejected and in which directions.

https://www.youtube.com/watch?v=w6hIXB62bUE ATC was being extremely cautious and diverting planes over quite a large area for quite some time to avoid the risk of debris hitting airplanes.

Re: Starship Flight 7

#629

Post by Alive-in-2025 »

dpifke wrote: post #280
terramex wrote: post #76

Looks like second stage broke up over Caribbean, videos of the debris (as seen from ground): https://x.com/deankolson87/status/1880026759133032662?t=HdHF... https://x.com/realcamtem/status/1880026604472266800 https://x.com/adavenport354/status/1880026262254809115 Moment of the breakup: https://www.instagram.com/reel/DE52_hVSeQz/

Preliminary indication is that we had an oxygen/fuel leak in the cavity above the ship engine firewall that was large enough to build pressure in excess of the vent capacity. Apart from obviously double-checking for leaks, we will add fire suppression to that volume and probably increase vent area. Nothing so far suggests pushing next launch past next month. https://x.com/elonmusk/status/1880060983734858130

This sounds like one of those "and also" things. I'd say you add fire suppression AND ALSO try more to reduce leaks. It's got to be really difficult to build huge massive tanks that hold oxygen and other gases under pressure (liquid methane too will have some vapor of course). Are leaks inherently going to happen?

This is meant to be a human rated ship of course, how will you reduce this danger? I know this stuff is hard, but you can't just iterate and say starship 57 has had 3 flights without leaks, we got it now. Since I have no expertise here, I can imagine all kinds of unlikely workarounds like holding the gas under lower pressure with humans on board or something to reduce the risk.

Re: Starship Flight 7

#630

Post by Albatross9237 »

me_me_me wrote: post #475
tsimionescu wrote: post #472

Earlier quoted context omitted.

The Apollo program was inventing all of this technology, and using only extremely rudimentary computers, still doing many calculations with slide rulers. SpaceX has all of the Apollo program's work to build on, and computers that could do all the computing work that the Apollo program ever made, in total, in probably a few minutes.

this doesn't even scratch the surface. Slow motion cameras and real time sensors for debugging hardware issues, computer simulations, 3d printing. Apollo program directors would advocate to start a nuclear war with ussr if they could get hands on that kind of tech. But also NASA landed two SUVs on mars first try, using skycrane, Full remote. they developed and built mars helicopter/drone (rip). First try. But spaceX…

SpaceX getting credit for innovating in their own way doesn't mean NASA doesn't get credit for all the great things it has done.
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