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SpaceX Starship Flight 13 livestream [video]

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Re: SpaceX Starship Flight 13 livestream [video]

#221

Post by wat10000 »

inglor_cz wrote: post #213
consensus1 wrote: post #71

Earlier quoted context omitted.

Rockets have a self destruct feature to avoid exactly this type of contingency

By the time that the booster returns to the landing zone, the Flight Termination System (FTS) is AFAIK no longer active and cannot be reactivated. Which makes sense because it is a bunch of high explosives, now nearing some valuable equipment. The SpaceX solution is to steer carefully and have the default trajectory end in the sea. Only if everything looks good, is the booster redirected to the tower.

I wonder what happens when things go wrong after everything looks good. They punched a good number of holes in their landing barges when they were perfecting Falcon 9 landings. And I imagine this crazy catch tower is a lot more expensive than a barge with a flat surface.

Re: SpaceX Starship Flight 13 livestream [video]

#222

Post by inglor_cz »

wat10000 wrote: post #221
inglor_cz wrote: post #213

Earlier quoted context omitted.

By the time that the booster returns to the landing zone, the Flight Termination System (FTS) is AFAIK no longer active and cannot be reactivated. Which makes sense because it is a bunch of high explosives, now nearing some valuable equipment. The SpaceX solution is to steer carefully and have the default trajectory end in the sea. Only if everything looks good, is the booster redirected to the tower.

I wonder what happens when things go wrong after everything looks good. They punched a good number of holes in their landing barges when they were perfecting Falcon 9 landings. And I imagine this crazy catch tower is a lot more expensive than a barge with a flat surface.

Falcon 9 engines (Merlins) cannot throttle down, they either run on max power or they don't. Which means that any attempts to land are incredibly risky. You have to reignite them at the precise moment to slow down the rocket to zero at the height of the landing platform, or else. That is why the maneuver is called "suicide burn", and it is incredible that someone actually perfected something as crazy as this. The landing legs can absorb a tiny error, but anything over that = Rapid Unscheduled Disassembly (Monty Python theme starts to play in the background...)

Raptors are much more finely controllable and both stages of Starship can even hover when necessary, so the total control envelope, while not perfect, is much larger. That is why they can even try to land into a steely embrace, with no landing legs used.

Re: SpaceX Starship Flight 13 livestream [video]

#223

Post by amanaplanacanal »

throwaway2037 wrote: post #208
amanaplanacanal wrote: post #22

Earlier quoted context omitted.

The tiny part of SpaceX that is actually about space, yes. Unfortunate that it has been bolted onto the hulk of Musk's AI fever dreams.

Tiny part? Huh? Falcon 9, Dragon, Starlink, Starship. That is a LOT of space.

You should look at the S1 they filed with the SEC. All of their space related stuff including starlink shows a total possible market of 2 trillion, whereas they show AI as over 26 trillion. Basically almost all of their value is AI, not space related activities.

Re: SpaceX Starship Flight 13 livestream [video]

#224

Post by _davide_ »

pudgywalsh wrote: post #42
appplication wrote: post #19

It’s interesting the cognitive dissonance this brings out in me. As much as I think Musk carries a fairly reprehensible aura, I would still like to see SpaceX succeed. Space has a funny, transcendent way of inspiring us.

Actual, literal Nazis got us to the Moon and frankly no one cared. Not then, not now. Try separating politics from the advancement of humanity, you'll feel better.

him being nazi was inconsequential, the richest person in earth being Nazi is.

> Try separating politics from the advancement of humanity, you'll feel better.

can't. won't.

Re: SpaceX Starship Flight 13 livestream [video]

#225

Post by wat10000 »

inglor_cz wrote: post #222
wat10000 wrote: post #221

Earlier quoted context omitted.

I wonder what happens when things go wrong after everything looks good. They punched a good number of holes in their landing barges when they were perfecting Falcon 9 landings. And I imagine this crazy catch tower is a lot more expensive than a barge with a flat surface.

Falcon 9 engines (Merlins) cannot throttle down, they either run on max power or they don't. Which means that any attempts to land are incredibly risky. You have to reignite them at the precise moment to slow down the rocket to zero at the height of the landing platform, or else. That is why the maneuver is called "suicide burn", and it is incredible that someone actually perfected something as crazy as this. The lan…

Merlin and Raptor can both throttle to about 40%. The difference is that Super Heavy has way more engines, so 40% of one engine is a lot less thrust relative to the mass of the nearly empty booster.

Did the suicide burn actually play a role in the various barge-holing events? It’s been a while but I don’t remember that being the hard part.

Re: SpaceX Starship Flight 13 livestream [video]

#226

Post by stinkbeetle »

throwaway2037 wrote: post #206
stinkbeetle wrote: post #101

Earlier quoted context omitted.

It might be possible. Allegedly they had previously asked the Australian government about towing the ship back to a port. Marine recovery can be much more difficult than it might seem though. Towing this nearly 200ft structure weighing a decent fraction of the weight of the boat that is not designed to be seaworthy, potentially full of explosive gasses and that could rapidly start breaking up and taking on water, nea…

> Allegedly they had previously asked the Australian government about towing the ship back to a port. Any sources? I cannot find any. What was their response?

> Any sources?

https://www.reuters.com/technology/space/spacex-talks-land-r...

> What was their response?

Not sure. As far as I know the US is very supportive of SpaceX for space supremacy and Australia would almost certainly go along with what the US administration asks. If it hasn't happened yet it's more likely because SpaceX didn't/couldn't do it than Australia denying the request.

Re: SpaceX Starship Flight 13 livestream [video]

#227

Post by inglor_cz »

wat10000 wrote: post #225
inglor_cz wrote: post #222

Earlier quoted context omitted.

Falcon 9 engines (Merlins) cannot throttle down, they either run on max power or they don't. Which means that any attempts to land are incredibly risky. You have to reignite them at the precise moment to slow down the rocket to zero at the height of the landing platform, or else. That is why the maneuver is called "suicide burn", and it is incredible that someone actually perfected something as crazy as this. The lan…

Merlin and Raptor can both throttle to about 40%. The difference is that Super Heavy has way more engines, so 40% of one engine is a lot less thrust relative to the mass of the nearly empty booster. Did the suicide burn actually play a role in the various barge-holing events? It’s been a while but I don’t remember that being the hard part.

I was mistaken, Merlins can indeed throttle down. Thanks for correction.

What they cannot is achieve thrust-to-weight ratio of When it comes to failed returns, I think that at least once they ran out of fuel several meters early(?)

Re: SpaceX Starship Flight 13 livestream [video]

#228

Post by parineum »

ceejayoz wrote: post #186
parineum wrote: post #183

Earlier quoted context omitted.

After it came out that he might have raped someone.

There were a lot of people on the left noting that a totenkopf was a big red flag warning of others lurking. The centrist consultants tried to push past it, as they often do, and that's one of the big issues I have with the Dem establishment. Meanwhile, the Republicans elected and continue to rabidly support a court adjudicated actual rapist ( https://www.washingtonpost.com/politics/2023/07/19/trump-car... ) to the P…

That's insane revisionism. The center Democrats do not support the progressive wing of the party. The DSA types were all in on him and willing to look past just about everything. It wasn't until the actual rape allegations that Bernie Sanders withdrew his endorsement.

> Meanwhile, the Republicans...

Meanwhile, whataboutism.

Re: SpaceX Starship Flight 13 livestream [video]

#229

Post by stinkbeetle »

stinkbeetle wrote: post #101
a34729t wrote: post #41

Earlier quoted context omitted.

They have a much biglier support vessel this time, almost 300ft long IIRC. So maybe they can recover it?

It might be possible. Allegedly they had previously asked the Australian government about towing the ship back to a port. Marine recovery can be much more difficult than it might seem though. Towing this nearly 200ft structure weighing a decent fraction of the weight of the boat that is not designed to be seaworthy, potentially full of explosive gasses and that could rapidly start breaking up and taking on water, nea…

Since I can't edit that message - it seems SpaceX is now intending to recover Starship. I am standing by to be wrong / impressed.

Re: SpaceX Starship Flight 13 livestream [video]

#230

Post by Teever »

WalterBright wrote: post #220
Teever wrote: post #218

Earlier quoted context omitted.

No, the arrest most certainly happened, it's corroborated from enough sources that this isn't in question, though from what I can tell the arrest report no longer exist, but there are contemporaneous notes made by Alfred Jodl. Additionally from a cursory search there are conflicting reasons given for the arrest including what you've mentioned and even communist accusations. When I said "Nazi" earlier I should have be…

Yes, von Braun was a card-carrying Nazi. But something to consider. Professors could not get their research papers published unless they were card-carrying Nazis. Von Braun could not have headed up the rocket program unless he was a card-carrying Nazi. Did he make a deal with the devil? Yes. He was also arrested by the Gestapo and threatened with execution if he was not more diligent in his efforts to develop the V2…

It is well documented that von Braun had contempt for the Nazis, the problem is that he didn't have enough contempt for them to not work for them and leave Germany when he had the chance.

Taking the position that it is acceptable to use slave labour to save your life from the authoritarians that you volunteered to work for during war is only a hop, skip and a jump away from saying that it is acceptable to use slave labour to save your life from the people attacking you during war.

This is but one of the moral hazards of the kinds of activities that von Braun wilfully participating in.

In a different world where the United States and Britain more closely followed the moral ideals that they profess as cornerstones of their nations von Braun and other Nazis would have been tried and executed for their actions. Or in the very least coerced to work for them in sparse cell in a remote location for the rest of his days.

The rehabilitation of von Braun and his admittance into American society is a great stain on the ethos of the nation.

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