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Starship Flight 5: Launch and booster catch [video]

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Re: Starship Flight 5: Launch and booster catch [video]

#821

Post by nine_k »

iwaztomack wrote: post #693

What parts of this can be reused? I bet the engine is OK, but seems like the sides of the ... tube ... were pretty roughed up. I guess that's probably the cheapest part of the assembly though.

Everything except the stage connector ring (which uses pyro bolts I believe) should be directly reusable, after an inspection, light brushing, and refueling / recharging.

Maybe the bottom uses some ablative material, then a new coat of it needs to be applied / attached.

All the internals should have enough resource for likely dozens of launches, if Falcon-9 is any indication.

Re: Starship Flight 5: Launch and booster catch [video]

#822

Post by avmich »

syncsynchalt wrote: post #718
kedv wrote: post #705

Earlier quoted context omitted.

Why is SpaceX choosing to land the booster on the Mechazilla arms instead of performing a soft ground landing like the Falcon 9 booster?

1) legs are heavy 2) empty rockets are stronger in tension than compression the scale of Superheavy is such that the above two items are making the arms scheme make sense. The number of engines also gives this rocket the ability to hover, which probably makes the scheme easier to pull off.

Spent rocket stages are empty of fuel, but not necessarily of the ullage gases, the pressure inside could be e.g. 3 atmospheres and that could be enough to provide some stiffness in the direction perpendicular to the axis.

Re: Starship Flight 5: Launch and booster catch [video]

#823

Post by jve »

Jugurtha wrote: post #812
jve wrote: post #811

Earlier quoted context omitted.

SpaceX likes to simplify and not to complexify things. And they demonstrated they can do landing accurately. Moreover I think Elon discusses the mechazilla arms in one of Tim Dodd interviews. They dont want longer arms, ratger shoeter. Think about physics involved for longer arms and how much more stress you will putt on the connection points.

> SpaceX likes to simplify and not to complexify things. And they demonstrated they can do landing accurately. Yes. Something falling into a web of cables. I'd say it may be simpler than optimally controlling that last SnakeX maneuver to be hugged by a short-armed T-Rex. > Think about physics involved for longer arms and how much more stress you will putt on the connection points. That's why I wasn't talking about ar…

Good luck not ruining rocket with that cable web. Now you got other problems to target into some cell. Moreover cables could be lingering depending on thrust. Or maybe thrust will just cut em easily.

Re: Starship Flight 5: Launch and booster catch [video]

#824

Post by smoovb »

timeon wrote: post #168
paulryanrogers wrote: post #155

Earlier quoted context omitted.

Improvements that make space flight more sustainable are welcome ... unless that means an order of magnitude more pollution in a less controllable form, like emissions. [Due to more frequent flights] Daily trips to space likely also mean more debris in space and falling to earth. I hope there is a balance that includes the lives of people near these sites and all of us sharing the same atmosphere.

I hope this is not going to be used for 'Earth point A -> Earth point B' travel.

Proposed 7 years ago - go anywhere on earth in an hour: https://www.youtube.com/watch?v=2tf2KpCG2fM

Re: Starship Flight 5: Launch and booster catch [video]

#825

Post by db48x »

rkagerer wrote: post #682
ChuckMcM wrote: post #516

Pretty impressive. The engineering team at SpaceX is really something. Some thoughts; The 'chopsticks catch' was amazing to watch. Seems like it adds a lot of risk and clearly the booster needs additional fire suppression systems :-) perhaps the tower could mount something that sprays the booster like the barges have for the F9 boosters. The heatshield held out for a much longer time, the asymmetric heating on the fl…

Seems like it adds a lot of risk I'm actually wondering about that. If I understand correctly, the arms can move up and down, and pivot around the tower. This allows them to correct for some error in the rocket trajectory and also (presumably) "soften" the final contact. Between the nozzles and the arms, it gives SpaceX a lot of degrees of freedom in the final seconds (you can see how the booster kind of "hovered" ri…

A good explanation of how it works, from before the catch: https://www.youtube.com/watch?v=ub6HdADut50

Re: Starship Flight 5: Launch and booster catch [video]

#826

Post by aksss »

Yacovlewis wrote: post #574

Based on this conversation, how many of y'all are actual rocket scientists? I'm blown away by the expertise in some of these comments

And here I was blown away by the ignorance of many of the questions. Why no landing legs? Why is this more impressive than the other rocket landings? What’s the thingy that fell off during separation? Sometimes I need to remind myself that other people have lives, I guess. XD

Re: Starship Flight 5: Launch and booster catch [video]

#827

Post by db48x »

ro_bit wrote: post #520

The catch looks amazing, but one thing I don't understand is why SpaceX needs the technology to catch a booster they've already demonstrated the ability to land boosters on barges. Is the arm more cost effective to scale compared to a barge?

It takes time for the barges to return the booster to the launch pad. They want to be able to launch Starship, have the booster land back at the launch pad, have the arms set it back down on the ground, and recycle the booster for another launch in just a few hours. Then the arms can be used to stack the booster and the next payload on the launch platform.

Re: Starship Flight 5: Launch and booster catch [video]

#828

Post by db48x »

mock-possum wrote: post #590
_djo_ wrote: post #530

Earlier quoted context omitted.

This booster is much, much larger than the Falcon 9 first stages that land on barges. It's ~70 metres high, versus ~40 metres for the Falcon 9 first stage, and weighs about 275 000 kg compared to the ~20 000 kg of the Falcon 9 first stage. In short, it would require such huge and heavy landing legs and landing barges that it probably wouldn't be feasible.

Holy shit I didn’t realize it’s an order of magnitude heavier

https://www.reddit.com/r/space/comments/exvu55/size_comparis... https://www.visualcapitalist.com/comparing-the-size-of-the-w...

Re: Starship Flight 5: Launch and booster catch [video]

#829

Post by smoovb »

dtquad wrote: post #426
jeswin wrote: post #414

Speaking as a non-American. SpaceX just made one of the most significant technological leaps in the last decade. This is obviously hugely significant in many ways, including retaining the US military edge. Yet the US administration hasn't congratulated SpaceX. Incredible.

There has been some kind of beef between Elon Musk and the Biden administration even before Musk's public right-wing turn. For example Biden has given speeches praising US EV vehicle manufacturers and not mentioning Tesla but mentioning all their competitors.

Yeah stuff like this - https://www.youtube.com/watch?v=s9ZmdIh1qpI
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