Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Starship Flight 5: Launch and booster catch [video]

twitter.com

Post reply on HN
Print view View original

881–890 of 1001 posts

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

#881

Post by m4rtink »

eco wrote: post #546
317070 wrote: post #540

Earlier quoted context omitted.

> Just to make sure that it completely submerges quickly. Why would they want to do that? (genuinly curious). I reckon there would be a lot of useful data left if they could recover or even just inspect the remains. The remains are one big tank, so it would have floated.

No doubt it would be very useful to recover. SpaceX isn't the only one who could pluck it out of the Indian ocean though. You don't want to leave a prototype for the most advanced Spacecraft ever made just sitting around for competitors to grab (most notably China which is currently speed running SpaceX-like designs).

Also a yacht of a fishing boat could run into it in the night and sink - eq it could become an unmarked floating hazard.

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

#882

Post by m4rtink »

oceanplexian wrote: post #805
norman784 wrote: post #767

Earlier quoted context omitted.

If Im not mistaken, they already delivered a payload in one of the previous flights, because they cut the transmission for a while and didn’t show the payload bay like one previous flight.

I’m not sure they are, if only because of the altitude. They only took Starship up to 200km, Starlink are nearly double that so while they do have thrusters that’s quite the distance. Starship is not really in a true orbit, I forget the exact terminology but the trajectory is designed to re-enter regardless of what happens with the the flight.

They actually made use of this this flight again - eq. they still did not perform a deorbit burn this flight & let the trajectory to pull them down to the atmosphere.

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

#883

Post by falconertc »

gcanyon wrote: post #573
dtquad wrote: post #183

Earlier quoted context omitted.

MIMO and nonlinear control theories are probably some of the hardest topics in all of engineering. SpaceX control system also has to compensate for the fuel moving inside their rockets so the control algorithms probably involve some kind of fast numerical fluid simulation. Another interesting thing SpaceX is doing is to use consumer-grade chips in triple redundancy configurations instead of using $100,000+ radiation-…

> control system also has to compensate for the fuel moving inside their rockets My stepfather worked as a programmer on the Apollo program, and the thing he always talked about as his biggest accomplishment was working on the "slosh problem" -- so yeah, props to the SpaceX team for managing that landing. And props to my stepdad for managing it on hardware that was... a billion times less capable? :-)

I might be misremembering but I think slosh was the failure cause for one of the three failed Falcon 1 flights. It was number 11 out of a pre-flight list of top 10 most likely failure scenarios. Definitely a difficult problem.

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

#884

Post by alceta »

bjamesking wrote: post #362

I was watching a youtube stream with tens of thousands of viewers and 20 seconds before launch it switched to an AI generated video of Elon on stage talking about his "crypto currency program". It was so well executed and generated, it nearly felt real. The violent anger I felt and still feel for scammers has ruined my day.

Same here. I was actively showing the (scammed) live stream to my 4yo daughter, and had to switch back to the live version for yet another 10minutes of wait.

Quite the embarassment, I think I begin to understand how my parents feel when they are completely unaware of some technical aspects I try to explain, and how easy it would be to scam them. Seems like it is getting easier to scam me, too.

To be fair, once they switched to Fakelon, it was quite clear. But I started the same stream again later as the YT app does not properly highlight the channel's name before clicking.

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

#885

Post by m4rtink »

boxed wrote: post #860
cpeterso wrote: post #654

Earlier quoted context omitted.

What’s the advantage of catching the booster over landing it in the ground? Catching it seems like an extra complication.

The reflected sound of the engines is enough to destroy the engines, ironically. That's also why the launch mount is so high. You'd need truly enormous legs, which wouldn't work for weight.

The load for landing and almost empty booster would be less, but otherwise yes, it would be much more than the single Merlin engine on the Falcon 9, with all associated issues (local scorching/spalling of the pad, acoustic issues, extra weight, longer turnaround, etc.).

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

#887

Post by nkoren »

Jugurtha wrote: post #797
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…

I'm wondering if they'll be using the vertical equivalent of arresting gear on aircraft carriers[0]. See when fighter jets land on aircraft carriers? There's a cable that decelerates them. That, but for vertical landing. The way these chopsticks are set forces the booster into a dangerous, snake like maneuver (a SnakeX maneuver) at the last second from a vertical setting, to get into the chopsticks. This maneuver is…

Next year, China says it will be testing a concept very similar to what you've described, with its Long March 10A rocket:

https://www.youtube.com/watch?v=27TvGDpPLNw

It will be interesting to see how these two approaches fare vs. one another.

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

#888

Post by GuB-42 »

flaburgan wrote: post #76
treespace8 wrote: post #14

I'm just so happy to see this level of progress. This another big step for opening up space. To think that one day this will be considered normal. 150 Metric tons sent on a fully reusable rocket. Thats like a 747 to space.

So, reusable is supposed to reduce the cost. But the space shuttle was reusable and it has been shutdown because it was too expensive. What is the differences between the two?

> What is the differences between the two?

More than 40 years and many lessons learned.

SpaceX took advantage of tech from both the US and Russia, including the experience with the Space Shuttle. They have better computers, better metallurgy, advanced 3D printing and their own experience with the Falcon 9.

There is no guarantee that it will reduce the costs that much, but will all that experience, the chances are success are higher than with the Space Shuttle.

One big issue that isn't talked about much and that SpaceX takes very seriously is simply a lack of demand. There is only so much stuff you want to put in space. Satellites are expensive, and even with disposable rockets, the launch is only a smaller fraction of the cost. It is already a problem with the Falcon 9 as they have a bunch of rockets and not much to do with them. Starlink, orbital refueling, and crazy ideas like earth to earth transport are all ways to address this problem.

It was a problem for the Space Shuttle too, they couldn't achieve the economies of scale they planned it for. It was supposed to fly for routine maintenance missions but it didn't work out.

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

#889

Post by m4rtink »

cyberax wrote: post #707
diebeforei485 wrote: post #472

Earlier quoted context omitted.

Only the US and China have landed successfully on Mars. China achieved this in 2021. Russia/USSR tried multiple times and didn't succeed. Other countries have sent satellites to orbit around Mars, which is not the same thing.

> Russia/USSR tried multiple times and didn't succeed. Pedant mode: the USSR did land softly on Mars, but the lander got caught in a dust storm and was not able to transmit back the data ( https://en.wikipedia.org/wiki/Mars_3 ).

The european Beagle 2 probe apparently survived as well, but failed to deploy: https://en.wikipedia.org/wiki/Beagle_2

But other than that, yeah, there are two Schiaparelli craters now on Mars. :P

(https://en.wikipedia.org/wiki/Schiaparelli_EDM)

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

#890

Post by m4rtink »

pfdietz wrote: post #775
cryptonector wrote: post #569

Earlier quoted context omitted.

> Second stage reuse seems the far more challenging problem. Sure, SpaceX has been doing first stage reuse for a long time now. But they have demonstrated landing the second stage successfully at sea twice now with the same sort of smoothness that they demonstrated once for the booster before they then caught the booster on the first real try. A partial list of unbelievably hard things that SpaceX has so far made see…

The hard part of 2nd stage reuse is surviving entry at orbital speeds. They are close to having that solved.

Yeah, I would say they already made a lot of progress - looked a lot less crazy now compared to the previous flight. :)
Post reply on HN