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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]

#941

Post by philipwhiuk »

ChuckMcM wrote: post #685
supportengineer wrote: post #597

Earlier quoted context omitted.

We could have had this all along.

That isn't exactly true though. For example, the neural net models that are used today in various GenAI startups were invented in the 1980s. But we couldn't have LLMs "all along" because we couldn't store the models, the training sets, or do the training compute with the computer hardware we had at the time. Similarly with rocketry there many technologies that have only been available in the last 10 - 15 years that m…

Not to mention solving the landing algorithm using work done for the Mars rovers.

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

#942

Post by cryptonector »

Fin_Code wrote: post #931
abustamam wrote: post #923

This is truly an amazing feat! Congratulations to the SpaceX team. Can someone explain to me exactly WHY it's such a big deal though? Like subjectively I can see it's incredible but while watching the video there were enormous applauses at points I knew were a big deal but I lacked the understanding of physics to truly appreciate.

The current Falcon rocket always expends a stage and lands a stage. Starship will land both stages. Also Starship is far larger and in rocketry there is something called the square cube law that means bigger is better. So its far more efficient. That leads to far cheaper mass to orbit costs.

In order to land not just the first stage but also the second stage more fuel will have to be carried on the ascent phase just to enable the recovery phase. This then necessitates weight savings elsewhere to avoid payload to orbit being cut way back. SpaceX chose to remove the landing system from both, the first and second stages (both because, after all if you can eliminate the landing system from one stage then you can eliminate it from the other).

This and other weight savings will enable high payload to orbit in a fully reusable launch platform.

Landing without legs requires something like this catch system -- something never done before, and clearly very difficult to do.

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

#943

Post by psb217 »

pj_mukh wrote: post #764
varenc wrote: post #600

Earlier quoted context omitted.

Great question! Could just be Real-Time Kinematic (RTK) GPS like someone mentioned. Essentially the landing arms know their position very precisely and they measure the tiny errors in GPS data, and send that correction data live to the rocket in real-time as it's landing. Once the rocket gets very very close it could also just be using vision systems to zero-in on exactly where the chopsticks are. To speculate more,…

ooooo Yea forgot about RTK GPS. I’ve always found them to be so brittle but that’s because I’m in a city. In the wide open sky, I’m guessing it’s pretty reliable. Vision systems would be pretty useless with the low visibility of the smoke and fire. So I thought maybe it was some kind of radar configuration. Anyways, I’d pay a lot of money to pick the brain of the GNC team here.

Why bother with GPS or other "absolute" coordinate systems? Once the rocket's in close, all that matters is relative position and orientation of the rocket with respect to the landing apparatus. Eg, if you had many sensors in known locations on the rocket and many sensors in known locations on the landing apparatus, and you could measure relative positions between all pairs of these sensors, you could get extremely precise relative position/orientation information without beaming information to satellites or whatever.

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

#944

Post by rndmize »

irunmyownemail wrote: post #932
hcks wrote: post #908

[flagged]

[flagged]

He's being sarcastic because the standing theme on the internet for most of the last decade is that Musk is an idiot who only got where he is because his parents are rich or he stole from other smarter/harder working people. SpaceX tends to put a hole in this idea since he founded and funded it himself, and they've made more progress in space travel in the last two decades than all existing government organizations and contractors have since the 70s.

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

#945

Post by cubefox »

systemvoltage wrote: post #163
renewiltord wrote: post #160

Earlier quoted context omitted.

The SpaceX clip is better https://x.com/spacex/status/1845442658397049011?s=46

Better than both, NSF's stream: https://x.com/nasaspaceflight/status/1845442658203734384

And here is the most beautiful shot: https://x.com/Cosmo_556/status/1845554958604657051

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

#946

Post by electriclove »

irunmyownemail wrote: post #932
hcks wrote: post #908

[flagged]

[flagged]

The people that dislike Musk (or are afraid of the mob that will go after them if they say something positive about him) can’t deny the amazing things he is accomplishing and so when anything good happens, they are quick to farm karma with thanking and congratulating everyone who isn’t Musk. It is intentional.

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

#947

Post by cryptonector »

TMWNN wrote: post #871
asadotzler wrote: post #659

Earlier quoted context omitted.

Everyone gets this wrong, cost is not price. SpaceX themselves launch Starlinks at about $1,200/kg but they charge customers closer to $12,000/kg. Do the math. Costs coming down are increases in SpaceX profits, not decreases in customer prices.

Besides what 55555 said, in the near term SpaceX has indeed passed at least some of the cost savings onto customers. NASA administrator Bill Nelson quoted a member of the Joint Chiefs as telling him that SpaceX had saved the US government $40 billion for just launching military payloads. https://www.fool.com/investing/2022/06/05/did-spacex-really-... > On the civilian side, SpaceX saved NASA $2 billion for just one p…

Sounds like those savings exceed the subsidies that some love to point out SpaceX has gotten from the government.

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

#948

Post by rlt »

strathmeyer wrote: post #601
FrustratedMonky wrote: post #598

Earlier quoted context omitted.

[flagged]

Musk bought SpaceX and Starlink just like Twitter.

Where did this meme come from? I’ve seen it twice in 2 days and it’s categorically false. Has the left wing echo chamber really brainwashed itself into believing Musk purchased all his successes and deserves no credit?

Even the “he bought Tesla” meme is lame. He invested in a tiny electric car startup and built it into the massive success it currently is.

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

#950

Post by TrapLord_Rhodo »

polemic wrote: post #726
qaq wrote: post #668

Earlier quoted context omitted.

Well if US would deploy global kinetic bombardment system that would def. be a game changer.

To get an inert object through the atmostphere and do real damage it has to be very large. That's a very inefficient way to use mass that you've boosted to orbit, even if it's relatively cheap to get there. So any weaponary they put up there will likely look fairly conventional. The speed of deployment and difficult of intercept would be the game-changer.

a 20 foot long Tungston rod hitting at 10km/s would release 416 gigajoules of energy. Pretty much a small nuclear bomb or about 100 tons of TNT.

It's impossible to intersept something going 10km/s.

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