Slight underperformance in the engines resulted in the the booster not reaching where it was supposed to be and the GNC systems automatically aborted to the gulf for safety.
Apparently the booster signaled it didn't have enough fuel to risk it. Either because it consumed more then expected on the way up, or a measurement error potentially.
At the last moment the exhaust turned green. That's consistent with the fuel running out, the engines running oxygen rich, and subsequently "engine rich". So I would put my money on actually running out vs a measurement error.
That's basically what Musk said, yes: that they need to work on both engine performance and performance consistency. He said they'd be cutting off the main engines one second sooner to provide more margin for boost-back.
Amazing that a one-second difference can matter, but those things go through tons of fuel every one of those seconds!
Their risk tolerance would probably be greater if both towers were fully operational. But any damage to the only functional tower during booster catch = an automatic abort to the ship catch one day later, and the ship catch is what was really interesting at this point of development.
It's difficult to underline how huge this is. This marks the first time in the history of rocketry that the upper stage of a rocket has returned home from orbit to a safe, upright landing.
(And to preempt the obvious objection: yes, maybe you can call the Space Shuttle an "upper stage of a rocket" if you squint hard enough, but it didn't do upright landings, none of its boosters were reusable and even the Shuttle itself was effectively rebuilt from scratch at exorbitant cost each time.)
It's sad to see a lot of media missing the point, eg as I type this BBC is reporting this as "SpaceX successfully catches part of Starship rocket on its return to Earth".
Whatever you call it, the Shuttle Orbiter wasn’t a complete stage in any case. It needed the external tank, which was never recovered.
SpaceX has now demonstrated all the pieces of a fully reusable launcher. Next comes putting them all together in the same flight, and hopefully demonstrating that the flights can become frequent and cheap. There’s no guarantee of that, but it’s looking good.
> yes, maybe you can call the Space Shuttle an "upper stage of a rocket" if you squint hard enough
Why wouldn't it count? It is not the first time in the history of rocketry that the part that is not the boosters returns home intact.
Sure, you can say "it's the first time in the history of rocketry that it lands upright", but you could also say "it's the first time in the history of rocketry that it is not white".
If you want to say how huge this is, tell me how different it is from landing the boosters. Because from the outside it sure as hell looks very similar.
What actually is the point of all this? I'm not trying to be a snarky contrarian, I've never had any interest whatsoever in space, star trek, "what's out there?", so I genuinely don't get it.
I'm not trashing people's interests, obviously I am the odd man out in not giving a damn, I just don't see what we're trying to achieve when there are so many issues we can't even figure out on earth.
I mean, you need to get money from somewhere to fund your dreams.
If it's datacenters in space then let be it. They are pretty cool as well. It seems a lot of people don't like them on Earth.
Reusable stages is very neat, but seems a little crazy to pay the tyranny of the rocket equation twice. I heard one person say that carrying fuel to land over the whole flight means it takes 23x more launches to get an equivalent payload to orbit.
Using modern technology, couldn't disposable first stages be produced much more cheaply than during the space race?
How much of modern manufacturing disposable booster's cost would be fuel vs metal?
It's not paying it twice. The rocket equation is about the ratio of the wet and dry mass, so for an expendable rocket you're always limited by the fact that there's an upper stage (and for the second stage the payload etc).
This is why SpaceX cares more about TWR for their engines than traditional rockets did. It goes from making a negligible difference to a huge component of how much fuel they need to keep for landing.
The booster doesn't go into orbit, starship ends up going 5x as fast. You need a booster to reach orbit though, so it makes sense to recycle the booster too. Why not do it? It doesn't use that much fuel coming back. They can also eventually fly it again quickly in theory (this is easier for the booster due to less stress).
You can be sure they'll have done the math on reusable boosters and it makes sense, or they wouldn't bother.
It doesn't take the same amount of fuel to land as it does to lift.
Speaking as a Kerbal Space program playing, internet commentor, It's probably <1% of the fuel to briefly counteract terminal velocity as it is to lift off and reach space.
How is it twice? Braking on the way down doesn't take nearly as much fuel as lift off so the "tyranny of the rocket equation" should be paid only once.
"I heard one person say that carrying fuel to land over the whole flight means it takes 23x more launches to get an equivalent payload to orbit."
I don't think that this is the case when using the atmosphere to shed most of your velocity, which is what we do when landing on Earth. Propulsive braking would be another story, but you can avoid that on bodies that do have some atmosphere. In our proximity, only the Moon and Mercury would need propulsive braking, but Moon's gravity is low and Mercury is hard to visit anyway.
That said, once you use the atmosphere to cushion what is basically a fall, the weight of the necessary heat shield comes to the equation too.
Kind of crazy to reduce the hardware on ship so much and move so much complexity to the ground. This can really only happen in a situation where anybody can throw out any dumb idea, because if you suggested this 20 years ago people would think you are an idiot.
Huge congratulations to the team.
booster was low on fuel, plus no mood of risking tower with boom, boosters are cheaper than towers.
Amazing that a one-second difference can matter, but those things go through tons of fuel every one of those seconds!
source: Scott Manley https://youtube.com/shorts/m2oGDCvDmdE?si=0AlX8sgHDihXCED6
If I understand correctly, the margin was tight enough not to take the risk of damaging the tower.
https://x.com/spacex/status/2121316300702056595
(And to preempt the obvious objection: yes, maybe you can call the Space Shuttle an "upper stage of a rocket" if you squint hard enough, but it didn't do upright landings, none of its boosters were reusable and even the Shuttle itself was effectively rebuilt from scratch at exorbitant cost each time.)
It's sad to see a lot of media missing the point, eg as I type this BBC is reporting this as "SpaceX successfully catches part of Starship rocket on its return to Earth".
SpaceX has now demonstrated all the pieces of a fully reusable launcher. Next comes putting them all together in the same flight, and hopefully demonstrating that the flights can become frequent and cheap. There’s no guarantee of that, but it’s looking good.
So that they can start polluting at a whole new scale. Fingers crossed!
Why wouldn't it count? It is not the first time in the history of rocketry that the part that is not the boosters returns home intact.
Sure, you can say "it's the first time in the history of rocketry that it lands upright", but you could also say "it's the first time in the history of rocketry that it is not white".
If you want to say how huge this is, tell me how different it is from landing the boosters. Because from the outside it sure as hell looks very similar.
- in orbit refueling
- moon landing
- Mars rendez-vous
- Mars landing
- humans on Mars
Nah, the game is to put data centers in space. Plus the Space Force dreams.
I'm not trashing people's interests, obviously I am the odd man out in not giving a damn, I just don't see what we're trying to achieve when there are so many issues we can't even figure out on earth.
Using modern technology, couldn't disposable first stages be produced much more cheaply than during the space race?
How much of modern manufacturing disposable booster's cost would be fuel vs metal?
I recommend talking with people who know more about spaceflight.
Yes, because asking on HN if such people would be willing to answer obviously gets you downvotes and comments like this.
This is why SpaceX cares more about TWR for their engines than traditional rockets did. It goes from making a negligible difference to a huge component of how much fuel they need to keep for landing.
You can be sure they'll have done the math on reusable boosters and it makes sense, or they wouldn't bother.
It doesn't take the same amount of fuel to land as it does to lift.
Speaking as a Kerbal Space program playing, internet commentor, It's probably <1% of the fuel to briefly counteract terminal velocity as it is to lift off and reach space.
I don't think that this is the case when using the atmosphere to shed most of your velocity, which is what we do when landing on Earth. Propulsive braking would be another story, but you can avoid that on bodies that do have some atmosphere. In our proximity, only the Moon and Mercury would need propulsive braking, but Moon's gravity is low and Mercury is hard to visit anyway.
That said, once you use the atmosphere to cushion what is basically a fall, the weight of the necessary heat shield comes to the equation too.
(But lose the bastard at the top, OK?)
Only catching both the booster and the rocket would top this one. But the rocket only being caught is still impressive regardless.
SpaceX below $1T is criminally undervalued.
It was meant to be a dual catch of the booster and the rocketship and only the rocketship itself was caught.
Only catching both of them in another mission would top this one.