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A fully refueled starship in leo is a big big ask, akin to getting a full shuttle stack into orbit. On-orbit refueling at such a scale has not been done yet an

A fully refueled starship in leo is a big big ask, akin to getting a full shuttle stack into orbit. On-orbit refueling at such a scale has not been done yet and is difficult to even think about doing. It isnt like KSP. The more efficient route would be to scrap starship and design a high-energy upper stage to be launched by the BFR instead, a purpose-built probe thrower. Starship is way to heavy to be a practical final stage for probes.

Alex-Programs 2y ago
On-orbit refuelling at such a scale does sound rather difficult, but they also fully intend to do it in the near future. They're certainly going to give it a good try. Also, if you don't want to make an entirely different second stage to put on top of superheavy, you should be able to fit a pretty substantial third stage in Starship's payload bay. Right now the payload bay doesn't open anywhere near enough for that, but hopefully in the future that'll be an option. And if you really want to make something go fast, you could refuel in orbit, give it a push from Starship, then deploy the third stage for another kick.
- rbanffy 2y ago
  > Right now the payload bay doesn't open anywhere near enough for that Shouldn't be too hard to design a starship with a blunt nose and place it under an expendable fairing. With a 1-ton probe the budget is 99 tons for a kick stage. That's a lot of delta-v. With some creative propulsion options, maybe even interstellar probes can be done.
sneak 2y ago
Everything you said is right, but on-orbit refueling is of course theoretically possible, and isn’t THAT huge of a leap given what SpaceX has already accomplished. Let’s not forget the space lasers, or the chopstick catch, or Starlink-live-streamed 4K views from the plasma shadow during reentry, or autonomous Dragon docking, etc. Sure, it’s hard, but that is perhaps the best engineering team in the history of humankind, and I think they’re up to the task. Additionally, people much smarter than me ALSO think they are up to the task, and they have more and higher-resolution data about the problem space, too. My money’s on they get it working. Maybe it takes five years or a dozen failures, but I’m confident that they will succeed eventually and there will be orbiting methane and lox fuel stations sooner rather than later.
- sandworm101 2y ago
  Those things were never seen as impossible, just difficult. Nobody has even a theoretical concept of how to move tons of liquid oxygen between rockets in orbit. And there is some talk of banning it as too dangerous. Remember all those pad explosions related to fuel issues? We cannot risk that much space debris as spaceX goes through a learning process.
  - kolinko 2y ago
    If I'm not mistaken, SpaceX is already contracted by NASA to do on orbit refuelling, and one of the recent starships did initial trials of fuel transmission (internal for now). Update: - source article - $58M contract to do that - https://www.teslarati.com/spacex-starship-nasa-contract-orbital-refueling-test/?utm_source=chatgpt.com https://www.teslarati.com/spacex-starship-nasa-contract-orbi... - chatgpt confirmation + links to more sources - https://chatgpt.com/share/e/674b5c1b-d318-8004-b79d-c0eefc59454a https://chatgpt.com/share/e/674b5c1b-d318-8004-b79d-c0eefc59...

Alex-Programs 2y ago

On-orbit refuelling at such a scale does sound rather difficult, but they also fully intend to do it in the near future. They're certainly going to give it a good try. Also, if you don't want to make an entirely different second stage to put on top of superheavy, you should be able to fit a pretty substantial third stage in Starship's payload bay. Right now the payload bay doesn't open anywhere near enough for that, but hopefully in the future that'll be an option. And if you really want to make something go fast, you could refuel in orbit, give it a push from Starship, then deploy the third stage for another kick.

rbanffy 2y ago
> Right now the payload bay doesn't open anywhere near enough for that Shouldn't be too hard to design a starship with a blunt nose and place it under an expendable fairing. With a 1-ton probe the budget is 99 tons for a kick stage. That's a lot of delta-v. With some creative propulsion options, maybe even interstellar probes can be done.

sneak 2y ago

Everything you said is right, but on-orbit refueling is of course theoretically possible, and isn’t THAT huge of a leap given what SpaceX has already accomplished. Let’s not forget the space lasers, or the chopstick catch, or Starlink-live-streamed 4K views from the plasma shadow during reentry, or autonomous Dragon docking, etc. Sure, it’s hard, but that is perhaps the best engineering team in the history of humankind, and I think they’re up to the task. Additionally, people much smarter than me ALSO think they are up to the task, and they have more and higher-resolution data about the problem space, too. My money’s on they get it working. Maybe it takes five years or a dozen failures, but I’m confident that they will succeed eventually and there will be orbiting methane and lox fuel stations sooner rather than later.

sandworm101 2y ago
Those things were never seen as impossible, just difficult. Nobody has even a theoretical concept of how to move tons of liquid oxygen between rockets in orbit. And there is some talk of banning it as too dangerous. Remember all those pad explosions related to fuel issues? We cannot risk that much space debris as spaceX goes through a learning process.
- kolinko 2y ago
  If I'm not mistaken, SpaceX is already contracted by NASA to do on orbit refuelling, and one of the recent starships did initial trials of fuel transmission (internal for now). Update: - source article - $58M contract to do that - https://www.teslarati.com/spacex-starship-nasa-contract-orbital-refueling-test/?utm_source=chatgpt.com https://www.teslarati.com/spacex-starship-nasa-contract-orbi... - chatgpt confirmation + links to more sources - https://chatgpt.com/share/e/674b5c1b-d318-8004-b79d-c0eefc59454a https://chatgpt.com/share/e/674b5c1b-d318-8004-b79d-c0eefc59...