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Please provide a reference showing that NASA thinks that Starship will lose 3/4 of the fuel, and there is no way to fix it.

by btilly 2y ago

kibwen 2y ago
“It’s in the high teens in the number of launches,” Hawkins said. That’s driven, she suggested, about concerns about boiloff, or loss of cryogenic liquid propellants, at the depot. [...] Critics of NASA’s selection of Starship for HLS have pointed to the number of launches as a weakness in the architecture. The Government Accountability Office, in its rejection of protests by Blue Origin and Dynetics of the Starship HLS award in 2021, noted that SpaceX required 16 launches overall for a Starship lunar lander mission. Elon Musk, chief executive of SpaceX, disagreed, calling the need for 16 launches “extremely unlikely” in an August 2021 social media post. He said a “max of 8” tanker launches should be needed to fuel the Starship lander, adding it could be as few as four. https://spacenews.com/starship-lunar-lander-missions-to-require-nearly-20-launches-nasa-says/ https://spacenews.com/starship-lunar-lander-missions-to-requ...
- btilly 2y ago
  Thank you for providing a reference. Sight unseen, I'm inclined to think that SpaceX is more likely right here. In particular part of the higher figure is a lower launch cadence. But SpaceX is building their technology around very rapid turnaround times. With multiple Starships, there is good reason to believe that they will not need to wait 6 days between launches. Of course this depends on FAA permission. Whether they get FAA permission may well depend on who wins the election. Musk has gone out of his way to place a big bet on Trump, and it is clear that Trump will happily get rid of red tape for Musk in return. My read is that part of the reason why Musk placed that bet on Trump is because the Biden/Harris administration has already decided to place lots of red tape in Musk's way. At first as a reaction to Musk's hostility towards unions and COVID restrictions on manufacturing, and then as a reaction against what Musk was doing with Twitter.
  - kibwen 2y ago
    The US government is throwing money hand-over-fist at SpaceX, the idea that the Biden administration is artificially obstructing SpaceX is not based in reality. Meanwhile, Trump is publicly anti-EVs and anti-self-driving-cars, so Musk's rabid cheerleading cannot be motivated by economic reasons.
    - JumpCrisscross 2y ago
      SpaceX is so strategically critical American interests that it’s implausible for either administration to kneecap it.
- JumpCrisscross 2y ago
  Would note that’s the GAO, not NASA. 16 launches is well within possibility, though unlikely that would ever be accepted as a final solution.
  - kibwen 2y ago
    The GAO is mentioned later, but the first quote is from "Lakiesha Hawkins, assistant deputy associate administrator in NASA’s Moon to Mars Program Office".
  - ethbr1 2y ago
    The nice thing about fuel launches though is that the cargo isn't valuable. You're not launching exquisite rovers or satellites -- you're launching a bunch of fuel. So if a reused Starship blows up on accent*, that's not great, but it's not terrible either. Load the next one and try again. * Obviously, you want to be much more careful on rendezvous
    - JumpCrisscross 2y ago
      > if a reused Starship blows up on accent, that's not great, but it's not terrible either You're correct. But Starship, being a multi-use spacecraft, can't capitalise on this differential. Fuel-only launch enables high-g launch options, e.g. rail guns. It could also enable low-reliability low-cost options, but the nature of space launch hasn't opened that niche up, and--I suspect--the nature of environmental regulations ensure it never will.
      - ethbr1 2y ago
        I'd make the point that it can, because {cost for relaunch} = {refurb cost} + {recertification cost}. And likewise, probability of relaunch success scales with the money and time spent on those other two. In fact, I'd strongly argue that fuel-to-orbit is Starship's version of Falcon's "Starlink demand seeding." It's win/win if SpaceX has a high-volume, low-payload-cost, revenue-generating demand for Starship, as it gives them a failure tolerant mission to push relaunches to failure and then use that data to improve future reuse reliability. Of all the things SpaceX has done, getting themselves into positive-feedback flywheels has been the smartest.

Please provide a reference showing that NASA thinks that Starship will lose 3/4 of the fuel, and there is no way to fix it.

by btilly 2y ago

Please provide a reference showing that NASA thinks that Starship will lose 3/4 of the fuel, and there is no way to fix it.

kibwen 2y ago

“It’s in the high teens in the number of launches,” Hawkins said. That’s driven, she suggested, about concerns about boiloff, or loss of cryogenic liquid propellants, at the depot. [...] Critics of NASA’s selection of Starship for HLS have pointed to the number of launches as a weakness in the architecture. The Government Accountability Office, in its rejection of protests by Blue Origin and Dynetics of the Starship HLS award in 2021, noted that SpaceX required 16 launches overall for a Starship lunar lander mission. Elon Musk, chief executive of SpaceX, disagreed, calling the need for 16 launches “extremely unlikely” in an August 2021 social media post. He said a “max of 8” tanker launches should be needed to fuel the Starship lander, adding it could be as few as four. https://spacenews.com/starship-lunar-lander-missions-to-require-nearly-20-launches-nasa-says/ https://spacenews.com/starship-lunar-lander-missions-to-requ...

btilly 2y ago
Thank you for providing a reference. Sight unseen, I'm inclined to think that SpaceX is more likely right here. In particular part of the higher figure is a lower launch cadence. But SpaceX is building their technology around very rapid turnaround times. With multiple Starships, there is good reason to believe that they will not need to wait 6 days between launches. Of course this depends on FAA permission. Whether they get FAA permission may well depend on who wins the election. Musk has gone out of his way to place a big bet on Trump, and it is clear that Trump will happily get rid of red tape for Musk in return. My read is that part of the reason why Musk placed that bet on Trump is because the Biden/Harris administration has already decided to place lots of red tape in Musk's way. At first as a reaction to Musk's hostility towards unions and COVID restrictions on manufacturing, and then as a reaction against what Musk was doing with Twitter.
- kibwen 2y ago
  The US government is throwing money hand-over-fist at SpaceX, the idea that the Biden administration is artificially obstructing SpaceX is not based in reality. Meanwhile, Trump is publicly anti-EVs and anti-self-driving-cars, so Musk's rabid cheerleading cannot be motivated by economic reasons.
  - JumpCrisscross 2y ago
    SpaceX is so strategically critical American interests that it’s implausible for either administration to kneecap it.
JumpCrisscross 2y ago
Would note that’s the GAO, not NASA. 16 launches is well within possibility, though unlikely that would ever be accepted as a final solution.
- kibwen 2y ago
  The GAO is mentioned later, but the first quote is from "Lakiesha Hawkins, assistant deputy associate administrator in NASA’s Moon to Mars Program Office".
- ethbr1 2y ago
  The nice thing about fuel launches though is that the cargo isn't valuable. You're not launching exquisite rovers or satellites -- you're launching a bunch of fuel. So if a reused Starship blows up on accent*, that's not great, but it's not terrible either. Load the next one and try again. * Obviously, you want to be much more careful on rendezvous
  - JumpCrisscross 2y ago
    > if a reused Starship blows up on accent, that's not great, but it's not terrible either You're correct. But Starship, being a multi-use spacecraft, can't capitalise on this differential. Fuel-only launch enables high-g launch options, e.g. rail guns. It could also enable low-reliability low-cost options, but the nature of space launch hasn't opened that niche up, and--I suspect--the nature of environmental regulations ensure it never will.
    - ethbr1 2y ago
      I'd make the point that it can, because {cost for relaunch} = {refurb cost} + {recertification cost}. And likewise, probability of relaunch success scales with the money and time spent on those other two. In fact, I'd strongly argue that fuel-to-orbit is Starship's version of Falcon's "Starlink demand seeding." It's win/win if SpaceX has a high-volume, low-payload-cost, revenue-generating demand for Starship, as it gives them a failure tolerant mission to push relaunches to failure and then use that data to improve future reuse reliability. Of all the things SpaceX has done, getting themselves into positive-feedback flywheels has been the smartest.