4 ms·

assemble it in space, on low earth orbit (LEO) with many trips of e.g. SpaceX Starship, kind of like the international space station was assembled piece by piec

assemble it in space, on low earth orbit (LEO) with many trips of e.g. SpaceX Starship, kind of like the international space station was assembled piece by piece over time.

hermitcrab 5y ago
Freeman Dyson made the point (from memory) that the main advantage was that it was powerful enough to lift a really big payload into orbit. If you were going to lift the parts into orbit using chemical rockets, then that was defeating a lot of the point of using the technology in the first place.
- murderfs 5y ago
  Right. Pretty much every other technology has to choose between high thrust and high specific impulse (i.e. efficiency). Chemical rockets have tons of thrust, but bad efficiency. Electric propulsion (ion drives, etc.) is really efficient, but most implementations have thrusts that are on the order of being able to lift a sheet of paper.
  - m4rtink 5y ago
    Well, there are quite a few ways of moving lots of stuff out of the gravity well without turning the Planet below into the Fallout franchise. The already mentioned reusable chemical rockets will loft quite a bit as long as they are really reusable and durable. Space elevators (there are still material challenges for Earht, but IIRC existing materials would be enough for Mars): https://en.wikipedia.org/wiki/Space_elevator https://en.wikipedia.org/wiki/Space_elevator Launch loops: https://en.wikipedia.org/wiki/Launch_loop https://en.wikipedia.org/wiki/Launch_loop Space fountains and active structures in general (are crazy but have high useful potential): https://en.wikipedia.org/wiki/Space_fountain https://en.wikipedia.org/wiki/Space_fountain Heck, there is a dedicated article for these in the Wikipedia! https://en.wikipedia.org/wiki/Non-rocket_spacelaunch https://en.wikipedia.org/wiki/Non-rocket_spacelaunch Still, I would say ideally you would want to move most of the heavy manufacturing to space & from space resources anyway. Then reusable chemical rockets might be good enough to move people and other compact high value cargo between Earth surface & space infrastructure.

assemble it in space, on low earth orbit (LEO) with many trips of e.g. SpaceX Starship, kind of like the international space station was assembled piece by piece over time.

hermitcrab 5y ago

Freeman Dyson made the point (from memory) that the main advantage was that it was powerful enough to lift a really big payload into orbit. If you were going to lift the parts into orbit using chemical rockets, then that was defeating a lot of the point of using the technology in the first place.

murderfs 5y ago
Right. Pretty much every other technology has to choose between high thrust and high specific impulse (i.e. efficiency). Chemical rockets have tons of thrust, but bad efficiency. Electric propulsion (ion drives, etc.) is really efficient, but most implementations have thrusts that are on the order of being able to lift a sheet of paper.
- m4rtink 5y ago
  Well, there are quite a few ways of moving lots of stuff out of the gravity well without turning the Planet below into the Fallout franchise. The already mentioned reusable chemical rockets will loft quite a bit as long as they are really reusable and durable. Space elevators (there are still material challenges for Earht, but IIRC existing materials would be enough for Mars): https://en.wikipedia.org/wiki/Space_elevator https://en.wikipedia.org/wiki/Space_elevator Launch loops: https://en.wikipedia.org/wiki/Launch_loop https://en.wikipedia.org/wiki/Launch_loop Space fountains and active structures in general (are crazy but have high useful potential): https://en.wikipedia.org/wiki/Space_fountain https://en.wikipedia.org/wiki/Space_fountain Heck, there is a dedicated article for these in the Wikipedia! https://en.wikipedia.org/wiki/Non-rocket_spacelaunch https://en.wikipedia.org/wiki/Non-rocket_spacelaunch Still, I would say ideally you would want to move most of the heavy manufacturing to space & from space resources anyway. Then reusable chemical rockets might be good enough to move people and other compact high value cargo between Earth surface & space infrastructure.