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starship orbits the moon, they build those rail launchers that launch non-organic payload from moon surface to moon orbit

by ge96 1y ago

PaulHoule 1y ago
Those at least look better than they did in the Moon is a Harsh Mistress and O'Neill periods. The US military has tested 2.5 km/s railguns, it takes just 3.5 km/s to get to the Earth-Moon L1 point. If the Starship could really land 100 tonnes, it could land one of those exclusive of power supply... It's not some huge thing that looks like a kilometer-scale maglev anymore. I could picture one of those things moving say 80 tons/day of bulk material if it wasn't for the problem of the barrel getting trashed in less than one day. The design of the catcher is a tough problem though and still unsolved. There are lots of answers that aren't so attractive, such as fielding a big piece of styrofoam that you'll eventually melt and reform or some kind of thing that throws a capture device with a cable attached at passing projectiles.
- numpad0 1y ago
  Railguns are cool, but I think superconductor based maglevs are more viable. They don't need any sophisticated controls for neither acceleration nor floatation. Hypothetically you can just fuel a cargo sled with LN2 to a fill line, give it a nudge, and it'll start rolling without needing any sophisticated computerized controls. Floatation is handled by pair of upoer and lower passive guide coils on the wall, just induction current can keep vehicles vertically centered. Propulsion is handled by constant alternating current on alternatingly pointed coils. Speed can be modulated between zero to max by merely modulating strength, not frequency or phase, of vehicle side magnets. It does need a lot of materials to build one with 3.5km/s max speed on the Moon, though, so a robotic Lunar foundry might have to be built first. But once that goes up... space megaprojects will be free, and launches from planetary surfaces will mainly be used for humans or valuable items.
  - PaulHoule 1y ago
    I think you are right that it looks more like a coilgun than the railgun. I hope it can be scaled to the size of the Paris gun because it could be sent in parts and could point high in the sky at the right spot. Enough material could be sent to the earth-moon L1 and L2 points to make a small artificial asteroid, radiation shields, etc.

starship orbits the moon, they build those rail launchers that launch non-organic payload from moon surface to moon orbit

by ge96 1y ago

starship orbits the moon, they build those rail launchers that launch non-organic payload from moon surface to moon orbit

PaulHoule 1y ago

Those at least look better than they did in the Moon is a Harsh Mistress and O'Neill periods. The US military has tested 2.5 km/s railguns, it takes just 3.5 km/s to get to the Earth-Moon L1 point. If the Starship could really land 100 tonnes, it could land one of those exclusive of power supply... It's not some huge thing that looks like a kilometer-scale maglev anymore. I could picture one of those things moving say 80 tons/day of bulk material if it wasn't for the problem of the barrel getting trashed in less than one day. The design of the catcher is a tough problem though and still unsolved. There are lots of answers that aren't so attractive, such as fielding a big piece of styrofoam that you'll eventually melt and reform or some kind of thing that throws a capture device with a cable attached at passing projectiles.

numpad0 1y ago
Railguns are cool, but I think superconductor based maglevs are more viable. They don't need any sophisticated controls for neither acceleration nor floatation. Hypothetically you can just fuel a cargo sled with LN2 to a fill line, give it a nudge, and it'll start rolling without needing any sophisticated computerized controls. Floatation is handled by pair of upoer and lower passive guide coils on the wall, just induction current can keep vehicles vertically centered. Propulsion is handled by constant alternating current on alternatingly pointed coils. Speed can be modulated between zero to max by merely modulating strength, not frequency or phase, of vehicle side magnets. It does need a lot of materials to build one with 3.5km/s max speed on the Moon, though, so a robotic Lunar foundry might have to be built first. But once that goes up... space megaprojects will be free, and launches from planetary surfaces will mainly be used for humans or valuable items.
- PaulHoule 1y ago
  I think you are right that it looks more like a coilgun than the railgun. I hope it can be scaled to the size of the Paris gun because it could be sent in parts and could point high in the sky at the right spot. Enough material could be sent to the earth-moon L1 and L2 points to make a small artificial asteroid, radiation shields, etc.