Russia plans to put a nuclear power plant on the moon in the next decade to supply its lunar space programme and a joint Russian-Chinese research station, as major powers rush to explore the earth's only natural satellite.
There’s only two sources of power on other planets/outer space, and that is nuclear and solar.
Wind and water and biomass and geothermal and fossil fuels are out of the question, because of lack of said things or lack of oxygen to burn anything.
That being said, “nuclear” only works if it’s steady-state and does not use water/air input. That excludes steam engines and such, and basically only leaves RTGs (Radioisotope Thermoelectric Generator).
These are solid-state devices (meaning they have no moving parts) and convert the heat directly into electricity using TEGs (Thermoelectric Generator). They don’t need water or air input.
RTGs have an overall fuel efficiency of around 3-5%, meaning they translate around 3-5% of the radioactive decay heat of the nuclear material into electric power output.
Wait, why would wind and water be rare on other planets? Finding good places to do water-based renewables is probably gonna be difficult on most planets, but shouldn’t most planets with atmospheres have wind?
yeah you’re right, air can be used on mars for example. (not wind though because wind is too weak at only 6 mbar atmospheric pressure, so it can barely move anything, and especially not a heavy rotary blade from a wind turbine.) but you could use the air to drive a stirling engine or sth, maybe, if you compress it first.
but the engine has to be really low-maintenance, because repairing it is basically out of the question. repairing something very far away from any larger civilization is really difficult. and typically, things that have no moving parts (steady-state) are much less likely to break, so have much longer lifetimes.
Reactors on earth are huge and built to run at 100% all the time because that’s the most economical way to do it. That is not a physics requirement, it’s just the most profitable for the current economic environment. You can design a reactor that can throttle output if you need to and many small modular reactors currently in the licensing approval process include this ability.
Nevermind the fact that a “large” RTG only puts out about 100 watts of electricity and it’s nuclear fuel must be bred in reactors beforehand. There is only enough RTG fuel for maybe 20 large units on the planet right now.
You can design a reactor that can throttle output if you need to
yeah i’ve been thinking about these reactors a lot. problem is, to make a reactor regulatable like that, the material must be fissable. I.e. you can’t use PU-238 (which has a half-life of 87 years and is typically used in RTGs today), instead you’d use U-235 or sth (which is used in big nuclear reactors today). Problem is, that material is fissable (i.e. it undergoes chain reaction and runs at or just below criticality) and that is why you can build bombs out of it. Then, to bring such a reactor into space, you’d have to lift it off with a rocket, and there’s your problem: You’d have to transport (large amounts of) fissable material with a rocket across earth into the sky. And that’s how you provoke international nuclear conflict.
There’s only two sources of power on other planets/outer space, and that is nuclear and solar.
Wind and water and biomass and geothermal and fossil fuels are out of the question, because of lack of said things or lack of oxygen to burn anything.
That being said, “nuclear” only works if it’s steady-state and does not use water/air input. That excludes steam engines and such, and basically only leaves RTGs (Radioisotope Thermoelectric Generator).
These are solid-state devices (meaning they have no moving parts) and convert the heat directly into electricity using TEGs (Thermoelectric Generator). They don’t need water or air input.
RTGs have an overall fuel efficiency of around 3-5%, meaning they translate around 3-5% of the radioactive decay heat of the nuclear material into electric power output.
Wait, why would wind and water be rare on other planets? Finding good places to do water-based renewables is probably gonna be difficult on most planets, but shouldn’t most planets with atmospheres have wind?
yeah you’re right, air can be used on mars for example. (not wind though because wind is too weak at only 6 mbar atmospheric pressure, so it can barely move anything, and especially not a heavy rotary blade from a wind turbine.) but you could use the air to drive a stirling engine or sth, maybe, if you compress it first.
but the engine has to be really low-maintenance, because repairing it is basically out of the question. repairing something very far away from any larger civilization is really difficult. and typically, things that have no moving parts (steady-state) are much less likely to break, so have much longer lifetimes.
Reactors on earth are huge and built to run at 100% all the time because that’s the most economical way to do it. That is not a physics requirement, it’s just the most profitable for the current economic environment. You can design a reactor that can throttle output if you need to and many small modular reactors currently in the licensing approval process include this ability.
Nevermind the fact that a “large” RTG only puts out about 100 watts of electricity and it’s nuclear fuel must be bred in reactors beforehand. There is only enough RTG fuel for maybe 20 large units on the planet right now.
yeah i’ve been thinking about these reactors a lot. problem is, to make a reactor regulatable like that, the material must be fissable. I.e. you can’t use PU-238 (which has a half-life of 87 years and is typically used in RTGs today), instead you’d use U-235 or sth (which is used in big nuclear reactors today). Problem is, that material is fissable (i.e. it undergoes chain reaction and runs at or just below criticality) and that is why you can build bombs out of it. Then, to bring such a reactor into space, you’d have to lift it off with a rocket, and there’s your problem: You’d have to transport (large amounts of) fissable material with a rocket across earth into the sky. And that’s how you provoke international nuclear conflict.