3 ms·
Whatever you do with internally generated energy, you either get it out or it accumulates, overheating you. You need 3-10 m^2 of radiators for every kW of powe
by PeterisP 6y ago
Whatever you do with internally generated energy, you either get it out or it accumulates, overheating you.
You need 3-10 m^2 of radiators for every kW of power you use. If your ship is powered (I mean internal power, not engine exhaust) by a 1MW reactor, then you need radiators close to the scale of a football field pushing out waste heat, no matter what tech that reactor uses.
- bombcar 6y agoDelightfully counterintuitive given the low temperatures of space - would it help said ships to hide on the dark side of the moon and avoid solar radiation?
- EForEndeavour 6y agoWhere does that 3-10 m^2 per kW estimate come from? The best I could guess based on my shaky grasp of radiation is to equate internally generated power to total radiated power using the Stefan-Boltzmann Law: https://www.wolframalpha.com/input/?i=1+kW%2F%28Stefan-Boltzmann+constant%29%2F%28203+to+275+K%29%5E4 https://www.wolframalpha.com/input/?i=1+kW%2F%28Stefan-Boltz... Based on that, you need 3-10 m^2 of radiative surface area per kilowatt, but that's assuming your equilibrium temperature is 203 to 275 K (-70 to 2 °C). Assuming I haven't made some basic mistake, couldn't you decide to heat part of your surface to some much higher temperature and radiate most of your internal power out of that part?
- PeterisP 6y agoThis is what our current spacecraft radiators manage. You also have to take into account that radiators also interact with the sun and with the rest of the spacecraft. Of course, you could have a heat pump pushing heat to a higher temperature surface, some current radiators do that, but it has its limitations requires more energy for the pump the higher temperature difference you want to sustain.