belbear wrote:
Radiating waste heat into deep space isn’t so difficult, on condition you shield your radiator from the sun. After all, space shows us a 3 Kelvin black-body and that’s really cold.
Right, but that is purely radiative cooling, which as I understand it isn’t nearly as efficient as conductive or convective cooling — there’s a reason that thermos bottles use vacuum flasks. As “cold” as space may be, you can cool things far more efficiently on earth by, for example, dumping heat into a lower temperature fluid. (I’m sure that some one with way more technical expertise could clarify what sized radiator would be needed to dump 5MW of heat into space.)
