kadoban parent
Yeah, radiative cooling/heating is actually super slow compared to any other type. This is why it's so hard to cool anything in space, it's your only option and it kind of sucks at its job.
Wouldn't the other option be ejecting heat "ballast"?
I'm sure that would lead to other issues (sure, ejecting it would move you, but you could just always eject it in the opposite of the direction you want to go, which is how spaceships work in the first place), but what if you had super-cooled ice in a thermos-like enclosure, and as you needed to cool you pulled some out, let it melt, then vaporized it, then superheated the steam, then vented that out the back?
I think you could do that, but mass in space is kind of hard to come by. If it wasn't (like if you're on the moon) you could just use the mass for conduction anyway. If you have to ship it up and consume it like that, that's expensive and limiting.
I'm not sure you can practically superheat the ballast without just causing more heat that you have to deal with. Maybe a heat pump works? Something about that feels vaguely wrong.