Comment by tyg13
12 hours ago
It all basically boils down to: in order to dissipate heat, you need something to dissipate heat into, e.g. air, liquid, etc. Even if you liquid cool the GPUs, where is the heat going to go?
On Earth, you can vent the heat into the atmosphere no problem, but in space, there's no atmosphere to vent to, so dissipating heat becomes a very, very difficult problem to solve. You can use radiators to an extent, but again, because no atmosphere, they're orders of magnitude less effective in space. So any kind of cooling array would have to be huge, and you'd also have to find some way to shade them, because you still have to deal with heat and other kinds of radiation coming from the Sun.
It's easier to just keep them on Earth.
What you're describing is one of two mechanisms of shedding heat which is convection, heating up the environment. What the long comment above is describing is a _completely_ different mechanism, radiation, which is __more__ efficient in a vacuum. They are different things that you are mixing up.
for a square solar array of side length L, a pyramid height of 3*L would bring the temperature to below 300K, check my calculation above.
people heavily underestimate radiative cooling, probably because precisely our atmosphere hinders its effective utilization!
lesson: its not because radiative cooling is hard to exploit on earth at sea level, that its similarily ineffective in space!