Well, how do you cool servers in space then?

Evaporative cooling is the way it happens down on earth - and that shuttles h2o molecules from dense useful clumps like aquifers and rivers to a less useful form spread out in the air. But evaporating h2o isn’t an option in space afaik - since there’s a shortage of air to take up the h2o. In fact I think radiative cooling is the only actual option in space.

That's the neat thing: you don't, or at least not in the megawatt range. A kilowatt can be done with radiative cooling but doesn't get you far with a hypothetical datacenter satellite.