A typical CPU heatsink dissipates 10-30% of heat through radiation, and the rest through convection. In space you're in a vacuum so you can't disipated heat through convection.
You need to rework your physical equipment quite substantially to make up for the fact you can't shed 70-90% of the heat in the same manner as you can down here on Earth
You need to rework your physical equipment quite substantially to make up for the fact you can't shed 70-90% of the heat in the same manner as you can down here on Earth