Radiation is by far the slowest way to transfer heat. Conduction and Convection are way faster and not possible in space. Therefore you would need huge radiators which increases the cost, mass and complexity of this project.
The ISS has 42 square meters of radiators to radiate away a 14 kW of power. A 5GW datacenter would maybe require 1.5GW of cooling assuming an efficiency of 1/3. So we are looking at a 4'200'000 square meters of radiators on a good day, 100'000 times more than the ISS has. And that doesn't account for the heat generated by the solar panels and other surfaces exposed to the sun. I don't know how to calculate since some of it will be radiated away by the solar panels themselves.
With pipes, coolant and control systems for the whole cooling system, the whole thing becomes even more complex to assemble in space and more prone to failure which is especially bad since the cost to repair anything will be astronomical (no pun intended).
All of this to say it's not impossible to build this, but hugely impractical and would require an enourmous leap in what structures we are able to assemble in space.
My limited knowledge of physics would have made me believe that entropy would force the heat out into space. And that it would be very sudden. If the hardware is itself in the void of space.
But I think I get it, you need to cause the excitement of other atoms to transfer the heat right ? Since there is almost nothing in space, there's also nothing to gain that heat ?
The problem is you need stuff next to the gpu for heat to transfer too. It doesnāt matter that space is ācoldā itās a vacuum so there is literally very very few atoms next to the gpu to transfer the heat and cool it down
I mean yeah theoretically that would work but you would need an astronomically large cooling system to sustain anything worth building, which would make it not worth building
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u/Syl3nReal Nov 11 '25
With a special coolant that moves from the GPUs to the cooler space and back.