alt Hacker NewsStefan-Boltzmann law means radiative heat transfer in space is approx. to the 4th power of the hot side of your radiator. Typical space based radiators operate around 350K. If you can increase the hot side of the refrigeration cycle by 4x (1400K) you increase heat transfer by 256x. Create a radiator design that can operate at this temp (multi-stage Brayton loops, heat pumps, possible liquid metal final stage) with a large enough surface area and now a datacenter in space seems possible.
It's a difficult engineering challenge but physically possible, and Elon is no stranger to engineering challenges.
Some numbers: assume an emissivity of 0.85, assume no absorption from the sun, assume heat rejected from both sides of a panel, a 1m^2 panel will reject 1.45kW/m^2 @ 350K.
At 900K its 62 kW/m^2. Not a trivial amount of heat.
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I was actually curious about this myself back when everyone was chiming in about how it was physically impossible.
This is first and foremost an engineering problem as you need to design a system that will both tolerate high heat and be able to pump even more heat to the radiators. The high temperature seems to be the primary objective to design for unless launch costs become absurdly low.
How much energy does it take to pump the heat from a primary loop at a temperature tolerated by the silicon to a secondary loop at 900 K? If we pick 300 K for simplicity, would we not need twice as much energy as we want to get rid of just to raise the temperature? 2 MW to raise 1 MW from 300 K to 900 K?