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legohead • yesterday at 6:29 PM • 1 reply • view on HN

and yet notice how the cooling video / section was the only one they didn't have a solution for... just saying "radiator" doesn't make sense - the radiator heats up too. it's how you get rid of the heat, not where you put it.

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GMoromisato • yesterday at 7:17 PM

Huh? Radiators are known technology. They have them on ISS; they have them on every Starlink satellite. This isn't like warp drive or antigravity.

Moreover, you can easily calculate how big of a radiator you need for a given power level and temperature. You can use the Stefan–Boltzmann law:

  A ~ (1000 P) / (2 e k T^4)
Where

  A is the radiator area in square meters
  P is the power in kilowatts
  e is emissivity (usually 0.9)
  k is the constant 5.67e-8
For a 1 kW test like Googles, you just need 1 square meter of radiators (assuming two-sided).

For SpaceX's 175 kW satellites, they will need ~170 square meters of radiators.

None of this is impossible or even difficult to calculate. That's why I think this is the laziest argument against space data centers. There are so many other more reasonable arguments (like whether they will be economically competitive) but people love to latch on to this one for some reason.

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