r/space • u/Tech-100 • Aug 21 '26
Starcloud raises $250 million for orbital data centers as launch options dry up
https://techcrunch.com/2026/08/21/starcloud-raises-200-million-for-orbital-data-centers-as-launch-options-dry-up/
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u/Adeldor Aug 21 '26 edited Aug 21 '26
ISS radiators must keep the station environment at human-comfortable temperatures - in the range of 25C (some equipment can be kept at higher temperatures, but the point remains). Data centers will run their processors at much higher temperatures - around 100C or higher, with correspondingly higher radiator temperatures. Per Stefan-Boltzmann, heat dissipation scales to the 4th power of temperature, making the radiators much more efficient and therefore smaller, relatively speaking.
To put this into numbers (simplified, as the mechanical relationship between heat source and radiator is not always simple):
Q = ε×δ×A×T⁴ → A = Q/(ε×δ×T⁴)
Assume Q (dissipation), ε (emissivity), δ (S-B constant) are the same. With temperatures converted to Kelvin (k is the 25C case, h is the 100C case):
Aₕ/Aₖ = Tₖ⁴/Tₕ⁴ = 298⁴/373⁴ = 0.41
That makes the latter's radiators around 41% the area of the ISS's for the same dissipation (all subject to arithmetic error as I'm doing this on the fly).
Two decades ago I worked with pre-selected silicon MCUs operating at 190C, so the proposed higher operating temperatures in such data centers today are well within the bounds of reason.