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> Cost of compute on Earth Power build Permitting Operating costs Land Energy costs Infrastructure Cooling > Cost of compute in sp

by jrflo 2mo ago

> Cost of compute on Earth Power build Permitting Operating costs Land Energy costs Infrastructure Cooling > Cost of compute in space Launch cost Operating costs Satellite build Infrastructure I thought it was pretty hilarious that they removed "cooling" as a requirement for orbital compute when it's actually way harder to keep something cool on a satellite than on earth. There is no matter floating around in orbit to dump heat into...

dlcarrier 2mo ago
They didn't mention it, because it's barely an inconvenience. Why does everyone seem to think it's super difficult? It's really easy to keep things cool in space. Radiant cooling is very effective when the background energy is 3° K. The radiators don't even need to be as large as the solar panels picking up energy. The most difficult challenge for satellite temperature regulation is the sudden changes in solar heating when passing in and out of Earth's shadow, but these satellites would be in an orbit that doesn't cross behind earth's shadow, making thermal regulation simpler than most low- and medium-Earth-orbit satellites. It's not like it's easy on earth. Servers on earth almost always require a heat pump between the computer and outside, whether directly cooling the computer or cooling the air in a room the computer is running in. Almost all of the cooling comes through convective action, which requires significant air or water movement, or if that isn't enough evaporating water may be needed.
- jrflo 2mo ago
  https://spectrum.ieee.org/orbital-data-centers-heat https://spectrum.ieee.org/orbital-data-centers-heat This analysis calculates 80 square meters of radiator surface area needed per rack, or 200,000 square meters per 100 MW. It's not to say it can't be done, I think orbital data centers could actually be a pretty good idea, but to say cooling is a nonissue is disingenuous. Innovations are needed there to make it work.
  - dlcarrier 2mo ago
    Again, that's less than the surface area needed for the solar panels, and the body of the satellite itself is included in that. As far as satellite design goes, the thermal design is easier than radiation hardening or vibration resistance, and unlike something running on earth, there's no ongoing costs associated with it. As far as things to worry about when designing a satellite, it's as much of an issue as making sure the power supplies are the right voltage and the radio is running on the right frequency, which is to say you check to make sure you got it right, but otherwise it's a non issue.

by jrflo 2mo ago

dlcarrier 2mo ago

They didn't mention it, because it's barely an inconvenience. Why does everyone seem to think it's super difficult? It's really easy to keep things cool in space. Radiant cooling is very effective when the background energy is 3° K. The radiators don't even need to be as large as the solar panels picking up energy. The most difficult challenge for satellite temperature regulation is the sudden changes in solar heating when passing in and out of Earth's shadow, but these satellites would be in an orbit that doesn't cross behind earth's shadow, making thermal regulation simpler than most low- and medium-Earth-orbit satellites. It's not like it's easy on earth. Servers on earth almost always require a heat pump between the computer and outside, whether directly cooling the computer or cooling the air in a room the computer is running in. Almost all of the cooling comes through convective action, which requires significant air or water movement, or if that isn't enough evaporating water may be needed.

jrflo 2mo ago
https://spectrum.ieee.org/orbital-data-centers-heat https://spectrum.ieee.org/orbital-data-centers-heat This analysis calculates 80 square meters of radiator surface area needed per rack, or 200,000 square meters per 100 MW. It's not to say it can't be done, I think orbital data centers could actually be a pretty good idea, but to say cooling is a nonissue is disingenuous. Innovations are needed there to make it work.
- dlcarrier 2mo ago
  Again, that's less than the surface area needed for the solar panels, and the body of the satellite itself is included in that. As far as satellite design goes, the thermal design is easier than radiation hardening or vibration resistance, and unlike something running on earth, there's no ongoing costs associated with it. As far as things to worry about when designing a satellite, it's as much of an issue as making sure the power supplies are the right voltage and the radio is running on the right frequency, which is to say you check to make sure you got it right, but otherwise it's a non issue.