Thread

Google’s Project Suncatcher to put ML infrastructure in space

233 points · 553 comments · xnx

zactato · 1790267254 · focus · HN ↗
How are they solving the heat dissipation issues?
1. lopsotronic · 1790268994 · focus · HN ↗
  For real. It's an enormous problem solved only with 1) sheer scale, and 2) Science Fiction.
  Both of those are expensive as hell, by the way.
  Cooling via radiation follows Stefan–Boltzmann: P = εσAT⁴. Let's assume a good surface (emissivity ~0.9) at 300 K (27 °C) at 400 W per square meter per side. A flat panel radiating from both faces into deep space gets 800 W/m, not including the losses from, say, the Sun, or from IR coming off the Earth. Now, input power. Sunlight in orbit ~1,360 W/m², assume ~22% cell efficiency, we got 300 W/m². So each 1 MW compute, 3,300 m² of solar panel and minimum 1,200–1,500 m² of radiator.
  In case ya didn't know - 1 MW is tiny from a present-day-datacenter perspective. It's like 8 racks. So we're talking orbital megastructures here, many many many square kilometers, and this is with all the best case assumptions, and magic radiator panels that never see the sun, or the earth, or the moon.
  This is just the basic numbers here, by the way. There's a garbage truck full of other unsolvable problems if you poke your head in there.
  Aside from the "Avoid Regulations" aspect, and the "Everything That Burns Deorbiting is Depreciation" aka "The Starlink Trick", I'm not sure what the hell the draw is.
  1. m4rtink · 1790273632 · focus · HN ↗
    Cooling in space is hard but not impossible - while current (IMHO stupid without advanced in space infra) space data center projects work with a couple MW, many advanced space propulsion concepts might have to reject hundreds of MW if not a couple GW.
    For that you might need more advanced stuff like liquid droplet radiators (<a href="https://en.wikipedia.org/wiki/Liquid_droplet_radiator" rel="nofollow">https://en.wikipedia.org/wiki/Liquid_droplet_radiator), heat sinks & pulsed operation. Still, it should be eventually doable.
    As for space data centers - I think the main issue is the complete lack of in space infrastructure for resource mining, processing and manufacturing & maintenance. It is kinda like building your first practical steam locomotive & the deciding to build directly an airliner. No suitable materils, experience, work force, material sources, etc.
    We eventually went from locomotives to airliner, in an incremental manner & expanding the supporting infrastructure to support the ever more ambitious projects.
    DanHulton · 1790281611 · focus · HN ↗
    It might be eventually doable, as an experiment or as a flex, sure. But it's never going to come close to being cost-reasonable versus the equivalent infrastructure here on earth.
    toephu2 · 1790289804 · focus · HN ↗
    > But it's never going to come close
    never? I doubt that.
    Technology will improve over time. Eventually I bet it will become cheaper.
    Have you tried building in the U.S.? Why do you think it's so expensive to build in the U.S.? It's due to regulation and red tape.
    unrented7977 · 1790292240 · focus · HN ↗
    Technology improves, but the laws of physics are constant and absolute (on human timescales).
    Thermodynamics says no today, no tomorrow, and no 100 years from now. That's not ever going to change.

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