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Comment by PunchyHamster

18 hours ago

just take cost of getting kg in space and compare it to how much solar panel will generate

Current satellites get around 150W/kg from solar panels. Cost of launching 1kg to space is ~$2000. So we're at $13.3(3)/Watt. We need to double it because same amount need to be dissipated so let's round it to $27

One NVidia GB200 rack is ~120kW. To just power it, you need to send $3 240 000 worth of payload into space. Then you need to send additional $3 106 000 (rack of them is 1553kg) worth of servers. Plus some extra for piping

Over 10 years ago, the best satellites had 500W/kg [2]. Modern solar panels that are designed to be light are at 200g per sqm [1]. That's 5sqm per kg. One sqm generates ca. 500W. So we're at 2.5kW per kg. Some people claim 4.3kW/kg possible.

Starship launch costs have a $100/kg goal, so we'd be at $40 / kW, or $4800 for a 120kW cluster.

120kW is 1GWh annually, costs you around $130k in Europe per year to operate. ROI 14 days. Even if launch costs aren't that low in the beginning and there's a lot more stuff to send up, your ROI might be a year or so, which is still good.

[1] - https://www.polytechnique-insights.com/en/columns/space/ultr... [2] - https://space.stackexchange.com/questions/12824/lightest-pos...

  • What if you treat that launch costs goal as just a marketing promise. Invest in reality, not in billionaire's fantasies.

    • > What if you treat that launch costs goal as just a marketing promise.

      Then it's roughly 10x-15x and still works.

      > Invest in reality, not in billionaire's fantasies.

      SpaceX has dramatically reduced payload cost already. How is that a fantasy?