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Comment by charlieflowers

2 months ago

Help me understand why not? I know solar power generation in space, and "beaming" the power back, was a naive idea. But this would actually use the power up there, mostly for training, but also for inference.

That claim seems reasonable. I have zero knowledge of the economics of launching and maintaining satellites though.

As I understand it, the problem is cooling. There isn't any medium to take away the heat, so the only option is to slowly radiate it away.

  • Anyone who has googled just once to ask if datacenters in space make any sense, has found out they don't because they can't get rid of heat.

    That leaves only two kinds of people left who are still talking excitedly about datacenters in space: The uninformed and the grifters.

    • The existence of starlink proves that this is false. Look at most current pitches, they don’t talk about GW-class monsters anymore. There’s absolutely nothing stopping a 20-30kW satellite bus the size of starlink (or I guess up to 100kW? once starship is available - it’s all about payload fairing diameter) from hosting ~1 rack of compute and antennas. The economics may or may not make sense, we’ll have to see.

      There’s very little research work needed to make this happen; it’s all about engineering some satellite buses and having them fly in close formation to get a “data center”. And this group of satellites in sun-synchronous orbit would relay to a comms constellation e.g. starlink itself) and operate as a global scale data center. The heat management and orbital mechanics are all straight forward really.

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    • The area you need in radiators is only half the area you need in solar panels. So it's definitely not a deal breaker.

      Its still very dumb because of economics, logistics, serviceability and more.

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    • SpaceX have presented on this and it's fairly straightforward and they already do it with starlink satellites, just at a larger scale. Sound like you are the uniformed one (or an EDS victim)

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    • Scott Manley, I’d say one of the top pop space youtubers say otherwise. If anything it’s easier in space. On earth most complexity in datacenter is cooling. In space you just radiate it away.

      And SpaceX already proven they can launch sort of datacenters 10k times by launching Starlink (up to 20KW of solar each IIRC).

      FWIW Musk should support Bernie Sanders more. Putting moratoriums on datacenters would make space based ones far more economical.

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Cost.

The economics don't work unless Starship is doing flights in quantity, and it has met or exceeded its cost targets.

Roughly, a single rack plus solar to power it in the $15m+ range just to launch. (This assumes power dissipation is handled via some means that does not require launch to orbit. Also does not include batteries.) Choose your own hardware for the rack, but call it < $5m.

SpaceX earning $15m every time someone launches a $5m rack would be a great business for SpaceX.

Use your own calculator/LLM, but mine is suggesting that the ~$7B Colossus 1 data center in TFA would be around $50B if launched on Falcon 9 (still ignoring cooling and batteries).

(There are obviously a lot of other asterisks. I'm ignoring power storage and heat dissipation. Maintenance probably doesn't matter given 75% of cost is in the launch. Network bandwidth could be a problem considering how DCs are used. Competition - if Company A spends $100B for $25B of actual AI infra, how competitive will they be against Company B who gets $100B for their $100B by spending it in Canada or Mexico, which they can do right now? Etc.)

None of this works without Starship, which has not set a date for its first LEO insertion test yet. Yet the whole point of orbital DCs is nothing on the ground can move fast enough, hence the rush to orbit...which can't really move at all right now.

No, it doesn't make any sense.

In space you get bit flips fairly quickly when using very small transistors. You would have to run stuff on fairly old hardware, which probably makes the whole thing economically inefficient for serious "computation in space".