Is It Really Impossible To Cool A Datacenter In Space?

It’s very easy to overestimate the difficulty of cooling things in space, unless you actually run the numbers. So please follow along as Scott Manley runs the numbers: < link to this video >. Basically a Starlink v3 satellite has an estimated power budget of 20kW. Add in the heat absorbed from the environment (both directly from sunlight and reflected off of the Earth) and you’ll find that it must reject about 22kW of heat. That’s a fair amount, but at 65°C it can radiate it all away just using it’s own surface area! No radiator required at all! Of course the power density of computer racks has been going up over the years. If you want to reach 100kW per satellite then they will need a modest radiator,…

I went in wanting this to look real bad. But the Scott Manley video alas has sort of convinced me this is pretty feasible, that the energy budget is quite doable. link to this video I do think this is a pretty generous estimate he ends up at. I don't think emissivity is perfectly well dealt with. I don't know if his earth reflection emissivity includes the high energy thermal transfer from particles that do exist on the near vacuum (exosphere be hit, ya'll) or if that matters. But his figures seem ballpark correct & my concerns are at best marginal.

The bit that I wasn't entirely sold on with his analysis was that he was working on 1 satellite per rack link to this video (YouTube auto transcribe) > ... but how do you scale this up right 20 kow used to be enough to power a full rack of computer gear but we're seeing predictions now of 100 kilowatts per rack and that's just one rack in a data center racks right the 48U 19in rack which is you know big and it's just dense with computers how does that fit into a flat satellite well it turns out that like 19in rack is about 50 cm wide it's about 1 m deep per unit and if you've got a 24 1/2 square meter satellite and you take all your one U units and stack them ... One rack per satellite doesn't seem lik…

link to this video "Is It Really Impossible To Cool A Datacenter In Space?" - Scott Manley tl;dr -> not impossible.

I don't see how that would lessen their concerns? Exactly because space is a vacuum, cooling is harder since you can't do convection. The math still checks out though. Scott Manley did a video on it, and the top comment has some corrections: link to this video

He starts with something hot today but viable, 80C. And he goes on to cite and discuss a M*sk tweet about hotter, 97C, and what that density that enables. link to this video and link to this video

it actually is not that impossible, and in fact can be done in a form factor not that different from Starlink satellites: link to this video