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[return to "Datacenters in space aren't going to work"]
1. kevdev+N6[view] [source] 2025-11-29 15:00:24
>>mindra+(OP)
As someone with a similar background to the writer of this post (I did avionics work for NASA before moving into more “traditional” software engineering), this post does a great job at summing up my thoughts on why space-based data centers won’t work. The SEU issues were my first though followed by the thermal concerns, and both are addressed here fantastically.

On the SEU issue I’ll add in that even in LEO you can still get SEUs - the ISS is in LEO and gets SEUs on occasion. There’s also the South Atlantic Anomaly where spacecraft in LEO see a higher number of SEUs.

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2. foobar+lk[view] [source] 2025-11-29 16:45:40
>>kevdev+N6
The only advantage I can come up with is the background temperature being much colder than Earth surface. If you ignored the capex cost to get this launched and running in orbit, could the cooling cost be smaller? Maybe that's the gimmick being used to sell the idea. "Yes it costs more upfront but then the 40% cooling bill goes away... breakeven in X years"
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3. wat100+rk1[view] [source] 2025-11-30 01:39:11
>>foobar+lk
Things on earth also have access to that coldness for about half of each day. How many data centers use radiative cooling into the night sky to supplement their regular cooling? The fact that the answer is “zero” should tell you all you need to know about how useful this is.
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4. foobar+Ct1[view] [source] 2025-11-30 03:17:12
>>wat100+rk1
The atmosphere is in the way even at night, and re-radiates the energy. The effective background temperature is the temperature of the air, not to mention it would only work at night. I think there would need to be like 50-ish acres of radiators for a 50MW datacenter to radiate from 60 to 30C. This would be a lot smaller in space due to bigger temp delta. Either way opex would be much much less than average Earth DC (PUE almost 1 instead of run-of-the mill 1.5 or as low as 1.1 for hyperscalers). But yeah the upfront cost would be immense.
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5. tstrim+1w1[view] [source] 2025-11-30 03:42:50
>>foobar+Ct1
I think you’re ignoring a huge factor in how radiative cooling actually works. I thought the initial question was fine if you hadn’t read the article but understand the downvotes due to doubling down. Think of it this way. Why do thermoses have a vacuum sealed chamber between two walls in order to insulate the contents of the bottle? Because a vacuum is a fucking terrible heat convector. Putting your data center into space in order to cool it is like putting a computer inside of a thermos to cool it. It makes zero fucking sense. There is nowhere for the heat to actually radiate to so it stays inside.
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6. foobar+Rw1[view] [source] 2025-11-30 03:49:54
>>tstrim+1w1
Pardon but this doesn't make sense to me. A 1 m^2 radiator in space can eliminate almost a kilowatt of heat.

>vacuum is a fucking terrible heat convector

Yes we're talking about radiating not convection

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7. kergon+jJ2[view] [source] 2025-11-30 16:39:59
>>foobar+Rw1
> A 1 m^2 radiator in space can eliminate almost a kilowatt of heat.

Assuming that this is the right order of magnitude, a 8MW datacenter discussed upthread would require ~8000 m^2, plus a fancy way of getting the heat there.

A kilowatt is nothing. The workstation on my desk can sustain 1 kW.

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8. mercut+O73[view] [source] 2025-11-30 19:32:42
>>kergon+jJ2
Why are you assuming active heat transfer? Passive is the way to go.
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