Comment by ceejayoz
3 months ago
> In the right orbit, a solar panel can be up to 8 times more productive than on earth, and produce power nearly continuously, reducing the need for batteries.
Sure. Now do cooling. That this isn't in the "key challenges" section makes this pretty non-serious.
A surprising amount of the ISS is dedicated to this, and they aren't running a GPU farm. https://en.wikipedia.org/wiki/External_Active_Thermal_Contro...
Barely mentioning thermal management seems at odds with the X principle of "Don’t use up all your resources on the easy stuff": https://blog.x.company/tackle-the-monkey-first-90fd6223e04d
This is absolutely the first thing I looked for too. They just barely mentioned thermal management at all. Maybe they know something I don't, but I know from past posts here that many people share this concern. Very strange that they didn't go there, or maybe they didn't go there because they have no solution and this is just greenwashing for the costs of AI.
No, they just literally assumed their design fits withing the operational envelope of a conventional satellite - the paper (which no one read, apparently) literally says their system design "assumes a relatively conventional, discrete compute payload, satellite bus, thermal radiator, and solar panel designs".
This is not the 1960s. Today, if you have an idea for doing something in space, you can start by scoping out the details of your mission plan and payload requirements, and then see if you can solve it with parts off a catalogue.
(Of course there's million issues that will crop up when actually designing and building the spacecraft, but that's too low level for this kind of paper, which just notes that (the authors believe) the platform requirements fall close enough to existing systems to not be worth belaboring.)
Since this isn't the 1960s, and it's Google with their resources, maybe they'd go for some superconducting logic based on Josephson Junctions, like RSFQ? In parts, at least?
So they wouldn't have the burden of cooling it down first, like on earth? Instead being able to rely on the cold out there, as long as it stays in the shadow, or is otherwise isolated from sources of heat? Again, with less mess to deal with, like on earth? Since it's fucking cold up there already? And depending on the ratio of superconducting logic vs. conventional CMOS or whatever, less need to cool that, because superconducting stuff emits less heat, and the remaining 'smartphony' stuff is easy to deal with?
If I had those resorces at hand, I'd try.
2 replies →
How much are you ready to bet against Elon's plans to scale up Starlink v3 for GPUs? Starlink v3 already has a 60M length solar array, so they're already solving dissipation for that size. Assume linear scaling to many thousands of modules.
From https://x.com/elonmusk/status/1984249048107508061:
"Simply scaling up Starlink V3 satellites, which have high speed laser links would work. SpaceX will be doing this."
From https://x.com/elonmusk/status/1984868748378157312:
"Starship could deliver 100GW/year to high Earth orbit within 4 to 5 years if we can solve the other parts of the equation. 100TW/year is possible from a lunar base producing solar-powered AI satellites locally and accelerating them to escape velocity with a mass driver."
> How much are you ready to bet against Elon's plans to scale up Starlink v3 for GPUs?
I'm sure they'll be ready right after the androids and the robotaxi and the autonomous LA-NYC summoning.
> Starlink v3 already has a 60M length solar array, so they're already solving dissipation for that size.
Starlink v3 doesn't exist yet. They're renders at this point. Full-sized v2s haven't even flown yet, just mass simulators.
https://en.wikipedia.org/wiki/Starlink#Satellite_revisions
I love your enthusiasm
Please post where you are creating the bet. You should make a lot of money from it
5 replies →
Cooling area seems similar to generation area, so maybe less than a key challenge?
GPT says 1000 W at 50 C takes about 3 m^2 to radiate (edge on to Earth and Sun), and generating that 1000 W takes about... 3 m^2 of solar panel. The panel needs its backside radiator clear to keep itself coolish (~100 C), so it does need to be a separate surface. Spreading a 1000 W point source across a 3 m^2 tile (or half that if two-sided?) is perhaps not scary, even with weight constraints?
Hmm, from an order-of-magnitude perspective, it looks like an (L shaped) Starlink v2 sat has 100 m^2 of panel, low 10 kW draw, and a low 100 m^2 body area. And there are 10 k of them. So want something bigger. A 100 x 100 m sheet might get you 10 sats per 100,000 GPU data center.
Regards ISS, ISS has its big self, basking in the sunlight, needing to be cooled. Versus "the only thing sun-lit is panel".
Just run your AI calculations on your favorite Cryoarithmetic Engine, no problem.
Point solar panels away from the Sun and they work as rudimentary radiators :).
More seriously though, the paper itself touches on cooling and radiators. Not much, but that's reasonable - cooling isn't rocket science :), it's a solved problem. Talking about it here makes as much sense as taking about basic attitude control. Cooling the satellite and pointing it in the right direction are solved problems. They're important to detail in full system design, but not interesting enough for a paper that's about "data centers, but in space!".
Cooling at this scale in space is very much not a solved problem. Some individual datacenter racks use more power than the entire ISS cooling system can handle.
It's solved on Earth because we have relatively easy (and relatively scalable) ways of getting rid of it - ventilation and water.
No, I meant in space. This is a solved engineering problem for this kind of missions. Whether they can make it work within the power and budget constraints is the actual challenge, but that's economics. No new tech is needed.
14 replies →
The article doesn’t even have the word “heat” in it.
The linked paper does.
that's easy - just put everything right behind the solar panels /s