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Data centers in space makes no sense

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Re: Data centers in space makes no sense

#631
My dark theory is that the goal is to run an AI overlord in space such that it is difficult to counter it from Earth.

If you assume that these people aren't completely stupid, then there is some reason why they want this workload running at great physical distance from all the people down on Earth. It's probably not to protect people on Earth. After all they'll happily deorbit satellites and other junk from orbit and let it rain down on us. And they will happily destroy the environment with all those rocket launches too. Therefore it must be to protect the workload from us.

What is a workload that is something that people would probably want to destroy, and which would also provide enough value to offset the expense to launch and run in space? The only thing that might make sense is a military AI platform. Think something that observes Earth, launches missiles, and controls terrestrial drone armies remotely, with relatively low latency.

It gets built and launched thanks to endless military budget, and once it is up there, running such an AI from space means that effectively the only people who can take it out are nation state level foes who can launch rockets into low earth orbit. And this thing is a satellite, probably part of a network that is watching the Earth all the time. Start building something that looks like a rocket launch site, and the AI will see, then you get hit by a missile or taken out by a drone first before you get a chance to attack the platform.

It sounds like sci-fi, but in the future, if we let it happen, there could absolutely be nearly invulnerable autonomous AI platforms in space overseeing everything, and making decisions, and issuing commands. Of course there could still be a massive solar flare event, or a Kessler syndrome event that releases us all from AI enforced servitude. Anyway, it's a not so fun thought experiment, and let's hope this stays sci-fi, so we can just enjoy a fun Hollywood film about this rather than experiencing it firsthand.

Re: Data centers in space makes no sense

#632
post #235

Earlier quoted context omitted.

It's exiting the 5th best social network and the 10th (or worse) best AI company and selling them to a decent company. It probably increases Elon's share of the combined entity. It delivers on a promise to investors that he will make money for them, even as the underlying businesses are lousy.

I'm confused about the level of conversation here. Can we actually run the math on heat dissipation and feasibility? A Starlink satellite uses about 5K Watts of solar power. It needs to dissipate around that amount (+ the sun power on it) just to operate. There are around 10K starlink satellites already in orbit, which means that the Starlink constellation is already effectively equivalent to a 50 Mega-watt (in a rou…

Square–cube law.

Re: Data centers in space makes no sense

#633

Earlier quoted context omitted.

It's exiting the 5th best social network and the 10th (or worse) best AI company and selling them to a decent company. It probably increases Elon's share of the combined entity. It delivers on a promise to investors that he will make money for them, even as the underlying businesses are lousy.

> 10th (or worse) best AI company You might only care about coding models, but text is dominating the market share right now and Grok is the #2 model for that in arena rankings.

Arena rankings, lol.

Openrouter is a decent proxy for real world use and Grok is currently 8% of the market: https://openrouter.ai/rankings (and is less than 7% of TypeScript programming)

Re: Data centers in space makes no sense

#634

Earlier quoted context omitted.

Resistive heating is a tremendously inefficient way to generate heat. Sometimes it's worth it if you get something useful in exchange (such as full spectrum light in the winter). But it's not all upsides. Heat pumps are magic . They're something like 300% efficient. Each watt generates 3 watts of useful heat.

Its not inefficient if you were creating the heat anyway, its a completely free byproduct.

Yeah. This. Obviously if the objective is just to generate heat only buy a heat pump and not a B200!

Re: Data centers in space makes no sense

#635
post #310

Earlier quoted context omitted.

Simply put no, 50MW is not the typical hyperscaler cloud size. It's not even the typical single datacenter size. A single AI rack consumes 60kW, and there is apparently a single DC that alone consumes 650MW. When Microsoft puts in a DC, the machines are done in units of a "stamp", ie a couple racks together. These aren't scaled by dollar or sqft, but by the MW. And on top of that... That's a bunch of satellites not e…

But the focus on building giant monolithic datacenters comes from the practicalities of ground based construction. There are huge overheads involved with obtaining permits, grid connections, leveling land, pouring concrete foundations, building roads and increasingly often now, building a power plant on site. So it makes sense to amortize these overheads by building massive facilities, which is why they get so big. T…

But why would you?

Space has some huge downsides:

* Everything is being irradiated all the time. Things need to be radiation hardened or shielded.

* Putting even 1kg into space takes vast amounts of energy. A Falcon 9 burns 260 MJ of fuel per kg into LEO. I imagine the embodied energy in the disposable rocket and liquid oxygen make the total number 2-3x that at least.

* Cooling is a nightmare. The side of the satellite in the sun is very hot, while the side facing space is incredibly cold. No fans or heat sinks - all the heat has to be conducted from the electronics and radiated into space.

* Orbit keeping requires continuous effort. You need some sort of hypergolic rocket, which has the nasty effect of coating all your stuff in horrible corrosive chemicals

* You can't fix anything. Even a tiny failure means writing off the entire system.

* Everything has to be able to operate in a vacuum. No electrolytic capacitors for you!

So I guess the question is - why bother? The only benefit I can think of is very short "days" and "nights" - so you don't need as much solar or as big a battery to power the thing. But that benefit is surely outweighed by the fact you have to blast it all into space? Why not just overbuild the solar and batteries on earth?

Re: Data centers in space makes no sense

#637
post #115

I would not assume cooling has been worked out. Space is a vacuum. i.e. The lack-of-a-thing that makes a thermos great at keeping your drink hot. A satellite is, if nothing else, a fantastic thermos. A data center in space would necessarily rely completely on cooling by radiation, unlike a terrestrial data center that can make use of convection and conduction. You can't just pipe heat out into the atmosphere or build…

"A satellite is, if nothing else, a fantastic thermos."

A satellite is quite unlike a thermos in the sense that it is carefully tuned to keep its temperature within a relatively narrow band around room temperature.[1] during all operational phases.

This is because, despite intended space usage, devices and parts are usually tested and qualified for temperature limits around room temperature.

[1] "Room temperature" is actually a technical term meaning 20°C (exceptions in some fields and industries confirm the rule).

Re: Data centers in space makes no sense

#638
post #235

Earlier quoted context omitted.

It's exiting the 5th best social network and the 10th (or worse) best AI company and selling them to a decent company. It probably increases Elon's share of the combined entity. It delivers on a promise to investors that he will make money for them, even as the underlying businesses are lousy.

I'm confused about the level of conversation here. Can we actually run the math on heat dissipation and feasibility? A Starlink satellite uses about 5K Watts of solar power. It needs to dissipate around that amount (+ the sun power on it) just to operate. There are around 10K starlink satellites already in orbit, which means that the Starlink constellation is already effectively equivalent to a 50 Mega-watt (in a rou…

Why would anyone think the unit cost would be competitive with cheap power / land on earth? If that doesn't make sense how could anything else?

Re: Data centers in space makes no sense

#639

It’s less about putting compute in space as occupying that space before anyone else does. For any reason: spying, space warfare, network and communication. First mover advantage, and all.

Bingo. I elaborated on this idea more in my comment: https://news.ycombinator.com/item?id=46884246

People are acting like a space data centre would be running a traditional workload. No, it's probably running a military one, some sort of AI powered modern version of Dead Hand (https://en.wikipedia.org/wiki/Dead_Hand). Autonomous warfare could get real dark, real fast.

Re: Data centers in space makes no sense

#640

Earlier quoted context omitted.

Resistive heating is a tremendously inefficient way to generate heat. Sometimes it's worth it if you get something useful in exchange (such as full spectrum light in the winter). But it's not all upsides. Heat pumps are magic . They're something like 300% efficient. Each watt generates 3 watts of useful heat.

I share your enthusiasm about heat pumps, but I wonder what the efficiency of using waste heat is. Couldn't it be competitive with heat pumps? As it's a waste product, isn't it reasonable to also expect it to be more than 100% efficient?

As a rule of thumb (obviously it varies) you spend about 1% pumping water round a heat network. So your CoP is around 99 if you consider heat truly free. It's actually higher as pump energy largely is converted to friction/heat.
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