Just on a mass basis it falls apart.

Best cost to orbit I am seeing is $1500/kg. A GPU rack is ~1500kg. Let’s imagine you can take a terrestrial data center rack, no scaffolding, solar panels, radiators, radios, propellant, or propulsion. Fly it into orbit, kick it out the airlock, and let it work through magic. That’s $2.2 million to get into position.

Industrial power rates are cheap, say $.10/kwh, but pretend you sign terrible deals, and it costs you $.30/kwh to run and cool a terrestrial GPU rack. A 150kw unit will then be (150x24x365x.3) =$394k/year.

You can operate the terrestrial version for 5.7 years before the two hit parity.

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ben_w a day ago | parent | next [-]

Yes for now; Alphabet is optimistic costs will come down.

They're projecting the learning curve, that the more you do it the cheaper it gets, continues arbitrarily far.

However, they recon it will take SpaceX launching 370,000 tons to LEO to make the costs come down enough to be worth it: https://arxiv.org/pdf/2511.19468

Even my bull case put that 10 years off, which is so far away it lacks relevance just because tech moves so much faster than that timescale; my bear case says that's about 45 years off.

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bushbaba 18 hours ago | parent | next [-]

What about, never? The fuel cost of launching these are immense. I'm not seeing how this is 'cheaper' this doesn't even take into consideration cooling.

BUT it doesn't need to be cheaper for there to be value. Its much harder to shoot down a space GPU farm than a terrestrial one. And its closer to space assets which might want it for targeting during times of war.

	▲	ben_w 18 hours ago \| parent [-]
		> Its much harder to shoot down a space GPU farm than a terrestrial one. Not by as much as you may hope. Getting a rocket up to altitude is much, much easier than getting one to orbital speed: https://what-if.xkcd.com/58/ Hitting satellites in orbit is still hard, but ASAT was demonstrated (albeit the target was designed for the test) by the USSR no later than 1968, and on a more arbitrary (end of life) satellite by the USA no later than 1985: https://en.wikipedia.org/wiki/Anti-satellite_weapon#List_of_... The severity of one single missile depends on the orbital configuration; I'm expecting everyone to declare "we have adjusted our strategic priorities elsewhere" (i.e. "this was a bad idea") well before there's a relevant quantity of them. Given how cheap laser welding has become, I also foresee ground-to-orbit lasers being credible. They still need quite a large aperture and corrective optics, but that's had known solutions for a while now thanks to astronomy. > And its closer to space assets which might want it for targeting during times of war. Not so far as I can see. If you want really low-latency you have edge compute on the weapon systems themselves; otherwise you use the existing satellite comms (e.g. Starlink) to just talk to something hardened outside weapons range.

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hedora a day ago | parent | prev [-]

Even if getting to orbit is free, the numbers don’t work.

5 years is a standard depreciation cycle for hardware, but plenty of machines last longer than that, but these satellites will not. On top of that, power distribution, cooling etc in the data centers is a huge percentage of cost and lasts much longer than 5 years.

If you think you can make a space air conditioner for less than a terrestrial one, I have a bridge to sell you.

	▲	ben_w 18 hours ago \| parent [-]
		Indeed. I've actually got to finish working on that blog post about why this is all a terrible idea; there are many different proposals for how this will work, and they all suck.

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LunaSea a day ago | parent | prev [-]

$1500 / kg seems incredibly low considering that launching a simple 1U cube sat costs roughly $200,000.