Retail cost per watt for terrestrial panel: under 45c
Manufacturing cost per watt of space grade solar panel: up to $450
Annual performance degradation of terrestrial solar panel: under 0.5%
That of space-grade solar panel: up to 2%
Life span of terrestrial panel: about 2x that of space panel.
Total difference in cost per watt feeding a DC load in space vs on land: about x400
And that's ignoring launch costs. It makes absolutely zero sense. And given the scale of production and investment in manufacturing, terrestrial is likely to stretch even further ahead in the cost stakes.
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.
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: <a href="https://arxiv.org/pdf/2511.19468" rel="nofollow">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.
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.
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: <a href="https://en.wikipedia.org/wiki/Anti-satellite_weapon#List_of_destructive_anti-satellite_tests" rel="nofollow">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.
derriz · · focus · HN ↗
Capacity factor of terrestrial solar panel: 23%
Retail cost per watt for terrestrial panel: under 45c
Manufacturing cost per watt of space grade solar panel: up to $450
Annual performance degradation of terrestrial solar panel: under 0.5%
That of space-grade solar panel: up to 2%
Life span of terrestrial panel: about 2x that of space panel.
Total difference in cost per watt feeding a DC load in space vs on land: about x400
And that's ignoring launch costs. It makes absolutely zero sense. And given the scale of production and investment in manufacturing, terrestrial is likely to stretch even further ahead in the cost stakes.
0cf8612b2e1e · · focus · HN ↗
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.
ben_w · · focus · HN ↗
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: <a href="https://arxiv.org/pdf/2511.19468" rel="nofollow">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.
bushbaba · · focus · HN ↗
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 · · focus · HN ↗
Not by as much as you may hope. Getting a rocket up to altitude is much, much easier than getting one to orbital speed:
<a href="https://what-if.xkcd.com/58/" rel="nofollow">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: <a href="https://en.wikipedia.org/wiki/Anti-satellite_weapon#List_of_destructive_anti-satellite_tests" rel="nofollow">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.