Only stating the solar panel - radiator area ratio and not mentioning the actual area that a data center should have, is a sin of omission - and a great one. Also, hand-waving numerous engineering problems just by saying “we’ve solve harder problems before / you can come up with a few designs” is the last thing I want to see in anything that comes up in Hacker News.
Allow me to propose a modest alternative to space data centers, namely mountaintop data centers. This would consist of a container full of servers and GPUs and what else goes into a data center, a wind turbine for power and a communication module (say laser or microwave) for communicating with a base station with a fiber connection. This would be lifted on top of a mountain by a helicopter and bolted in place. Cooling would be provided by heat sinks exposed to the outside air. Some of the nodes could relay traffic from other nodes on remote mountain tops out of sight of the base station.
This scheme has many advantages over space data centers including launch costs, cooling, connection latency, servicability and ease of recycling.
I think we can't rule out the explanation that all the ideas of space data centers could be connected to a desire by some of finding additional applications for rockets that can transport stuff to space.
It is a comment on the absurdity of orbital data centers. Mountaintop data centers sound absurd, but are more feasible and efficient than orbital ones in nearly every aspect.
What advantage does a mountaintop have versus a more accessible earth-based location?
I suspect one of the motivations for space datacenters is to try to stay out of the reach of all jurisdictions so you Musk can start to run his companies as an autonomous state.
Space data centers are physically possible but don't make financial sense. The total cost of an orbital datacenter over five years is at least 2–3x that of a terrestrial one.
But those economics don't matter to SpaceX, because the main purpose of its orbital data centers is to create a use case for Starship. Starship has to fly frequently to iron out the kinks, encounter and fix rare (1/1000) failure situations, and optimize the launch cadence which pushes launch costs down. Plus Starship needs to fly a lot before it's ready for crewed flight. The long-term goal is a Starship optimized for crewed interplanetary travel. Orbital data centers are a payload that bring in some revenue, and provide a reason to launch constantly.
It's the same thing they did with Starlink to make Falcon 9 as reliable and rapidly reusable as it is.
There’s so much data center capacity being built all over the Earth. Thousands of large projects across US / China / Europe / Middle East. It would be astonishing if something that’s never been done before could be so cost-competitive immediately.
Starlink wasn’t the first time LEO communications constellations were attempted. Multiple 1990s projects did it (Iridium, GlobalStar…) and went bankrupt.
It took 30 years to make the concept work. SpaceX investors seem to be assuming the space data center business will be immediately viable.
Based on very specific assumptions: “…the world in which AI demand is so overwhelming as to exceed the already formidable datacenter capacity additions” — but also this same world is one where GPU chip supply is abundant, there just isn’t enough data centers to put them in.
This does not seem like the likeliest scenario to me.
I still don’t see what the advantage is. Of course it’s physically possible to build a datacenter in space, but I can’t imagine land prices being that high that the same data center on earth wouldn’t be cheaper. Even just due to launch costs and the more sophisticated equipment needed for space.
One advantage that does come to mind in light of the Iran war (and the loss of an AWS DC) is difficulty in attacking it, even when it’s directly above foreign territory. I wonder if one of the intended customers will be gov/military? Conjoined spy satellite/DC for some function maybe?
I doubt it'll make sense any time soon, but some arguments I can think of are that solar in space can easily be ~50% more efficient at any moment while also being continuous (enough) in the right orbit.
An even more radical idea is to put nuclear in space which would sidestep all the earthly hurdles (beyond the launch).
The real issue is that the power situation in LEO is still actually terrible! Your solar is a little more performant, but you're plunged into hard shade every 45 minutes.
I think calling solar a little more performant is underselling it. Once you have LEO getting to a better orbit costs relatively little. Getting from LEO to the moon is only like 30% more than getting from ground to LEO.
What I don't understand about building a space data center is that you need radiators to release heat. Otherwise, it will become a space thermos. What's even more incomprehensible is that you would need specialized equipment for space radiation, and GPUs are consumables. To make that profitable, you would need pricing that is many times higher than the cost of a regular data center. I don't understand why there are people who actually fall for this. If I say this, people will call me someone who mocks others' challenges, but it seems like they're saying physical problems can be overcome too easily.
If that's the case, wouldn't it be better to just put it in the desert? Realistically, if noise from calculations is the problem, placing it in a remote area would be more economical.
Whyyyy are we not building distributed data centers under driveways? I want one under my driveway to melt the snow. It can use my power and water hookups if it pays for them.
I think it's a vary valid option to launch swarms of datacenters into space. I think a few decades to a hundred years from now, it will be the norm. Until then, we can find plany of land to do it. Instead a launch, you just need a battery. Much cheaper. All the rest stays the same.
Seems reasonable that the area needed would be less than the solar panels. Since it sould be more efficient to dump heat than collect energy from light.
This isn't terribly practical. Yes, we can deal with heat. The trouble is cost, and dealing with high energy radiation both flipping bits and corrupting the silicon.
Only stating the solar panel - radiator area ratio and not mentioning the actual area that a data center should have, is a sin of omission - and a great one. Also, hand-waving numerous engineering problems just by saying “we’ve solve harder problems before / you can come up with a few designs” is the last thing I want to see in anything that comes up in Hacker News.
Allow me to propose a modest alternative to space data centers, namely mountaintop data centers. This would consist of a container full of servers and GPUs and what else goes into a data center, a wind turbine for power and a communication module (say laser or microwave) for communicating with a base station with a fiber connection. This would be lifted on top of a mountain by a helicopter and bolted in place. Cooling would be provided by heat sinks exposed to the outside air. Some of the nodes could relay traffic from other nodes on remote mountain tops out of sight of the base station.
This scheme has many advantages over space data centers including launch costs, cooling, connection latency, servicability and ease of recycling.
I think we can't rule out the explanation that all the ideas of space data centers could be connected to a desire by some of finding additional applications for rockets that can transport stuff to space.
A better idea is to put them on Mars, so people actually think before they send a stupid question.
What would be accomplished by doing this vs placing them basically anywhere else on earth?
https://en.wikipedia.org/wiki/A_Modest_Proposal
It is a comment on the absurdity of orbital data centers. Mountaintop data centers sound absurd, but are more feasible and efficient than orbital ones in nearly every aspect.
What about the rough weather and difficulty of maintenance, especially in rough weather?
What advantage does a mountaintop have versus a more accessible earth-based location?
I suspect one of the motivations for space datacenters is to try to stay out of the reach of all jurisdictions so you Musk can start to run his companies as an autonomous state.
Space data centers are physically possible but don't make financial sense. The total cost of an orbital datacenter over five years is at least 2–3x that of a terrestrial one.
But those economics don't matter to SpaceX, because the main purpose of its orbital data centers is to create a use case for Starship. Starship has to fly frequently to iron out the kinks, encounter and fix rare (1/1000) failure situations, and optimize the launch cadence which pushes launch costs down. Plus Starship needs to fly a lot before it's ready for crewed flight. The long-term goal is a Starship optimized for crewed interplanetary travel. Orbital data centers are a payload that bring in some revenue, and provide a reason to launch constantly.
It's the same thing they did with Starlink to make Falcon 9 as reliable and rapidly reusable as it is.
2-3x sounds like a very low estimate.
There’s so much data center capacity being built all over the Earth. Thousands of large projects across US / China / Europe / Middle East. It would be astonishing if something that’s never been done before could be so cost-competitive immediately.
Starlink wasn’t the first time LEO communications constellations were attempted. Multiple 1990s projects did it (Iridium, GlobalStar…) and went bankrupt.
It took 30 years to make the concept work. SpaceX investors seem to be assuming the space data center business will be immediately viable.
SemiAnalysis' report on orbital data centers estimated 4x terrestrial costs in 2026, then parity around ~2040.
https://newsletter.semianalysis.com/p/to-boldly-go-the-case-...
Based on very specific assumptions: “…the world in which AI demand is so overwhelming as to exceed the already formidable datacenter capacity additions” — but also this same world is one where GPU chip supply is abundant, there just isn’t enough data centers to put them in.
This does not seem like the likeliest scenario to me.
My guess is: it just sounds cool.
Like the cybertruck
There was also this[1] analysis in late 2025 from a former NASA engineer that looked at the impracticability.
[1] https://taranis.ie/datacenters-in-space-are-a-terrible-horri...
I still don’t see what the advantage is. Of course it’s physically possible to build a datacenter in space, but I can’t imagine land prices being that high that the same data center on earth wouldn’t be cheaper. Even just due to launch costs and the more sophisticated equipment needed for space.
One advantage that does come to mind in light of the Iran war (and the loss of an AWS DC) is difficulty in attacking it, even when it’s directly above foreign territory. I wonder if one of the intended customers will be gov/military? Conjoined spy satellite/DC for some function maybe?
I doubt it'll make sense any time soon, but some arguments I can think of are that solar in space can easily be ~50% more efficient at any moment while also being continuous (enough) in the right orbit.
An even more radical idea is to put nuclear in space which would sidestep all the earthly hurdles (beyond the launch).
The real issue is that the power situation in LEO is still actually terrible! Your solar is a little more performant, but you're plunged into hard shade every 45 minutes.
I think calling solar a little more performant is underselling it. Once you have LEO getting to a better orbit costs relatively little. Getting from LEO to the moon is only like 30% more than getting from ground to LEO.
True, but lifting the fuel to power that “small” orbital boost is unintuitively expensive
What I don't understand about building a space data center is that you need radiators to release heat. Otherwise, it will become a space thermos. What's even more incomprehensible is that you would need specialized equipment for space radiation, and GPUs are consumables. To make that profitable, you would need pricing that is many times higher than the cost of a regular data center. I don't understand why there are people who actually fall for this. If I say this, people will call me someone who mocks others' challenges, but it seems like they're saying physical problems can be overcome too easily.
I have the feeling that the only reason that might actually be done is to escape from any kind of jurisdiction. In space no one can hear you compute.
If that's the case, wouldn't it be better to just put it in the desert? Realistically, if noise from calculations is the problem, placing it in a remote area would be more economical.
The desert is still under someone’s jurisdiction. Perhaps the best on-planet comparison is creating a man made island in the middle of the ocean.
Whyyyy are we not building distributed data centers under driveways? I want one under my driveway to melt the snow. It can use my power and water hookups if it pays for them.
Aren't some bitcoin farms used for heating in some places, like agriculture in greenhouses?
I think it's a vary valid option to launch swarms of datacenters into space. I think a few decades to a hundred years from now, it will be the norm. Until then, we can find plany of land to do it. Instead a launch, you just need a battery. Much cheaper. All the rest stays the same.
Seems reasonable that the area needed would be less than the solar panels. Since it sould be more efficient to dump heat than collect energy from light.
This isn't terribly practical. Yes, we can deal with heat. The trouble is cost, and dealing with high energy radiation both flipping bits and corrupting the silicon.
I'll add another to the list of relevant links in the comments: https://spectrum.ieee.org/orbital-data-centers-heat
See also:
https://www.youtube.com/watch?v=FlQYU3m1e80
And also: https://www.youtube.com/watch?v=JAcR7kqOb3o
See also https://andrewmccalip.com/space-datacenters with some models and numbers you can play with.