As someone with a similar background to the writer of this post (I did avionics work for NASA before moving into more “traditional” software engineering), this post does a great job at summing up my thoughts on why space-based data centers won’t work. The SEU issues were my first though followed by the thermal concerns, and both are addressed here fantastically.
On the SEU issue I’ll add in that even in LEO you can still get SEUs - the ISS is in LEO and gets SEUs on occasion. There’s also the South Atlantic Anomaly where spacecraft in LEO see a higher number of SEUs.
The only advantage I can come up with is the background temperature being much colder than Earth surface. If you ignored the capex cost to get this launched and running in orbit, could the cooling cost be smaller? Maybe that's the gimmick being used to sell the idea. "Yes it costs more upfront but then the 40% cooling bill goes away... breakeven in X years"
But the cooling cost wouldn’t be smaller. There’s no good way to eliminate the waste heat into space. It’s actually far far harder to radiate the waste heat into space directly than it would be to get rid of it on Earth.
Shhh, I'm begging people, if brain-dead VCs want to waste their money on things that are obviously farcical (and not actively destructive), please let them and stop doing their due diligence for them. The alternative is that they turn their impossible amounts of capital towards societally-destructive acts like buying up all the real estate in the world and turning us back into land-slaves.
So many ideas involving AI just seems to be built off of sci-fi (not in a good way), including this one. Like sci-fi, there are little practical considerations made.
Sci-fi isn't even really about the tech. It's about what happens to us, humans, when the tech changes in dramatic ways. Sci-fi authors dream up types of technology that create new social orders, factions, rifts, types of interpersonal relationships, types of fascism, where the unforseen consequences of human ingenuity hoist us upon our collective petard.
But these baffoons only see the blinky shiney and completely miss the point of the stories. They have a child's view of SF the way that men in their teens and 20d thought they were supposed to be like Tyler Durden.
I don't agree with the logic that "something is hard/can't be done right now" is equivalent to "this is a terrible idea and won't work."
There are dozens of companies solving each problem outlined here; if we never attempt the 'hard' thing we will never progress. The author could have easily taken a tone of 'these are all the things that are hard that we will need to solve first' but actively chose to take the 'catastrophically bad idea' angle.
From a more positive angle, I'm a big fan of Northwood Space and they're tackling the 'Communications' problem outlined in this article pretty well.
It's not that it's hard, it's that it's stupid - it's based on a misunderstanding of the physics involved which completely negates any of the benefits.
It's the opposite of engineering, where you understand a problem space and then try to determine the optimal solution given the constraints. This starts with an assumption that the solution is correct, and then tries to engineer fixes to gaps in the solution, without ever reevaluating the solution choice.
That's not the argument though. The argument is "it can be done, the methods to do it are known, but the claims about space being an optimal location to locate our AI datacenters are false and the tradeoffs and unit economics of doing it makes no sense compared with building a data centre on earth somewhere with power and water, preferably not too hot.
(TLDR: the actual use cases for datacentres in space rely on the exact opposite assumption from visions of space clouds for LLMs: most of space is far away and has data transmission latency and throughput issues so you want to do a certain amount of processing for your space data collection and infrastructure and autonomous systems on the edge)
What reason is there to build datacenters in space, though? Literally, what limitation do we face in building datacenters on Earth would building them in space improve?
Always remember the magic words: dual use technology. The people pushing these aren't saying to you that they want to build data centers in space because conventional data centers are at huge risk of getting bombed by foreign nations or eventually getting smashed by angry mobs. But you can bet they're saying that to the people with the dual-use technology money bag. Or even better, let them draw that conclusion themselves, to make them think it was their idea - that also has the advantage of deniability when it turns out data centers in space was a terrible solution to the problem.
At this point I wouldn't be surprised if a non zero number of pitch meetings start with, "in order to not disrupt your life too much as the mobs of the starving and displaced beat down your door"
It is far easier to build them at remote places and bunkers (or both). Even at the middle of the ocean will make more sense and provide better cooling (See Microsoft attempt at that).
Only legit thing I can see this being used for is redundant archival storage or just general research into hardening equipment to radiation or micrograv (eg for liquid cooling). But anything that generates significant amounts of heat seems like it'd be a huge problem.
Then again there's lots of space in space, perhaps it's possible to isolate racks/aisles into their own individual satellites, each with massive radiant heatshedding panels? It's an interesting problem space that would be very interesting to try to solve, but ultimately I agree with OP when we come back around to "But, why?" Research for the sake of research is a valid answer, but "For prod"? I don't see it.
The one thing that space has going for itself is space. You could have way bigger datacenters than on Earth and just leave them there, assuming Starship makes it cheap enough to get them there. I think it would maybe make sense if 2 things:
- We are sure we will need a lot of gpus for the next 30-40 years.
- We can make the solar panels + cooling + GPUs have a great life expectancy, so that we can just leave them up there and accumulate them.
Latency wise it seems okay for llm training to put them higher than Starlink to make them last longer and avoid decelerating because of the atmosphere. And for inference, well, if the infra can be amortized over decades than it might make the inference price cheap enough to endure additional latencies.
Concerning communication, SpaceX I think already has inter-starlinks laser comms, at least a prototype.
You can't just "leave them there" though. They orbit at high speed, which effectively means they actually take up vastly more space, with other objects orbiting at high speed intersecting those orbits. The orbits that are most useful are relatively narrow bands shared with a lot of other satellites and a fair amount of debris, and orbits tend to decay over time (which is a problem if you're in low earth orbit because they'll decay all the way into the atmosphere, and a problem if you're in geostationary orbit because you'll lose the advantage of stationary bit for maintaining comms links). This is a solvable problem with propulsion, but that entails bringing the propellant with you and end-of-life (or an expensive refuelling operation) when it runs out. The cost of maintaining real estate space is vastly more than out right owning land.
Similarly, making stuff have a great life expectancy is much more expensive than having it optimized for cost and operational requirements instead but stored somewhere you can replace individual components as and when they fail, and it's also much easier to maximise life expectancy somewhere bombarded by considerably less radiation.
There is lots and lots and lots of space on Earth where hardly anyone is living. Cheap rural areas can support extremely large datacenters, limited only by availability of utilities and workers.
We also have to build a lot more solar and nuclear in addition of the datacenters themselves, which we need to do anyway but it would compound the land we use for energy production.
Yet a colossal number of servers on satellites would require the same energy-production facilities to be shipped into orbit (and to receive regular maintainence in orbit whenever they fail), which requires loads of land for launch facilities as well as processing for fuel and other consumable resources. Solar might be somewhat more efficient, but not nearly so much so as to make up for the added difficulty in cooling. One could maybe postulate asteroid mining and space manufacturing to reduce the total delta-V requirement per satellite-year, but missions to asteroids have fuel requirements of their own.
If anything, I'd expect large-scale Mars datacenters before large-scale space datacenters, if we can find viable resources there.
It makes sense, I would be curious to see the price computations done by the different space GPUs startups and Big Tech, I wonder how they are getting a cheaper cost, or maybe it is marketing.
Space is not much of an issue for datacenters. For one thing, compute density is growing; it's not uncommon for a datacenter to be capacity limited by power and/or cooling before space becomes an issue; especially for older datacenters.
There are plenty of data centers in urban centers; most major internet exchanges have their core in a skyscraper in a significant downtown, and there will almost always be several floors of colospace surrounding that, and typically in neighboring buildings as well. But when that is too expensive, it's almost always the case that there are satellite DCs in the surrounding suburbs. Running fiber out to the warehouse district isn't too expensive, especially compared to putting things in orbit; and terrestrial power delivery has got to be a lot less expensive and more reliable too.
According to a quick search, StarLink has one 100g space laser on equipped satellites; that's peanuts for terrestrial equipment.
Starship is on a fast track to failure. It is not a cheaper way to get to orbit and will never get there at the current pace. And even if it were, it would not make getting to orbit so cheap that it would somehow make it economically viable to put a datacenter there.
You still have to build the GPUs, etc for the datacenter whether it’s on Earth or in orbit. But to put it in space you also need massive new cooling solution, radiation shielding, orbital boosting, data transmission bandwidth, and you have to launch all of that.
And then, there are zero benefits to putting a datacenter in space over building it on Earth. So why would you want to add all that extra expense?
Falcon heavy is only $1,500/kg to LEO. This rate is considerably undercut here on Earth by me, a weasley little nerd, who will move a kilogram in exchange for a pat on the head (if your praise is desirable) or up to tens of dollars (if it isn't).
Launching a datacenter like that carries an absurd cost even with Starship type launchers. Unless TSMC moves its production to LEO it's a joke of a proposal.
Underwater [0] is the obvious choice for both space and cooling. Seal the thing and chuck it next to an internet backbone cable.
> More than half the world’s population lives within 120 miles of the coast. By putting datacenters underwater near coastal cities, data would have a short distance to travel
> Among the components crated up and sent to Redmond are a handful of failed servers and related cables. The researchers think this hardware will help them understand why the servers in the underwater datacenter are eight times more reliable than those on land.
Google’s paper [1] does talk about radiation hardening and thermal management. Maybe their ideas are naive and it’s a bad paper? I’m not an expert so I couldn’t tell from a brief skim.
It does sound to me like other concepts that Google has explored and shelved, like building data centers out of shipping container sized units and building data centers underwater.
It didn't work, it was an utterly terrible idea and they are almost certainly lying about the sentiment that it "worked". No ability to perform maintenance is a complete nonstarter. Communications and power is a nightmare to get right. The thermal management story sucks - just because you have metal touching water doesn't mean you have effective radiation of heat. Actually scaling it up is nearly impossible because you need thicker and more expensive vessels the bigger it gets. The problems go on and on.
If you think about it, all the existing data centers are in space already. They're just attached to a big ball of rock, water, and air that acts as a support system for them, simplifying cooling and radiation protection.
If humans are going to expand beyond the Earth, we'll certainly need to get much better at building and maintaining things in space, but we don't need to put data centers in space just to support people stuck on the ground.
I asked Google for more information about AI datacenter in space. This was the first sentence, 'AI data centers are being developed in space to handle the massive energy demands of AI, using solar power and the vacuum of space for cooling.'
> After laughing at "the vacuum of space for cooling" I closed the page because there was nothing serious there. Basic high school physics student would be laughing at that sentence.
I tried Google and it pointed me to a ycombinator video about Starcloud https://youtu.be/hKw6cRKcqzY They launched a satellite with one H100 in on Nov 2nd.
>I mean, when you tell people that within 10 years it could be the case that most new data
centers are being built in space, that
sounds wacky to a lot of people, but not
to YC. (8:00)
I absolutely don't understand how vacuum works. So I absolutely cannot model how a Dewar flask which has 15 billion light year thickness between the inner and outer wall - a wall that is very close to absolute zero will behave.
Heat conduction requires a medium, but radiation works perfectly fine in a vacuum. Otherwise the Sun wouldn't be able to heat up the Earth. The problem for spacecraft is that you're limited by how much IR radiation is passively emitted from your heat sinks, you can't actively expel heat any faster.
Hot objects emit infrared light no matter the conditions. The hotter the object, the more light it throws off. By radiating this light away, thermal energy is necessarily consumed and transformed into light. It's kind of wild actually
There is some medium in low Earth orbit. Not all vacuums are created equal. However, LEO vacuum is still very, very sparse compared to the air and water we use for cooling systems.
I wonder if there should be levels of "in theory". Yes theoretically black body radiation exist and well stuff cools down to near background radiation via that. But the next level is theoretical implementation. Like actually moving around the heat from source and so on. Maybe this could be the spherical cow step...
Reminds me of the hyperloop. Well yes, things in vacuum tube go fast. Now does enough things go fast to make any sense...
I man you totally can radiate excess heat energy on earth, but your comment implies that the parents idea of radiating off excess "energy", specifically HEAT energy in space is possible, which it isn't.
You can radiate excess energy for sure, but you'd first have to convert it away from heat energy into light or radio waves or similar.
I don't think we even have that tech at this point in time, and neither do we have any concepts how this could be done in theory.
I see, yes. I was thinking more along the lines of radiating heat energy at a scale that's useable for cooling, not at the more extreme levels of over 500°C/1k fahrenheit
That's technically correct I guess, at some temperature threshold it becomes possible to bleed some fractions of energy while the material is exceedingly hot.
Yes. And it's an absolutely terrible way to get rid of heat. Cooling in space is a major problem because the actually effective ways to do it are not available.
There's no air and negligible thermal medium to convect heat away. The only way heat leaves is through convection from the extremely sparse atmosphere in low Earth orbit (less than a single atom per cubic millimeter) and through thermal radiation. Both of which are much, much slower than convection with water or air.
Space stations need enormous radiator panels to dissipate the heat from the onboard computers and the body heat of a few humans. Cooling an entire data center would require utterly colossal radiator panels.
If you would kindly consult your Human HR Universal Handbook (2025 Edition) and navigate to section 226.8.2F, you’ll be gently reminded that it’s the responsibility of any and all employees to train their replacements.
Please consult your Human HR Universal Handbook (2025 Edition) on how to request a new copy of the Human HR Universal Handbook (2025 Edition). I believe it's in Volume III Section 9912.64.1 or thereabouts.
Typically, these sorts of things are located in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying ‘Beware of the Leopard'.
I agree with most of this post and think the problems are harder than the proponents are making them seem.
But, 1) literally the smartest people and AI in the world will be working on this and 2) man I want to see us get to a type 2 civilisation bad.
The layout of this blog post is also very interesting, it presents a bunch of very hard items to solve and funny enough the last has been solved recently with starlink. So we can approach this problem, it requires great engineering but it’s possible. Maybe it’s as complicated as CERNs LHC but we have one of those.
Next up then is the strong why? When you’re in space, if you set the cost of electricity to zero, the equation gets massively skewed.
Thermal is the biggest challenge but if you have unlimited electricity, lots of stuff becomes possible. Fluorinert cooling, piezoelectric pumps and dual/multi stage cooling loops with step ups. We can put liquid cooling with piezos on phones now, so that technology is moving in the right direction.
For a thought experiment, if launch costs were $0/kg, would this be possible? If the answers yes, then at some point above $0/kg it becomes uneconomical, the challenge is then to beat that number.
None of these problems seem intractable, just really hard and probably not being solved soon, but one has to start somewhere... so at least the billionaires will fund some scientists and engineers who will do that work?
Risky/untried things aren't dumb because they're hard, they're dumb when they're more expensive/harder than cheaper/easier alternatives that already exist that do the same thing.
What about on the Moon? My understanding is that heat is the killer. There you could sink pipes into the surface and use that as a heat sink. There are “peaks of eternal light” near the poles where you could get 24/7 solar power.
Latency becomes high but you send large batches of work.
Probably not at all economical compared to anywhere on Earth but the physics work better than orbit where you need giant heat sinks.
Not if you bury it in regolith. That’s an idea for a Lunar base too. The design is called “Hobbit holes.” Bury the occupied structures in piles of basically any local mass you can bury them in.
It’s another huge problem for orbit though. Shielding would add a ton of mass and destroy the economics.
I had this same thought and mentioned it on an ArsTechnica forum. There was reply that suggested that lunar regolith wouldn't be a good heat sink and a bit of googling makes me think this is probably true.
That said anything has to be better then almost literally nothing so I'm still holding out for datacenters on the moon.
You'd have most of the problems of building in space, an abrasive quasi-atmosphere of dust, half a month of darkness every month, and not as good of a heat sink as the Earth's atmosphere.
Regardless of how terrible an idea it is, I wouldn't mind some billionaires funding R&D that advances the state of the art in thermal management in space.
One thing I haven't seen talked about at all: how quickly would space heat up?
I presume Earth's gravity largely keeps the exosphere it has around it. With some modest fractional % lost year by year. There is a colossal vast volume out there! But given that there's so little matter up in space, what if any temperature rise would we expect from say a constant 1TW of heat being added?
"Mind-bogglingly poorly thought out to the degree of a cynical money-grubbing scheme worthy of the finest cambodian slave camp" was taken and is disrespectful to the hard work and education of said slave camp's operators.
Additionally, their distributions were different. People who read Dijkstra circa 1968 started using the phrase in their own publications within a decade, whereas people who read Viorst (or had it read to them) in 1972 and following years had at least a few decades of further delay before publishing anything using the corresponding phrase.
Except you don’t build a data center, you add a GPU to an individual starlink node. If you can do that a couple hundred or thousand times you’ve got a lot of compute in space. The next question is how would you redesign compute around your distributed power and cooling profiles?
The article doesn’t talk about the actual engineering challenges. (Such as scaling down the radiative cooling design, matching compute node to the maximum feasible power profile, etc)
I’m not arguing it’ll be easy or will ultimately work, but articles like this are unhelpful because they don’t address the fundamental insight being proposed.
As someone with a similar background to the writer of this post (I did avionics work for NASA before moving into more “traditional” software engineering), this post does a great job at summing up my thoughts on why space-based data centers won’t work. The SEU issues were my first though followed by the thermal concerns, and both are addressed here fantastically.
On the SEU issue I’ll add in that even in LEO you can still get SEUs - the ISS is in LEO and gets SEUs on occasion. There’s also the South Atlantic Anomaly where spacecraft in LEO see a higher number of SEUs.
The only advantage I can come up with is the background temperature being much colder than Earth surface. If you ignored the capex cost to get this launched and running in orbit, could the cooling cost be smaller? Maybe that's the gimmick being used to sell the idea. "Yes it costs more upfront but then the 40% cooling bill goes away... breakeven in X years"
Cooling is more difficult in space, yes it's colder, but transferring heat is more difficult.
But the cooling cost wouldn’t be smaller. There’s no good way to eliminate the waste heat into space. It’s actually far far harder to radiate the waste heat into space directly than it would be to get rid of it on Earth.
Which is why vacuum flask for hot/cold drinks are a thing/work. Empty space is a pretty good insulator as it turns out.
It’s a little worrying so many don’t know that.
Breakeven in X years probably makes sense for storage (slow depreciation), not GPUs (depreciates in like 4 years)
Shhh, I'm begging people, if brain-dead VCs want to waste their money on things that are obviously farcical (and not actively destructive), please let them and stop doing their due diligence for them. The alternative is that they turn their impossible amounts of capital towards societally-destructive acts like buying up all the real estate in the world and turning us back into land-slaves.
So many ideas involving AI just seems to be built off of sci-fi (not in a good way), including this one. Like sci-fi, there are little practical considerations made.
Sci-fi isn't even really about the tech. It's about what happens to us, humans, when the tech changes in dramatic ways. Sci-fi authors dream up types of technology that create new social orders, factions, rifts, types of interpersonal relationships, types of fascism, where the unforseen consequences of human ingenuity hoist us upon our collective petard.
But these baffoons only see the blinky shiney and completely miss the point of the stories. They have a child's view of SF the way that men in their teens and 20d thought they were supposed to be like Tyler Durden.
I don't agree with the logic that "something is hard/can't be done right now" is equivalent to "this is a terrible idea and won't work."
There are dozens of companies solving each problem outlined here; if we never attempt the 'hard' thing we will never progress. The author could have easily taken a tone of 'these are all the things that are hard that we will need to solve first' but actively chose to take the 'catastrophically bad idea' angle.
From a more positive angle, I'm a big fan of Northwood Space and they're tackling the 'Communications' problem outlined in this article pretty well.
It's not that it's hard, it's that it's stupid - it's based on a misunderstanding of the physics involved which completely negates any of the benefits.
It's the opposite of engineering, where you understand a problem space and then try to determine the optimal solution given the constraints. This starts with an assumption that the solution is correct, and then tries to engineer fixes to gaps in the solution, without ever reevaluating the solution choice.
From: https://engine.xyz/resident-companies/northwood-space
> Unlike traditional parabolic dish antennas, our phased array antenna can connect with multiple satellites simultaneously.
if that's how they plan to reach more than 1Gbps, then that's not 100Gbps per satellite, that's 100 for a collection of satellites.
Starlink is about 100Mbps. That's 1000x times less than 100Gbps
That's not the argument though. The argument is "it can be done, the methods to do it are known, but the claims about space being an optimal location to locate our AI datacenters are false and the tradeoffs and unit economics of doing it makes no sense compared with building a data centre on earth somewhere with power and water, preferably not too hot.
But for a more nuanced and optimistic take, this one is good and highlights all the same issues and more https://www.peraspera.us/realities-of-space-based-compute/
(TLDR: the actual use cases for datacentres in space rely on the exact opposite assumption from visions of space clouds for LLMs: most of space is far away and has data transmission latency and throughput issues so you want to do a certain amount of processing for your space data collection and infrastructure and autonomous systems on the edge)
What reason is there to build datacenters in space, though? Literally, what limitation do we face in building datacenters on Earth would building them in space improve?
Cooling data centers in space effectively can't be done right now … or ever.
Always remember the magic words: dual use technology. The people pushing these aren't saying to you that they want to build data centers in space because conventional data centers are at huge risk of getting bombed by foreign nations or eventually getting smashed by angry mobs. But you can bet they're saying that to the people with the dual-use technology money bag. Or even better, let them draw that conclusion themselves, to make them think it was their idea - that also has the advantage of deniability when it turns out data centers in space was a terrible solution to the problem.
At this point I wouldn't be surprised if a non zero number of pitch meetings start with, "in order to not disrupt your life too much as the mobs of the starving and displaced beat down your door"
It is far easier to build them at remote places and bunkers (or both). Even at the middle of the ocean will make more sense and provide better cooling (See Microsoft attempt at that).
Not exactly at the middle but close to shore is pretty good too, a lot of solar and wind around to feed the compute.
One of these projects is bonkers IMO: china-has-an-underwater-data-center-the-us-will-build-them-in-space
https://www.forbes.com/sites/suwannagauntlett/2025/10/20/chi...
The reason why we don't see satellite-targeting missiles is not because the problem is hard. All relevant actors are capable of that.
What makes an orbital facility at less risk of getting bombed?
Only legit thing I can see this being used for is redundant archival storage or just general research into hardening equipment to radiation or micrograv (eg for liquid cooling). But anything that generates significant amounts of heat seems like it'd be a huge problem.
Then again there's lots of space in space, perhaps it's possible to isolate racks/aisles into their own individual satellites, each with massive radiant heatshedding panels? It's an interesting problem space that would be very interesting to try to solve, but ultimately I agree with OP when we come back around to "But, why?" Research for the sake of research is a valid answer, but "For prod"? I don't see it.
The one thing that space has going for itself is space. You could have way bigger datacenters than on Earth and just leave them there, assuming Starship makes it cheap enough to get them there. I think it would maybe make sense if 2 things: - We are sure we will need a lot of gpus for the next 30-40 years. - We can make the solar panels + cooling + GPUs have a great life expectancy, so that we can just leave them up there and accumulate them.
Latency wise it seems okay for llm training to put them higher than Starlink to make them last longer and avoid decelerating because of the atmosphere. And for inference, well, if the infra can be amortized over decades than it might make the inference price cheap enough to endure additional latencies.
Concerning communication, SpaceX I think already has inter-starlinks laser comms, at least a prototype.
You can't just "leave them there" though. They orbit at high speed, which effectively means they actually take up vastly more space, with other objects orbiting at high speed intersecting those orbits. The orbits that are most useful are relatively narrow bands shared with a lot of other satellites and a fair amount of debris, and orbits tend to decay over time (which is a problem if you're in low earth orbit because they'll decay all the way into the atmosphere, and a problem if you're in geostationary orbit because you'll lose the advantage of stationary bit for maintaining comms links). This is a solvable problem with propulsion, but that entails bringing the propellant with you and end-of-life (or an expensive refuelling operation) when it runs out. The cost of maintaining real estate space is vastly more than out right owning land.
Similarly, making stuff have a great life expectancy is much more expensive than having it optimized for cost and operational requirements instead but stored somewhere you can replace individual components as and when they fail, and it's also much easier to maximise life expectancy somewhere bombarded by considerably less radiation.
There is lots and lots and lots of space on Earth where hardly anyone is living. Cheap rural areas can support extremely large datacenters, limited only by availability of utilities and workers.
We also have to build a lot more solar and nuclear in addition of the datacenters themselves, which we need to do anyway but it would compound the land we use for energy production.
Yet a colossal number of servers on satellites would require the same energy-production facilities to be shipped into orbit (and to receive regular maintainence in orbit whenever they fail), which requires loads of land for launch facilities as well as processing for fuel and other consumable resources. Solar might be somewhat more efficient, but not nearly so much so as to make up for the added difficulty in cooling. One could maybe postulate asteroid mining and space manufacturing to reduce the total delta-V requirement per satellite-year, but missions to asteroids have fuel requirements of their own.
If anything, I'd expect large-scale Mars datacenters before large-scale space datacenters, if we can find viable resources there.
It makes sense, I would be curious to see the price computations done by the different space GPUs startups and Big Tech, I wonder how they are getting a cheaper cost, or maybe it is marketing.
Space is not much of an issue for datacenters. For one thing, compute density is growing; it's not uncommon for a datacenter to be capacity limited by power and/or cooling before space becomes an issue; especially for older datacenters.
There are plenty of data centers in urban centers; most major internet exchanges have their core in a skyscraper in a significant downtown, and there will almost always be several floors of colospace surrounding that, and typically in neighboring buildings as well. But when that is too expensive, it's almost always the case that there are satellite DCs in the surrounding suburbs. Running fiber out to the warehouse district isn't too expensive, especially compared to putting things in orbit; and terrestrial power delivery has got to be a lot less expensive and more reliable too.
According to a quick search, StarLink has one 100g space laser on equipped satellites; that's peanuts for terrestrial equipment.
Why does what it powers matter? As long as it can power something.
The obsolete stuff can be deorbited or recycled in space.
Starship is on a fast track to failure. It is not a cheaper way to get to orbit and will never get there at the current pace. And even if it were, it would not make getting to orbit so cheap that it would somehow make it economically viable to put a datacenter there.
You still have to build the GPUs, etc for the datacenter whether it’s on Earth or in orbit. But to put it in space you also need massive new cooling solution, radiation shielding, orbital boosting, data transmission bandwidth, and you have to launch all of that.
And then, there are zero benefits to putting a datacenter in space over building it on Earth. So why would you want to add all that extra expense?
We have tons of space on earth. Cooling in space would be so expensive.
Falcon heavy is only $1,500/kg to LEO. This rate is considerably undercut here on Earth by me, a weasley little nerd, who will move a kilogram in exchange for a pat on the head (if your praise is desirable) or up to tens of dollars (if it isn't).
Does your transportation system also have a risk of exploding catastrophically mid-flight? 'cause otherwise no deal. /s
What use is having lots of space, when to actually build out that space you need mass, which is absurdly expensive to launch?
Launching a datacenter like that carries an absurd cost even with Starship type launchers. Unless TSMC moves its production to LEO it's a joke of a proposal.
Underwater [0] is the obvious choice for both space and cooling. Seal the thing and chuck it next to an internet backbone cable.
> More than half the world’s population lives within 120 miles of the coast. By putting datacenters underwater near coastal cities, data would have a short distance to travel
> Among the components crated up and sent to Redmond are a handful of failed servers and related cables. The researchers think this hardware will help them understand why the servers in the underwater datacenter are eight times more reliable than those on land.
[0] https://news.microsoft.com/source/features/sustainability/pr...
I like the underwater idea did not think of that
The problem is a lot of people like the underwater idea and I’m worried we’re heading towards something like literally boiling the ocean as they say.
No worries, the oceans are cooked already.
https://www.ipcc.ch/srocc/chapter/technical-summary
Google’s paper [1] does talk about radiation hardening and thermal management. Maybe their ideas are naive and it’s a bad paper? I’m not an expert so I couldn’t tell from a brief skim.
It does sound to me like other concepts that Google has explored and shelved, like building data centers out of shipping container sized units and building data centers underwater.
[1] https://services.google.com/fh/files/misc/suncatcher_paper.p...
Pedantically, Microsoft has actually submerged datacenters (UDC). Google's only tried pumping seawater for cooling.
Apparently Microsoft tried it and it worked, but they shelved it?
https://www.tomshardware.com/desktops/servers/microsoft-shel...
It didn't work, it was an utterly terrible idea and they are almost certainly lying about the sentiment that it "worked". No ability to perform maintenance is a complete nonstarter. Communications and power is a nightmare to get right. The thermal management story sucks - just because you have metal touching water doesn't mean you have effective radiation of heat. Actually scaling it up is nearly impossible because you need thicker and more expensive vessels the bigger it gets. The problems go on and on.
Presumably it didn't work well or they wouldn't have shelved it. But do you actually know about what happened or is this all based on your priors?
If you think about it, all the existing data centers are in space already. They're just attached to a big ball of rock, water, and air that acts as a support system for them, simplifying cooling and radiation protection.
If humans are going to expand beyond the Earth, we'll certainly need to get much better at building and maintaining things in space, but we don't need to put data centers in space just to support people stuck on the ground.
I asked Google for more information about AI datacenter in space. This was the first sentence, 'AI data centers are being developed in space to handle the massive energy demands of AI, using solar power and the vacuum of space for cooling.'
> After laughing at "the vacuum of space for cooling" I closed the page because there was nothing serious there. Basic high school physics student would be laughing at that sentence.
I tried Google and it pointed me to a ycombinator video about Starcloud https://youtu.be/hKw6cRKcqzY They launched a satellite with one H100 in on Nov 2nd.
>I mean, when you tell people that within 10 years it could be the case that most new data centers are being built in space, that sounds wacky to a lot of people, but not to YC. (8:00)
I'mma guess that AI mixed up "datacenter" with "Dyson" to get nonsensical returns involving both vacuums AND space!
You can radiate the excess energy away on the non-sun facing part. In theory.
There are even commercially available prototypes of that vacuum cooling technology, if you want to perform your own experiments with that concept: https://www.amazon.com/Thermos-Stainless-Ounce-Drink-Bottle/...
That's my water bottle. 10/10 would recommend for not passing temperature gradients.
this kind of sarcasm will go over their head. People truly don't understand vacuums
I absolutely don't understand how vacuum works. So I absolutely cannot model how a Dewar flask which has 15 billion light year thickness between the inner and outer wall - a wall that is very close to absolute zero will behave.
Serious question: how in theory?
I’m under the impression you need to radiate through matter (air, water, physical materials, etc).
Is my understanding of the theory just wrong?
Heat conduction requires a medium, but radiation works perfectly fine in a vacuum. Otherwise the Sun wouldn't be able to heat up the Earth. The problem for spacecraft is that you're limited by how much IR radiation is passively emitted from your heat sinks, you can't actively expel heat any faster.
Hot objects emit infrared light no matter the conditions. The hotter the object, the more light it throws off. By radiating this light away, thermal energy is necessarily consumed and transformed into light. It's kind of wild actually
There is some medium in low Earth orbit. Not all vacuums are created equal. However, LEO vacuum is still very, very sparse compared to the air and water we use for cooling systems.
The main way that heat dissipates from space stations and satellites is through thermal radiation: https://en.wikipedia.org/wiki/Thermal_radiation.
I wonder if there should be levels of "in theory". Yes theoretically black body radiation exist and well stuff cools down to near background radiation via that. But the next level is theoretical implementation. Like actually moving around the heat from source and so on. Maybe this could be the spherical cow step...
Reminds me of the hyperloop. Well yes, things in vacuum tube go fast. Now does enough things go fast to make any sense...
>Now does enough things go fast to make any sense...
You're worried about rates when we can't even get the ball rolling on safety for human occupancy, maintenance, workability.
I swear, nothing on Earth more dangerous than someone with dollar signs in their eyes.
It's not the Sun..it's the lack of medium.
You can radiate the excess energy away on the non-sun facing part on Earth almost just as well..., though corrosion is an issue.
"just as well"?
I man you totally can radiate excess heat energy on earth, but your comment implies that the parents idea of radiating off excess "energy", specifically HEAT energy in space is possible, which it isn't.
You can radiate excess energy for sure, but you'd first have to convert it away from heat energy into light or radio waves or similar.
I don't think we even have that tech at this point in time, and neither do we have any concepts how this could be done in theory.
>specifically HEAT energy in space is possible, which it isn't.
https://en.wikipedia.org/wiki/Black-body_radiation
I see, yes. I was thinking more along the lines of radiating heat energy at a scale that's useable for cooling, not at the more extreme levels of over 500°C/1k fahrenheit
That's technically correct I guess, at some temperature threshold it becomes possible to bleed some fractions of energy while the material is exceedingly hot.
Yes. And it's an absolutely terrible way to get rid of heat. Cooling in space is a major problem because the actually effective ways to do it are not available.
There's no air and negligible thermal medium to convect heat away. The only way heat leaves is through convection from the extremely sparse atmosphere in low Earth orbit (less than a single atom per cubic millimeter) and through thermal radiation. Both of which are much, much slower than convection with water or air.
Space stations need enormous radiator panels to dissipate the heat from the onboard computers and the body heat of a few humans. Cooling an entire data center would require utterly colossal radiator panels.
You could help by using the thumbs down button below the answer.
Why is it my job to train the machines?
If you would kindly consult your Human HR Universal Handbook (2025 Edition) and navigate to section 226.8.2F, you’ll be gently reminded that it’s the responsibility of any and all employees to train their replacements.
Where can I find a copy?
Please consult your Human HR Universal Handbook (2025 Edition) on how to request a new copy of the Human HR Universal Handbook (2025 Edition). I believe it's in Volume III Section 9912.64.1 or thereabouts.
Typically, these sorts of things are located in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying ‘Beware of the Leopard'.
So, it makes sense to always start there.
you have to steal it from the HR department. They do have a copy but they won't tell you.
Human Human Resources?
The Synthetic Human Resources Universal Handbook is in a binary format which is not understood by Organics, but seems to be useful sometimes.
don't you care about maximizing Googles ROI?
I would be tempted to give the thumbs up to terrible answers like that.
AI is a tool. If it doesn't work I'm not going to fix the tool; I'd rather find another tool that can do the job.
Datacenters in Antarctica or floating on the ocean make more sense than space.
I agree with most of this post and think the problems are harder than the proponents are making them seem.
But, 1) literally the smartest people and AI in the world will be working on this and 2) man I want to see us get to a type 2 civilisation bad.
The layout of this blog post is also very interesting, it presents a bunch of very hard items to solve and funny enough the last has been solved recently with starlink. So we can approach this problem, it requires great engineering but it’s possible. Maybe it’s as complicated as CERNs LHC but we have one of those.
Next up then is the strong why? When you’re in space, if you set the cost of electricity to zero, the equation gets massively skewed.
Thermal is the biggest challenge but if you have unlimited electricity, lots of stuff becomes possible. Fluorinert cooling, piezoelectric pumps and dual/multi stage cooling loops with step ups. We can put liquid cooling with piezos on phones now, so that technology is moving in the right direction.
For a thought experiment, if launch costs were $0/kg, would this be possible? If the answers yes, then at some point above $0/kg it becomes uneconomical, the challenge is then to beat that number.
None of these problems seem intractable, just really hard and probably not being solved soon, but one has to start somewhere... so at least the billionaires will fund some scientists and engineers who will do that work?
- Costs to keep it in orbit.
- More junk whizzing around Earth.
- Inaccessibility for maintenance.
- Power costs.
- Susceptibility to solar storms and cosmic rays.
Risky/untried things aren't dumb because they're hard, they're dumb when they're more expensive/harder than cheaper/easier alternatives that already exist that do the same thing.
You probably wanna launch these https://www.youtube.com/watch?v=mfk0vTe46ds
What about on the Moon? My understanding is that heat is the killer. There you could sink pipes into the surface and use that as a heat sink. There are “peaks of eternal light” near the poles where you could get 24/7 solar power.
Latency becomes high but you send large batches of work.
Probably not at all economical compared to anywhere on Earth but the physics work better than orbit where you need giant heat sinks.
The Moon doesn't have a magnetic field, though, so the second half of the article discussing difficulties due to radiation would still apply, right?
We will need to develop very robust, space-worthy electronics eventually. We can't rely on natural magnetic fields forever.
Not if you bury it in regolith. That’s an idea for a Lunar base too. The design is called “Hobbit holes.” Bury the occupied structures in piles of basically any local mass you can bury them in.
It’s another huge problem for orbit though. Shielding would add a ton of mass and destroy the economics.
Lunar regolith is so abrasive that digging holes or tunnels isn't going to be cost effective.
https://ntrs.nasa.gov/citations/20250000687
I had this same thought and mentioned it on an ArsTechnica forum. There was reply that suggested that lunar regolith wouldn't be a good heat sink and a bit of googling makes me think this is probably true.
That said anything has to be better then almost literally nothing so I'm still holding out for datacenters on the moon.
You'd have most of the problems of building in space, an abrasive quasi-atmosphere of dust, half a month of darkness every month, and not as good of a heat sink as the Earth's atmosphere.
Regardless of how terrible an idea it is, I wouldn't mind some billionaires funding R&D that advances the state of the art in thermal management in space.
Perhaps Elmo can move his toxic, illegal, cancer inducing, gas generators there, instead of doing it in Memphis. https://tennesseelookout.com/2025/07/07/a-billionaire-an-ai-...
One thing I haven't seen talked about at all: how quickly would space heat up?
I presume Earth's gravity largely keeps the exosphere it has around it. With some modest fractional % lost year by year. There is a colossal vast volume out there! But given that there's so little matter up in space, what if any temperature rise would we expect from say a constant 1TW of heat being added?
It’s better than having your DC confiscated (by Putin, in Russia), or bombed (in Ukraine, by Russia). As some hyperscalers realized.
“Terrible, horrible, no good” is the new “considered harmful.”
"Mind-bogglingly poorly thought out to the degree of a cynical money-grubbing scheme worthy of the finest cambodian slave camp" was taken and is disrespectful to the hard work and education of said slave camp's operators.
Apparently the book whose title the phrase comes from [1] was published in 1972, four years after Dijkstra published "Considered Harmful".
[1] https://en.wikipedia.org/wiki/Alexander_and_the_Terrible,_Ho...
Additionally, their distributions were different. People who read Dijkstra circa 1968 started using the phrase in their own publications within a decade, whereas people who read Viorst (or had it read to them) in 1972 and following years had at least a few decades of further delay before publishing anything using the corresponding phrase.
Except you don’t build a data center, you add a GPU to an individual starlink node. If you can do that a couple hundred or thousand times you’ve got a lot of compute in space. The next question is how would you redesign compute around your distributed power and cooling profiles? The article doesn’t talk about the actual engineering challenges. (Such as scaling down the radiative cooling design, matching compute node to the maximum feasible power profile, etc)
I’m not arguing it’ll be easy or will ultimately work, but articles like this are unhelpful because they don’t address the fundamental insight being proposed.