It looks like the ISS active cooling system has a maximum cooling capacity that could handle the equivalent of a single-digit number of racks (down to 1 for an AI-focused rack).
... and then you realize that because it is space, there's almost nothing out there to absorb the heat ...
new vc rule: no investing in space startups unless their founders have 1000 hours in KSP and 500 hours in children of a dead earth
If YC is hell bent on lighting piles of money on fire, I can think of some more enjoyable ways.
Radiators work great in space. Stefan-Boltzmann's law. The ISS's solar panels are MUCH smaller than the radiators. Considering datacenters on Earth have to have massive heat exchangers as well, I really think the bUt wHaT aBoUt rAdiAtOrs is an overblown gotcha, considering every satellite still has to dump heat and works just fine.
Even here on earth, contemporary GPU racks for AI have had to move to liquid cooling because it is the only way to extract enough heat. At 120 kW for 18x 1U servers (GB200 NVL72), the power density is waaay beyond what you can do with air even.
The last time Starcloud was doing the rounds on HN, I estimated that they need to be pumping water at a flow rate of 60 000 liters per second, if you use the numbers in their whitepaper. That's a tenth of the Sacramento river, flowing in space through a network with a million junctions and hoping nothing leaks.
> The ISS's solar panels are MUCH smaller than the radiators.
The whitepaper also says that they're targeting use cases that don't require low latency or high availability. In short: AI model training and other big offline tasks.
For maintenance, they plan to have a modular architecture that allows upgrading and/or replacing failed/obsolete servers. If launch costs are low enough to allow for launching a datacenter into space, they'll be low enough to allow for launching replacement modules.
All satellites launched from the US are required to have a decommissioning plan and a debris assessment report. In other words: the government must be satisfied that they won't create orbital debris or create a hazard on the ground. Since these satellites would be very large, they'll almost certainly need thrusters that allow them to avoid potential collisions and deorbit in a controlled manner.
Whether or not their business is viable depends on the future cost of launches and the future cost of batteries. If batteries get really cheap, it will be economically feasible to have an off-the-grid datacenter on the ground. There's not much point in launching a datacenter into space if you can power it on the ground 24/7 with solar + batteries. If cost to orbit per kg plummets and the price of batteries remains high, they'll have a chance. If not, they're sunk.
I think they'll most likely fail, but their business could be very lucrative if they succeed. I wouldn't invest, but I can see why some people would.
I was implying an unspoken obvious "but why would you?"
But of course the answer I missed was you don't, you make money from people who, for whatever reason, want to drink from shoes.
This is hiding so, so much complexity behind a simple hand wavy “modular”. I have trained large models on thousands of GPUs, hardware failure happen all the time. Last example in date: an infiniband interface flapping which ultimately had to be physically replaced. What do you do if your DC is in space? Do you just jettison the entire multi million $ DGX pod that contains the faulty 300$ interface before sending a new one? Do you have an army of astronauts + Dragons to do this manually? Do we hope we have achieve super intelligence by then and have robots that can do this for us ?
Waving the “Modular” magic key word doesn’t really cut it for me.
Something tells me that the price of batteries is already cheap enough for terrestrial data centers to make more economic sense than launching a datacenter - which will also need batteries - into space.
They will calm down.
Any purported advantages have to contend with the fact that sending the modules costs millions of dollars. Tens to hundred millions
This is true even if your company moves the actual launching to, say, a platform in international waters- you (either a corporation or an individual) are still regulated by your home country, and that country is responsible for your actions and has full enforcement rights over you. There is no area beyond legal control, space is not a magic "free from the government" area.
To escape the law you need to hide or protect something on earth (your ground station(s), downlinks). If you can hide or protect that infrastructure on earth, why bother putting the computers in space?
Who said that Starcloud's business model is about commercial services? At https://news.ycombinator.com/item?id=44397026 I rather speculate that Starcloud's business model is about getting big money defense contracts.
Meanwhile, you, the actual human being the government wants to coerce, are still on the earth, where someone can grab you and beat you with a wrench
Unless you go up there with it and a literal lifetime supply? Although I guess if you don't take much it's still a lifetime supply...
Nations come and go. In my lifetime, the world map has changed dozens of times. Incorporate in a country that doesn't look like it's going to be around very long. More than likely, the people running it will be happy to take your money.
This principle was established when Nazis were convicted for war crimes at Nuremburg for violating treaties that their predecessor state the Weimar Republic signed, even after the Nazi's repudiated those treaties and claimed they were signed by an illegitimate state, and that they were a new Reich, not like the Wiemar Republic.
Basically if territory changes hand to an existing state that state will obviously still have obligations, and if a new state is formed, then generally it is assumed to still carry the obligations of the previous state. There is no "one weird trick" to avoid international law. I assure you that the diplomats and lawyers 80 years ago thought of these possibilities. They saw what resulted from the Soviet and Nazi mutual POW slaughters, and set up international law so no one could ignore it.
And more critically - they have successor states.
The Russian Federation is treated as the successor to the USSR in most cases (much to the chagrin of the rest of the CIS) and Serbia is treated as the successor to Yugoslavia (much to the chagrin of the rest)
But if international waters isn't enough (and much cheaper) then I don't think space will either. Man's imagination for legal control knows no bounds.
You wait (maybe not, it's a long wait...), if humankind ever does get out to the stars, the legal claims of the major nations on the universe will have preceded them.
> Servers outside any legal jurisdiction
Others have weighed in on the accuracy of this, with a couple pointing out that the people are still on the ground. There's a thread in _Critical Mass_ by Daniel Suarez that winds up dealing with this issue in a complex set of overlapping ways.
Pretty good stuff, I don't think the book will be as good as the prior book in the series. (I'm only about halfway through.)
Plus you can just have a couple of politicians from each major power park their money on that satellite.
unless everybody is angry at satellite in which case it is a price everybody is even eager to pay.
>Plus you can just have a couple of politicians from each major power park their money on that satellite.
I've long had the idea that there are fashions in corruption and a point at which to be corrupt just becomes too gauche and most politicians go back to being honest.
This explains the highly variant history of extreme corruption in democracies.
At any rate while the idea that the cure for any government interference is to be sufficiently corrupt sounds foolproof in theory I'm not sure it actually works out.
If I was a major politician and you had my competitors park their money on your satellite it would become interesting for me to get rid of it. Indeed if you had me and my competitors on the satellite I might start thinking how do I conceal getting my money out of here and then wait for best moment to ram measure through to blow up satellite.
See: https://unusualwhales.com/politics. Some of these politicians on both sides are very good and consistent stock pickers indeed.
I'm sorry but what logic is it you're referring to here? Is it the idea that there are fashions in corruption? If so by that logic we are probably in an era of high corruption.
Is it the idea that if I were a corrupt politician and I had equally corrupt enemies I would use my knowledge of their corruption to dirty trick them? Because ... dirty tricking them and getting them to lose all their finance at one time is not quite the same as passing a law making it difficult for everyone to get more finance from hereon out.
I'm not following exactly what logic of mine you think you've defeated with observing that there are a lot of corrupt politicians nowadays?
2026, we will get ransomware from space!
The RaaS groups have hundreds of millions of dollars so in theory they actually could get something like that setup if they wanted.
Ahem, cloud ransomware.
But what about when we’re making multi-year journeys to Mars and we need a relay network of “space data centers” talking to each other, caching content, etc?
We may as well get ahead of the problems we’ll face and solve them in a low-stakes environment now, rather than waiting to discover some novel failure scenario when we’re nearing Mars…
How would this work? Planets orbit at different speeds, so you can't build a chain of relays to another planet. I can imagine these things orbiting planets, but is that worth it compared to ground-based systems?
Cooling isn't actually any more difficult than on Earth. You use large radiators and radiate to deep space. The radiators are much smaller than the solar arrays. "Oh but thermos bottles--" thermos bottles use a very low emissivity coating. Space radiators use a high emissivity coating. Literally every satellite manages to deal with heat rejection just fine, and with radiators (if needed) much smaller than the solar arrays.
Latency is potentially an issue if in a high orbit, but in LEO can be very small.
Equipment upgrades and maintenance is impossible? Literally, what is ISS, where this is done all the time?
Radiation shielding isn't free, but it's not necessarily that expensive either.
Orbital maintainence is not a serious problem with low cost launch.
The upside is effectively unlimited energy. No other place can give you terawatts of power. At that scale, this can be cheaper than terrestrially.
Modern solar panels are way more efficient than the ancient ones in ISS, at least 10x. The cooling radiators are smaller than solar panels because they are stacked and therefore effectively 5x efficient.
Unless there are at least 2x performance improvements on the cooling system, the cooling system would have to be larger than solar panels in a modern deployment.
Additionally, you wouldn’t use cutting edge 35% triple junction cells for a space datacenter, you’d use silicon cells like Starlink and ISS use. 22% efficient with 90% full factor, given 1350W/m^2 and thus 270W/m^2, to provide enough power for that radiator you’d need a solar panel 3.4 times as big, and that’s if you were in 24/7 sunshine. If you’re in a low orbit that’s obscured almost half the time, it’s 6-7 times as big.
Why do people keep making these obviously wrong claims when a paragraph of arithmetic shows they’re wrong? Do the math.
There will probably be a lot more edge computing in the future. 20 years ago engineers scoffed at the idea of deploying code into a dozen regions (If you didn’t have a massive datacenter footprint) but now startups do it casually like it’s no big deal. Space infrastructure will probably have some parallels.
The Chinese project involves a larger number of less powerful inference-only nodes for edge computing, compared to Starcloud's training-capable hyperscale data centers.
[1] Andrew Jones. "China launches first of 2,800 satellites for AI space computing constellation". Spacenews, May 14, 2025. https://spacenews.com/china-launches-first-of-2800-satellite... [2] Ling Xin. "China launches satellites to start building the world’s first supercomputer in orbit". South China Morning Post, May 15, 2025. https://www.scmp.com/news/china/science/article/3310506/chin... [3] Ben Turner. "China is building a constellation of AI supercomputers in space — and just launched the first pieces". June 2, 2025. https://www.livescience.com/technology/computing/china-is-bu...
Are there many startups actually taking real advantage of edge computing? Smaller B2B places don't really need it, larger ones can just spin up per-region clusters.... and then for 2C stuff you're mainly looking at static asset stuff which is just CDNs?
Who's out there using edge computing to good effect?
If starcloud integrated with something like starlink, using the laser inter satellite links to distribute ground comms across a network of satellites, then the datacenter maintaining a direct link to a base station is probably a non-issue for most purposes.
It's outside of any jurisdiction, this is a dream come true for a libertarian oligarch.
For your other concerns, the risks are worth it for customers because of the main reward: No laws or governments in space! Technically, the datacenter company could be found liable but not for traffic, only for take-down refusals. Physical security is the most important security. For a lot of potential clients, simply making sure human access to the device is difficult is worth data-loss,latency and reliability issues.