I'm confused about the level of conversation here. Can we actually run the math on heat dissipation and feasibility?
A Starlink satellite uses about 5K Watts of solar power. It needs to dissipate around that amount (+ the sun power on it) just to operate. There are around 10K starlink satellites already in orbit, which means that the Starlink constellation is already effectively equivalent to a 50 Mega-watt (in a rough, back of the envelope feasibility way).
Isn't 50MW already by itself equivalent to the energy consumption of a typical hyperscaler cloud?
Why is starlink possible and other computations are not? Starlink is also already financially viable. Wouldn't it also become significantly cheaper as we improve our orbital launch vehicles?
Simply put no, 50MW is not the typical hyperscaler cloud size. It's not even the typical single datacenter size.
A single AI rack consumes 60kW, and there is apparently a single DC that alone consumes 650MW.
When Microsoft puts in a DC, the machines are done in units of a "stamp", ie a couple racks together. These aren't scaled by dollar or sqft, but by the MW.
And on top of that... That's a bunch of satellites not even trying to crunch data at top speed. No where near the right order of magnitude.
It's like this. Everything about operating a datacenter in space is more difficult than it is to operate one on earth.
1. The capital costs are higher, you have to expend tons of energy to put it into orbit
2. The maintenance costs are higher because the lifetime of satellites is pretty low
3. Refurbishment is next to impossible
4. Networking is harder, either you are ok with a relatively small datacenter or you have to deal with radio or laser links between satellites
For starlink this isn't as important. Starlink provides something that can't really be provided any other way, but even so just the US uses 176 terawatt-hours of power for data centers so starlink is 1/400th of that assuming your estimate is accurate (and I'm not sure it is, does it account for the night cycle?)
> The maintenance costs are higher because the lifetime of satellites is pretty low
Presumably they're planning on doing in-orbit propellant transfer to reboost the satellites so that they don't have to let their GPUs crash into the ocean...
> Presumably they're planning on doing in-orbit propellant transfer to reboost the satellites so that they don't have to let their GPUs crash into the ocean
Hell, you're going to lose some fraction of chips to entropy every year. What if you could process those into reaction mass?
This brings a whole new dimension to that joke about how our software used to leak memory, then file descriptors, then ec2 instances, and soon we'll be leaking entire data centers. So essentially you're saying - let's convert this into a feature.
And just like that you've added another not never done before, and definitely not at scale problem to the mix.
These are all things which add weight, complexity and cost.
Propellant transfer to an orbital Starship hasn't even been done yet and that's completely vital to it's intended missions.
Or maybe they want to just use them hard and deorbit them after three yesrs?
>1. The capital costs are higher, you have to expend tons of energy to put it into orbit
putting 1KW of solar on land - $2K, putting it into orbit on Starship (current ground-based heavy solar panels, 40kg for 4m2 of 1KW in space) - anywhere between $400 and $4K. Add to that that the costs on Earth will only be growing, while costs in space will be falling.
Ultimately Starship's costs will come down to the bare cost of fuel + oxidizer, 20kg per 1kg in LEO, i.e. less than $10. And if they manage streamlined operations and high reuse. Yet even with $100/kg, it is still better in space than on the ground.
And for cooling that people so complain about without running it in calculator - https://news.ycombinator.com/item?id=46878961
>2. The maintenance costs are higher because the lifetime of satellites is pretty low
it will live those 3-5 years of the GPU lifecycle.
Current cost to LEO is $1500 per kg
That would make your solar panel (40kg) around $60K to put into space.
Even being generous and assuming you could get it to $100 per kg that's still $4000
There's a lot of land in the middle of nowhere that is going to be cheaper than sending shit to space.
> will come down to the bare cost of fuel + oxidizer
And maintenance and replacing parts and managing flights and ... You're trying to yadda-yadda so much opex here!
It is SpaceX/Elon who bet billions on that yadda-yadda, not me. I wrote "If" for $10/kg. I'm sure though that they would easily yadda-yadda under sub-$100/kg - which is $15M per flight. And even with those $100/kg the datacenters in space still make sense as comparable to ground based and providing the demand for the huge Starship launch capacity.
A datacenter costs ~$1000/ft^2. How much equipment per square foot is there? say 100kg (1 ton per rack plus hallway). Which is $1000 to put into orbit on Starship at $100/kg. At sub-$50/kg, you can put into orbit all the equipment plus solar panels and it would still be cheaper than on the ground.
100 x 100 is 10,000.
> Everything about operating a datacenter in space is more difficult than it is to operate one on earth
Minus one big one: permitting. Every datacentre I know going up right now is spending 90% of their bullshit budget on battlig state and local governments.
It's also infinitly easier to get 24/7 unadulterated sunlight for your solar panels.
But since building a datacenter almost anywhere on the planet is more convenient than outer space, surely you can find some suitable location/government. Or put it on a boat, which is still 100 times more sensible than outer space.
> since building a datacenter almost anywhere on the planet is more convenient than outer space, surely you can find some suitable location/government
More convenient. But I'm balancing the cost equation. There are regimes where this balances. I don't think we're there yet. But it's irrational to reject it completely.
> Or put it on a boat, which is still 100 times more sensible than outer space
More corrosion. And still, interconnects.
> More corrosion
Surely given starlinks 5ish year deorbit plan, you could design a platform to hold up for that long... And instead of burning the whole thing up you could just refurbish it when you swap out the actual rack contents, considering that those probably have an even shorter edge lifespan.
Starlinks are built to safely burn up on re-entry. A big reusable platform will have to work quite differently to never uncontrollably re-enter, or it might kill someone by high velocity debris on impact.
This adds weight and complexity and likely also forces a much higher orbit.
If you think there is no papework necessary for launching satellites, you are very very wrong.
> If you think there is no papework necessary for launching satellites, you are very very wrong
I would be. And granted, I know a lot more about launching satellites than building anything. But it would take me longer to get a satellite in the air than the weeks it will take me to fix a broken shelf in my kitchen. And hyperscalers are connecting in months, not weeks.
Swear that fella is like the Elon Musk of HN - when he talks about subject outside of his domain he gets caught out.
> when he talks about subject outside of his domain
Hate to burst your bubble. But I have a background in aerospace engineering. I’ve financed stuff in this field, from launch vehicles to satellites. And I own stakes in a decent chunk of the plays in this field. Both for and against this hypothesis.
So yeah, I’ll hold my ground on having reasonable basis for being sceptical of blanket dismissals of this idea as much as I dismiss certainty in its success.
This is a huge one. What Musk is looking for is freedom from land acquisition. Everything else is an engineering and physics problem that he will somehow solve. The land acquisition problem is out of his hands and he doesn't want to deal with politicians. He learned from building out the Memphis DC.
Maybe, but I'm skeptical, because current DCs are not designed to minimize footprint. Has anyone even built a two-story DC? Obviously cooling is always an issue, but not, directly, land.
Now that I think of it, a big hydro dam would be perfect: power and cooling in one place.
Skepticism is valid. The environmentalists came after dams too.
He "learned" by illegally poisoning black people
> an engineering and physics problem that he will somehow solve
no he won't
What ? This is Hacker News man. Talk substance. Not some rage baiting nonsense.
https://theblackwallsttimes.com/2025/05/27/elon-musks-memphi...
So freedom from law and regulation?
Well let's face it. Not all law and regulation is created equal. Look at Europe.
So why does he not build here in Europe then? Getting a permit for building a data center in Sweden is just normal industrial zoning that anyone can get for cheap, there is plenty of it. Only challenge is getting enough electricity.
I meant Europe is an example of how not to do regulation. The problem you just mentioned. If you get land easily electricity won't be available and vice versa.
I mean, you don't have zoning in space, but you have things like international agreements to avoid, you know, catastrophic human development situations like kessler syndrome.
All satellites launched into orbit these days are required to have de-orbiting capabilities to "clean up" after EOL.
I dunno, two years ago I would have said municipal zoning probably ain't as hard to ignore as international treaties, but who the hell knows these days.
> you have things like international agreements to avoid, you know, catastrophic human development
Yes. These are permitted in weeks for small groups, days for large ones. (In America.)
Permitting is a legitimate variable that weighs in favor of in-space data centers.
that may have been the case before but it is not anymore. I live in Northern VA, the capital of the data centers and it is easier to build one permit-wise than a tree house. also see provisions in OBBB
What counts towards a bullshit budget? Permitting is a drop in the bucket compared to construction costs.
> is spending 90% of their bullshit budget on battlig state and local governments
Source? I can't immediately find anything like that.
Parent just means "a lot" and is using 90% to convey their opinion. The actual numbers are closer to 0.083%[1][2][3][4] and parent thinks they should be 0.01-0.1% of the total build cost.
1. Assuming 500,000 USD in permitting costs. See 2.
2. Permits and approvals: Building permits, environmental assessments, and utility connection fees add extra expenses. In some jurisdictions, the approval process alone costs hundreds of thousands of dollars. https://www.truelook.com/blog/data-center-construction-costs
3. Assuming a 60MW facility at $10M/MW. See 4.
4. As a general rule, it costs between $600 to $1,100 per gross square foot or $7 million to $12 million per megawatt of commissioned IT load to build a data center. Therefore, if a 700,000-square foot, 60-megawatt data center were to be built in Northern Virginia, the world’s largest data center market, it would cost between $420 million and $770 million to construct the facility, including its powered shell and equipping the building with the appropriate electrical systems and HVAC components. https://dgtlinfra.com/how-much-does-it-cost-to-build-a-data-...
Yeah, I was trying to be nicer than "you're making it up" just in case someone has the actual numbers.
> Source? I can't immediately find anything like that
I’ve financed two data centers. Most of my time was spent over permitting. If I tracked it minute by minute, it may be 70 to 95%. But broadly speaking, if I had to be told about it before it was solved, it was (a) a real nuisance and (b) not technical.
Starlink provides a service that couldn't exist without the satellite infrastructure.
Datacenters already exist. Putting datacenters in space does not offer any new capabilities.
Amazon’s new campus in Indiana is expected to use 2.2GW when complete. 50Mw is nothing, and that’s ignoring the fact that most of that power wouldn't actually be used for compute.
> Isn't 50MW already by itself equivalent to the energy consumption of a typical hyperscaler cloud?
xAI’s first data center buildout was in the 300MW range and their second is in the Gigawatt range. There are planned buildouts from other companies even bigger than that.
So data center buildouts in the AI era need 1-2 orders of magnitude more power and cooling than your 50MW estimate.
Even a single NVL72 rack, just one rack, needs 120kW.
50MW is on the small side for an AI cluster - probably less than 50k gpus.
if the current satellite model dissipates 5kW, you can't just add a GPU (+1kW). maybe removing most of the downlink stuff lets you put in 2 GPUs? so if you had 10k of these, you'd have a pretty high-latency cluster of 20k GPUs.
I'm not saying I'd turn down free access to it, but it's also very cracked. you know, sort of Howard Hughesy.
High latency to earth but low latency (potentially) to other satellites.
> A Starlink satellite uses about 5K Watts of solar power. It needs to dissipate around that amount (+ the sun power on it) just to operate.
This isn't quite true. It's very possible that the majority of that power is going into the antennas/lasers which technically means that the energy is being dissipated, but it never became heat in the first place. Also, 5KW solar power likely only means ~3kw of actual electrical consumption (you will over-provision a bit both for when you're behind the earth and also just for safety margin).