[tristanj]

Economics calculator for Orbital vs Terrestrial Data Centers

https://andrewmccalip.com/space-datacenters

You can play around with the cost sliders to estimate the economics, but even being quite optimistic, space data centers cost ~2-3x of their terrestrial counterparts.

[PowerfulWizard]

To remove heat by radiation there's a big benefit to running the GPUs hotter as the radiation will be proportional to the fourth power of temperature. This resource is using 85 deg C versus 60 deg C for OP which will improve cooling performance.

If Nvidia/SpaceX can make the chips run at a higher temperature that would help a lot although I assume it would have already been done if it were possible. Another option is to add a heat pump to raise radiator temperature if the smaller radiator mass can pay for the heat pump mass.

[cornholio]

If radiator temperature is critical you can just run a heat pump to boost it. Modern heat pumps can get pretty close to the Carnot limit for the temperature interval, for example a pump cooling to 300K and dumping out heat at 400K (125°C) will have a theoretical COP limit of 4 and a practical limit of 2.5-3.

That means that for every 3 units of heat your chips emit, you will use a 4th unit to spin the pump. If your panels generate 150kW, you will only have 113kW available for compute and the rest is cooling. Radiators will more than halve vs 340K operation, so it's net beneficial.

It's all a giant techno-economic optimization problem: the extra mass of solar panels you need vs saved radiators vs mass of the pump, the die temperatures you achieve and corresponding performance, durability and chip price point etc.

[Recurecur]

The answer seems to be large, lightweight sunshades to protect the radiative coolers. That would avoid the degradation due to UV radiation mentioned in the article and would also increase the efficiency of the coolers.

[cucumber3732842]

Could they run the chips at "normal" temperatures and then heat pump that all into some other mass that lives at "aerospace alloy" temperatures and radiates it away more efficiently?

[PowerfulWizard]

I think it's possible, I'm not familiar with what's really been tried but I see that there are some publications on it, for example there's an ESA project under way: https://connectivity.esa.int/archives/projects/heat-pump-cen...

[mc32]

Sorry but wouldn’t space based DCs need radiation hardened parts which are typically a few generations behind SoTA? Do the centers deploy massive shields to protect the electronics?

[PowerfulWizard]

I haven't heard of that being a problem for Starlink, whatever they've done there seems to be working. The Orbital AI would be at a higher orbit but still within LEO which reduces the radiation. I wonder if occasional bit flips even matter for typical AI calculations. Quantization seems to suggest a lot of the lower bits aren't all that important. Either way SpaceX has already had success building systems with commercial-off-the-shelf products in space.

To me the biggest problem of the system is the dependence on launch cost. The more launch cost can be lowered the more viable the system is and the more options there are for solving every problem. But IMO the reason Musk is building this system is to lower launch cost. He needs a project that can fund a high volume of launches and create economies of scale to lower launch cost, the way that Starlink did for Falcon 9.

[bigbadfeline]

> I haven't heard of that being a problem for Starlink, whatever they've done there seems to be working.

Starlink doesn't need GPUs, they use hardened chips. The first question is, can whatever works as a 2nm GPU work where Starlink is?

The second question is even funnier: Starlink satellites have a limited lifespan and regularly burn up in the atmosphere when they fall back to Earth - that's due to the need to fly them at low altitudes where, coincidentally, the radiation is lower.

Where then will the flying data centers be - high with higher radiation or low with a higher fall rate? And I doubt those heavy birds are going to burn up fully before hitting somebody's head.

[biomcgary]

But, datacenter development in space does not deal with local NIMBYs, just centralized decision-makers that are easier to "influence".

[nba456_]

The NIMBYs are coming for space launch sites, too.

[arjie]

That particular concern is currently covered as far as SpaceX is concerned since it launches under DoD coverage. See the California Coastal Commission and the fact that they had to apologize etc. for attempted overreach.

[lispisok]

The point of datacenters in space is about control not economics. They dont want the masses which they are trying to replace with AI and robots to have access to the datacenters running everything.

[bayindirh]

Why people always take the worst parts of SciFi novels and try to built torment nexus?

Again, we're getting closer to Hyperion Cantos here.

[rbanffy]

Your view is much more optimistic than mine. For me, they want servers that the police can’t easily seize with keys in memory.

[rstuart4133]

Why did the word "skynet" pop into my mind?

[jmpman]

You might be on to something. Starship is moving its launch facility to Florida. Elon previously suspected a sniper shooting at the SpaceX rockets. Moving the launches to Cape Canaveral would make them much harder for a sniper to target. And his terrestrial data centers are easily accessible for anyone who has a grudge with him. Moving those to space would also isolate him from the masses uprising.

https://arstechnica.com/space/2025/05/spacex-pushed-sniper-t...

[OutOfHere]

You are altogether externalizing the cost of carbon dioxide emissions that humanity has to pay for. The resulting global warming is not a joke. The heat problem cumulatively is bigger on Earth than it would be in space.

[xnx]

Cost = emmissions

[DoctorOetker]

No, cost is not directly proportional to emissions.

Heat emission in space is not problematic for humans

[xnx]

Are you counting the emissions to get the datacenters into space?

[OutOfHere]

That's an environmental and financial cost, but it's a one time cost. For datacenters on Earth, the emissions are continuous.

[fulafel]

Are there going to be self sustaining server factories in space? The hw needs updating every few years.

[krunck]

They'll pay the price if it means their data centers are immune to the anger of the commoners who are being surveilled, analyzed, and manipulated by systems running on these data centers.

[brokenmachine]

>their data centers are immune to the anger of the commoners who are being surveilled

If the commoners are attacking infrastructure, there's still always going to be ground stations that can be attacked.

[its-summertime]

I think the more likely goal would be immunity to regulation.

[rbanffy]

You can’t release the files the police was never able to seize in the first place.

[_DeadFred_]

I'm still expecting a crypto satellite network to phone app now that normal phones have became satellite connectible. Something outside oversight.