we’d need 250,000 square metres of radiation area. The largest current radiator in space is probably the ISS, at around a thousand square metres. Is scaling that up by 250x a lot? Yes, but it’s not necessarily ridiculous. (pos) https://stratechery.com/2026/the-spacex-ipo-and-data-centers-in-space/ There is no reason that space data centers would look like data centers on earth. What makes far more sense is to think about an individual satellite as something akin to a rack. Right now the largest Starlink satellite in orbit is the V2 Mini Direct-to-Cell, which measures 7.4 meters by 2.7 meters by 0.3 meters (estimated); an NVL72 rack from Nvidia, meanwhile, measures 2.2 meters by 1.1 meters by 0.6 meters, so we’re already in the right size range. The V2 Mini Direct-to-Cell consumes (and dissipates) up to an estimated 25kW of energy; the NVL72 up to 135kW, and it can fit a 1 trillion parameter model quantized to FP4.
The big shortcoming for a rack-satellite is power and its dissipation, but going from 25kW to 135kW is certainly within the realm of possibility — and given that you don’t need much of the cooling and power distribution usage on earth, something closer to 100kW might deliver similar performance.
The main case for ODCs ((orbital data centers)) is the cost of energy: space solar panels in the right orbits receive more constant and intense sunlight compared to Earth. Moreover, ODCs don’t currently face the same permitting and regulatory delays as on Earth, cause fewer ongoing environmental harms compared to grid or onsite natural gas-powered data centers, and may be more secure against data exfiltration. We find that the cost-competitiveness case for ODCs depends almost entirely on Starship achieving reusability comparable with what SpaceX achieved with Falcon: space-based solar reaches cost parity with present-day off-grid terrestrial power continuously at roughly $250/kg to orbit, and becomes cheaper than any current terrestrial energy source at around $50/kg, from the present-day launch cost of roughly $1,500/kg. Radiative cooling, often cited as a fatal obstacle, appears surprisingly manageable — potentially even cheaper than on Earth. However, ODCs may require substantial (perhaps ~38%) extra non-compute hardware (like solar, racks, and cooling) over 5 years to compensate for their inability to swap out failed chips, and inter-satellite bandwidth limitations likely confine ODCs to inference workloads, at least early on.
Assuming no transformative AI, but continued demand for data center buildout, we estimate that ODCs are unlikely to represent a meaningful share of compute before 2030, but become cost-competitive with present-day terrestrial data centers within 3–5 years if Starship development stays on track.
It seems much easier to shoot down a defenseless, slow-moving thing in low earth orbit than something on earth or underground (which could be covered by SAMs, patrolled by fighter jets, shielded by thick cement).
space data centers are not cost-competitive with terrestrial data centers.
My argument examines the different parts of a datacenter (chips, interconnect, comms, cooling, energy, etc.) and shows that in space the cost per unit of performance is worse at every step. If every step is more expensive in space, then terrestrial data centers must be cheaper.
He provided a lot of links to read though (I didn’t read them):
Further reading on space data centers, with an emphasis on good technical arguments and actually doing math.
A few casual arguments made in favor of space datacenters include the following:
Space can provide free solar energy 24 hours a day
Cooling is “free”. Some erroneously point to space being cold as a key positive
Communications latency in space is low as you’re just sending light through a vacuum
There is no need for permitting in space… so far…
Many of these points sound like they hold merit on the surface, but a deeper analysis of each apparent advantage reveals a far more complex story.
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Space-Earth datacenter cost parity opens the door, but in our base case, there is still ample terrestrial capacity—so going into space is a matter of preference and optimization rather than necessity. But if regulatory and capacity bottlenecks starve terrestrial datacenter capacity—space becomes a necessity.
Collecting opinions on whether data centers in space is a good idea (parent index):
(neg) https://taranis.ie/datacenters-in-space-are-a-terrible-horrible-no-good-idea/
(neg) https://news.ycombinator.com/item?id=46876105 (People saying why it won’t work)
(pos) https://research.google/blog/exploring-a-space-based-scalable-ai-infrastructure-system-design/
(neg) https://arstechnica.com/space/2026/03/orbital-data-centers-part-1-theres-no-way-this-is-economically-viable-right/
(pos) https://www.seangoedecke.com/space-ai-datacenters-do-not-have-a-cooling-problem/ (Why cooling is possible in space)
(neg) https://www.lesswrong.com/posts/65ECgHzWxTRvt8XWK/will-we-really-put-data-centers-in-space
For missile defense
(idea) https://www.lesswrong.com/posts/MEBcfgjPN2WZ84rFL/o-o-s-shortform?commentId=i3pG9mLXuQkAfxity
(neg) https://www.lesswrong.com/posts/Y5cQYKYwAb2WwXXQQ/tech-i-m-skeptical-of-and-why#Space_data_centers: I find this unconvincing with biased arguments all the way
He provided a lot of links to read though (I didn’t read them):
(neg) https://newsletter.semianalysis.com/p/to-boldly-go-the-case-for-space-datacenters
Some additional links offered by ChatGPT that I did not read
(“depends”) https://arstechnica.com/space/2026/07/how-hard-is-it-to-build-orbital-data-centers-actually/