IEEE Spectrum published a comprehensive analysis of "orbital data centers" — the idea of putting data centers in space to take advantage of solar power and radiative cooling. The verdict from thermodynamics: orbital data centers are not economically viable for at least 10 years, due to the heat rejection problem in vacuum.
The "orbital data center" hype: the idea has been around for years — put a data center in low Earth orbit (LEO), power it with solar panels, and use radiative cooling (heat radiates to the cold sky) to keep it cool. The pitch is "unlimited solar power + free cooling = cheap compute." Several startups (Axiom Space, Lumen Orbit, Starcloud) have raised funding on this idea.
The thermodynamics reality: the analysis shows that the heat rejection problem is much harder than the hype suggests. In vacuum, the only way to reject heat is radiation, which is highly inefficient at the temperatures a data center requires. A 1MW data center in LEO requires a 10,000 m² radiator — about the size of two football fields. The launch cost alone is $500M-$1B, and the radiator adds another $200M.
The economic verdict: even with optimistic assumptions about launch cost reduction and solar panel efficiency, orbital data centers cost 5-10× more than terrestrial data centers in the near term. The "decade before landing" timeline is the most optimistic — the analysis suggests 15-20 years is more realistic.
The bigger takeaway: "physics-first" analysis is essential for hype-y ideas. The "orbital data center" pitch is appealing in the abstract, but the thermodynamics make it impractical for the foreseeable future. For the industry, this signals that the "compute is moving to space" narrative is premature, and terrestrial data centers (with renewable energy) will remain the dominant paradigm for the next decade+.