SpaceX has proposed launching up to 1 million data centres into low Earth orbit, but cooling, radiation, space debris, and the costs of launch and orbital assembly must be overcome before it can be implemented, MIT Technology Review reported on Thursday (local time).

SpaceX filed an application with the U.S. Federal Communications Commission (FCC) in January. The goal is to expand artificial intelligence (AI) computing without relying on terrestrial power grids or cooling water. Jeff Bezos said last year that large-scale computing would move into space, and Google is pushing to launch a test constellation of 80 satellites as early as next year. Washington state startup Starcloud launched a satellite carrying Nvidia H100 GPUs in November last year.

The first problem to solve is cooling. Space data centres must be placed in an orbit that receives continuous sunlight, meaning equipment temperatures do not drop below 80 degrees. In space, there is no convection of air or water, so heat must be removed only through radiation. This requires large radiator surfaces. A 2024 feasibility study by Thales Alenia Space found Europe could place gigawatt-class space data centres into orbit before 2050.

Radiation is also a major variable. Space radiation can cause bit flips, performance degradation and permanent damage. Existing radiation-hardened space electronics are expensive and lag in performance. Nvidia unveiled AI computing hardware for orbital data centres in mid-March, but memory and storage devices are also vulnerable to radiation, and there must be a way to replace and reconfigure them when failures occur. Concerns also remain that intense space weather could cause satellite electronic equipment to shut down all at once.

Congestion in low Earth orbit is another obstacle. LuneXus Space estimated total low Earth orbit capacity at about 240,000 satellites. Astronomers voiced opposition, saying that if large-scale replacements on a five-year cycle become reality, re-entry debris could increase from 3 to 4 pieces a day to one every 3 minutes.

The economics also remain uncertain. Large space data centres cannot be carried on a single rocket launch and must be assembled in orbit, but there is no advanced robotic system yet to do the job. In the short term, small servers that process Earth-observation satellite imagery directly in space are more likely to take hold first.