Peter Howson, Northumbria University, Newcastle
AI companies increasingly want to move their operations into space. Elon Musk’s SpaceX has applied to launch over a million AI data centre satellites and ultimately build them on the moon.
Jeff Bezos, Google, OpenAI and others have similar plans. The idea is to harness 24/7 solar energy and, in Bezos’s vision at least, to move all polluting industries off-world, re-zoning Earth for humans and nature.
It’s an intriguing plan. But once you factor in the whole life cycle, from water and rocket fuel used to launch these satellites into space, to keeping them cool and eventually disposing of old satellites, the environmental case becomes less clear.
Outer space, out of mind
Off-worlding polluting industries is not a new idea. In the 1970s, when the last Iranian oil crisis caused rocketing fuel prices, Nasa kicked off a plan to build huge solar plants in space. The idea flopped when the oil began to flow again.
Nasa also explored the prospect of storing nuclear materials on the moon and blasting hazardous waste at the sun. These plans may have been feasible from an engineering perspective but were politically impossible due to the risk of radioactive particles eventually falling back to earth.
Since data centers need so much energy, much of it for AI, such astronomical ideas are back on the table. Regular Earth-based data centers were responsible for around 5% of all electricity used in the US last year, for instance, mostly using fossil fuels. Their share of US power demand will likely triple by 2028.
The fragile frontier
That’s why the cold vacuum of space, with its endless supply of solar energy, is being pitched as a more sustainable alternative to big, noisy, hot data centers in our back yards.
Meanwhile, a recent petition from environmental law charity Earthjustice, is calling for a comprehensive review. They argue these proposals fail to acknowledge any environmental impact. “This is not just poor planning and a missed opportunity”, the petition states, “it violates federal law”.
Indeed, SpaceX’s planning applications come with assurances of no meaningful environmental impact. “It’s always sunny in space,” according to Musk, who says orbital data centers are “obviously the only way to scale”.
Yet data centers in space would be even more prone to overheating than those on earth. That’s because, like a Thermos flask, space keeps things hot. There’s no water or air to carry excess heat away. Instead, keeping powerful AI chips cool in orbit requires massive ammonia-filled radiators that let heat escape as infrared radiation. This isn’t very efficient and those radiators are much larger than the computers they cool. Lifting these huge structures to orbit would require a lot of rocket fuel.