A Post Saying Space Data Centers Cannot Be Cooled Draws 5 Million Views and Sparks a Wide Debate About Elon Musk's Orbital Compute Plans
My respect for Elon Musk has mostly vanished, but I still thought that at least he is a good engineer (Teslas are great cars). But that last bit also got a blow after hearing him say that it is easier to "cool things down" in space. The opposite is true. A vacuum is the best possible isolator. In space you can only dissipate heat through radiation. It is extremely unlikely these data centers in space will ever happen (and certainly not in our lifetimes).
Context
Whether data centers in orbit can shed their heat decides if space compute is a real path for AI or a distraction, and the argument is now very public.
Elon Musk has promoted putting AI compute on satellites in orbit. In a vacuum there is no air to carry heat away, so satellites can only shed heat by radiating it, which needs large radiator surfaces. Jan Broersen's post questioning the idea became one of the most viewed AI related posts of the day.
Deep dive
Jan Broersen (@broudsov) posted on the morning of Nov 2 ET that his respect for Elon Musk had mostly vanished, and that his view of Musk as a good engineer took a blow after hearing him say it is easier to cool things down in space. Broersen wrote that the opposite is true: a vacuum is the best possible insulator, so in space heat can only be dissipated through radiation. He called it extremely unlikely that data centers in space will ever happen, and certainly not in our lifetimes. The post passed 5 million views and drew more than 3,600 replies.
The post set off a wider argument. phil beisel (@pbeisel) quoted it, pointing out that there are 11,184 Starlink satellites in orbit cooling through their radiative structures, while noting those satellites do not have the same heat loads as compute satellites. In a later post he said people explaining why cooling a compute satellite is impossible were repeating past doubts about SpaceX and Tesla. Musk reposted that post.
On the research side, Rohan Anil (@_arohan_), who says he develops training algorithms used for frontier models, shared a write up on training across separate compute islands and eventually in space. Jerry Tworek (@MillionInt) quoted a post by elie (@eliebakouch) and wrote that space datacenters actually make sense. Musk reposted him too.
Both sides agree that heat in orbit must leave by radiation. The open dispute is whether radiators big and light enough to cool AI chips can be launched cheaply enough to matter.
What to expect next
Watch for concrete numbers from SpaceX or other companies on radiator size, power per satellite and launch cost, which would settle much of the argument. Research on training across distant clusters, like the write up Rohan Anil shared, will matter whether or not compute ever goes to orbit. Expect the debate to return every time Musk talks about orbital compute.