If the sun can radiate heat into space, why is this a problem for data centers in space?

Elsewhere, I linked to a New York Times article (gift link) about Google’s plan to launch an experimental AI data center in space later this week. The article mentions how the cooling will occur.

The biggest challenge was how to cool the A.I. chips, which heat up when they perform calculations and process information. Fans, which typically help dissipate the heat, do not work in space. So the Silicon Valley company instead developed a cooling system that uses layers of conductive material to expel the heat into space.

The bottom layer is made up of Google’s A.I. chips, which sit on a green motherboard. The next layer consists of “thermal interface material,” a pale green putty that comes in sheets like Fruit Roll-Ups and connects the chips to layers of aluminum and copper, radiating heat away from the motherboard. Finally, there is a radiator panel, which projects heat into space.

The chips can operate for about 15 minutes in space before needing to be shut down so they can cool off, said Travis Beals, Google’s senior director of product management for Project Suncatcher. During that time, the chips can process short queries so Google’s A.I., known as Gemini, can respond.

So, yes, radiation is being used to dissipate heat. But that’s not enough, which is why the system will work for only a short time before being shut down to allow it to cool.