Google will test four AI chips in orbit, where cooling limits runs to minutes

Google’s Project Suncatcher is moving from a research paper to a hardware test in orbit. The first prototype, integrated into a Planet satellite for SpaceX’s Transporter-18 mission, carries four Trillium Tensor Processing Units and roughly one kilowatt of solar power. Google says the launch will test whether ordinary data-center accelerators can survive rocket vibration, sustained acceleration, radiation, and the thermal extremes of low Earth orbit. The company reports that ground tests exposed components to loads as high as 50 to 100 times Earth’s gravity and subjected TPUs to proton radiation while they ran AI workloads. The early result is encouraging: Google says the chips withstood more total ionizing dose than expected over a five-year mission. The harder problem may be heat. A vacuum has no air to move across hot chips, so the satellite uses thermal-interface material, heat pipes, and radiators. Ars Technica reports that the TPUs will run for about fifteen minutes at a time before shutting down to cool. That is an experiment, not an orbital data center. The next planned milestone is a two-satellite test in 2027 using high-bandwidth laser links precise enough to connect moving spacecraft over short distances. Google’s original vision is ambitious because low Earth orbit can receive near-continuous sunlight, which the company estimates could generate up to eight times more solar power than comparable panels on Earth. Yet abundant input energy does not solve heat rejection, launch cost, maintenance, debris, latency, or the need for dense inter-satellite networking. The October test matters precisely because it converts a cinematic promise into failure data.