Google's Suncatcher Puts Four TPUs in Orbit on About 1 Kilowatt of Solar Power

Google's first Project Suncatcher satellite reached orbit on October 1 aboard SpaceX's Transporter-18 rideshare from Vandenberg Space Force Base, carrying four Trillium TPUs. The company says it has made contact and that the spacecraft is operating as expected, according to coverage of the launch.

What Suncatcher's first satellite carries

The prototype was built with Planet and is about the size of a refrigerator, according to Hardware Busters. It carries four Trillium-generation TPUs fed by roughly 1 kilowatt of solar arrays, in a sun-synchronous orbit at about 650 kilometres. That outlet reports up to six months of AI experiments. Google's own post does not give the altitude or the TPU count, so treat those figures as single-source.

One kilowatt is about the draw of a single high-end gaming PC. The prototype is not a data centre; it is a test article for whether the chips and their cooling survive.

What Google tested on the ground

Travis Beals, Senior Director, Paradigms of Intelligence at Google, wrote that the Trillium TPUs survived a radiation total ionizing dose greater than they would receive in a five-year space mission, tested at UC Davis's Crocker Nuclear Laboratory. Hardware Busters adds that the beam was 67 MeV protons, that there were no hard failures, and that the high-bandwidth memory showed uncorrectable errors at a rate the team judged "likely acceptable for inference".

Launch loads were also tested: Google gives up to 10 times the force of gravity for the spacecraft and 50 to 100 g for individual components. Cooling relies on heat pipes and radiators, checked in a thermal vacuum chamber. Space gives up to eight times the solar power available on the ground, in Google's words, but no air to carry heat away.

The gap between four chips and a constellation

	This prototype	Google's long-term sketch
Satellites	1	81 within a 1 km radius
TPUs	4	dozens per satellite
Inter-satellite link	none	10 Tbps needed vs 1 to 100 Gbps today
Launch cost	not stated	about $200 per kilogram

The link gap is the hardest line. Closing it takes optical links 100 to 10,000 times faster than current ones. Google compares the pointing problem to hitting a coin-size target from miles away while both ends move. A two-satellite laser test is planned for 2027, per the Google post.

The launch-cost target of about $200 per kilogram is the other variable, and it depends on reusable boosters like the ones in our report on the Falcon Heavy NRO launch.

On the ground, the same question of how much compute fits in a given power budget shows up in antirez's DeepSeek V4.1-Flash setup on a 128 GB Mac.

What would change this read is the first telemetry. If the HBM error rate in orbit matches the ground beam test, the chips are not the obstacle and the links and launch price are. Google's plan puts the next two prototype satellites in early 2027.