Suncatcher Satellite Operational
Google Suncatcher’s prototype space data center is online and communicating with the ground after launching earlier this month alongside more than 100 other spacecraft on a SpaceX Falcon 9 rocket.
The satellite, which carries four Google Tensor Processing Units (TPUs) and generates up to 1 kW of electricity, is intended to pave the way for future networks of close-flying satellites performing large inference workloads in orbit. However, the power demands of the TPU mean it can only turn one on for about twenty minutes at a time, complicating the already tricky business of space-to-ground communications.
Running Gemma 4 in Orbit
After a commissioning process that tested out the satellite’s subsystems over about three weeks, the spacecraft was ready to work. When engineers on the ground sent their first prompt this week, they asked the model pre-loaded onto the satellite, Google DeepMind’s Gemma 4, to write a haiku about being in space. And thus:
Blue marble belowData streams in silent graceStarlight feeds my core. ✨
Google said it tested the model with space-themed limericks and asked the spacecraft to report on the orbital conditions around the satellite.
Engineers confirmed that the satellite was operating nominally during initial testing.
Radiation and Hardware Testing
The ongoing test campaign will examine how the chips perform under thermal stress and in the space radiation environment. Google has extensively tested its TPUs in particle accelerators on Earth, but now needs to see how radiation’s real effects on their hardware in space affect their processor. Radiation can cause bit flips—causing a stored value in computer memory—and that in turn can corrupt data without triggering typical monitoring tools.
Testing on the ground suggested the impact of radiation would be minimal for inference workloads and more of a problem for training a model, but now the Google team will get to assess those dynamics in reality, not a simulation.
Future Orbital Deployments
If the TPU onboard this spacecraft proves capable, the next step will be launching two more satellites equipped with advanced chips in 2027. Those spacecraft will support higher power generation and demonstrate inter-satellite optical links.
Google’s Starcloud project is largely alone among visions for space-based data centers in planning on high-speed links between the satellites to support coherent distributed workloads; other commercial efforts expect to perform inference loads on individual satellites.
Alphabet, Google’s parent company, holds a significant investment stake in SpaceX, and both companies anticipate utilizing heavy-lift launch vehicles for future orbital infrastructure.
Suncatcher researchers noted that achieving learning-driven cost reductions will require extensive flight heritage from heavy-lift rockets as Google designs infrastructure intended to be economical in the 2030s.
The Suncatcher prototype satellite has four TPUs onboard, but can only operate one at a time due to power constraints.
