Google puts four TPUs in orbit on October 1. The experiment is whether they survive.

On October 1 a refrigerator-sized satellite called MVP, built with the Earth-imaging company Planet, goes up on SpaceX's Transporter-18 rideshare from Vandenberg. It carries four of Google's Trillium TPUs into a sun-synchronous orbit at roughly 650 km, running on about a kilowatt of solar power.

That is the entire payload. Four chips, one kilowatt, one year of experiments. A single modern AI training rack draws more power than this satellite generates.

What the mission is actually for

Not compute. Survival.

The question Project Suncatcher has to answer first is whether data-center-class accelerators still work after launch vibration in the 50 to 100g range, under sustained radiation, and inside the thermal extremes of low orbit, where there is no air to carry heat away and cooling has to be done by radiating it into space.

Google has already run the ground half of that test: Trillium TPUs were exposed to a 67 MeV proton beam simulating roughly five years in orbit while running workloads. The reported result was no hard failures, with uncorrectable errors in high-bandwidth memory at a rate the team judged likely acceptable for inference. "Likely acceptable for inference" is a precise and honest phrase. It is not the same as "works".

Why the idea exists at all

The premise is power. In the right orbit a solar array sees near-constant sunlight and can produce several times what the same panel produces on the ground, with no grid connection, no substation queue and no water. Set against what we wrote yesterday about a 2.45 GW campus in New Mexico held up by a gas pipeline and an air-quality permit, the appeal is obvious: orbit has no permitting authority.

Google described the destination in November 2025 as clusters of roughly 81 satellites flying within a kilometre of each other, linked optically so the constellation behaves as one machine. Google's own description. The next step it commits to publicly is two prototype satellites with Planet by early 2027 to test short-range laser links at high bandwidth.

What this changes for anyone today

Nothing operational. No workload moves to orbit this year, or next.

What it changes is the shape of the argument. Until now "AI compute in space" was a slide. After October 1 there is either telemetry from four real chips in a real radiation environment, or there is a failure with a cause attached. Both are worth more than the slide.

The constraint to watch is not chips. It is heat and bandwidth. Rejecting a kilowatt thermally in vacuum is solvable; rejecting megawatts is a different engineering problem entirely. And a cluster is only one machine if the optical links between satellites carry something close to intra-rack bandwidth, which is exactly what the 2027 pair is meant to find out.

What is unknown

Whether the launch holds its date. Whether the TPUs run cleanly for the full experiment window rather than a few weeks. What the actual error rates look like in orbit versus the beam line. What any of this costs per unit of useful compute, which nobody has published and which decides whether the idea is an industry or a research paper.

What to watch

The launch itself on October 1, then first telemetry. After that, the 2027 two-satellite laser link test, which is the real gate. If inter-satellite bandwidth disappoints, the 81-satellite cluster does not become a computer; it becomes 81 small computers that cannot talk fast enough.

Reporting note: Source-based analysis, not independent verification. The constellation ambition and the Planet partnership come from Google's own statements. The October 1 launch specifics, orbit, power figure and radiation test details come from published reporting and have not been confirmed by us. We have not seen the mission's technical documentation.