Overview
- Google published a research plan for tightly clustered, solar‑powered satellites carrying TPUs and linked by free‑space optical connections in dawn–dusk low Earth orbit.
- A learning mission with Planet targets two prototype satellites by early 2027 to test TPU operation in space and validate optical inter‑satellite links for distributed machine learning.
- Bench tests demonstrated 800 Gbps each way on a single optical transceiver pair, while radiation trials on Trillium (v6e) TPUs showed irregularities only after ~2 krad(Si) with no hard failures up to 15 krad(Si).
- Google’s models indicate tens‑of‑terabits‑per‑second networking could be reached by flying satellites hundreds of meters apart with modest station‑keeping, though thermal control, high‑bandwidth downlinks, and reliability remain open challenges.
- Cost modeling projects launch prices below $200/kg in the mid‑2030s could make orbital compute cost‑comparable per kW‑year, with environmental benefits still debated given launch emissions and concerns over debris plus astronomy impacts; other efforts include NTU research, a Thales study, and Starcloud’s Nvidia‑powered test this month.