US regulators clear first orbital mirror as start-up plans 50,000-strong sunlight-reflecting fleet

US officials have approved a mission to launch a giant mirror into space that would reflect sunlight onto shadowed parts of Earth, Nature reported (https://www.nature.com/articles/d41586-026-02218-9), in a step toward a controversial plan to "turn night into day."

The start-up Reflect Orbital, based in Hawthorne, California, received approval from the US Federal Communications Commission on 9 July to launch its first satellite, Eärendil-1, later this year into an orbit 625 km above Earth (https://www.nature.com/articles/d41586-026-02218-9). The mini-fridge-sized craft will deploy a mirror the size of a tennis court yet 28 times thinner than a human hair, illuminating a patch of roughly 24 square kilometres on the planet's surface; the company says the light can be switched off on demand.

Reflect Orbital says its manufactured "daytime" could boost agricultural productivity, aid natural-disaster relief and allow solar panels to generate electricity at night, with the longer-term goal of placing 50,000 mirrors in orbit by 2035 to deliver "full noon" brightness in selected areas (https://www.nature.com/articles/d41586-026-02218-9).

Astronomers have warned the beams would interfere with sensitive telescope equipment and worsen light pollution. "With 50,000 satellites, that would probably mean the end of ground-based astronomy, or optical astronomy, at least," said Roohi Dalal, deputy director of public policy at the American Astronomical Society in Washington DC (https://www.nature.com/articles/d41586-026-02218-9).

The company rejects that claim. A spokesperson said it "demonstrates a lack of understanding of our technology" and that guard rails are in place to avoid disrupting astronomers' work; Reflect Orbital says feedback from the astronomical community has "already materially informed the design of our spacecraft and operational plans" (https://www.nature.com/articles/d41586-026-02218-9).

Engineers also note technical hurdles. Darren McKnight, a senior technical fellow at debris-tracking firm LeoLabs, said a single hardware or software error could cause faulty deployment, and that the mirror's orbit carries a high concentration of atomic oxygen and common centimetre-scale debris that could erode or strike the ultra-thin reflective surface (https://www.nature.com/articles/d41586-026-02218-9).

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