Scientists Urge FCC Review of Satellite Mirror Plans
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- Reflect Orbital plans to deploy satellites with large reflective mirrors to redirect sunlight onto areas 5-6km wide "on demand," with brightness adjustable from "full moon to full noon" for solar energy, disaster response, and agriculture.
- SpaceX has proposed launching up to 1 million satellites to create a solar-powered AI computing network in low Earth orbit, a plan the company says would cut terrestrial datacenter energy and cooling demands.
- Presidents of four international scientific societies (EBRS, SRBR, Japanese Society for Chronobiology, Canadian Society for Chronobiology), representing roughly 2,500 researchers from more than 30 countries, told the FCC the orbital deployment would be a "significant alteration of the natural night-time light environment at a planetary scale."
- A separate letter from five sleep and chronobiology societies warned that "circadian disruption is not mere inconvenience; it is a physiological mechanism driving major adverse health consequences," and urged that altering the night sky be treated with the same seriousness as climate change or ocean acidification.
- Dr Miroslav Kocifaj of the Slovak Academy of Sciences modeled that satellites and debris currently add 3-8 microcandela per square metre to night sky brightness, a figure he projects could rise to 5-19 microcandela by 2035, nearing the threshold astronomers set for preserving naturally dark skies.
- DarkSky International CEO Ruskin Hartley said existing satellites have already increased diffuse night sky brightness by roughly 10%, warned "there could be times and places where satellites outnumber the visible stars," and flagged risks of intense glare or blinding flashes if mirror systems malfunction or drift off target.
- Prof Tami Martino of the University of Guelph cautioned that biological systems can detect light changes far below what humans perceive as bright, meaning even sub-moonlight additions to the night sky could "ripple through ecosystems in ways we do not yet fully understand."
Why it matters: The FCC is weighing commercial applications from Reflect Orbital and SpaceX that, if approved, could add up to 1 million new satellites and active night-time illumination to low Earth orbit. Sleep and biological-rhythm researchers representing 2,500 scientists across 30+ countries are calling for a full environmental review and caps on satellite reflectivity before deployment, arguing that the night-time light environment underpins sleep, migration, plant cycles, and marine food webs. With modeling showing sky glow potentially rising to 5-19 microcandela/m² by 2035, the dispute turns a regulatory filing into a planetary-scale environmental question.
