Proposed new satellite fleets may destroy the night sky
Two new proposals for fleets of orbiting data centers and reflective satellites could pose an unprecedented threat to ground-based astronomy, astronomers warn in a new study. The spacecraft would not only leave destructive trails across telescope images, the analysis finds, but also brighten the night sky by as much as 300%, leaving observatories to peer through a haze of scattered light that would veil stars. “Essentially, we lose all the faint stuff for which we built the telescopes in the first place,” says Olivier Hainaut, an astronomer at the European Southern Observatory (ESO).
Hainaut’s research, which has been accepted for publication in Astronomy & Astrophysics, examines two recent commercial proposals. In July 2025, the company Reflect Orbital sought permission from the U.S. Federal Communications Commission (FCC) to launch a test satellite carrying an 18-meter-wide reflector that would beam sunlight onto nighttime Earth. The company’s aim is to launch 50,000 such reflectors to extend the operating hours of solar power arrays, mines, and emergency responders with artificial daylight. And in January, launch company SpaceX asked FCC to approve as many as 1 million solar-powered satellites that would act as orbiting data centers making use of copious solar power and avoiding pesky zoning regulations on Earth.
Individual astronomers and groups such as ESO and the American Astronomical Society have urged FCC to reject the proposals. Reflect Orbital’s plan drew 1800 public comments and SpaceX’s about 1500—far more than FCC filings typically receive. The agency has yet to rule on either proposal.
Astronautics engineer Hugh Lewis of the University of Birmingham welcomes the study’s examination of sky brightness. “It’s a global effect,” he says. “So it’s an incredibly important, incredibly valuable study.” Some of the proposed new constellations involve very large satellites whose brightness will be hard to reduce, Lewis says: “You don’t need too many of those before there is an effect.” [Continue reading…]