Nighttime solar plan upsets astronomers

A startup that aims to keep solar farms running at night by reflecting sunlight from space has sparked controversy among astronomers whose work relies on dark skies.

- By Coco Liu

REDIRECTING sunlight to solar farms at night may have environmental pitfalls.

(BRIAN VAN DER BRUG Los Angeles Times)

California-based Reflect Orbital recently requested a license from the Federal Communications Commission to launch a demonstration satellite in 2026 as its first step to creating a constellation that will redirect sunlight to precise locations on demand. The startup says it plans to launch dozens more over the next two years, with a goal of having about 4,000 satellites in orbit by 2030.

Reflect Orbital’s plan has won the backing of investors who include Sequoia Capital and tech billionaire Baiju Bhatt. But although its mission is to extend the operating hours of solar farms, astronomers say doing so will come at the expense of their research.

“Tlluminating the ground at night with 4,000 bright satellites of this kind is potentially ruinous to state-of-the-art, ground-based optical astronomy,” says Anthony Tyson, the chief scientist of the Rubin Observatory, which will begin its sky survey next year.

Although Reflect Orbital says the redirected light from its first demonstration satellite will be similar to the illumination of a full moon, that would still be “blindingly bright” for sensitive astronomy cameras, Tyson says.

“Like other large ground-based telescopes, Rubin relies on dark skies,” he says of the observatory in Chile.