A California start-up’s plan to launch thousands of mirrors into orbit has caused a lot of excitement among astronomers and wildlife experts. The company Reflect Orbital aims to maximize the energy production of solar farms by redirecting sunlight towards them at night.
Reflect Orbital recently applied for a license from the Federal Communications Commission (FCC) to launch a demonstration satellite called EARENDIL-1 in April 2026. Once in orbit, the satellite will deploy a 3,600-square-foot (334-square-meter) mirror designed to direct sunlight toward targeted solar farms on Earth. This would be the first step toward the company’s goal of deploying a constellation of 4,000 such satellites by 2030.
“The cost that this brings not only to astronomy, but to all of civilization — as well as the ecological impacts — is not worth it, in my opinion,” Siegfried Eggl, assistant professor of astrophysics at the University of Illinois at Urbana-Champaign and co-leader of the IAU Center for the Protection of Dark and Quiet Skies, told Gizmodo.
Reflect Orbital did not respond to Gizmodo’s request for comment at the time of publication. A company spokesperson told Space.com that it intends to conduct an environmental impact assessment before building the constellation.
Would Reflect Orbital’s plan even work?
Reflect Orbital’s website promises that its constellation will provide “continuous and reliable access to energy, day or night, to increase electricity production.” That pledge won support from big investors and a $1.25 million small business innovation research contract from the U.S. Air Force.
On paper, the concept is relatively simple: use a hand mirror to reflect a spot of sunlight on the wall. But in practice, this approach may not be as effective as Reflect Orbital hopes, according to astronomers Michael JI Brown of Monash University and Matthew Kenworthy of Leiden University.
In a recent article for The Conversation, they explain that due to the size and distance of the Sun, a reflected beam would spread out and be about 15,000 times fainter than the midday Sun once it reached the Earth’s surface, although this would still be much brighter than the full Moon.
“If a single 54-meter (177-foot) satellite is 15,000 times fainter than the midday Sun, it would take 3,000 to reach 20 percent of the midday Sun. That’s a lot of satellites to illuminate a region,” Brown and Kenworthy write. Since these satellites would orbit Earth so quickly, well over 4,000 would be needed to provide continuous illumination, they add.
And that’s if everything goes as planned, Eggl said. Imagine, for example, that a piece of space debris or a meteorite hits one of these mirrors and causes it to fall. “Once this thing collapses, you basically get a gigantic beacon that uncontrollably lights up parts of the Earth,” he explained.
The consequences of light pollution
Darkness is a dwindling resource on which astronomers fundamentally depend. Light pollution poses a growing threat to their research, with global levels increasing by around 10% per year since the advent of LED lights.
“When you have mirrors that shine even in the approximate direction of where the telescopes are, the brightness of the sky is going to increase significantly,” Eggl explained. “It will be like having a full Moon every night, and it will be devastating for astronomy.” This would prevent telescopes from imaging the very faint objects that astronomers need to observe.
Light pollution also threatens many animal species whose behavior has evolved to align with natural day-night cycles. “By effectively extending daylight hours through artificial light and blurring the lines between day and night, light pollution interferes with the circadian rhythms, physiology and behavioral patterns of countless species,” David Smith, head of advocacy and social change at invertebrate charity BugLife, told Space.com.
Reflect Orbital’s FCC license application is still awaiting approval, and Eggl hopes regulators will take the scientific community’s concerns seriously. “But given what they’re proposing, I don’t see how it could be hugely disruptive to all sorts of things,” Eggl said.
