California startup Reflect Orbital has applied for a government license to launch a giant mirror into space next year. The mission is meant to be the first step in the company’s ambitious plan to harness a constellation of more than 4,000 solar reflectors to boost solar power generation during dusk on Earth.
According to the company’s application to the Federal Communications Commission (FCC), Reflect Orbital wants to fly its EARENDIL-1 demonstration satellite next year, with a planned launch date of April. Once in orbit, the satellite will deploy a mirror measuring 60 by 60 feet (18 by 18 meters) to demonstrate its ability to direct sunlight to targets on Earth. The company, which awarded $1.25 million Small Business Innovation Research (SBIR) contract of the US Air Force in May, said its future constellation would provide light on demand after sunset and before sunrise to paying customers on Earth, extending daylight hours.
But the project, which promises to help increase clean energy production during morning and evening peak hours, has alarmed astronomers and biodiversity experts concerned about the effects of light pollution the constellation will produce.
Orbital thinking complaints on its website that its constellation will produce solar energy at night, improve crop growth, eventually replace city lighting, provide emergency lighting in disaster areas, and allow people to work at night.
Reflect Orbital’s spokesperson told Space.com in an email that by 2030, the company envisions a constellation of 4,000 of these satellites, circling Earth in a sun-synchronous orbit following the boundary between day and night. (Satellites in sun-synchronous orbits circle the planet from pole to pole and pass over a given location on Earth at the same solar time each day.)
The company said in its FCC license application that the proposal had “received significant interest from commercial and government partners,” that it had already secured full funding for the demonstration mission, and that it had received “more than 250,000 requests for service.”
Astronomers and biodiversity experts, however, are expressing concerns about the development, calling for an environmental study of the effects of space mirrors on life on Earth.
“The reflectors will direct their light (even after they pass their target) because they obviously can’t turn it off,” John Berentine, an astronomer at the Silverado Hills Observatory in Tucson, Arizona, and a consultant at Dark Sky Consulting, told Space.com. “The beam reflected from these satellites is very intense, four times brighter than the full moon, and they will fly several satellites in formation. This will have an effect on wildlife in the directly illuminated area, but also, through atmospheric scattering, on surrounding areas.”
Robert Massey, deputy executive director of the UK’s Royal Astronomical Society, said the astronomy community was “seriously concerned about the development, its impact and the precedent it sets”.
“The main goal of this project is to light up the sky and extend daylight and obviously, from an astronomical point of view, it’s pretty catastrophic,” Massey told Space.com.
Reflect Orbital said the company takes these concerns seriously and wants to use the upcoming demonstration mission to limit the possible negative effects of reflected light.
“Our service is highly localized,” the spokesperson wrote. “Each reflection covers a defined area of 5 kilometers for a limited period of time rather than providing continuous or widespread illumination.”
Once the satellite passes the target region, the mirror will move away from the planet’s surface, the spokesperson explained.
“During the 2026 demonstration, observers at designated test sites will see the reflection as a bright, moving star,” the spokesperson wrote. “The illuminated area on the ground will be a soft lunar glow.”
Astronomers and biodiversity experts have been waging a war against light pollution for years. Data shows that since the advent of LED lamps, global light pollution levels have increased by approximately 10 percent per yearvirtually erasing the stars from the night sky. Where some 18 years agowe would see 250 stars at night, we only find around a hundred today. But increasing levels of light pollution have also been linked to decline in insect populations and the increasing incidence of sleep disorders and depression in humans.
“Light pollution fundamentally disrupts the natural day-night cycle that has governed life on Earth for billions of years,” said David Smith, head of advocacy and social change at invertebrate charity BugLifeSpace.com said in an email. “By effectively extending daylight hours through artificial light and blurring the boundaries between day and night, light pollution interferes with the circadian rhythms, physiology and behaviors of countless species.”
Astronomers are also concerned about the effects of the growing number of satellites on their observations. SpaceX’s Starlink, in particular, has been the subject of controversy because its thousands of spacecraft, flying at low altitudes of 340 miles (550 kilometers), leave traces on their images.
AST SpaceMobile, which is developing a constellation of giant space antennas beaming high-speed internet directly to smartphone users on Earth, has also come under fire since the harm that its fleets do to astronomy.
But Massey said none of these projects aim to reflect sunlight back to Earth, unlike Reflect Orbital. In fact, astronomers have praised SpaceX for its continued attempts to reduce the reflectivity of its spacecraft, either by applying light-absorbing paints or visors..
“The satellite constellations we’ve been dealing with create light pollution as an accidental byproduct,” Massey said. “It’s something we hope we can manage and mitigate. But with this project, sky brightening is the central premise.”
Berentine said that outside of directly illuminated areas, at distances of up to a hundred kilometers, space mirrors will appear in the sky as very bright stars. These artificial stars, moving across the sky in rapid succession, will disrupt astronomical observations but potentially also confuse migrating birds.
He added that although Reflect Orbital has discussed the development with the astronomical community, many questions remain unanswered.
The Reflect Orbital spokesperson said the company intends to conduct an environmental impact assessment before building the constellation and hopes to use the demonstration mission next year to “collaborate with experts to better understand the ecological sensitivities of each service site.”