Thousands of huge mirrors will be launched into space by a small California startup to reflect sunlight onto Earth at night. Reflect Orbital wants to launch “selling sunlight,” from orbit, according to the company.
More light for cities, farms, and solar panels initially sounds futuristic and beneficial.
However, many scientists consider it to be a big issue, especially astronomers: they warn that this project could harm the night sky, disturb people and wildlife, put pilots in more danger, and make low Earth orbit more hazardous.
How the space mirror plan would work
Founded in 2021, Reflect Orbital plans to send about 4,000 massive mirrors into low-Earth orbit. They would all be about the size of a tennis court. Sunlight from the Earth’s daytime side would be captured by these mirrors and reflected onto particular regions of the night side.
The company believe this extra light would:
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Extend the generation of solar energy after sunset.
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Allow farmers to harvest crops at night.
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Replace some street lighting in cities
The company has requested authorization from the Federal Communications Commission (FCC) of the United States to launch EARENDIL-1, an experimental satellite, in 2026. An area around 5 km wide could be illuminated by this satellite’s 18-meter reflector, which would be four times brighter than a full moon. Mirrors up to 54 meters across have been proposed in future plans.
They caution that placing thousands of bright moving mirrors in orbit would be equivalent to covering the sky with new artificial stars. In comparison with accidental reflections from internet satellites, this light interference would be deliberate and constant.
Why experts believe the project is almost impossible
The project is “highly unlikely to come to fruition,” according to Fionagh Thomson, a space ethics researcher at Durham University. She highlights that operating thousands of huge mirrors in low Earth orbit—an area already crowded with satellites and space debris—is extremely complex and risky.
Similar initiatives were made by Russia with its Znamya satellites in 1993 and 1999. Both missions were unsuccessful because the satellites burned up in the atmosphere after reentry and the mirrors were difficult to control.
The benefits that were promised are also a major problem. Even if solar farms were receiving this reflected light, they would only generate a very small amount of additional energy because it is thousands of times weaker than actual sunlight. Before continuing on its orbit, each mirror could only illuminate a single location on Earth for about 4 minutes. Therefore, even if the system functioned with no problems, it would be incredibly expensive and not that useful in comparison to conventional renewable energy on the ground.
Astronomers like Samantha Lawler, point out that the approval process is even more terrifying than the technology because a single business could change the night sky’s appearance for the entire world with enough money and regulatory approval.
Threats to the planet, the sky, and nature
Many astronomical observations would be impossible with thousands of mirrors around. Some stars would disappear behind artificial reflections, and flashes could ruin long-exposure images. In serious cases, a bright reflection seen through a telescope could even cause eye damage.
The natural cycle of light and dark is vital to many plants and animals. Extremely bright and artificial lights could confuse nocturnal species and disturb ecosystems.
Also, the mirrors would be vulnerable to space debris and micrometeorites. Random flashes could be sent across the sky if a damaged mirror spins out of control. Low Earth orbit is already being pushed to its limits by planned satellites.
However, the fact that Reflect Orbital only intends to conduct a thorough environmental assessment after the launch of its first satellite is what concern experts the most.