A Startup Wants to Put 50,000 Mirrors in Space. The Goal: Make Sunlight Available at Night.

3 min readWith the launch of Sputnik in October 1957, humanity officially entered the satellite era, and in the ensuing decades, the thousands of satellites sent into space have drastically changed life on the ground. These sprawling networks of orbital spacecraft provide us with constant GPS navigation, communication, weather forecasting, and an unprecedented level of scientific surveys. But for ground-based astronomers, satellites have been a steadily growing headache.Problems really started back in 2019 when SpaceX launched the first cadre of Starlink satellites, and almost immediately their immense number and brightness disrupted ground-based observations of space. Today, there are more than 11,000 Starlink satellites, and scientists worry about their impact on next-generation telescopes, including the new Vera Rubin Observatory in Chile.Now astronomers may have an even bigger problem on their hands: Reflect Orbital. If you haven’t heard of this company, that’s not surprising. Unlike SpaceX, they currently don’t have any satellites in orbit at all, but what they plan to do with those satellites once they’re nestled within Earth’s orbit has astrophysicists begging for the federal government to intervene.“This is not a ‘concern’—this is like a bullet in your head,” Princeton University astrophysicist Gaspar Bakos told Sky & Telescope. “It’s the end of ground-based astronomy.”So what exactly has astronomers like Bakos up in arms? Well, Reflect Orbital bills itself as a “sunlight-as-a-service” company whose constellation of 50,000 satellites, each armed with massive mirrors, directs sunlight toward dark areas of the planet. The company says users could conceivably call for sunlight on demand to power solar panels or aid in nighttime search-and-rescue operations. But this altruistic vision likely obscures more lucrative use-cases for the military. That seems especially likely given the going rate for sunlight: $5,000 an hour, according to Sky & Telescope. That price is well beyond the budget of most search-and-rescue groups.Then there’s life on the ground. Plants and animals, humans included, depend on a day-night cycle that’s existed since Earth formed in the fiery cauldron of our star’s protoplanetary disk. Artificial sunlight could throw that rhythm off. Reflect Orbital CEO Ben Nowack dismissed these fears to the outlet Payload by saying that some people once feared light bulbs.“I think a lot of people are scared of new things,” Nowack told Payload. “Similar concerns and fears were brought up when light bulbs were introduced to the world, and people were worried about circadian rhythm and like, is this godly?…I think it’s a sign that we’re doing something that’s really new and really important.”On October 10, Reflect Orbital conducted a test of its technology near the town of Independence, California. As previously noted, the company doesn’t have any satellites in space yet, so instead they used giant, angled flood lights to mimic what the beam would look like from space and invited search-and-rescue groups to the demonstration. For astronomers, the blinding light confirmed their worst fears. Those fears have only grown since mid-July, when the Federal Communications Commission approved the company’s request to build a demonstration satellite called Earendil-1. The name continues the annoying trend of startups borrowing from The Lord of the Rings for their technologies.“You might think a space mirror could illuminate a customer’s solar farm or a rescue site while leaving everything else untouched,” Macquarie University astrophysicist Richard de Grijs wrote for The Conversation. “That’s not quite how it works, because Earth’s atmosphere doesn’t respect sharp boundaries.”A study in The Astrophysical Journal of Letters showed how molecules and aerosols would scatter this reflected sunlight, and another study detailed how a satellite with a 54-meter mirror (which is the operational goal) would still be brighter than our planet’s lone satellite if you were eight miles away from the beam. Within the beam, light would appear 40 times brighter than the moon, and the sky would be as luminous as after-sunset twilight. If Reflect Orbital reaches its planned 50,000-satellite constellation, the night sky would become three to four times brighter overall, according to the European Southern Observatory.For now, the company is forging ahead with its plan to launch its first satellites with India’s Skyroot Aerospace, which will require authorization with the Indian National Space Promotion and Authorisation Centre. This means the company could technically sidestep U.S. regulatory approval entirely.“This whole question we have is: Who owns the night sky?” University of Alabama astronomer Michelle Wooten told Sky & Telescope. “I really feel that people should have a say on what their night sky looks like.”Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough.