The FCC approved Reflect Orbital’s first satellite, Eärendil-1, on July 9 to test space mirrors that would reflect sunlight from low Earth orbit onto the ground. The move clears the way for a live test of a system critics say could affect astronomy and the environment, while Reflect Orbital says it wants to prove the idea can work at all.
Eärendil-1 and low Earth orbit
Eärendil-1 is a 142-kilogram spacecraft scheduled to launch later this year, and it will deploy a thin-film reflector 18 meters on a side while orbiting 600 to 650 kilometers above Earth. Reflect Orbital says the test is meant to direct reflected sunlight to specific areas on Earth for several minutes at a time, which is the basic performance question behind the project.
Ben Nowack and the FCC filing
Ben Nowack said, “We’re grateful to the FCC for recognizing the importance of testing novel technologies in space,” and added, “This license is the first step toward rigorously testing our technology’s efficacy and the safeguards we have developed.”
That pitch is not the only one in play. Reflect Orbital says it has seen strong interest in using the technology for construction sites and search-and-rescue efforts, and it also proposes using such satellites to reflect sunlight onto terrestrial solar farms to increase energy production.
Tony Tyson and the sky-brightness risk
The FCC approved the satellite even though astronomers and environmentalists warned the system could harm astronomy and disrupt plant and animal cycles. Tony Tyson, a distinguished research professor at the University of California, Davis and chief scientist of the Vera C. Rubin Observatory, called the Reflect Orbital plans “even crazier” than the broadband satellite constellations astronomers have worried about for several years.
At a June 4 National Academies meeting, Tyson said, “Imagine the sky full of moons.” His concern was practical, not rhetorical: he said the thin-film reflectors might not precisely direct sunlight and could scatter it over a wider area, which would make the light harder to control and the sky brighter where observatories are trying to work.
The European Southern Observatory warning
The European Southern Observatory said in a July 1 statement that the full constellation of 50,000 satellites proposed by Reflect Orbital would increase background sky brightness at its facilities by a factor of three to four, and that the brighter sky would limit the ability of telescopes to detect faint objects.
Reflect Orbital submitted its application nearly a year ago and generated nearly 1,900 comments, mostly critical of the potential impacts of the system. The FCC said it largely concluded that any impacts of Eärendil-1 on astronomy or the environment were outside its jurisdiction, so the immediate question now is not whether the concept has critics, but how much sunlight the first satellite can actually throw and how accurately it can place it.
