Science fiction becomes reality: Giant mirrors in space are approved

A science fiction concept has taken a step closer to reality as a U.S.-based startup has received approval to launch a satellite designed to reflect sunlight onto Earth. This project, developed by Reflect Orbital, aims to create artificial daylight by using a massive mirror in space. The first satellite, named Earendil-1, features a reflective surface measuring 54 meters in diameter. Its primary function is to redirect sunlight to specific locations on Earth, potentially offering illumination during nighttime hours for paying customers. The Federal Communications Commission (FCC) granted permission for this launch after reviewing the company's application last year. According to reports, the satellite is intended to serve as a demonstration model for future applications involving large-scale solar reflection technology. The decision to approve the launch was met with significant concern from several scientific organizations. The American Astronomical Society raised alarms about potential risks associated with the satellite’s operation. These include possible eye damage to amateur astronomers using telescopes of appropriate size, temporary glare issues for drivers and pilots, and adverse effects on astronomical research conducted by publicly funded institutions. The society emphasized the need for a thorough risk assessment before proceeding with such a launch. Despite these warnings, the FCC proceeded with its approval, citing the importance of promoting new technologies and services for public benefit under U.S. communications law. The commission also noted that it is primarily responsible for frequencies outside the radio spectrum and considered the likelihood of harm to be low. Reflect Orbital envisions a much larger deployment of similar satellites in the future. The company's founder, Ben Nowack, mentioned plans for up to 250,000 units positioned at an altitude of 600 kilometers above Earth. This number would surpass the total count of all existing satellites currently in orbit, including debris from past missions. However, experts have pointed out limitations regarding the practical effectiveness of such a vast network. For instance, scientists Michael Brown and Matthew Kenworthy explained in an analysis for The Conversation that even with 250,000 satellites, the light coverage would be limited. They estimated that only certain areas near twilight could receive illumination before the satellites themselves enter Earth's shadow. Even then, the brightness achieved would amount to roughly 20 percent of midday sunlight intensity at just 80 positions on Earth. To demonstrate the feasibility of their concept, Reflect Orbital conducted a test using a hot air balloon equipped with a smaller mirror measuring 2.5 meters in diameter. The experiment showed that it was possible to reflect approximately half of the energy from midday sun onto the ground. Nevertheless, Brown and Kenworthy calculated that for a satellite-based mirror operating at an altitude of 800 kilometers, the required size would need to be significantly larger—more than eight times eight kilometers in dimensions. Recent discussions suggest varying estimates for the scale of the project, ranging from at least 4,000 to as many as 50,000 satellites. During an interview with Bloomberg, representatives from Reflect Orbital assured that they would avoid placing satellites directly over astronomical observatories. They acknowledged that light scattered from space would cover several kilometers but committed to providing precise information about each satellite's location. It should be noted that the FCC's current approval applies specifically to one satellite, while most concerns relate to the implications of deploying numerous such satellites simultaneously. As the project moves forward, ongoing dialogue between technological innovation and environmental impact remains crucial. While the potential benefits of artificial daylight generation are being explored, careful consideration must be given to how such systems might affect both human activities and scientific endeavors. The balance between advancing new technologies and preserving observational capabilities in astronomy continues to be a topic of discussion among stakeholders involved in space exploration and regulation.