Space Mirrors to Light Earth at Night Get FCC Green Light

A California-based startup, Reflect Orbital, has secured Federal Communications Commission (FCC) approval to launch a prototype satellite named Earendil-1. The mission aims to test the feasibility of using large mirrors in orbit to reflect sunlight onto specific areas of Earth after sunset. This groundbreaking project, slated for a low Earth orbit launch later in 2026, could usher in a new era of artificial illumination, though it has already sparked debate among the astronomical community.

The Earendil-1 satellite is designed to deploy an 18-meter (59-foot) film reflector. If this initial test proves successful, Reflect Orbital has ambitious plans to construct a constellation of up to 50,000 such mirrors. These orbiting reflectors would create patches of sunlight after dark, with the potential to illuminate areas up to 5 kilometers (3 miles) wide. The projected intensity of this reflected light, ranging from 0.8 to 2.3 lux, significantly surpasses the illumination provided by a full Moon, which typically measures between 0.05 and 0.3 lux on a clear night.

Reflect Orbital suggests a wide array of applications for its technology. The company envisions using the redirected sunlight to aid in disaster zones and search-and-rescue operations, extend working hours for industrial sites, boost agricultural yields, and even potentially reduce light pollution by replacing conventional city lights. Defense operations are also listed as a potential beneficiary of this novel illumination system. According to the company's website, the goal is to provide targeted, on-demand light sources.

Astronomers voice significant concerns

Despite the potential benefits, Reflect Orbital's proposed constellation has drawn sharp criticism from astronomers worldwide. Concerns center on the potential disruption to ground-based astronomical observations. A recent report by the European Southern Observatory (ESO) analyzed the impact of bright satellite constellations, concluding that a full fleet of Reflect Orbital's mirrors could render every image captured by observatories like the Rubin Observatory unusable. DarkSky International echoed these sentiments, calling for rigorous transparency, environmental review, and public accountability before any such systems are deployed.

In response to these criticisms, Reflect Orbital has stated its commitment to mitigating the effects on astronomy. The company is a member of the International Astronomical Union’s Centre for the Protection of the Dark and Quiet Sky and claims to be working closely with astronomers. Reflect Orbital stated in an emailed statement that its satellites would "systematically avoid redirecting light near observatories." Furthermore, the company emphasized that its satellites' default state would be "off," with full control to deactivate, dim, or relocate the light spot at any time. "Every spot of light we deliver will be requested, approved and contained," the company asserted. "We will only provide redirected sunlight when it is signed off by the appropriate authorities in the relevant jurisdiction."

The FCC, in its decision regarding Earendil-1, acknowledged the concerns raised by the astronomical community but determined that these issues fell outside its regulatory jurisdiction. The agency stated that potential impacts on astronomy "are not a basis for denial of or additional conditions on Reflect Orbital’s operations." This ruling clears the path for Reflect Orbital's initial launch, marking a significant step forward for the ambitious space mirrors project.