The key facts
- Reflect Orbital plans to reflect sunlight from orbit onto designated points on Earth; on July 9 the FCC approved the first test satellite EARENDIL-1 with an 18×18 m mirror.
- On October 10, near Mount Whitney (California), a ground demonstration was held with spotlights simulating the light spot; no space mirror was used.
- The American Astronomical Society (8,500+ astronomers) asked back in March for the application to be denied; calculations show brightness above a full Moon and impact on the sky up to ~30 km.
Ground Demonstration and Regulator Approval
In October, Reflect Orbital conducted a ground demonstration in California of its future lighting system. Earlier, the US regulator issued permission for the operation of the first experimental satellite — EARENDIL-1. On October 10, in the Lone Pine area near Mount Whitney, a test was held with powerful spotlights simulating the light spot that the orbiting spacecraft are expected to create. Volunteers from search and rescue services took part in the demonstration. No space mirror was used in this test — the light was provided by equipment installed on the ground.
The Essence of the Project
The Reflect Orbital project is based on reflecting sunlight from orbit onto designated points on Earth. The company expects to use such lighting in the energy sector and other tasks requiring additional light. The first experimental spacecraft is to deploy a mirror measuring 18×18 meters. The US Federal Communications Commission (FCC) on July 9 authorized the placement of this demonstration satellite and its operation on the requested radio frequencies. This decision does not constitute approval of the entire future constellation of satellites.
Astronomers' Objections
The American Astronomical Society, representing more than 8,500 professional and amateur astronomers, asked back in March for the company's application to be denied. The organization expressed concern about interference with ground-based astronomical observations and other possible consequences.
Scientific Assessment of Brightness
In September, a study by Miroslav Kocifaj, Gáspár Bakos, and František Kundracik was published in the journal Astrophysical Journal Letters, calculating the propagation of light in the atmosphere. The model took into account air molecules, aerosols, and light re-reflected from the illuminated ground surface. One of the scenarios considered a 54×54-meter mirror. According to the calculations, for an observer inside the illuminated zone, the light may appear significantly brighter than a full Moon. Scattered light can noticeably affect the night sky at a distance of approximately up to 30 kilometers: even at 14 kilometers, the light of one such mirror will likely exceed full-moon sky brightness over a significant portion of the sky.
