Can humans create artificial daylight from space? This US satellite will try just that

For as long as humans have existed, sunset has marked the end of the day. That rhythm may soon face its biggest technological challenge yet. A California startup has received regulatory approval to launch a satellite that aims to reflect sunlight back to Earth after dark — an idea that could redefine nighttime while raising uncomfortable questions about who gets to control the sky. 

The satellite, called Eärendil-1, recently received approval from the US Federal Communications Commission (FCC), clearing the way for a demonstration mission. If successful, it would become the first spacecraft designed to redirect natural sunlight onto selected areas of Earth, not by generating light but by acting as a giant mirror in orbit. 

A mirror instead of a light source 

Unlike conventional satellites, Eärendil-1 is not equipped with powerful lamps or lasers. Instead, it carries an ultra-thin reflective film measuring around 18 metres across. Once deployed in orbit about 625 kilometres above Earth, the mirror will be oriented to bounce sunlight onto a specific location shortly after sunset. 

The objective is modest but ambitious: provide temporary illumination over relatively small areas for short periods. The mission is intended primarily as a proof of concept to demonstrate whether lightweight orbital mirrors can be controlled with sufficient precision. 

What could artificial sunlight be used for? 

Reflect Orbital believes the technology could eventually find applications in situations where temporary natural illumination would be valuable. 

Emergency response teams working after earthquakes, floods or wildfires could benefit from additional daylight without relying entirely on diesel-powered lighting systems. Search-and-rescue operations, large construction projects and infrastructure maintenance are also among the potential use cases. 

The company has even suggested that orbital mirrors could one day provide additional sunlight to solar farms, extending the amount of energy they generate beyond normal daylight hours. However, these possibilities remain theoretical until the technology is successfully demonstrated. 

Scientists see a different future 

While the concept has attracted interest for its engineering potential, it has also triggered widespread concern among astronomers. 

Modern observatories already contend with thousands of satellites crossing the night sky, making it harder to observe distant galaxies, faint stars and exoplanets. A satellite specifically designed to reflect sunlight could significantly increase light pollution, affecting both professional astronomy and amateur skywatching. 

Researchers also warn that artificial illumination at night could disrupt wildlife that depends on natural darkness, including migratory birds, nocturnal animals and insects whose behaviour is closely tied to Earth's day-night cycle. 

A much bigger ambition 

The debate is not only about one satellite. Reflect Orbital has outlined a long-term vision of deploying a constellation that could eventually include tens of thousands of mirror satellites.

While the current FCC approval covers only the demonstration mission, critics argue it could pave the way for much larger commercial deployments if the technology proves successful. 

That possibility has intensified calls for stronger international rules governing activities that could permanently alter the appearance of the night sky. 

A regulatory grey area 

The approval has also highlighted a gap in space governance. 

The FCC's review focused primarily on communications and radio-frequency issues rather than the broader environmental or astronomical consequences of reflecting sunlight from orbit. As commercial activity in space accelerates, experts say existing regulations may not be equipped to address technologies capable of changing Earth's nighttime environment. 

Eärendil-1 is still an experimental mission, and many questions remain unanswered. Can reflected sunlight be controlled with the required accuracy? Will the benefits outweigh the environmental and scientific concerns? And where should regulators draw the line as private companies push the boundaries of what is possible in space?