Earendil-1

Earendil is a flat mirror in orbit. It redirects sunlight to a site on the ground while that site is in darkness.

Our ApproachApproach

Earendil is a flat mirror in orbit. It redirects sunlight to a site on the ground while that site is in darkness, delivering a ~5 km spot at 0.1 lux for a few minutes per pass. More satellites overhead means more light; the constellation is the dimmer.

When a disaster takes down the grid, an alternative light source is the path to safety and a beacon for rescuers. Light is the promise that we can help our community in need and do our duty.

Sheriff Stephanie J. Rennie
Search and Rescue, Lone Pine County

Artificial light relies on electricity, fuel, and physical infrastructure like poles and wires. Reflected sunlight requires none of this. It extends access to sunlight in precise areas for finite periods of time without adding new ground infrastructure.

About 5 km across. The spot is the image of the sun cast by a flat mirror, so its size follows from the sun’s angular width and the distance to the satellite.

One satellite gives about the brightness of a full moon. More satellites overhead add their light to the same spot.

About four minutes per pass, while the satellite is in view of the site.

Yes, the light is adjustable. It can effectively be “turned on and off” by rotating the satellite and the timing can be scheduled so that it operates only during requested hours. In addition, the brightness is adjustable (from full moon to full noon) when multiple satellites are in orbit.