#Ikaros

Solar Sails and Lightsails: Sailing to the Stars on Photons

Light carries momentum. When photons bounce off a reflective surface, they push it — imperceptibly at first, but in the vacuum of space with no air resistance, that gentle push accumulates for years and years. Solar sails use sunlight to accelerate spacecraft without carrying any fuel at all. Laser-driven lightsails could push them to a fraction of the speed of light.