A spacecraft powered by sunlight is expected to launch on June 22, capping off a years long odyssey for The Planetary Society. This project, Light Sail 2 is not a large spacecraft. Quite the opposite in fact, being roughly the size of a bread loaf. Whilst not fulfilling Carl Sagan’s dream of using solar sails to explore the galaxy, it is an exciting reminder about the potential of space travel and highlights the fact that we do not need to rely entirely on expensive and environmentally damaging rocket fuel.
The spacecraft works by being dropped into space on board a larger vessel (in this instance the Prox-1) and then deploying a screen, roughly the size of a boxing ring. This sail then uses photons (which have no mass but carry momentum) in order to boost the spacecraft higher and higher. After a month of this solar pressure, the spacecraft will soar as high as 450 miles (720 kilometers) above Earth, which is double the altitude of the International Space Station.
"If successful, LightSail 2 will become the first spacecraft to raise its orbit around the Earth using sunlight," Planetary Society representatives said in the statement.