Solar Sail Proves Photon Acceleration Works, as it Twists and Turns Under the SunS

Less than two months after being unfurled in space, Japan's IKAROS solar sail accomplished its ambitious aim—becoming the first spacecraft to travel in space, powered by the sun. Now, it's demonstrated its fine steering ability.

Measuring 20m diagonally, the solar sail is made from aluminized plastic, which is as thin as the diameter of a red blood cell. 0.0003-inches thin, in fact. The material it's made from reflects the solar radiation back towards the sun, which is how it propelled itself through space. The liquid crystal lining the outside of the solar sail reflects different volumes of sunlight, and is responsible for steering it through space, with the Aerospace Exploration Agency back in Japan controlling the angles. [New Scientist]