Maiden Voyage of Modern Solar Sail Ship

New Scientist: Maiden voyage for first [sic] true [modern] space sail.

ICARUS'S wings melted when he flew too close to the sun. Here's hoping a similar fate doesn't befall his namesake, the solar sail due to be unfurled by Japan's aerospace exploration agency (JAXA) next week. If all goes to plan, it will be the first spacecraft fully propelled by sunlight.

Solar sails like IKAROS, short for Interplanetary Kite-craft Accelerated by Radiation Of the Sun, aim to move forward by harnessing the momentum of photons colliding with it. The idea may be decades old, but solar sails have remained largely untested. Several sails have been unfurled in space to test deployment, and spacecraft like NASA's Mercury probe, Messenger, have used the pressure of sunlight to alter trajectories. But no spacecraft has used a sail as its primary means of propulsion.

Made of polyimide resin, IKAROS's sail measures 20 metres from corner to corner, but is just 0.0075 millimetres thick. To survive the launch and the trip into space, the gossamer sail will be folded accordion-style, then wrapped around the centre of the spacecraft.