Japan is due to fire a H-IIA rocket into space tomorrow, with a rather special payload aboard: The Ikaros space yacht, a beautiful vehicle that’s an experimental test bed for solar sail technology.
The launch is scheduled for early Japan time on Tuesday morning (18:44 EST today), and the H-IIA is actually carrying two major payloads: In addition to Ikaros, it’s ferrying the Venus Planetary Climate Orbiter aloft too, a partner vehicle to the Venus Express spacecraft already launched by the European Union’s space agency. This’ll hit Venus space in December and carry out observations of Venus’s fascinatingly odd climate from a highly elliptical orbit. There’re also four mini-satellites aboard the rocket, each designed to support research tasks needed by Japanese academics and research organizations.
But it’s Ikaros that’s the eye-catching machine among the crop, the one that will appeal to the more sci-fi minded among you. Its name is a homage to the Greek myth about the young chap who flew too close to the sun … but Ikaros isn’t actually headed sunwards. Instead, it’s designed to ride the sun’s rays. Developed at a cost of some $16 million dollars, the International Kitecraft Accelerated by Radiation of the Sun (great acronym!) is a solar sail that launches in a small canister, but which will unfurl in space to a huge reflective square about 46-feet on a side. Its skin is mere fractions of a millimeter thick, designed to be light but strong, and highly reflective–vital for its task of reflecting solar radiation back toward the sun. This action causes a microscopic but measurable force on the sail itself, which is thus propelled through space. And though the effect takes a long time to build up, the acceleration is continuous–and future spacecraft may use giant sales as a way of exploring the solar system without hauling volatile and heavy fuel around.
And Ikaros isn’t just about revolutionary solar sail experiments–the frail skin is also a thin-film solar power generation system, making it the first powered solar sail ever flown.
Watch for the photos after the launch: This thing should be way more beautiful in the flesh than in that rendered image.