Japanese 'space yacht' to sail on solar power

12:00 AM CDT on Wednesday, April 28, 2010

TOKYO – The Japan Aerospace Exploration Agency plans to launch the world's first satellite powered by a giant solar sail to demonstrate next-generation renewable energy technology, the agency said Tuesday.
SPACE BY SAIL: The 20-meter, $16 million sail will be wrapped around the "space yacht" at liftoff and will unfurl once the craft leaves the Earth's atmosphere, the agency said. The flexible sail is covered in a film of solar cells. The technology is being developed to one day replace fixed solar panels because it can be shaped to fit in small and irregularly shaped places, said Hiroaki Benten at Kyoto University.
HOW IT WORKS: The sail propels the craft using resistance created by energy from the sun in much the same way as the wind propels a sailboat across the water. Photons, or solar energy particles, bounce off tiny mirrors, providing enough thrust for satellites to perform maneuvers such as rotating or hovering, the agency said. Solar sails can also use ion propulsion like conventional satellites. The panels generate electricity to ionize gas, which it emits at high speed to thrust the satellite.
WHAT'S NEXT: The Ikaros will be launched from Tanegashima Space Center on May 18. Its mission will conclude within six months, and the Japanese space agency plans to launch a larger sail-powered satellite in the early part of the next decade to explore Jupiter and the Trojan asteroids. Ikaros, a homonym for Icarus, the figure in Greek myth who flew too close to the sun and fell into the sea, stands for Interplanetary Kite-craft Accelerated by Radiation of the Sun.

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