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IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) is a solar sail which gathers sunlight as propulsion by means of a large sail. This spacecraft was launched May 20, 2010 together with the Akatsuki Venus Climate Orbiter aboard an H-IIA launch vehicle. This solar powered sail craft will employ both photon propulsion and thin film solar power generation during its interplanetary cruise.
The Planetary Society has assembled a page of resources for the press on JAXA's deep-space missions, including IKAROS. For the latest news on IKAROS, visit The Planetary Society Blog.
About IKAROS
Is IKAROS energy-saving?
IKAROS is a satellite to navigate space, deploying a large solar sail. Traditional satellites always needed fuels wherever their destinations were. The asteroid probe Hayabusa was driven by ion engines, which were energy-saving but still needed fuel called xenon gas.
Flyable without fuel, IKAROS is more than energy saving – it requires no energy. IKAROS can both approach to and recede from the Sun with elaborate use of its solar cells and the pressure of sunlight.
How does IKAROS fly?
Earth makes one revolution a year around the sun. The Earth's orbit around the sun is constant because the centrifugal force produced by the earth's orbital motion and the force of the sun's gravity are balanced. What would happen if Earth slowed down in its orbit? Earth would get closer to the Sun as the centrifugal force weakened. The same dynamics apply to IKAROS.
Imagine that IKAROS is orbiting the Sun at the same speed and in the same orbit as Earth. If IKAROS speeds up, with its large sail inclined toward the Sun, it will start moving away from the sun, heading outward toward the orbit of Mars. But, if it slows down, it will start falling downward to the Sun and approach to the orbit of Venus.
What is IKAROS' destination?
IKAROS is planned to approach Venus' orbit after a six-month flight. Then, it will travel, relying only on the solar force, until it reaches the far side of the Sun three years after launch.
What does IKAROS look like?
At launch, it has a fat, short cylindrical shape. A polyamide sail is wound tightly around it. The sail is designed to be deployed in space by centrifugal force produced by rotation of the satellite itself.
(http://www.planetary.org/explore/topics/ikaros/)
Read also:
IKAROS Begins Attitude Control by Louis Friedman
http://www.planetary.org/blog/article/00002567/
Lou Friedman in Japan: IKAROS sail deployment proceeding
http://www.planetary.org/blog/article/00002523/
