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IKAROS

IKAROS

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. Some key updates:

2010-07-01: IKAROS Begins Attitude Control
2010-06-15: IKAROS' deployable camera captures perfect sail photos
2010-06-10: Successful sail deployment and solar power generation! Hooray!!
2010-06-09: Progress -- with pictures! -- on IKAROS' sail deployment
2010-06-08: IKAROS team proceeds with final stage of sail deployment!
2010-06-07: IKAROS update: rotation rate inexplicably increasing
2010-06-06: IKAROS sail deployment delayed until at least Tuesday
2010-06-05: Lou Friedman in Japan: Taking things slowly with IKAROS sail deployment
2010-06-04: Lou Friedman in Japan: IKAROS sail deployment proceeding
2010-06-03: Lou Friedman is "our man in Japan" to watch IKAROS sail deployment
2010-05-31: Photo proof of good progress on IKAROS sail deployment
2010-05-25: Initial checkout of IKAROS complete
2010-05-21: All's well on IKAROS and Shin-en
2010-05-20: Akatsuki, IKAROS, UNITEC-1, and your names are on their way to Venus

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.