JAXA announced January 26, 2011 the end of the period of normal operation of the mission IKAROS (Interplanetary Kite-craft by Accelerated Radiation of the Sun). The mission objectives were met, “said Osamu MORI, the project manager in the Division IKAROS Scientific JAXA. He was first able to deploy the sail and to prove that its cells could well provide electrical power, then check that the veil could accelerate, and finally to validate navigation techniques with the new spacecraft.
IKAROS was launched May 21, 2010 with the probe Venus AKATSUKI. Ikaros is a square sail of about 14 m square, made of a polyimide material as fine as 7.5 microns. Solar cells are integrated into the membrane. The central part of the probe, which houses the electrical systems, has a diameter of 1.6 m for a thickness of 1m. The total mass of the demonstrator is 315kg. In June 2010, the sail was fully extended and rotated at a speed of between 1 and 2.5 revolutions per minute. This process of unfolding was monitored by a camera placed at the center of the sail, then dropping a camera which allowed to observe the veil in its entirety. The power supply was tested on June 10 and was able to demonstrate a power supply of about 40 W. JAXA then began surveillance by Doppler measurement of the acceleration of the sail pressure exerted by the sun. June 9, JAXA has been able to determine that the solar pressure on IKAROS equivalent to a force of 1.1 mN. Finally, between June and November 2010, sailing has seen its rate increase of 100 m / s. Finally, in December last, JAXA engineers conducted a test of navigation, the approach to Venus, which showed that the trajectory of the probe could well be controlled to some extent (not IKAROS suffered a parabolic trajectory exactly close to Venus). To rotate the sail IKAROS, JAXA uses a special coating placed on certain parts of the sail, the properties of transparency can be changed when there is a current flow, thus producing a torque about the center of gravity of the demonstrator.
IKAROS therefore falls now in its second phase of operation, which lasted until March 2012. The veil is always followed by the antenna located at the JAXA Usuda. This second phase will increase knowledge of new navigation techniques using solar sails. During this phase, IKAROS also continue the operation of its small onboard experiments: GAP (detecting GRBs) ALLADDIN (space dust detector), transmitter and VLBI (used for precise orbit determination). After being approached Venus qu’AKATSUKI same time, sailing IKAROS should cross Earth’s orbit again later in the year 2011, operating on an elliptical heliocentric orbit between the orbits of Venus and Earth. JAXA is still considering a preliminary basis for future mission using a solar sail to observe the vicinity of Jupiter. This mission would use a probe with this time a hybrid propulsion system (a combination of an ion engine and conventional chemical propellants, in addition to the sail itself). The Japanese space agency intends to build expertise in this new technology that will offer innovative solutions to future missions to explore the solar system.
Space Activities Commission, January 26, 2011