Planetary News ARCHIVE

October 18, 2005

Hayabusa Maps Itokawa in More Detail

The Hayabusa spacecraft flew down to an altitude of 6.8 kilometers from the surface of Asteroid Itokawa on September 30. This maneuver was intended to enable Hayabusa, a falcon, to observe Itokawa in more detail to select two touching-down points for her sample collection scheduled for next month. The spacecraft arrived at the targeted asteroid on September 12 and continued preliminary investigation since then by keeping 20-kilometer distance from it.

Courtesy:JAXA/ISAS

Hayabusa acquired a new image on October 4 from distance of 6.8 kilometers from Itokawa. The improved view of the asteroid identifies a rugged surface covered with littered boulders and smooth and flat terrain, suggesting existence of ponds of fine dust.

Courtesy:JAXA/ISAS

Above are the comparative close-up images of Itokawa’s surface taken by Hayabusa on September 12 (left) and October 4 (right).These two images suggest that the asteroid is lacking craters to be caused by the bombardment of other bodies. Itokawa is found to be the same s-type of asteroid with Eros on which NASA’s Near-Shoemaker spacecraft successfully landed three years ago.

So far the mission has been going well with detailed global mapping of the tiny asteroid nearly completed. According to the mission team’s score list, the spacecraft has succeeded in obtaining half of a perfect score of 500 points so far. Obviously full marks will be given to the mission when sample collection is ensured in June 2007.

On-board instruments are all in good shape now. However, one concern has mounted because the second attitude stabilizing control wheel went out of order on October 2 in the wake of the loss of the first one on July 31. The mission team has been working hard to keep the spacecraft going on and on to make the upcoming sampling operation successful with remaining one unit of attitude stabilizing control wheel.

In November, Hayabusa will make two touch-and-go contacts with Itokawa to collect some grams of surface materials. The artist concept by JAXA/ISAS