Hayabusa Status Report 10 October 2005

As already reported, Hayabusa lost one reaction wheel (X-axis) on July 31st and has taken an alternative flight mode using two wheels for the attitude stabilization.

On October 3rd, another Y-axis reaction wheel was found not functioning. The incident occurred at 23:08 JST on Oct. 2nd, while it is not operated from Japan.

On the malfunction of Y-axis wheel

When the incident occurred, Hayabusa was under the autonomous asteroid tracking mode. The task was with no trouble compensated by RCS (chemical engines) and the observation had been maintained.

Currently, Hayabusa continues the attitude stabilization using one wheel plus two RCS engines. And subsequent observation plan is studied after adequate amount of information is gathered.

Note, Z-axis wheel has no problem from launch and in good health.

Affect to Further Hayabusa Flight Activity

Still under a detailed study. Fortunately, global mapping is almost completed. In terns of guidance and navigation, Hayabusa uses radio measuremets, and no problem is foreseen. Operation team is analyzing how to reduce fuel consumption for attitude stabilization. Activity plan will be updated and reported, as soon as the strategy is fixed.

Effect to Further Hayabusa Flight Activity

Image downloaded on October 4.