Current status of asteroid sample return mission HAYABUSA and its science objective

An engineering spacecraft HAYABUSA(MUSES-C) was launched by an MV-5 rocket in May 9 2003. It is the world-first asteroid sample return mission. The target asteroid is an Apollo type asteroid 25143 ITOKAWA(1998 SF36), whose size, rotational period, and spectral type are about 600m, 12.1h, and S-type, respectively. Since the launch the spacecraft has been cruising nearly along the earth orbit under the sound operation of the ion-engine. Onboard observations of point source objects were carried out by an imaging camera, a near-infrared spectrometer, and an X-ray spectrometer for the instrumental calibration. In May this year it will approach the earth and via gravity-assist transferred to the orbit toward the target asteroid. In June 2005 it arrives near the asteroid and makes observation by hovering at altitude of 6km above the asteroid sun-lit surface. Sampling of the surface material is made by shooting a small bullet and catching the surface ejecta in touch-on-and-go-away style. The spacecraft will come back near the earth and the reentry capsule separated from the main spacecraft will be recovered in Australia. The initial analysis of the sample will be carried out in Japanese facilities for one year according to the scheduled program, and in the following years the sample will be distributed to the worldwide scientists selected through announcement of opportunities.