The Hayabusa (はやぶさ) (formerly MUSES-C (ミューゼスＣ)) unmanned space mission is to collect a sample of material from an asteroid (25143 Itokawa) and return the sample to Earth for analysis. Other scientific objectives of the mission include detailed studies of the asteroid's shape, spin, topography, color, composition, density, and history.

Mission profile

The spacecraft was launched on 9 May, 2003 at 04:29:25 UTC on an M-5 rocket from the Uchinoura Space Center (still called Kagoshima Space Center at that time). Following launch, the name Muses-C was changed to Hayabusa (the Japanese word for falcon) and the spacecraft was put into a transfer orbit to bring it to 25143 Itokawa, a 0.3 x 0.7 km near-Earth object. The ion engines were successfully test-fired starting in May. Rendezvous with the asteroid will occur in June 2005. Note that the spacecraft will not go into orbit around the asteroid, but will remain in a station-keeping heliocentric orbit close by. Hayabusa will initially survey the asteroid surface for about three months from a distance of about 20 km in the "home position", a region roughly on a line connecting the Earth with the asteroid on the sunward side. This is global mapping phase 1, the phase angle during this phase will be small, no greater than 20 - 25 degrees. Global mapping phase 2, which will last for about a week, will take place from a position near the terminator, affording high phase angle views of the asteroid. Following this the spacecraft will move back to the home position and then move close to the surface for a series of soft landings and collection of samples at three sites. On-board optical navigation will be employed extensively during this period because the long communication delay prohibits ground-based real-time commanding. The samples, with a total mass of approximately one gram, will be held inside a separate re-entry capsule. (The lander was also to deploy a small rover supplied by NASA onto the surface of the asteroid, but the rover was cancelled by NASA due to budget constraints.)

After a few months in close proximity to the asteroid, the spacecraft will fire its engines to begin its cruise back to Earth. The re-entry capsule will be detached from the main spacecraft at a distance of about 300,000 to 400,000 km from the Earth, and the capsule will coast on a ballistic trajectory, re-entering the Earth's atmosphere in June 2007. The capsule will experience peak decelerations of about 25 G and heating rates approximately 30 times those experienced by the Apollo spacecraft. It will land via parachute near Woomera, Australia. This scenario is a change from the original plan to launch in July 2002 to the asteroid 4660 Nereus.

External links

• NASA page on mission
• JAXA page on mission