Hayabusa (formerly known as MUSES-C) is getting very, very close to its target asteroid Itokawa, and should be arriving soon! Hayabusa, which means "falcon" in Japanese, is a daring mission design: it is going to land a little surface hopper on Itokawa, and will also return samples from the asteroid to Earth. If they succeed, it'll be the first sample return mission from an asteroid.
One of the oddest things about this mission is that although they'll spend a couple of months at Itokawa, they will not really be orbiting the asteroid. The asteroid is just too small for that, less than a kilometer in diameter. Instead, they're using ion engines basically to match their heliocentric orbit with Itokawa's. The relative speed between the two right now is only about 10 meters per second, and will decrease until it is nearly zero.
Yesterday, we got a message from Tasuku Iyori of The Planetary Society of Japan, updating us on the current plans for Hayabusa:
Mid-September: Arrival at Itokawa
From mid-September through the end of October: Investigation by circling around the asteroid
Early Novmeber: Putting out target markers and Minerva, the hopping mini-robot down on Itokawa
From mid-November to the end of the month: Contact with the asteroidal surface for sample collection. As things stand now, collection will be done twice.
December: Hayabusa will leave Itokawa
Summer of 2007: Earth re-entry of the, sample capsule which will be retrieved in Australia hose "target markers" that Hayabusa will drop on Itokawa have special significance for us at The Planetary Society: wrapped inside one of the markers is a thin film of aluminum foil engraved with 877,490 names collected by us and the Japanese space agency.
Hayabusa is already getting images of Itokawa. Here's a little animation from August 23 and 24, in which Itokawa can be seen to move with respect to the background stars. The images were taken from a distance of less than 10,000 kilometers.
The Planetary Society of Japan also has a recent update from Yasunori Matogawa, an Associate Executive Director at JAXA, about the recent status of Hayabusa. We'll be posting more updates on our website, too, so stay tuned!