From Wekipedia - Hayabusa was an unmanned spacecraft developed by the Japan Aerospace Exploration Agency (JAXA) to return a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis. Launched on 9 May 2003 and rendezvoused with Itokawa in mid-September 2005. After arriving at Itokawa, Hayabusa studied the asteroid’s shape, spin, topography, colour, composition, density, and history. In November 2005, it landed on the asteroid and collected samples in the form of tiny grains of asteroidal material, which were returned to Earth aboard the spacecraft on 13 June 2010.
Other spacecraft, notably Galileo and NEAR Shoemaker both sent by NASA, have visited asteroids before, but the Hayabusa mission was the first time that an attempt was made to return an asteroid sample to Earth for analysis.
Hayabusa spacecraft is a platform for testing new technology and the primary objective of the Hayabusa project is the world’s first implementation of microwave discharge ion engines. Hence ‘operation of ion engines for more than 1000 hours’ is an achievement, and the rest of the milestones are a series of world’s first-time experiments built on it.
HAYABUSA was chosen No.2 of “Breakthrough of the Year,2011” by Science Magazine.