The ion engines cruise operation and the earth swingby of "Hayabusa" (Muses-C)

The Hayabusa spacecraft launched last May has made a successful voyage to the asteroid Itokawa by way of Earth gravity assist this May. The operation of Hayabusa has been well performed by intelligent operation tools that have saved a lot of manpower concerned. This paper reports the latest Hayabusa spacecraft status and how the swingby operation, including navigation and guidance, were performed. This paper makes it clear that the arrival time at the asteroid Itokawa is postponed 2 months owing to the solar cell performance degradation inflicted by last year's historically large solar explosion.