JAXA’s unmanned Hayabusa spacecraft fires its ion engines to depart asteroid 25143 Itokawa, embarking on a five-year trek back to Earth to return surface samples it obtained of the asteroid. Hayabusa has experienced numerous technical glitches, and continues to experience further problems, including a total loss of contact with Earth for several weeks. Only two out of the vehicle’s four ion engines are still functional, and its battery system is only partially reliable, but it is carrying its precious cargo of the first sample material from an asteroid back to Earth.
