Hayabusa to begin long journey back to Earth

Sparky writes: "Japan is planning to set the Hayabusa spacecraft on a trajectory back to Earth next month after a delay of more than a year, but it's far from certain that it will get back safely. It was supposed to retrieve asteroid debris, but it's thought that a computer error meant that this didn't happen. A fuel leak means that it's chemical thrusters are out of action, and the craft is relying on it's weaker ion engines. The journey back will take 3 years, and the capsule will be on Earth in June 2010 — even if it is empty."