The Rosetta Spacecraft left planet Earth in 2004. During its twelve year lifetime this robotic emissary traveled 5 billion miles on 6 trips around the Sun, flew by Earth three times, visited Mars, and cruised by two asteroids. Rosetta needed to take such a long path to use the gravity of Earth and Mars to accelerate it to a speed which would allow it to rendezvous with a comet. Upon arrival, Rosetta successfully spent two years studying the comet at close range and sent a probe to it's surface. It's life ended when its human masters put it on a collision course with Comet 67P's nucleus.