NASA's Dawn spacecraft arrived at the giant asteroid Vesta in July 2011 and is set to depart on Sept. 4, 2012 PDT (Sept. 5 EDT).
Dawn Set to Leave Protoplanet Vesta

NASA's Dawn spacecraft arrived at the giant asteroid Vesta in July 2011 and is set to depart on Sept. 4, 2012 PDT (Sept. 5 EDT).