Dawn is a robotic spacecraft sent by NASA on a space exploration mission to the two largest members of the asteroid belt — Vesta and the dwarf planet Ceres. The Dawn mission is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Launched on September 27, 2007, Dawn reached Vesta on July 16, 2011, which it will orbit and explore until 2012. It is scheduled to reach Ceres in 2015. It will be the first spacecraft to visit either body. Dawn is the first spacecraft to orbit an extraterrestrial body before continuing under powered flight to a second such body. Previous multi-target missions — such as the Voyager program — have instead been rapid planetary flybys. - Source: Wikipedia