The Dawn mission is designed to perform a scientific investigation of the main-belt asteroid (4) Vesta and the dwarf planet (1) Ceres in order to obtain new information to help answer questions about the formation and evolution of the early solar system. It will be the first mission to orbit a main-belt asteroid and the first to orbit two target bodies. The mission is enabled by an ion propulsion system, which the spacecraft will use to rendezvous with and go into orbit about each of these bodies. Dawn is the ninth project in the Discovery Program of the National Aeronautics and Space Administration (NASA), and was launched on September 27, 2007.