The ambitious Dawn mission, launched in September 2007, is one of NASA’s most remarkable ventures into the solar system. The spacecraft has recently completed a spectacular exploration of Vesta and is now traveling to Ceres; these were among the last uncharted worlds in the inner solar system prior to Dawn. They are the two most massive residents of the main asteroid belt. Ceres is so large that it is included in the category of dwarf planets, along with Pluto. Remnants from the time that planets were formed, Ceres and Vesta hold clues that will help scientists understand the dawn of the solar system. Dawn orbited Vesta from July 2011 to September 2012 and returned astonishing views of this fascinating world. It is the only spacecraft ever to orbit an object in the asteroid belt. Such a mission would be impossible without the use of ion propulsion, a technology that has mostly been in the domain of science fiction, but which was tested extensively on the Deep Space 1 mission, paving the way for Dawn. Dr. Marc Rayman, Dawn’s Chief Engineer and Mission Director at JPL, will describe the Dawn mission and its use of ion propulsion as well as its two exotic destinations. He will also share the excitement and profundity of controlling a spacecraft in deep space.
