The Dawn probe fitted with an ion thruster has the mission to determine the conditions that prevailed at the dawn of our solar system by analysing two of the largest protoplanets still intact since that time: the asteroids Ceres and Vesta located between Mars and Jupiter.
Dawn is a NASA robotic spacecraft built with some European cooperation, with components contributed by partners in Germany, Italy, and the Netherlands. The Dawn mission is managed by NASA's Jet Propulsion Laboratory. The mission was approved in 2001, and after several postponements, Dawn was launched on 27 September 2007. It entered orbit around Vesta on 16 July 2011 and will explore it until 5 September 2012. It will then head for Ceres, which it should reach in February 2015.
The Dawn probe
(Credits: Dawn Science team)