McFadden plays a key role as scientist on the Dawn mission to Vesta and Ceres.
Raymond is the deputy principal investigator for the Dawn mission to study the dwarf planet Ceres and asteroid Vesta; this mission may teach us a lot about how the inner solar system -- the terrestrial planets -- evolved differently than the gas giants in the outer solar system.
Joy is the manager of the Dawn Science Center. His job is to be the liaison between scientists and the people commanding the spacecraft.
Rayman is a project system engineer. He was involved in the design of the Dawn spacecraft and mission to the asteroids and helped to determine answers to important questions including how we're going to talk to the spacecraft from Earth, how we're going to build, test and launch the spacecraft, how we're going to collect the science data we need from the asteroids, and, finally, what we're going to do with those data.