Missions to the Jupiter Trojans

During the last French prospective Conference in Biarritz, in early 2009, a fly-by mission to the Jupiter Trojans was proposed by the European scientific community. The asteroids population situated at the Jupiter Lagrange points L4 and L5 , (i.e. 60 degrees backwards and forward from Jupiter’s orbit), is not well known. Their study by low distance fly-bys would allow unique information to be obtained concerning their origins, but also about the origins and the formation of Jupiter. Knowledge of their properties can provide a key to the dynamical and physical processes that characterize the early stages of planetary formation. Such a mission will be proposed by CNES to the International community in the framework of ESA Cosmic Vision 2, or even in a larger international framework, if budgetary constraints demand a greater budget. In order to propose new missions toward Jupiter’s Trojans, it is necessary to determine optimal trajectories to be able to reach them, and move around them at the lowest mass and energy cost. The trade-off concerning the trajectories, together with determining parameters to be able to perform this mission are described in the paper. The environmental constrains, the various methods and the various hardware solutions will be presented for the complete mission including: propulsion, thermal control, AOCS, power systems, among others. At last, a system synthesis will be proposed and the constraints of such a mission underlined.