On the restricted 3-body problem for the Saturn-enceladus system. Mission geometry and orbit design for plume sampling missions

Enceladus has been identified as one of the most interesting targets for future space missions after plume ejecta were discovered in the Tiger Stripes region. Many concepts, aiming to search for habitable zones beyond Earth, require passing through this plume to collect samples of the ejecta. This orbit design is not a trivial task due to the vicinity of Enceladus to Saturn, which causes non-negligible third body perturbations and strongly deflects the orbit of a spacecraft around Enceladus. In this paper we address this problem by extensively studying the Circular Restricted Three Body Problem and linearly stable Halo orbits passing close over Enceladus’ South Pole. Some resonance solutions are then evaluated considering the elliptical problem and, finally, a preliminary validation is given by integrating the spacecraft in a model based on latest planetary/satellite ephemerides.