Connecting low-energy orbits in the Saturn System

Abstract

Based on Cassini’s findings, scientists think that the Saturn system is home to multiple moons that could be hospitable to life. This has given impulse to several mission proposals and to investigations on new, efficient and effective ways to reach and explore the major moons of Saturn and the ring system. The bulk of the proposed solutions is based on the patched conics technique, implying fast approaches with low ΔV requirements and involving use of chemical propulsion. A trajectory designed with the low-energy orbits of the three-body problems of Saturn and each of its Inner Large Moons (Mimas, Enceladus, Tethys, Dione) offers interesting alternative observation scenarios. In this work, the case of planar Lyapunov orbits is analysed for the purpose. Their hyperbolic invariant manifolds are used to connect consecutive moons. However, since these objects do not overlap in configuration space, a strategy based on lowthrust maneuvers is developed, and preliminary results are presented. With a continuous thrust of 25 mN magnitude, it is possible to connect Tethys and Dione in just 50 days using 9 kg of propellant. The needed power can be provided by three radioisotope thermoelectric generators.