Cycler Trajectories in Planetary Moon Systems

Free-return cycler trajectories repeatedly shuttle a spacecraft between two bodies using little or no fuel. Here, the cycler architecture is proposed as a complementary and alternative method for designing planetary moon tours. Previously applied enumerative cycler search and optimization techniques are generalized and specifically implemented in the Jovian and Saturnianmoon systems. Overall, hundreds of idealmodel ballistic cycler geometries are found and several representative cases are documented and discussed. Many of the ideal model solutions are found to remainballistic in a zero radius sphere of influence patched conic ephemerismodel, andpreliminarywork in a high-fidelity fully integrated model demonstrates near-ballistic cycles for several example cases. In the context of recentCassini discoveries, the Saturn–Titan–Enceladus system is investigated in themost detail andmany promising solutions result. Several of the high-energy Titan–Enceladus cyclers find immediate application as Cassini extended missions options that provide frequent low-altitude Enceladus flybys.