Energy-optimal Transfer Trajectory Design for Callisto Exploration

Abstract This paper proposes an energy-optimal transfer trajectory design methodology for Callisto exploration missions, utilizing Galilean moon gravity assists to minimize velocity increments (ΔV) within the Jovian system. The methodology establishes a simplified global three-impulse evaluation model, incorporating: Jupiter periapsis capture maneuver, apoapsis adjustment maneuver and Callisto capture maneuver, to compute the minimum total ΔV for candidate gravity-assist sequences. For the selected fuel-efficient sequences, resonant gravity-assist modulation techniques are employed to satisfy flyby altitude constraints, enabling state transitions between consecutive Galilean moon encounters. This framework achieves energy-optimal trajectory design without incorporating ephemeris constraints. In the end, two representative sequences (Ganymede-Europa-Ganymede-Callisto and Ganymede-Callisto-Ganymede-Callisto) are designed using this methodology, both demonstrating total ΔV requirements of 1.7 km/s.