Low-Energy Endgame Trajectory Design for Callisto Orbiter

Abstract

Callisto is a promising target for future Jovian system exploration due to its high scientific value and low-radiation environment. This paper proposes a new low-energy endgame that can achieve a low-Δv transfer with short flight times for Callisto orbiting and landing missions. In contrast to the endgames designed for other Galilean moons, the proposed Callisto endgame would perform interior transfers from Ganymede in the low-energy region rather than exterior transfers. The definition and analysis of the Callisto endgame are completed using the Tisserand–Poincaré graph. Tisserand-leveraging transfers and isolating blocks techniques are used to search for different trajectory arcs in the endgame. The developed trajectory solver is able to find an optimal complete endgame trajectory with constraints on the initial state and the orbit around Callisto. In the designed scenarios, the spacecraft can complete the transfer from the Ganymede resonance orbit to the polar science orbit around Callisto with a minimum Δv of 712.3 m/s and a transfer time of about 140 days, which is a significant improvement compared to the high-energy endgame.