Preliminary Contingency Trajectory Planning for Europa Clipper's Galilean Moon Tour

The Europa Clipper, now en route to the Jovian system, will employ highly eccentric orbits around Jupiter to conduct over 50 Europa flybys to investigate the moon’s habitability. In the event of a system anomaly or instrument failure during this intensive phase of visiting Galilean moons, the spacecraft must abandon its nominal path and quickly transition to an orbit with reduced radiation exposure and minimal risk of unintended moon encounters to mitigate further risk. However, designing such a trajectory is challenging due to the strong dynamical sensitivity of the Jovian system and the broad search space of possible multi-flyby sequences among Galilean moons involving impulsive maneuvers. This paper presents a trajectory design framework that identifies feasible escape routes under these mission-critical contingency scenarios. The method combines Keplerian energy analysis to select candidate target orbits, a broad search for transfer sequences under a full-ephemeris two-body model, and subsequent refinement in a high-fidelity dynamical model. Representative solutions demonstrate the existence of viable escape trajectories, providing a key first step towards the contingency mitigation that is essential for the Europa Clipper's science observation campaign.