Understanding flow around planetary moons via finite-time Lyapunov exponent maps

This contribution focuses on the use of finite-time Lyapunov exponent (FTLE) maps to investigate spacecraft motion within the context of the circular restricted three-body problem as a conceptual model. The study explores the advantages and limitations of FTLE maps by examining spacecraft trajectories in the vicinity of the Jovian moons, Ganymede and Europa. The paper introduces an atlas of FTLE maps for different energy levels surrounding Ganymede, highlighting critical regions that define types of motion and energy thresholds. Additionally, the authors also explore the symmetry relationships of the Lagrangian coherent structures that are defined within the FTLE maps. Establishing relationships between initial conditions within the FTLE maps is essential for understanding trajectory behaviors in the neighborhoods of moons. The results demonstrate that by utilizing FTLE maps, a better understanding of spacecraft behavior in the vicinity of celestial bodies emerges, potentially enabling more precise mission planning and execution. The findings and methodologies are extendable to other planet–moon systems, providing a valuable framework for future space missions.