Chaotic Dynamics and Zero-Velocity Structures in the Pluto-Charon CR3BP

Abstract: Pluto and Charon are a dwarf binary system with a high mass ratio $\mu$, preventing Trojan companions. This instability creates ideal intersections for low-energy pathways that spacecraft can traverse and serves as an important test case for stability at Lagrange points for high $\mu$ binaries. This study models the Pluto-Charon system in the planar Circular Restricted Three-Body Problem (CR3BP) and compares the tadpole and horseshoe orbits of a massless particle with known low-$\mu$ orbits. Moreover, it compares the trajectories for instances where the L1 neck is opened and closed, and exhibits the corresponding zero-velocity curves; RK4 integration was used to update the position and velocity of the particle. The simulations consistently showed chaotic and unpredictable trajectories, where small changes in initial parameters could completely alter the results; trajectories displayed the influence of higher values of $\mu$ on the stability of binary systems. These findings confirm that Pluto-Charon cannot host long-lived Trojan companions and instead behaves as a system of chaotic transport. Future work could extend the study to include the spatial or elliptic three-body problem, further refining the understanding of instability in high-$\mu$ binaries.