Low-energy weak stability boundary transfers to Pluto's moons: Preliminary trajectory design via triangular libration point

By patching the invariant manifolds of collinear libration points Lyapunov orbits of two restricted three body problem (CR3BP), Koon (2001) successfully constructed low-energy Earth-Moon transfers in the Sun-Earth-Moon system. It reveals the essential mechanism of low-energy cislunar transfers, i.e., weak stability boundary (WSB), from the viewpoint of dynamical system. This paper is devoted to the construction of low-energy WSB transfers using the invariant manifolds of triangular libration points. Koon's method is applied to two of Pluto's moons, Charon and Hydra. Specifically, Hydra is treated as a contact binary system due to its irregular shape. Numerical Results show a remarkably small fuel consumption, i.e., ∼39 m/s for Pluto-Charon transfers and ∼159 m/s for Pluto-Hydra transfers. Finally, combining with the heteroclinic connections around Hydra, a sample trajectory for end-of-life mission of Pluto probe is built up achieving Pluto-Hydra low-energy transfer and encircling Hydra body at the cost of 7 m/s fuel consumption. Therefore, Charon and Hydra can act as potential targets of Pluto end-of-life mission from the engineering viewpoint. The WSB trajectories obtained in this paper can work as initial guess of differential correction scheme to achieve real trajectories in more complicated gravity fields.