Low-energy transfer for a DRO-orientated asteroids capturing and utilizing mission

Near Earth Asteroids pose significant risks of potential impacts on Earth, while simultaneously offering valuable opportunities for asteroid capturing missions. This study investigated the possibility of using distant retrograde orbits (DROs) in the Earth-Moon system as a parking orbit for asteroids capturing missions. Previous research has mainly focused on capturing asteroids into unstable orbits like Lyapunov orbits where no maneuver is needed inserting into these orbits. However, the stability of DROs makes the previous methods not suitable and rises the difficulty to design a low-energy transfer to DROs. To address the limitation, this paper proposed an approach for identifying transfer behaviours around DROs by developing the applications of Finite-Time Lyapunov Exponent (FTLE) fields. By applying the method of FTLE fields to identify the transfer behaviours around DROs, efficient insertion angles for DROs are achieved and low-energy transfer trajectories to DROs are acquired. Numerical simulations indicate that the insertion speed increment of DROs is less than the station-keeping speed increment of Lyapunov orbits. Additionally, to expand the application of captures asteroids, this study investigated the feasibility and efficiency of using captured asteroids as an enhanced kinetic impactor for asteroid defence missions.