Design of transfer trajectories from cislunar orbits to the retrograde Geo-Synchronous Orbit

Retrograde Geo-Synchronous Orbit (RGSO) possesses unique orbital characteristics and has shown great potential in satellite surveillance and space debris observation. However, for various reasons, direct insertion into RGSO from the Earth is uneconomical and impractical. Thus, a novel transfer pathway from cislunar orbits to the RGSO is proposed. By selecting the distant retrograde orbit (DRO) and near rectilinear halo orbit (NRHO) as initial orbits, a two-step transfer design method is adopted in the bicircular restricted four-body problems (BR4BP). Both the two-tangential-impulse and three-tangential-impulse transfers are constructed and analysed. Transfer orbits are classified based on different properties, some of which utilize lunar gravity assist and the weak stability boundary theory. Results indicate that the transfer from the DRO to the RGSO is a better option, with the minimum transfer cost of 1.4 km/s.