Leveraging the Hill restricted four-body problem to investigate the ephemeris transition characteristics in the Earth-Moon L2 halo orbit region

Abstract The Earth-Moon L 1 , L 2 halo orbit families support a variety of options for lunar surface activities as well as other developments in the cislunar region. The planned operational orbit for NASA’s Gateway is the 9:2 L 2 synodic resonant halo orbit. Furthermore, orbits from this family could serve as staging locations for future missions to near-Earth asteroids and Mars, hubs for servicing logistics, and nodes for sensor networks. Therefore, it is essential to understand the dynamics that govern the halo orbit regions. Previously, a sub-region in the L 2 halo family of the Earth-Moon system, termed the “Interface Region” was identified to be particularly challenging when transitioning the solutions from this L 2 halo family sub-region to the Higher-Fidelity Ephemeris model (HFEM). Recent research suggests that the intermediate models incorporating pulsation in the Earth-Moon motion offer more insight into the dynamics governing this general underlying flow. This investigation aims to characterize the interface region by understanding the dynamical structures via the Hill Restricted Four-Body Problem (HR4BP).