Computing an optimized trajectory between Earth and an EML2 halo orbit

Abstract

According to the Global Exploration Roadmap, which reflects the international effort to define feasible and sustainable exploration pathways to the Moon, near-Earth asteroids and Mars, the next step for manned space exploration is the Moon as second home in the Solar System. In that perspective, the Earth-Moon Libration points (EML points) have been a topic of great interest in recent years since EML1 and EML2 were suggested as advantageous locations of space hubs in the Moon neighborhood. To materialize this vision, detailed studies are needed to investigate transfers between Earth and the vicinity of EML2 and the strategies to reduce associated maneuver costs. This work is framed within the perspective of a future deep space habitat in halo orbit around EML2, and this paper intends to provide quantitative results so as to select the best deployment scenario of the station. The main purpose is to determine the best transfer trajectory between a low-Earth orbit and a halo orbit around EML2 in terms of cost and duration. Two different kinds of attractive transfer strategies have been identied. Station deployment and cargo missions would use Weak Stability Boundary (WSB) trajectories whereas manned flights would exploit a fly-by strategy as it shows an advantageous compromise between short trip duration and efficiency.