Ephemeris validation of Rendezvous Guidance in Lunar NRHO

The paper proposes a comparison between the circular restricted three body problem, the elliptic restricted three body problem and an Ephemeris model for describing rendezvous and berthing manoeuvres in the presence of a non negligible third body influence. The context in which the work was developed is the autonomous rendezvous operations in Cislunar space for ESA’s HERACLES mission. The purpose of the mission is to show the progress of autonomous operations in space. In particular, the paper focuses on the final part of this mission: the autonomous rendezvous between a passive vehicle on a NRHO and an active vehicle coming from the Moon surface. The work also analyzes the approaching guidance, designed under elliptic restricted three body problem hypotheses, with the Earth-Moon Ephemeris model implemented in the General Mission Analysis Tool (GMAT) by NASA.