Exploring the Geometry of Departure Trajectories from an Earth-Moon near Rectilinear Halo Orbit

Abstract

To facilitate NASA’s Artemis program involving the first crewed lunar missions in over fifty years, current plans are to establish an outpost near the Earth-Moon L2 Lagrange point: the Gateway. The purpose of this deep space station is to serve as a staging area for missions to the lunar surface as well as further into the solar system. An L2 southern near rectilinear halo orbit (NRHO) was selected to place the Gateway for a number of advantages. This thesis centers on analyzing thrust-enabled departure trajectories from this NRHO using both the circular restricted three body problem (CR3BP) and an ephemeris model. Data sets of trajectories, generated in each of the CR3BP and ephemeris models using the General Mission Analysis Tool (GMAT), are divided into classes based on whether the solutions experience an escape through L1, L2, or a lunar surface impact. Each of these data sets is input to an agglomerative hierarchical clustering algorithm to separate solutions with distinct geometries. This approach is able to identify several types of departure trajectories in the CR3BP as well as the ephemeris model for each event class with potential applications for operations in cislunar space.