Analysis of parking orbits and transfer trajectories for mission design of cis-lunar space stations

Abstract

Future human space exploration activities will very likely incorporate space stations and platforms located in the Earth–Moon system, in particular in lunar orbit or in the Lagrange points. It is reasonable to start assembly and mission logistics from today's frequently used near-Earth orbits, such as the ISS orbit, in order to utilize common launcher systems and other infrastructure elements. This contribution deals with the conceptual design of cis-lunar space missions and presents results based on analytic analysis as well as numerical trajectory computation taking gravitational perturbations of multiple celestial bodies into account. While analytic methods generate data suitable for initial estimates and general assessments on delta-v and transfer time for rather fast trajectories, the selected approach also covers long transfer time missions and allows direct and easy access to other relevant mission parameters. The report gives an overview of the perturbation shares in various orbits and trajectories in Earth vicinity and along in and outbound lunar transfers. Then, it addresses the long-term evolution of selected Earth-bound orbits that are likely to be used as staging or parking locations (on the way to and from the Moon). A summary of results is included on how these orbits are being altered by perturbations over time and consequential impacts on mission parameters like delta-v, transfer time and periods for preferable in- and outbound transfer window periods.