**Authors: **Mauro Pontani Angelo Miele

**Publish Date**: 2012/11/16

**Volume:** 157, **Issue:** 3, **Pages:** 866-887

## Abstract

The problem of identifying orbits that enclose both the Earth and the Moon in a predictable way has theoretical relevance as well as practical implications In the context of the restricted threebody problem with primaries in circular orbits periodic trajectories exist and have the property that a third body eg a spacecraft can describe them indefinitely Several approaches have been employed in the past for the purpose of identifying similar orbits In this work the theorem of image trajectories proven five decades ago is employed for determining periodic image trajectories in Earth–Moon space These trajectories exhibit two fundamental features i counterclockwise departure from a perigee on the far side of the Earth and ii counterclockwise arrival to a periselenum on the far side of the Moon An extensive systematic numerical search is performed with the use of a modified Poincaré map in conjunction with a numerical refinement process and leads to a variety of periodic orbits with various interesting features for possible future lunar missions

**Keywords:**