Dynamic Mechanisms for Spacecraft Disposal from Sun–Earth Libration Points

Abstract

This work investigates end-of-life trajectories for spacecraft in orbit about the sun–Earth and libration points. A decommission plan is often required during the mission design process. The spacecraft’s natural departure dynamics are studied in both the circular restricted three-body problem and an ephemeris model. In particular, the roles of the unstable manifold and forbidden regions in determining disposal outcomes are considered. A close correspondence is observed between the models when computing the probabilities of return to the Earth neighborhood. A simple maneuver scheme, which uses regions partitioned by the zero-velocity surfaces to prevent returns to the Earth vicinity, is also analyzed. Disposal maneuver costs less than are possible for many initial libration point orbits during a decommissioning phase lasting less than one year.