Electric Solar Wind Sail Optimal Transit in the Circular Restricted Three Body Problem

This paper analyzes the transfer orbits within a Sun-[Earth+Moon] system for a spacecraft whose primary propulsion system is an Electric Solar Wind Sail. The planetary system is approximated through the Circular Restricted Three Body Problem and the spacecraft motion is studied in an optimal framework in which the performance index is the flight time. Minimum time transfers are studied using an indirect approach, and the optimal control law is found in analytical form as a function of the problem parameters. Optimal transfers between equilibrium points are discussed and interesting symmetries in the spacecraft trajectories are pointed out along with an analytical proof of their existence. A mission scenario consistent with the Geostorm concept is analyzed and the effectiveness of the propulsion system is emphasized for missions involving a tour through a subset of the classical Lagrangian points.