Solar sail-based deep space transfers using V-infinity leveraging maneuvers

The aim of this paper is to investigate two-dimensional interplanetary transfers between circular orbits for a spacecraft equipped with a solar sail and analyze in which scenarios a V• leveraging maneuver is a convenient strategy to reduce the mission length and its cost. Assuming an Earth circular orbit and an optical force model to describe the sail propulsive acceleration, an optimal control problem is formulated to study the leveraging maneuver that maximizes the final hyperbolic excess velocity for a given flight time. Starting from the outputs of this optimization problem, minimum-time trajectories are calculated in the special cases of a rendezvous with Mars and a flyby with asteroid 243 Ida. For a given initial excess velocity provided in the launch phase, the overall flight time is compared to the time required to perform a direct transfer towards the designated target, with the aim of identifying when the leveraging maneuver leads to a reduction in the total mission length. The leveraging maneuver may sometimes allow the spacecraft to be launched with a hyperbolic excess velocity smaller than that necessary in a direct transfer, thus reducing the cost of the mission.