Ricerc@Sapienza

Earth-Mars cycling spacecraft have been proposed as potentially beneficial to Mars exploration. There are many types of cyclers, but their common characteristic is that they have a heliocentric trajectory that brings them close to both Earth andMars at regular intervals. As usually envisioned, a large cycler spacecraft would consist of most of the required mass (for example, for life support), and the crew would travel to and from both planets in a smaller "taxi" vehicle. The taxi vehicle trajectories would necessarily be hyperbolic; such trajectories have not received as much attention as the cycler trajectories but, unless they can be flown with reasonable propellant consumption and safety, the cycler concept is not feasible. In this work, propellant-minimizing transfers are found for both impulsive and low-thrust hyperbolic rendezvous. A heuristicmethod, called particle swarm, is used for the global optimization.