Preliminary Design of Low-Thrust Multiple Gravity-Assist Trajectories

Abstract

The availability of electric engines as primary sources of propulsion has opened the doors to new scenarios for future interplanetary missions, but has increased the complexity of trajectory design. This paper proposes a novel approach to the preliminary design of interplanetary trajectories characterized by a combination of low-thrust propulsion and multiple gravity-assist maneuvers. Low-thrust arcs are obtained by shaping the trajectory through a set of parameterized pseudoequinoctial elements. The characterization of the solution space for a particular set of planetary encounters and a range of launch dates is then performed through a global optimization method, blending a particular evolutionary algorithm with a deterministic domain decomposition technique. The effectiveness of the proposed approach is demonstrated through a number of examples of the design of low-thrust, gravity-assist interplanetary trajectories.