Trajectory Design Combining Low-Thrust and Gravity Assist Manoeuvres

Abstract

In this chapter a direct method based on a transcription by Finite Elements in Time has been used to design optimal trajectories aiming to reach a high inclined low-perihelion orbit about the Sun, exploiting a combination of gravity assist manoeuvres and low-thrust propulsion. A multiphase parametric approach has been used to introduce swing-bys among thrust and coast arcs. Gravity manoeuvres are at first modelled with a linked-conic approximation and then introduced through a full three-dimensional propagation including perturbations by the Sun. Finally a meaningful test case is presented to illustrate the effectiveness of the proposed approach