Optimal Low-Thrust Invariant Manifold Trajectories via Attainable Sets

A method to incorporate low-thrust propulsion into the invariant manifolds technique is presented in this paper. The low-thrust propulsion is introduced by means of special attainable sets that are used in conjunction with invariant manifolds to define a first-guess solution. This is later optimized in a more refined model where an optimal control formalism is used. Planar low-energy low-thrust transfers to the moon, as well as spatial low-thrust stable-manifold transfers to halo orbits in the Earth moon system, are presented. These solutions are not achievable via patched-conics methods or standard invariant manifolds techniques. The aim of the work is to demonstrate the usefulness of the proposed method in delivering efficient solutions, which are compared with known examples.