Optimal low-thrust trajectories to earth-moon L2 halo orbits (circular problem)

Development of optimal low-thrust transfer trajectories required between Earth and an Earth-Moon L2 halo orbit is examined. A general optimal solution method is constructed using sequential nonlinear programming to find minimum-propellant spacecraft transfers. Only a single thrust phase of the trajectory (using tangential steering) is optimized with the spacecraft traveling the remaining time on the stable manifold of the halo insertion point. The solution method is demonstrated for a number of insertion points on two different reference halos for the circular restricted three-body problem.