Optimal manoeuvring between quasi-periodic orbits

In the past halo orbits were used for most of the spacecraft missions going to the Lagrange point regions. However, other natural motions exist near these points presenting some advantages compared to halos. Quasi-periodic motions on invariant tori are associated with frequencies and amplitudes and surround the halo and vertical Lyapunov orbits. In this paper main characteristics of quasi-periodic orbits around the far-side Lagrange point in the Earth-Moon system are discussed. Optimal manoeuvres are identified to vary properties (phases, amplitudes) of an orbit. The proposed techniques utilise the stable manifold allowing for single manoeuvre transfers. The separation of spacecraft from a periodic orbit and a rendezvous scenario are discussed with respect to future missions, that have to cope with regular vehicle traffic, rendezvous and docking activities. Fuel-optimal transfers from a halo to a quasi-periodic orbit are identified in order to separate spacecraft. A second scenario assumes two spacecraft with a given phase separation on a quasi-periodic orbit. A target orbit is defined in which the spacecraft rendezvous. Parameter studies show that phase and amplitude changes strongly depend on the time when the manoeuvre is performed.