Interplanetary and Lunar Transfers Using Libration Points

In this paper a technique based on the invariant manifolds theory has been optimized and applied to cases of practical interest: interplanetary transfers (among inner planets) and low energy transfers to the Moon. In the former case the manifolds of Sun-Planet systems, not intersecting in the configuration space, are connected by splitting the full four-body problem into two three-body problems and linking the corresponding transit orbits through a conic arc. Low energy transfers to the Moon, instead, have been obtained by targeting, through a Lambert's three-body arc, a piece of the stable manifold associated to the L1 point of the Earth-Moon system. The proposed patching conic-manifolds method exploits the two gravitational attractions of the bodies involved in the transfer to change the energy level of the spacecraft and to perform a ballistic capture and a ballistic repulsion. The effectiveness of this approach is demonstrated by a set of solutions found for Venus, Mars and Moon transfers.