Leveraging Weak-Stability Boundaries for Libration Points Escapes and Disposal

In the near future, the exploitation of the cislunar environment will open the frontier of space for increasingly daring and challenging explorations. Low energy transfers in this context have a fundamental role, especially when the objective is to reduce at the most the propellant use and to enable new classes of missions. In fact, leveraging the gravity of the Earth, Moon and the Sun,16 allows to construct transfers which are particularly efficient, although with an increase in complexity and sensitivity. The objective of this work is to exploit low-energy transfers to efficiently escape the cislunar space. First, escape trajectories from the Earth-Moon Libration Point L2 are built in the Bi-Circular Restricted Four-Body Problem (BCR4BP) framework,18 accounting for the Sun-Earth-Moon-probe interaction, and the trajectories with the desired characteristics are saved in a database. Secondly, a clustering step is performed, employing dynamical systems theory to gain insights embedded in the BCR4BP dynamical flow, to reduce the dimension of the database and extract the different escape trajectories families as a function of the design variables used. Then, an initial condition generator based on the database and on numerical patching technique is implemented, giving the possibility to construct initial guesses once the desired heliocentric transfer toward Near Earth Asteroids is assigned. The methodology is deeply tested and its strengths and weaknesses are highlighted and discussed.