Guidance and Control for Phasing, Rendezvous and Docking in the Three Body Lunar Space

The renewed interest in Moon exploration motivates this thesis work, whose primary goal is the development of a fully safe, realistic, and automatic rendezvous strategy between a passive vehicle and an active one orbiting in trans-lunar. The first step of the research was to extend the 3-DOF translational model of the relative motion to a full 6-DOF described in the LVLH reference frame, which results in the most suitable for the design of the guidance. Nevertheless, it entails difficulties due to the need of expressing the various quantities within a non-inertial reference frame. Once the dynamics were defined under the CR3BP and the ER3BP is formulated the following step was to include the description of the sensors and the actuators in the model to ensure the reliability of the proposed GNC solution even in the presence of non-idealities. Therefore the selection and the design of proper Guidance and Control algorithm was fundamental at this point. In fact, later in this thesis the two techniques to control the attitude and the full model are discussed to accomplish the approaching maneuver in the exemplificative scenario of the ESA's HERACLES mission were presented. Afterward, the safety, in particular, the passive safety concept is introduced and different techniques to guarantee it is discussed. The main underlying idea is to exploit the concept, of stable and unstable manifolds to intrinsically guarantee some properties at each Hold-point. A study on the phasing part is also included in this elaborate, it is mostly a preliminary study based on the \gls{CR3BP} hypotheses but it provides significant results on the expected energy consumption Delta V boundaries to guide a spacecraft from a Moon LLO to the LOPG NRHO. In conclusion, the thesis compensates for another lack in the literature with the comparison between the Ephemeris model and CR3BP and ER3BP models, to validate all the proposed results and to identify the related limits. All the discussed work is currently implemented as a MATLAB simulator, called ROSSONERO, that allows the simulation of multiple rendezvous/phasing trajectories.