The interest in space missions involving the equilateral Lagrangian points is expected to grow in the near future. In fact, these points represent a strategic location both for space observation and, as considered in this thesis, for the departure of missions towards Near-Earth Asteroids. Among these small bodies there is a huge number of Potentially Hazardous Objects —PHOs—, which may impact the Earth with serious consequences. The study of such objects is the first crucial step for the risk mitigation of such an undesired event. The rendezvous with a PHO is essential to study the properties of the body and to monitor its orbit characteristics.