• orbit determination
• celestial mechanics
• trajectory design
• reentry
• Libration Point Orbits
• optimization

In this thesis we tackle the problem of studying a spacecraft reentry from a Sun-Earth Libration Point Orbit and we try to keep under control the ground uncertainty. The idea is to design a low-cost maneuver in terms of impulse budget, and then exploiting orbit determination techniques (usually used in the context of asteroid dynamics and impact monitoring) to constrain the impact location and the impact corridor on ground. The work is divided into two parts: in the first part we deal with trajectory design, while in the second part we discuss the orbit determination problem. Reentry trajectories are designed within the framework of the Circular Restricted Three Body Problem model Sun-Earth-Spacecraft (CR3BP) exploiting an optimizer based on the Genetic Algorithm and employing just one tangential impulse; whereupon the problem is treated as an orbit determination problem of an object impacting the Earth. Optical observations of the spacecraft are simulated and from them a full orbit determination procedure is executed. At the end the Semilinear method is used to draw the impact corridor.