Preliminary design of orbital trajectories for life detection missions around Saturn's moon Enceladus

Enceladus is one of Saturn's icy moons and despite its relatively small size, it has become one of the most promising places for the search of extraterrestrial life in our Solar System. Under its icy surface, Enceladus possesses a vast water reservoir where a multitude of organic compounds has been detected by the Cassini-Huygens mission. One of the most interesting aspects of this moon is the presence of active geysers (plumes) that erupt directly from its subsurface ocean. These plumes are located primarily in the south polar region and they offer a unique opportunity to analyze the composition of the moon's ocean without the need to land on and drill through its surface. The plumes contain water vapor, salts, organic molecules and other complex compounds, which suggest that the environment beneath the icy shell could support microbial life. This thesis work focuses on the study of preliminary orbital trajectories for a future life detection mission to Enceladus. Through GMAT (General Mission Analysis Tool) simulations the motion of a satellite around the moon is studied, highlighting the challenges of maintaining it in orbit due to Saturn's gravitational influence. Several orbital configurations are analyzed to determine the optimal parameters that would allow a spacecraft to pass over the plumes multiple times, enabling the collection of material samples from the moon's subsurface ocean. Moreover, the possibility of performing orbit stabilization maneuvers to maintain a desired trajectory over time is explored for various configurations. Finally, a potential mission architecture involving CubeSats is proposed. Specifically, 6U CubeSats are considered, each equipped with scientific payloads designed to analyze plume material and search for biosignatures. These CubeSats would be carried inside a mothership to Saturn where they would be deployed into low-altitude orbits around Enceladus. In these orbits, the CubeSats could pass over the plumes multiple times and at different altitudes, allowing the collection of a diverse range of material.