Celestial Minor Bodies are of great interest from a scientific point of view, due to the valuable data they gather related to the formation of the Solar System. They have also raised interest from the perspective of resource exploitation. Accordingly, the number of missions to asteroids and comets has greatly increased in recent years. The data obtained in these missions are giving us important insights on composition, structure and history of those bodies.
From an engineering perspective, in turn, there are challenges to be faced in order to increase the scientific return of this kind of missions. One key aspect is the modelling of the gravitational field, because it enables safe close proximity operations. Usually, the lack of accurate knowledge of the shape of the minor body prevents one from producing a high-fidelity model of the gravity field before the launch of the mission. Therefore, models are elaborated from data collected in-situ. Nonetheless, close proximity operations require a high level of autonomy on-board, favouring lightweight and accurate gravity models to be used during final phases. In this talk, a comparison of state-of-the-art gravitational modelling techniques will be provided, as well as a new optimisation procedure for a mascons description. In addition, three relevant engineering applications for close proximity operation around minor bodies are presented: 1) trajectory optimisation; 2) navigation using Convolutional Neural Networks and 3) robust control for a powered landing.