The exploration of Mars represents one of the most ambitious missions for the conquest of space. It is not just a question of pushing man into territories never before physically reached, but also of deepening scientific knowledge through the search for possible forms of past microbial life and the analysis of rocks and craters, comparing them with those on Earth. Furthermore, a possible future colonisation of the red planet would open up significant economic scenarios linked to the exploitation of new resources and the development of advanced technologies. This thesis aims to study and optimise trajectory control during the landing phase on Mars.