Targeting and Descent Trajectories for Moon Missions

All the major Space-Powers are looking back again at the exploration of the Moon, this time “to stay”. Driven by scientific, geopolitical and economic purposes, the -still today- totally unexplored Moon South Pole is set as the preferred target region where to land. Being rich of water-ice (permafrost), this region results to be the most attractive for the development of stable human settlements. Through also the involvement of space private companies, the race is on! Through the European Space Agency (ESA), Europe wants to play a key role in such a fascinating and challenging rush. Never been on the Moon, Europe is now going to put its best efforts on the so-called Argonaut program, representing the European answer to the new Moon call. The objective is to independently develop a lunar lander able to carry over the lunar surface a greater amount of mass (> 1.5 tons). Consequently, this thesis has been fit into this operative and competitive context by aiming to develop a set of tools providing autonomous mission analysis capabilities, without relying on commercial mission analysis software. The problems addressed are then two: that of computing the necessary trajectory correction maneuver and that of optimizing the descent trajectory at Moon arrival. With the purpose of fulfilling these needs, this thesis is based on the optimization methods further employed in the creation of the software developed for Thales Alenia Space Italy (TAS-I), using the MATLAB language. The descent dynamics have been written in a Celestial Body-Fixed reference frame, continuing previous development work done at TAS-I with simpler models. The new insights into the problem allowed to improve the previous dynamical model, with the new equations given in the Appendix. The Moon targeting was instead studied using the Circular Restricted Three-Body Problem (CR3BP), and also a higher precision model, importing ephemeris data from the SPICE Toolkit, accounting for the presence of the Sun. This method also allows to export the trajectory data in the SPICE Enhanced software COSMOGRAPHIA, to realistically represent the optimized trajectories profiles. Finally, the B-Plane targeting method has been investigated too.