Optimal Control of a Solar Sail for an Interplanetary Mission to an Asteroid

Solar sailing is a non-traditional propulsion system that is attracting growing interest due to its various benefits compared with traditional chemical propulsion. A solar sail generates thrust through the momentum exchange resulting from the interaction between the sail surface and the incident solar radiation. This propulsion method provides continuous thrust without requiring any propellant consumption. These characteristics make solar sailing a viable option for long-duration missions. This thesis focuses on orbit optimization for an interplanetary mission targeting an asteroid, carried out with a solar sail-propelled CubeSat. The study of asteroids is a topic of interest in various fields. The ancient origin of these celestial bodies makes them an essential source of information on the history and formation of our Solar System, the origin of the Moon and the development of life on our planet. The various types of asteroids offer a great reservoir of rare materials, making them an interesting location for space mining. Regarding \ac{NEA}, planetary defence is necessary against \ac{PHA}. The compact size and low mass of a CubeSat make it a good candidate for solar sail propulsion. Trajectory optimization, for the heliocentric phase of the mission, is performed using an indirect mathematical method. The motion equations of the sail are obtained from the two-body problem, including the contribution of solar radiation pressure. The optimal control theory is applied to formulate the problem and the Pontryagin’s Maximum Principle provides the optimal sail orientation at each point of the trajectory. The formulation of the problem results in a boundary value problem, which is solved using an indirect Newton-like mathematical method. Numerical analyses are carried out for different asteroids demonstrating the feasibility of the mission.