• solar sail
• equilibrium points
• feedback control law
• wrinkles
• three-body problem
• electrochromic materials
• early-warning mission
• Lagrangian points

The objective of this thesis is to evaluate the impact that wrinkles have on the stability and control of a solar sail in the proximity of an L1-type artificial equilibrium point in the Sun-[Earth+Moon] circular restricted three-body problem. These equilibrium locations can be exploited in order to monitor the solar activity and send an early-warning signal to the Earth if potentially dangerous events, such as coronal mass ejections, take place. Firstly, a pre-existing experimental thrust model for wrinkled sails has been generalized to also include the contribution due to diffuse reflection, then suitable feedback control laws have been proposed and tested in the MATLAB environment to show the possibility of stabilizing the motion of a wrinkled sail by means of a set of reflectivity control devices. These devices can change their optical properties upon application of an electric voltage, therefore allowing the sail to modify its lightness parameter and attitude without employing complex and unreliable mechanisms or consuming propellant.