Attitude control strategies for small satellite observation of a collaborative target

In-space devices are rapidly increasing in number and variety. Although small spacecraft have already established a heritage, the industry is proving to be dynamic and evolving. Small sizes allow to achieve more efficient structures and consequently both lower costs and simpler designs. This thesis proposes a method to carrying out a close-range observe of a collaborative target with a CubeSat while performing a helix trajectory. The thesis objective is to devise a time-variant attitude maneuver to perform the observation, to choose a proper control solution and to build a model to test the solution and carry up a performance evaluation. To determine whether the design meets the re-quirements numerical simulations are carried out using Matlab and Simulink. To include ensemble type errors Montecarlo campaign and worst-case analyses are carried out. The first part of this work is dedicated to the development of the Mission simulator, focusing on the design of the time-variant reference attitude, the multibody dynamics model of the satellite, the SMC law, and the environmental disturbances. In the second part the solution is test the performance of the attitude controllers to show that is able to reject the environmental disturbances and the model uncertainties. All modelling and simulations are made in Matlab/Simulink environment.