Study of Innovative Architectures for Agile Earth Observation Satellites

Today, the space sector needs new generation S/Cs capable to meet demanding agile requirements. The study performed in this report shows the possibility to control a S/C attitude through systems based on CMGs: these devices, assembled in an array, can generate the big torques required to ensure the S/C agility. The principal problem in using this kind of actuators, is the possibility to arrive in singular configurations, which make the array incapable of producing torque in one or more directions. For this reason, singularity avoidance and escape techniques have been implemented in order to obtain an efficient and robust S/C control.