Load-sharing robust control of spacecraft formations: deep space and low Earth elliptic orbits

The design of autonomous and collaborative control strategies to govern the relative distances among multiple spacecraft in formation with no ground intervention is discussed. A coordinated load-sharing control structure for formation flying and a robust methodology to control spacecraft formations under slow time-varying and uncertain parameters are the main objectives. The method shares the load according to frequency specifications and takes into account the uncertainty and the multi-input-multi-output characteristic of the system. The methodology is applied to control spacecraft in formations in both deep space and low Earth elliptic orbits