Multi-mode Controller for Propellantless Spacecraft Translational Maneuvering Through Orientation Changes Only

Translational relative motion of a spacecraft in a gravity field can be induced by orientation changes. As orientation changes can be effected by electrically driven momentum exchange devices, for instance, reaction wheels, such maneuvers do not require fuel or thrust and hence can be performed during propulsion system failures or when the onboard fuel is limited. In this paper, a multi-mode controller is developed to effect such maneuvers which switches between control gains and intermediate target trajectories to extend the closed-loop domain of attraction of a conventional LQR controller and to satisfy state and control constraints.