PRINCIPAL AXIS MISALIGNMENT CONTROL FOR DECONING OF SPINNING SPACECRAFT

Deconing controllers are developed for a spinning spacecraft, where th e control mechanism is that of axial or radial moving masses used to p roduce intentional, transient principal axis misalignments. A single-m ass axial controller is used to motivate the concept, and then axial a nd radial dual-mass controllers are described. The two-mass problem is of particular interest because spacecraft imbalances can be simultane ously removed with the same control logic. Each controller is tested v ia simulation for its ability to eliminate existing coning motion for a range of spin rates. Both controllers are developed via a linear-qua dratic-regulator synthesis procedure, which is motivated by their mult i-input/multi-output nature. The dynamic coupling in the radial two-ma ss control problem introduces some particularly interesting design com plications.