State feedback ℋ/sub ∞/-suboptimal control of a rigid spacecraft

A state feedback /spl Hscr//sub /spl infin//-suboptimal control problem on TSO(3) for a rigid spacecraft with three control torques and disturbances is addressed, the Hamilton-Jacobi inequality associated with a corresponding state feedback /spl Hscr//sub /spl infin//-suboptimal control problem on TS/sup 3/ is solved globally. The /spl Hscr//sub /spl infin//-suboptimal state feedback on TS/sup 3/ involves the Euler parameters and solves the original problem on TSO(3) when the initial values of the Euler parameters are appropriately chosen.