A method of robust fault tolerant attitude control, based on adaptive sliding mode control is proposed for an
on-orbiting spacecraft in the presence of partial loss of actuator effectiveness and external disturbance. In this approach,
adaptive technique is employed to estimate the minimum value of actuator fault, and a sliding mode attitude controller is
then designed to achieve fault tolerant control and external disturbance rejection. For the designers, the real minimum value
of the fault is not required to be known in advance exactly, and the great robustness to fault is guaranteed. The simulation
results of an application to spacecraft attitude adjustment maneuver show that great fault tolerant capability can be achieved
even under partial loss of actuator effectiveness.