Abstract: This paper investigates the problem of attitude compound control for spacecraft with multiple moving appendages. The representative dynamical model of twocoupled rigid bodies is established and the coupling relationship is analyzed. And a finitetime disturbance observer (FTDO) is designed to estimate the disturbances introduced by appendages and the external environment. The total disturbance is actively compensated via the terminal sliding mode controller (TSMC). By using the extended Lyapunov stability theory, the finitetime convergence of the main body’s control system is proved. To reduce the influence of spacecraft attitude maneuver to the appendages, a controller with angular acceleration compensation is considered. The simulation results show that the developed method can accurately estimate and compensate the total disturbance with a high control precision and faster system response.

Key words: moving appendages, compound control, FTDO, active compensation, TSMC