Abstract: The control problem of a flexible spacecraft during a large-angle maneuver is studied and a direct output feedback control method is proposed. It is shown that a linear output feedback is effective for asymptotic stability of the flexible spacecraft with a few control devices. The number of the required control devices and their location have been given. Optimal index of the direct output feedback control is also given.In this way, it is achieved that the large-dimension nonlinear system is controlled by using a few control devices.

Key words: flexible spacecraft, nonlinear, Liapunov Method, number of control device.