Abstract: The manipulator motion is planned to adjust the satellite attitude,which is the base of the manipulator.The method not only saves the propellant used for the attitude control,but also can serve as a backup means for the conventional attitude control system.Firstly,the state equation of the free-floating space robot system is established with the joint angles and the satellite attitude as its state variables,and the joint angular velocities as its input variables.Based on the theory of system controllability,the path connecting the system initial state with the desired state is planned,and the satellite attitude and joint angle can be controlled at the same time only using the manipulator joint motion. Lastly,the energy consumption is analyzed theoretically,and the near optimal algorithm to minimize the power cost function is presented.The numerical simulation results show the validity of the method.