Abstract: An agile payload orientation system for a space satellite comprises a three-axis gimbal (30) for coupling an appended body (20) containing the payload (24, 25, 26, 27) to a main body (10) of the satellite. The appended body (20) also contains moment control gyroscopes (29), which are responsive to external command for changing the orientation of the appended body (20) relative to an inertial reference. The gimbal (30) comprises three separate torquer-resolver units (31, 32, 33), which are connected to each other in series so that their axes are mutually orthogonal to each other and coincide at a single point (34) located at the center of mass of the appended body (20). Since the center of mass of the appended body (20) does not move when the appended body (20) is rotated about the axis of any of the torquer-resolver units (31, 32, 33), a change in orientation of the appended body (20) can be made without disturbing the orientation of the main body (10).