Experiments With a Momentum Exchange Actuator for Ultralight Flexible Spacecraft

Performing slew maneuvers of large flexible structures in space is challenging and even ground testing which is necessary to establish actuator working, control scheme and corresponding flexible structure dynamics. The paper presents a design of a small scale Control Moment Gyroscope (CMG) prototype and a lightweight flexible structure built for performing slew maneuvers. The 1.2 m × 1.2 m flexible structure is highly compliant along the maneuver direction allowing the study of its elastic deformations. Smooth polynomial maneuvers are performed with the CMG-structure system mounted on an air bearing, the central hub orientation and structural dynamics are measured. Finally, input shaping is applied to the original maneuver using Zero Velocity (ZV) shaper and the results are presented.