Active Nutation Damping Utilizing Spacecraft Mass Properties

Active nutation damping generally requires a unique element to provide the necessary damping torques, plus a nutation-sensing system to properly monitor and control the active element by closed-loop action. This paper describes and analyzes, by computer- assisted mathematical techniques, a nutation damper for a dual-spin spacecraft which does not require an active ¿element¿. Damping is achieved through the inherent cross-axis torques generated by the spacecraft products of inertia and the existing motor controlling the relative spin rates of the two dynamic components comprising the spacecraft.