Breakwell Memorial Lecture: Attitude dynamics of satellite—From spinning satellite to space robot

This paper deals with attitude motions of a spacecraft. A spacecraft is a mechanical system composed of many rigid and elastic bodies. The degrees of freedom of motion of a spacecraft strongly interact with each other through the angular momentum conservation law. Therefore, an attitude motion may become unstable by various factors. This paper explains the following unstable attitude motions: (1) thermally induced nutation of a spin stabilized satellite with elastic appendages; (2) unstable attitude motion of a dual-spin stabilized satellite during a despin maneuver and (3) unstable attitude motion of a space robot caused by the motion of a manipulator. On the other hand, the attitude motion of a spacecraft can be controlled by using the strong interactions between the degrees of freedom of motion through the angular momentum conservation law. As an example, this paper discusses control of the attitude motion of a spacecraft with two reaction wheels.