Attitude Control Systems: Gyro vs CMG

This lecture discusses methods for gyro-based attitude control systems, starting with reaction wheels used on Hubble and then moving on to Control Moment Gyros (CMGs) used on the International Space Station. It explains how the conservation of angular momentum affects the vehicle's reaction to changes in the spinning wheel's angular velocity, and how CMGs work by changing the orientation of the gyroscope to control the spacecraft's orientation. The lecture also covers the cluster of four CMGs used on the US segment of the International Space Station to maintain its attitude and orientation.