Control moment gyroscope

A Control Moment Gyroscope (CMG) is a spacecraft attitude control system that uses gyroscopic principles to change orientation. It consists of a high-speed spinning rotor mounted on gimbals. When the gimbal axis is rotated, the rotor’s angular momentum vector shifts, generating a reaction torque that reorients the spacecraft. CMGs provide high torque, fast response, and fuel-free operation, making them ideal for long-duration missions. They are widely used in satellites, telescopes, and space stations for precise pointing and stabilization. Compared to reaction wheels, CMGs deliver greater control authority for agile spacecraft maneuvers.