Control moment gyroscope
![NASA personnel handle a single Control Moment Gyroscope for the International Space Station.](/Images/godic/202501/06/ISS_gyroscope2749.jpg")
![](/Images/godic/202501/06/CMG2749.png")
A control moment gyroscope (CMG) is an attitude control device generally used in spacecraft attitude control systems. A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotor’s angular momentum. As the rotor tilts, the changing angular momentum causes a gyroscopic torque that rotates the spacecraft.