Apollo Inertial Measurement Unit Inertial Rate Integrating Gyro mockup (inoperative shell only), measuring approximately 5.25″ tall by 2.5″ in diameter, with a NASA Apollo label affixed to the top. In fine condition. Three IRIGs were mounted on the Apollo Command Module and Lunar Module IMU stable platform and sensed displacement in three dimensional space. The magnitude and direction of displacement were converted to output signals that drove gimbal torque motors to restore the stable platform back to its ‘nulled’ alignment.
