Demonstration model of the Apollo Command Module and its Inertial Measurement Unit (IMU) used by Dr. Charles Stark 'Doc' Draper to explain the three-axis control points and notional positioning of the IMU, mounted within three wooden gimbals and measuring an overall 24″ x 18″ x 19″. Dusty and in very good condition, with cracks to one edge of the clear acrylic shell.
Known as the 'father of inertial navigation,' Doc Draper pioneered the use of gyroscopes and accelerometers to measure a spacecraft's movement within a stable frame of reference. Derived from the guidance system that Draper had developed for the Polaris missile, the Apollo Inertial Measurement Unit (IMU) was able to keep track of the spacecraft's velocity and position, relaying that information to the Apollo Guidance Computer (AGC) so that any necessary corrections to the spacecraft's trajectory could be made. IMUs were installed in both the Apollo Command Module and Lunar Module as important components of the Primary Guidance, Navigation, and Control System (PGNCS). Draper founded the MIT Instrumentation Laboratory in the 1930s. It was renamed for him as the Charles Stark Draper Laboratory in 1970 and became independent of MIT in 1973. From the Don Eyles Apollo Computer Collection.
Terms and abbreviations used in our descriptions.