Imprint on the Moon (1969)

A behind the scenes look at the development, construction and delivery of the Instrument Unit for Apollo. The Instrument Unit was the computer nerve center for the launch vehicle—controlling the Saturn rocket until Apollo was safely headed to the Moon. It determined when to fire the Saturn’s three rockets, when to jettison them and where to point them. Included in the IU’s equipment were devices to sense altitude, acceleration, velocity and position, as well as the computer to lay out the desired course and give control signals to the engines to steer the Saturn on that course.