This is one of several Instrument Units (IU) presently in the NASM collections. The Instrument Unit was mounted above the third stage of a Saturn V, or the second stage of a Saturn 1-B, and provided guidance for the launch vehicle. (Apollo Command and Lunar Modules had their own, separate on-board guidance systems.) Instrument Units were manufactured by IBM for the Saturn program.
An instrument unit consisted of a large ring that provided structural strength, inside of which were mounted a digital computer, an inertial reference unit, batteries, and other components. The IU for the Saturn V had the same dimensions as those for the Saturn 1B, but some of the components installed on it were different, reflecting the different needs of the two launch vehicles. This Unit is an unflown, development model for the 1-B.
Transferred to the National Air and Space Museum from NASA in 1975.
Transferred from the National Aeronautics and Space Administration