The Saturn V instrument unit, the “brains” of the Saturn V launch vehicle, was manufactured in the east high bay at International Business Machines (IBM) in Huntsville, Ala. IBM was the prime contractor for development and fabrication of the instrument unit. The instrument unit was designed by engineer’s at NASA’s Marshall Space Flight Center in Huntsville, and the ring configuration with electronics boxes mounted on the inside was based on the design of the instrument unit for the smaller Saturn I rocket. As with modern rocket avionics systems, the instrument unit was vital to the proper flight of the vehicle because it contained the navigation, guidance, control, and sequencing equipment. Three feet tall, twenty-one feet in diameter, and weighing about 4,000 pounds, the instrument unit was mounted atop the S-IVB, the rocket’s third stage, between the S-IVB stage and the Apollo spacecraft.
Image credit: NASA