The introduction notes, "The Saturn V launch vehicle is being developed by the National Aeronautics and Space Administration's George C. Marshall Space Flight Center for Project Apollo; Saturn I and Saturn IB vehicles are providing the early testing and support for Project Apollo. The nerve center of the Saturn is its guidance and control system. An airborne digital computer provides the link which closes both the guidance and control loops,making verification of the flight computer program of vital importance. During a powered flight this onboard digital computer program can be divided into four major parts:a) guidance, including navigation, b) control, c) vehicle sequencing, and d) computer telemetry."