The Site Activation Board focused its attention in the fall of 1965 on the 500-F test - a dress rehearsal for the new Saturn V rocket and launch complex 39. Plans for the 500-F test vehicle dated back to early 1962 when LOD engineers were still studying the use of barges to move the giant Saturn V to its launch pad. As the facilities checkout vehicle, 500-F would test the mating of the stages in the assembly building, the fit of the service platforms, the launcher-transporter operation, the propellant loading system, and the test connections to the mobile launcher and support equipment. Each dummy stage would duplicate the flight configuration, ordnance, and umbilical connections of its live counterpart. Although inert, the retrograde rockets, ullage rockets, and shaped charges would have the dimensions of the live ordnance. This allowed the launch team to practice ordnance installation. Facility checkout would culminate with a "wet test" to verify the storage and transfer of the propellants. The wet test would involve hundreds of components: pneumatic valves, liquid sensors, time delay relays, pressure switches, circuit breakers, pumps, motors, fans, vaporizers, vents, and the burn pond. The launch team scheduled the delivery of the 500-F stages at the Cape nine months before the first Saturn V flight. The Office of Manned Space Flight translated this into a tentative July 1965 test date.20
This was not to be. When George Mueller revised the Apollo schedule in November 1963, erection of the SA 500-F stages on the mobile launcher slipped back to 1 February 1966. Marshall would deliver an S-IVB- F stage (used in the Saturn IB checkout of LC-34) in May 1965, and the S-IC-F and S-II-F stages in January 1966. General Phillips announced the Apollo launch schedule in February 1965, as follows:
There was little margin for error. In December 1964, Dr. Arthur Rudolph, Saturn V Program Manager in Huntsville, asked KSC to agree to a delay in delivery dates for the 500-F and AS-501 launch vehicles. After reviewing the schedules for equipment installation and checkout, the 500-F test, and AS-501, Petrone replied that there was no room for delay. KSC had already eliminated the detailed receiving inspection for the 500-F and 501 vehicles. Although Marshall's contract with Douglas omitted the digital data acquisition system test for 500-F propellant loading, KSC would not waive this check. The schedule did include several weeks of learning time, primarily in crawler operations with a space vehicle aboard the mobile launcher. Petrone, however, considered the 500-F schedule "optimistic since it does not allow time for resolution of major difficulties which may occur."22