Chapter 19

APOLLO 4: THE TRIAL RUN

The Significance of AS-501

The problems of the spacecraft threatened, but did not extinguish, the hopes of reaching the moon within the decade. Much depended on the outcome of the first Saturn V mission. If the largest launch vehicle and launch complex yet built both performed satisfactorily, the Apollo program could still meet its schedule.

A successful mission would achieve several significant goals. It would mark: the first launch from launch complex 39, the first flight of the integrated Apollo-Saturn V space vehicle, the initial trials of the first (S- IC) and second (S-II) stages of the Saturn V launch vehicle, the first shutdown and restart in space of the third stage (S-IVB) engine, and the first demonstration of the Apollo spacecraft's ability to reenter the earth's atmosphere at the speeds and temperatures it would reach on return from a mission to the moon. Many other benefits would accrue if the unmanned earth-orbital mission succeeded. The adequacy of ground tracking, telemetry, and communications operations at stations around the world could be evaluated. The launch vehicle stages and spacecraft modules would carry additional research and development instrumentation to measure the performance of their internal components. A total of 4,098 in-flight measurements - about 2/3 of them for the launch vehicle, 1/3 for the spacecraft - were scheduled.1

The results of this mission would confirm or deny the validity of a major management decision made in the fall of 1963-the use of all-up flight testing. Designed to result in an overall time saving, all-up testing meant that all launch vehicle stages and spacecraft modules (essentially in their final configuration) would be tested together on each flight. Previous practice had favored a gradual buildup of subsystems, systems, stages, and modules in successive flight tests.2 Based in part on the unqualified successes of the first four Saturn I missions, but made before any Apollo spacecraft had flown, the eggs-in- one-basket decision involved a calculated risk. Success in all-up testing was the quickest way to accomplish a manned lunar landing. On the other hand, failure of the first Saturn V mission would be a major catastrophe.

For KSC the first flight of the Apollo-Saturn V had a narrower, but more important, objective than that of the total mission. For the first time the facilities, equipment, procedures, and checkout crews would be put to the test. The 500-F facility checkout tests had instilled a certain degree of confidence (while revealing much that remained to be done), but this would be "the real thing." This time, every action would lead toward those moments when the first-stage engines would ignite, the hold-down arms on the launcher platform would retract, and the Apollo-Saturn V vehicle would be committed to flight. In the process of receiving, assembling, testing, and launching this first Apollo-Saturn V, KSC civil service managers and the launch vehicle, spacecraft, and launch support contractor crews would be learning to work together as a unit. It would prove a difficult task for all concerned - and not without its rough moments - but, in the end, a well-functioning launch team would be the reward.