The first operational Saturn 5 Moon rocket, with the Apollo 4 Command and Service Module (SCM) on top, had been sitting on Pad 39A at the Kennedy Space Center in Florida since its rollout on August 26, 1967. The stack was undergoing a series of tests, and one of the most important was the Count Down Demonstration Test (CDDT). This test was essentially a dress rehearsal for the planned Apollo 4 launch, with the vehicle powered up and fully fueled. The CDDT began on September 27 and was planned to last six days. Due to many unforeseen technical challenges that had to be overcome, it was finally concluded 17 days later on October 13. It was those challenges and the solutions to overcome them that were critical lessons learned about how to prepare a Moon rocket for flight, such as the intricacies of fueling a 363-foot tall rocket.
Director of Launch Operations Rocco Petrone said of the countdown demonstration, “We learned a lot. The program came to fruition.”
The valuable lessons learned during the test made the countdown to the actual launch in November go remarkably smoothly. Getting Apollo 4 and its Saturn 5 ready for flight was an important milestone on the way to landing men on the Moon before the end of the decade.
