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To the Moon by Way of Testing

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In the early months of 1968 the space program was moving at an ever-increasing pace. Preparations were under way for Apollo 7, the first manned Apollo flight in late fall, while fully stacked Saturn V rockets were being launched in a series of unmanned flights. However, before Apollo 7, a few key tests would have to be successful in the previous summer.

Unknown to the casual historian, and forgotten by history, a few events that in Houston, TX were regarded as some of the most important in the space program at the time. In the early summer of 1968, the fate of the space race may have hinged itself at the Space Environment Simulations Lab (SESL). SESL comprised two massive vacuum chambers that tested the fledgling Apollo spacecraft and Lunar Module (LM) in an environment that mimicked space in every way except weightlessness. With the Apollo spacecraft tested in Chamber A and the LM tested in the smaller Chamber B, the two ships would be subjected to extreme temperatures and lighting found in space.

The success of a manned thermal vacuum test of the Apollo command module in June of 1968 was considered paramount. For Apollo, a manned test in Chamber A would be a kind of vindication after the Apollo 1 crew was killed by a fire that occurred during a ground test. The Apollo spacecrat of 1968 was a much improved version of the Block I ship involved in the fire. Officially designated 2TV-1, or Block II Thermal Vacuum Test number 1, the eight day manned test would mimic a voyage in space and reassure everyone that a ground test could go well. Changes in atmosphere, pressure, and fireproofing inside the new spacecraft would be tested for the first time with a crew inside.

Not only would the results of this manned test help clear the way for the Apollo 7 flight in a few months, it would also show that the space program had learned from the mistakes of the fire. In fact, NASA planners gave the construction of the 2TV-1 (CSM-098) spacecraft more priority than its sister ship Apollo 7(CSM-101). This thinking also applied to the LM that was tested in Chamber B. It’s construction was considered more important than the line of LM’s that would eventually be launched into space.

Originally, the 2TV-1 test was scheduled for February of 1967, but with the changes and delays after the fire, the Apollo newly improved spacecraft was not finished until the spring of 1968. After several delays, North American Aviation delivered the Block II CSM-098 to Johnson Space Center Houston, where SESL was housed. Apollo 7, which was being built and tested at the same time, was essentially the same ship, except for a few flight critical pieces of hardware. Because changes to 2TV-1 had to be made also to Apollo 7, the manned test had to be completed at least one month before the actual Apollo 7 flight.