With just two weeks remaining until the dual launches of a Soviet Soyuz and an American Apollo spacecraft, workers at the Kennedy Space Center (KSC) completed the final dress rehearsal for the Apollo Saturn vehicle’s countdown to launch on July 15, 1975. The American and Soviet crews of the Apollo-Soyuz Test Project (ASTP) wrapped up their final training sessions while maintaining strict medical isolation. They participated in the final joint mission simulation between the two control centers and brushed up on their language skills.
Left: The ASTP Saturn IB on Launch Pad 39B during the wet phase of
the CDDT. Right: ASTP Apollo crewmembers (left to right) Slayton, Stafford
and Brand after the conclusion of the CDDT.
At KSC’s Launch Complex 39, engineers completed the Countdown Demonstration Test (CDDT) between June 25 and July 3. During the CDDT, engineers rehearsed all the steps of the actual countdown, including fueling the rocket, right up until the moment of ignition of the first stage engines. They concluded that “wet” phase of the test on July 2, after which they drained the rocket of propellants, reset the countdown and the next day the astronaut crew of Commander Thomas P. Stafford, Command Module Pilot Vance D. Brand, and Docking Module Pilot Donald K. “Deke” Slayton participated in the final few hours of the exercise to complete the “dry” phase of the test. They donned their spacesuits and climbed aboard the Command Module atop the Saturn IB rocket, just as if on launch day, and continued the practice countdown until just before engine ignition. The successful execution of the CDDT was the final milestone to be completed before beginning the countdown for the final Apollo-Saturn launch.
Left: ASTP Apollo crewmembers (left to right) Stafford, Brand and Slayton
reviewing Earth observation maps and photographs with geologist Farouk
al-Baz (wearing mask) during preflight isolation. Right: ASTP Soyuz
crewmembers Kubasov (left) and Leonov during final preflight training.
Apollo astronauts Stafford, Brand, and Slayton began their three-week Flight Crew Health Stabilization Plan, commonly known as the preflight quarantine, on June 24, during which they were limited to certain work and training areas at KSC and the Johnson Space Center (JSC) and only medically-screened personnel could come into close contact with them. The goal of the quarantine was to prevent the crew from contracting any contagious illnesses that could either cause a change in crew assignments or a delay to the mission. Soyuz cosmonauts Commander Aleksei A. Leonov and Flight Engineer Valeri N. Kubasov similarly began their preflight isolation program at the Gagarin Cosmonaut Training Center in Star City outside Moscow on June 27. Between June 29 and July 1, all five crewmembers participated in the final 56-hour joint mission simulation between the two control centers in Houston and Kaliningrad (now Korolev) outside of Moscow. The American crew participated from an Apollo spacecraft simulator at JSC while the Soviet crew were in a Soyuz simulator in Star City. The Apollo astronauts conducted additional stand-alone simulations of solo phase activities such as launch and reentry. During any free time, the astronauts and cosmonauts brushed up on their language skills since protocols dictated that during joint operations all crewmembers speak the others’ language.
To be continued…