Apollo Soyuz Engineering Test Project for "Cogito Ergo Es" Part 1

Video from the channel MrSilvestris about Apollo–Soyuz, linked on its Above Ten Thousand entry. Duration: 6:14. Language: English. Video type: Documentary.

Excerpt from an educational documentary about the engineering of the 1975 Apollo-Soyuz mission, with statements from astronaut Vance Brand. It raises the main technical problem of joining two spacecraft designed secretly and separately during the Cold War, and how it was solved.

It presents the joint flight as a symbol of the thaw between the United States and the Soviet Union and of the end of space race tensions. The plan was to launch a Soyuz from Baikonur and an Apollo from Cape Canaveral so they could dock in orbit. Brand recalls the challenge of working with those who were then seen as enemies, and highlights the docking system developed and the foundation the mission laid for cooperation between the Eastern bloc and the West.

The two spacecraft had incompatible atmospheres. Soyuz kept air at Earth-surface pressure, while Apollo's crew breathed pure oxygen at a much lower pressure. Moving from one to the other without transition could cause nitrogen bubbles to form in the blood, as happens to divers who ascend too quickly. Engineers added a decompression chamber to Apollo, where the astronauts waited for the pressure to equalize before moving into Soyuz. The video includes the docking, which Brand describes as a slight jolt followed by the latches closing, and the opening of the hatch between the two spacecraft.