The Soyuz 7K-OK is a Soviet spacecraft designed for crewed missions to low Earth orbit. It was part of the Soyuz program, which aimed to develop reliable transportation for astronauts. The spacecraft featured a three-module design, including an orbital module, a reentry module, and a service module, allowing for various mission profiles. Launched for the first time in 1967, the Soyuz 7K-OK was instrumental in the early stages of human spaceflight. It served as a platform for missions that included docking with space stations like Salyut and conducting scientific experiments in space.