Soyuz 7K-TM

Apollo-Soyuz Test Project 1975 version of the Soyuz spacecraft (Soyuz 7K-TM) served as a technological bridge to the third generation Soyuz-T (T - транспортный, Transportnyi meaning transport) spacecraft (1976–1986).

The Soyuz ASTP spacecraft was designed for use during the Apollo Soyuz Test Project as Soyuz 19. It featured design changes to increase compatibility with the American craft. The Soyuz ASTP featured new solar panels for increased mission length, an APAS-75 docking mechanism instead of the standard male mechanism and modifications to the environmental control system to lower the cabin pressure to 0.68 atmospheres (69 kPa) prior to docking with Apollo. The ASTP Soyuz backup craft flew as the Soyuz 22 mission, replacing the docking port with a camera.