Kosmos 638 () was an uncrewed test of the 1975 Apollo–Soyuz Test Project Soyuz. It carried an APAS-75 androgynous docking system.

This was followed by another uncrewed test of this spacecraft type, Kosmos 672. It was a Soyuz 7K-TM spacecraft.

When the air was released from the orbital module (which is ejected before re-entry of the capsule) it caused unexpected motions with the spacecraft. This led to the next test also being uncrewed.

Mission parameters

• Spacecraft: Soyuz-7K-TM №71

• Mass: 6510 to 6680kg

• Crew: None

• Launched: April 3, 1974

• Landed: April 13, 1974

See also

• Kosmos 672

• Soyuz 16

References