Kosmos 638

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

Kosmos 638

Soyuz 7K-TM
Mission type	Orbital test flight
Operator	Soviet space program
COSPAR ID	1974-018A
SATCAT no.	7234
Mission duration	9 days, 21 hours and 35 minutes
Spacecraft properties
Spacecraft	Soyuz 7K-TM s/n 71
Manufacturer	NPO Energia
Launch mass	6,570 kg (14,480 lb)
Start of mission
Launch date	3 April 1974, 07:30 (1974-04-03UTC07:30Z) GMT[1]
Rocket	Soyuz-U
Launch site	Baikonur 31/6
End of mission
Disposal	Deorbited
Landing date	13 April 1974, 05:05 (1974-04-13UTC05:06Z) GMT[1]
Orbital parameters
Reference system	Geocentric
Perigee altitude	187 km (116 mi)
Apogee altitude	309 km (192 mi)
Inclination	51.8°
Period	89.4 min
Soyuz programme ← Soyuz 13 Kosmos 656 → Kosmos (satellites) ← Kosmos 637 Kosmos 639 →

This was followed by another uncrewed test of this spacecraft type, Kosmos 672.^[2] It was a Soyuz 7K-TM spacecraft.^[2]

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.^[2] This led to the next test also being uncrewed.^[2]

Mission parameters

• Spacecraft: Soyuz-7K-TM №71
• Mass: 6510 to 6680 kg
• Crew: None
• Launched: April 3, 1974
• Landed: April 13, 1974

See also

• Kosmos 672
• Soyuz 16