Soyuz 15

This article is about the 1974 mission. For the mission identified by NASA as ISS Soyuz 15, see Soyuz TMA-11.

Soyuz 15

Mission duration	2 days, 12 minutes, 11 seconds
Orbits completed	32
Spacecraft properties
Spacecraft type	Soyuz 7K-T/A9
Manufacturer	NPO Energia
Launch mass	6,760 kilograms (14,900 lb)
Crew
Crew size	2
Members	Gennadi Sarafanov Lev Dyomin
Callsign	Дунай (Dunay - "Danube")
Start of mission
Launch date	August 26, 1974, 19:58:05 (1974-08-26UTC19:58:05Z) UTC
Rocket	Soyuz
Launch site	Baikonur 1/5
End of mission
Landing date	August 28, 1974, 20:10:16 (1974-08-28UTC20:10:17Z) UTC
Landing site	48 kilometres (30 mi) SW of Tselinograd
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Perigee	173 kilometres (107 mi)
Apogee	236 kilometres (147 mi)
Inclination	51.6 degrees
Period	88.5 minutes
---- Soyuz programme (Manned missions) ← Soyuz 14 Soyuz 16 →

Soyuz 15 (Russian: Союз 15, Union 15) was a 1974 manned space flight which was to have been the second mission to the Soviet Union's Salyut 3 space station with presumably military objectives.

Launched 26 August 1974, the Soyuz spacecraft arrived at the station, but cosmonauts Lev Dyomin and Gennadi Sarafanov were unable to dock because the electronics in the Igla docking system malfunctioned. Without sufficient fuel for prolonged attempts at manual docking, the mission had to be abandoned. The cosmonauts powered down all nonessential systems in the Soyuz and waited until the next day for reentry. The crew landed 28 August. Analysis of the launch window was cited by observers for concluding a flight of 19 to 29 days had been planned.

In the event of the failure, official TASS statements merely claimed that the mission was intended to practice docking maneuvers with the Salyut 3 station. They also said that a new automatic docking system was tested which would be used on future Progress transport craft.

The failed mission exposed a number of serious design flaws in the Soyuz 7K-T spacecraft, namely its lack of reserve propellant and electrical power for repeated docking attempts. In addition, the Igla docking system was found to be in major need of improvement. Since it was impossible to carry out these changes before Salyut 3 finished its operating lifespan, they had to wait for future space stations. The backup spacecraft for the Soyuz 15 mission was placed in storage and later flown as Soyuz 20 despite being past its intended shelf life.

Crew

Position	Cosmonaut
Commander	Gennadi Sarafanov First spaceflight
Flight Engineer	Lev Dyomin First spaceflight

Backup crew

Position	Cosmonaut
Commander	Boris Volynov
Flight Engineer	Vitaly Zholobov

Reserve crew

Position	Cosmonaut
Commander	Vyacheslav Zudov
Flight Engineer	Valery Rozhdestvensky

Mission parameters

• Mass: 6,760 kg (14,900 lb)
• Perigee: 173 km (107 mi)
• Apogee: 236 km (147 mi)
• Inclination: 51.6°
• Period: 88.5 min