Soyuz 15

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.^[2]

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.^[3] 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.^[3]

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.^[2] They also said that a new automatic docking system was tested which would be used on future Progress transport craft.^[3]

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

Backup crew

Reserve crew

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

References

Soyuz human spaceflight programme
Main topics	Soyuz (rocket family) Soyuz (spacecraft) Baikonur Cosmodrome Site 1/5 Site 31/6 List of Soyuz missions List of Soviet manned space missions List of Russian manned space missions
Current missions	Soyuz MS-02 MS-03
Future missions	2017 Soyuz MS-04 MS-05 MS-06 MS-07 2018 Soyuz MS-08 MS-09 MS-10
Past missions (by spacecraft type)	Soyuz 7K-OK (1966–1970) Kosmos 133† Soyuz 7K-OK No.1† Kosmos 140 Soyuz 1† Kosmos 186 188 212 213 238 Soyuz 2 3 4 5 6 7 8 9 Soyuz 7K-L1 (1967–1970) (Zond lunar programme) Kosmos 146 154† Zond 1967A† 1967B† Zond 4 1968A† 1968B† 5 6 1969A† Zond-M 1† M 2† Zond 7 8 9 10 Soyuz 7K-L1E (1969–1970) Soyuz 7K-L1E No.1† Kosmos 382 Soyuz 7K-LOK (1971–1972) Soyuz 7K-LOK No.1† No.2† Soyuz 7K-OKS (1971) Soyuz 10† 11† Soyuz 7K-T (1972–1981) Kosmos 496 573 Soyuz 12 Kosmos 613 Soyuz 13 Kosmos 656 Soyuz 14 15† 17 18a† 18 20 (uncrewed) 21 23† 24 25† 26 27 28 29 30 31 32 (uncrewed landing) 33† 34 (uncrewed launch) 35 36 37 38 39 40 Soyuz 7K-TM (1974–1976) Kosmos 638 672 Soyuz 16 19 (Apollo–Soyuz Test Project) 22 Soyuz 7K-S (1974–1976) Kosmos 670 772† 869† Soyuz-T (1978–1986) Kosmos 1001† 1074 Soyuz T-1 (uncrewed) T-2 T-3 T-4 T-5 T-6 T-7 T-8† T-9 T-10a† T-10 T-11 T-12 T-13 T-14 T-15 Soyuz-TM (1986–2002) Soyuz TM-1 (uncrewed) TM-2 TM-3 TM-4 TM-5 TM-6 TM-7 TM-8 TM-9 TM-10 TM-11 TM-12 TM-13 TM-14 TM-15 TM-16 TM-17 TM-18 TM-19 TM-20 TM-21 TM-22 TM-23 TM-24 TM-25 TM-26 TM-27 TM-28 TM-29 TM-30 TM-31 TM-32 TM-33 TM-34 Soyuz-TMA (2002–2012) Soyuz TMA-1 TMA-2 TMA-3 TMA-4 TMA-5 TMA-6 TMA-7 TMA-8 TMA-9 TMA-10 TMA-11 TMA-12 TMA-13 TMA-14 TMA-15 TMA-16 TMA-17 TMA-18 TMA-19 TMA-20 TMA-21 TMA-22 Soyuz-TMA-M (2010–2016) Soyuz TMA-01M TMA-02M TMA-03M TMA-04M TMA-05M TMA-06M TMA-07M TMA-08M TMA-09M TMA-10M TMA-11M TMA-12M TMA-13M TMA-14M TMA-15M TMA-16M TMA-17M TMA-18M TMA-19M TMA-20M Soyuz MS (2016–present) Soyuz MS-01
Uncrewed missions are designated with Kosmos numbers; crewed missions get a Soyuz number. Failed missions are denoted with a † symbol. Cancelled missions are in italics.