Soyuz 15

Soyuz 15
Mission typeSalyut 3 crew transport
OperatorSoviet space program
COSPAR ID1974-067A Edit this at Wikidata
SATCAT no.7421
Mission duration2 days, 12 minutes
Orbits completed32
Spacecraft properties
SpacecraftSoyuz 7K-T No.4
Spacecraft typeSoyuz 7K-T/A9
ManufacturerOKB-1
Launch mass6,570 kg (14,480 lb)[1]
Landing mass1,200 kg (2,600 lb)
Crew
Crew size2
MembersGennady Sarafanov
Lev Dyomin
CallsignДунай (Dunay - "Danube")
Start of mission
Launch date26 August 1974, 19:58:05 UTC
RocketSoyuz 11A511
Launch siteBaikonur 1/5[2]
End of mission
Landing date28 August 1974, 20:10:16 UTC
Landing site48 km (30 mi) at the southwest of Tselinograd
Orbital parameters
Reference systemGeocentric orbit[3]
RegimeLow Earth orbit
Perigee altitude254 km (158 mi)
Apogee altitude275 km (171 mi)
Inclination51.60°
Period89.60 minutes

Soviet stamp featuring Sarafanov and Dyomin (1974)

Soyuz 15 (Russian: Союз 15, Union 15) was an August 1974 crewed space flight which was to have been the second mission to the Soviet Union's Salyut 3 space station with presumably military objectives.[4]

Launched 26 August 1974, the Soyuz spacecraft arrived at the station, but cosmonauts Gennady Sarafanov and Lev Dyomin 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.[5] The crew landed 28 August 1974. Analysis of the launch window was cited by observers for concluding a flight of 19 to 29 days had been planned.[5]

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.[4] They also said that a new automatic docking system was tested which would be used on future Progress transport craft.[5]

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.

  1. ^ Cite error: The named reference Display was invoked but never defined (see the help page).
  2. ^ "Baikonur LC1". Encyclopedia Astronautica. Archived from the original on 15 April 2009. Retrieved 4 March 2009.
  3. ^ Cite error: The named reference Trajectory was invoked but never defined (see the help page).
  4. ^ a b Clark, Phillip (1988). The Soviet Manned Space Program. New York: Orion Books, a division of Crown Publishers, Inc. ISBN 0-517-56954-X.
  5. ^ a b c Newkirk, Dennis (1990). Almanac of Soviet Manned Space Flight. Houston, Texas: Gulf Publishing Company. ISBN 0-87201-848-2.