Soyuz 31 (Russian: Союз 31, Union 31) was a 1978 Soviet crewed space flight to the Salyut 6 space station.[2] It was the seventh mission to and sixth successful docking at the orbiting facility. The Soyuz 31 crew were the second to visit the long-duration Soyuz 29 resident crew.

Soyuz 31
Bykowski (above) and Jähn (below)
OperatorSoviet space program
COSPAR ID1978-081A Edit this at Wikidata
SATCAT no.11010
Mission durationCapsule:
67 days, 20 hours and 12 minutes
Original crew:
7 days, 20 hours and 49 minutes
Spacecraft properties
Spacecraft typeSoyuz 7K-T
ManufacturerNPO Energia
Launch mass6,800 kg (15,000 lb)
Crew
Crew size2
LaunchingValery Bykovsky
Sigmund Jähn
LandingVladimir Kovalyonok
Aleksandr Ivanchenkov
CallsignЯстреб (Yastreb - "Hawk")
Start of mission
Launch date26 August 1978, 14:51:30 (1978-08-26UTC14:51:30Z) UTC
RocketSoyuz-U
Launch siteBaikonur 1/5[1]
End of mission
Landing date2 November 1978, 11:04:17 (1978-11-02UTC11:04:18Z) UTC
Landing site140 km (87 mi) SE of Dzhezkazgan
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude196.8 km (122.3 mi)
Apogee altitude259.9 km (161.5 mi)
Inclination51.64 degrees
Period88.81 minutes
Docking with Salyut 6
Docking portAft port
Docking date28 August 1978, 16:37:37 UTC[2]
Undocking date7 September 1978, 16:37:37 UTC[3]
Time docked10 days
Redocking with Salyut 6
Redocking portFront port
Redocking date7 September 1978, 16:37:37 UTC[3]
Unredocking date2 November 1978, 11:04:17 UTC[2]
Time redocked55 days, 18 hours and 26 minutes
Valery Bykovsky with Sigmund Jähn

Soyuz 31 carried Valery Bykovsky and Sigmund Jähn, the first German cosmonaut, into space. They swapped Soyuz craft with the long-duration crew and returned to Earth in Soyuz 29, the resident crew returned to Earth in Soyuz 31.

Crew

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Position Launching crew Landing crew
Commander   Valery Bykovsky
Third and last spaceflight
  Vladimir Kovalyonok
Second spaceflight
Research Cosmonaut/Flight Engineer   Sigmund Jähn
Only spaceflight
  Aleksandr Ivanchenkov
First spaceflight

Backup crew

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Position Crew
Commander   Viktor Gorbatko
Research Cosmonaut   Eberhard Köllner

Mission parameters

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  • Mass: 6,800 kg (15,000 lb)
  • Perigee: 196.8 km (122.3 mi)
  • Apogee: 259.9 km (161.5 mi)
  • Inclination: 51.64°
  • Period: 88.81 minutes

Mission highlights

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Soyuz 31, the third Intercosmos flight, was launched 26 August 1978. Cosmonauts Bykovsky and Jähn were greeted by resident crew Vladimir Kovalyonok and Aleksandr Ivanchenkov when they docked at the aft port of the Salyut 6 space station the next day. The visitors brought with them fresh onions, garlic, lemons, apples and other food for the long-duration crew, then in space for more than two months.[4]

The presence of the East German cosmonaut was seen as significant because of the presence of the MKF-6M camera on the space station, built by the Carl Zeiss works at Jena.[5] Medical and biological experiments were carried out, including an audio experiment which tested sound and noise perception limits.[4] An experiment called Berolina used the Splav furnace to process an ampoule of bismuth and antimonide with the material between two plates in the ampoule. The tree structure which resulted was four to six times larger than what had been produced on the ground.[4] Another experiment tested using different photographic films on the station's interior.

 
Assembly of Soyuz 31 on a 1978 USSR stamp

The Soyuz 31 crew swapped craft with the Soyuz 29 crew so as to supply the long-duration crew with a fresh craft. On September 2, the engines of Soyuz 29 were tested, 25 experiment containers with 100 experimental results were transferred, along with exposed film, and seat liners and centering weights were exchanged. The Soyuz 31 crew left in Soyuz 29 the next day and landed 140 km southeast of Dzhezkazgan.[4]

The standard recovery procedure was changed with this flight, observers noted.[5] In the past, the recovery of a civilian Salyut crew had been made on the orbit following the one which provided a nominal launch opportunity to Salyut. With this and subsequent flights, the landing occurred during the orbit which provided the nominal launch opportunity. The effect of this change was to have a landing window open some two to three days earlier than otherwise.[5]

The crew on the station subsequently boarded the Soyuz 31 vehicle and redocked it to the forward port, thus freeing the aft port for a forthcoming Progress supply ship. They returned to Earth 2 November in the craft after setting a new space-endurance record of 139 days.

References

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  1. ^ Mark Wade. "Baikonur LC1". Encyclopedia Astronautica. Retrieved 4 March 2009.
  2. ^ a b c "Spaceflight mission report: Soyuz 31". SPACEFACTS.de. Retrieved 13 September 2024.
  3. ^ a b "Relocations of Manned Spacecraft". SPACEFACTS.de. Retrieved 13 September 2024.
  4. ^ a b c d Dennis Newkirk (1990). Almanac of Soviet Manned Space Flight. Houston, Texas, USA: Gulf Publishing Company. ISBN 0-87201-848-2.
  5. ^ a b c Phillip Clark (1988). The Soviet Manned Space Program. New York, USA: Orion Books. ISBN 0-517-56954-X.