Backup crew

Mission parameters

• Mass: 6800 kg (14,991.4 lb)
• Perigee: 196.8 km (122.3 mi)
• Apogee: 259.9 km (161.5 mi)
• Inclination: 51.64°
• Period: 88.81 minutes

Mission highlights

Soyuz 31, the third Intercosmos

Intercosmos

Interkosmos was a space program of the Soviet Union designed to include members of military forces of allied Warsaw Pact countries in manned and unmanned missions...

 flight, was launched 26 August 1978. Cosmonauts Bykovsky and Jahn were greeted by resident crew Vladimir Kovalyonok

Vladimir Kovalyonok

-Honours and awards:* Hero of the Soviet Union, twice * Order of Merit for the Fatherland, 3rd class * Order of Military Merit * Three Orders of Lenin...

 and Aleksandr Ivanchenkov

Aleksandr Ivanchenkov

Aleksandr Sergeyevich Ivanchenkov is a retired Soviet cosmonaut who flew as Flight Engineer on Soyuz 29 and Soyuz T-6, he spent 147 days, 12 hours and 37 minutes in space....

 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.

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

Jena

Jena is a university city in central Germany on the river Saale. It has a population of approx. 103,000 and is the second largest city in the federal state of Thuringia, after Erfurt.-History:Jena was first mentioned in an 1182 document...

. Medical and biological experiments were carried out, including an audio experiment which tested sound and noise perception limits. An experiment called Berolina used the Splav furnace to process an ampoule

Ampoule

An ampoule is a small sealed vial which is used to contain and preserve a sample, usually a solid or liquid. Ampoules are commonly made of glass, although plastic ampoules do exist....

 of bismuth

Bismuth

Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...

 and antimonide

Antimonide

Antimonides are compounds of antimony with more electropositive elements. The antimonide ion is Sb3−.Many of them are flammable or decomposed by oxygen when heated since the antimonide ion is a reducing agent....

 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. Another experiment tested using different photographic films on the station's interior.

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

Dzhezkazgan

Jezkazgan or Zhezkazgan , formerly known as Dzhezkazgan , is a city in Karagandy Province, Kazakhstan, on a reservoir of the Kara-Kengir River. The city population is of 90,000...

.

The standard recovery procedure was changed with this flight, observers noted. 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.

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.