|Given names:||Leonid Ivanovich||Valeri Viktorovich|
|Spacecraft (Launch):||Soyuz 35||Soyuz 35|
|Launchtime:||13:38 UTC||13:38 UTC|
|Spacecraft (Landing):||Soyuz 37||Soyuz 37|
|Landingtime:||09:49 UTC||09:49 UTC|
|Mission duration:||184d 20h 11m||184d 20h 11m|
|Given names:||Vyacheslav Dmitriyevich||Boris Dmitriyevich|
Launch from the Baikonur Cosmodrome; landing with Soyuz 37 capsule 140 km southeast of Dzheskasgan.
Valentin Lebedev was scheduled to be Leonid Popov's Flight Engineer, but he required an operation after injuring his knee while working out on a trampoline. Valeri Ryumin, of the last crew to visit Salyut 6, was called in to fill his place.
Following a one day solo flight Soyuz 35 docked with Salyut 6 on April 10, 1980. The cosmonauts became the fourth resident crew.
The space station was in good, but not in perfect shape, when the crew arrived. Upon entering Salyut 6, Valeri Ryumin noted that the two viewports in the transfer compartment had lost their transparency. The windows also had many chips in them caused by micrometeoroids and orbital debris.
The cosmonauts had a rather busy time onboard the station. They replaced components of the attitude control system and life support system, installed a new caution and warning system, synchronized the station's clocks with those in the TsUP, added an 80 kg storage battery, and replaced air from tanks in Progress 8.
By April 15, 1980, the Progress tanker had been emptied of supplies, and the crew filled it with garbage and deorbited the craft April 25, 1980. Two days later, Progress 9 was launched, docking with the facility on April 29, 1980. The next day, the first-ever transfer of water between a tanker and a Salyut station was completed. Cargo transfers and refueling operations were completed by May 12, 1980. With this flight, the resupply of the Salyut was complete for the long-duration crew.
Several scientific experiments were performed as biological cultivation tests, photography of Earth surface, materials science Kristall or Splav-01 materials processing furnaces. Minor repair work was carried out by the crew and "Lotos" was carried out, an experiment involving using special moulds to make plastic items with a quick-setting material. Additional experiments involved production of polyurethane foam, exploring its utility in assembling structures in orbit.
Progress 9 was undocked May 20, 1980, leaving the rear port vacant for the arrival of the next crew. Soyuz 36 was launched May 26, 1980. Valeri Kubasov and Bertalan Farkas swapped Soyuz craft with the long-duration crew, departing the station in Soyuz 35 on June 03, 1980. The next day, Leonid Popov and Valeri Ryumin entered Soyuz 36, undocked it from the station, then redocked it 90 minutes later at the vacant front dock. The rapid switch of ferry vehicles, along with the launch of Soyuz 36 at almost the earliest possible date to allow a crew recovery in the nominal window, caused observers to speculate the secretive Soviets were possibly planning a second Intercosmos mission to recoup the time lost after the Soyuz 33 failure. A launch indeed was soon in the offing, but not the predicted mission.
Soyuz T-2 was launched June 05, 1980 with Yuri Malyshev and Vladimir Aksyonov on what turned out to be the first manned mission of the new Soyuz T variant. The craft docked at Salyut 6's rear port the next day. The mission proved to be a short one, as they undocked in the craft they arrived on only two days after first greeting the resident crew.
The fourth resident crew returned to their routine. Leonid Popov and Valeri Ryumin relied heavily on the running track and bicycle ergometer to maintain their fitness so they could return safely to Earth after their prolonged stay in weightlessness. On June 15, 1980 their running track broke, but the cosmonauts avoided repairing it for several days, because 'it meant unscrewing a lot of bolts and would take a lot of time to repair.' However, doctors on the ground ordered them to increase their level of exercise, so they had to repair the track. Also at about this time, the cosmonauts repaired the Kaskad attitude control system, in the process expending a large amount of fuel.
The fourth resident crew carried out repairs of the station's Kaskad attitude control system and performed materials processing experiments. On July 01, 1980, Leonid Popov and Valeri Ryumin received Progress 10 at the station. Replacement equipment was unloaded from the supply tanker, as were regular crew supplies. Supplies included a Polaroid camera, a color television monitor, and tapes of Soviet pop music. The tanker was undocked from the complex on July 17, 1980 after refueling the station and deorbited July 19, 1980. Also on July 19, 1980, Leonid Popov and Valeri Ryumin sent their greetings from the station to the 1980 Summer Olympics, wishing the athletes happy starts in a live communication between the station and the Central Lenin Stadium where the opening ceremony was held. They appeared on the stadium's scoreboard and their voices were translated via loud speakers.
From July 24, 1980 - July 31, 1980 Viktor Gorbatko and Pham Tuân of Vietnam visited the station, arriving in Soyuz 37, and returned to Earth in Soyuz 35. Pham Tuân's experiments involved observing Vietnam from space, life sciences (including tests of growth of Vietnamese azolla water ferns, with application to future closed-loop life support systems), and materials processing. After the crew had departed, on August 01, 1980, Soyuz 37 was repositioned by rotating Salyut 6, freeing the aft port for Soyuz 38.
From September 19, 1980 - September 26, 1980 an international crew again visited the station. The Soyuz 38 docking occurred in darkness. As the spacecraft approached Salyut 6, the station crew could see only its 'headlights. Valeri Ryumin filmed ignition and operation of the transport's main engine. Arnaldo Tamayo Méndez of Cuba and Soviet cosmonaut Yuri Romanenko docked without incident. Twenty-seven material processing and medical experiments were carried out by the visiting crew. As the Soyuz 35 crew was returning to Earth soon, the Soyuz 38 crew didn't swap their craft when they returned on September 26, 1980.
The launch, therefore, of Progress 11 on September 28, 1980 came as surprise to observers, as it was assumed cosmonauts due to return to Earth would not need fresh supplies. Indeed, by the time the Soyuz 35 crew returned on October 11, 1980, the Progress was only partially unloaded.
The crew set a new spaceflight record.
Last update on November 23, 2013.