Soyuz 35 - Crew Launch, Station Activation

Crew Launch, Station Activation

Soyuz 35 was launched 9 April 1980 with Leonid Popov and Valery Ryumin aboard for a planned rendezvous with the orbiting Salyut 6 space station. The launch followed increased recent activity with the unmanned space station. An unmanned test craft, Soyuz T-1, spent several months docked to the station until it was undocked 23 March and deorbited 25 March. Progress 8, an unmanned supply tanker, was launched almost immediately afterwards, on 27 March, and it docked with the rear dock port of the two-dock facility. Several manoeuvres were carried out by 2 April using the Progress to adjust the station's orbit.

Valentin Lebedev had been scheduled to be Popov’s flight engineer, but he was disqualified from launch after suffering a knee injury in a trampoline accident. As none of the back-up crew had previous flight experience (required since the failure of the Soyuz 25 mission), Ryumin had been given the choice of replacing Lebedev or delaying the mission. This despite having completed a six-month mission only the previous August. Ryumin's family was upset by this turn of events.

The Soyuz 35 crew docked with and entered the space station on 10 April, using the vacant front port. Ryumin read the traditional note left by the previous crew, a note he had written with no expectation he would be the one receiving it. Upon entering Salyut 6, 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 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 Mission Control Center, added an 80 kilograms (180 lb) storage battery, and replaced air using tanks aboard the Progress 8 supply craft.

By 15 April, the Progress tanker had been emptied of supplies, and the crew filled it with garbage and deorbited the craft 25 April. Two days later, Progress 9 was launched, docking with the facility on 29 April. The next day, the first-ever transfer of water between a tanker and a Salyut station was completed. Cargo transfers and refuelling operations were completed by 12 May. With this flight, the resupply of the Salyut was complete for the long-duration crew.

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.