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 storage battery, and used Progress 8 to refill the life support system's oxygen and nitrogen tanks. On 15 April, Progress 8's mission was completed. The crew loaded it with garbage, after which it was undocked and deorbited three days later. Then 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. Soyuz 36 and Soyuz T-2 crews visit Progress 9 was undocked 20 May, leaving the rear port vacant for the arrival of the next crew. Soyuz 36 was launched 26 May with Valery Kubasov and Hungarian cosmonaut Bertalan Farkas. The flight was originally scheduled for 5 June 1979, but was cancelled due to the Soyuz 33 failure. The launch was a part of the Soviet Intercosmos program whereby guest cosmonauts from allied nations would visit the space station, typically for about a week. Upon boarding, the visiting crew carried out some Hungarian experiments, including one measuring radiation doses received by the crew and another studying the formation of interferon in human cells under weightless conditions. Kubasov and Farkas returned to Earth in Soyuz 35, leaving the resident crew with the fresh Soyuz 36, which they then flew around to the front port of Salyut 6, a maneuver taking about 90 minutes. 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 5 June with Yury Malyshev