and Vladimir Aksyonov on what turned out to be the first crewed mission of the new Soyuz T variant. The craft docked at Salyut 6's rear port the next day. As they were merely testing the Soyuz, the mission lasted just two days after which they departed and returned to Earth. The resident crew carried out repairs of the station's Kaskad attitude control system and performed materials processing experiments. On 1 July, Popov and 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 17 July after refuelling the station and deorbited 19 July. Also on July 19, Popov and 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. First Asian and Cuban cosmonauts, end of mission Observers anticipated a Cuban Intercosmos mission for the approaching launch window, but were proven wrong when the first Asian cosmonaut, Pham Tuan of Vietnam, was launched aboard Soyuz 37 with Viktor Gorbatko on 23 July. The launch was timed to take advantage of the world's focus on the Soviet Union during the Olympic games. The visiting crew swapped craft and left on the docked Soyuz 36 craft, returning to Earth on 31 July. Pham Tuan's flight also had political implications as he was a decorated flying ace from the Vietnam War and had shot down several American aircraft, a fact that the Soviet media readily pointed out. The mission was interpreted as a subtle means of retaliation against the United States for boycotting the Olympics. The following day, Popov and Ryumin boarded Soyuz 37 and redocked it to the front port, suggesting to observers that another crew's launch was coming shortly. That was not to occur, nor was another Progress supply tanker soon launched. The crew performed a joint experiment with scientists on the ground, using their Yelena-F gamma ray telescope. The experiment was designed to compare measurements with another telescope on the ground, but the weather balloon the experiment was using malfunctioned and thieves stole much of the equipment