missiles is at least 8 kilometers. Numerous air-to-air combat victory claims by the MiG pilots of the VPAF against U.S. combat aircraft have been counter-claimed as losses to surface-to-air missiles or anti-aircraft artillery, as it's considered "less embarrassing" than losing to an enemy pilot. In 1973, Tuân was granted the title of "Hero of the People's Armed Forces" in Vietnam. In 1980, Tuân was awarded the "Vietnam Labor Hero" distinction. In 1989, Tuân was given the position of "Deputy Commander" within the Vietnam People's Air Force. He was promoted to the rank of Lieutenant General in 1999. During the year 2000, Tuan was the position of "Director of the General Department of Defense Industry". He eventually retired from government positions at the end of 2007. Tuân received numerous distinctions for his service, including the Ho Chi Minh Order. He also was awarded the Order of Lenin and the rare honor of being one of the few foreigners to receive the title "Hero of the Soviet Union". Interkosmos program Tuân reached the rank of lieutenant colonel in the VPAF before eventually training to be a research cosmonaut in the joint USSR-Vietnamese space program. Tuân was initially sent to the USSR to train as a radar engineer. There was a shortage of eligible Vietnamese pilots. This was due to most of the applicants not passing the fitness tests. Tuân was pressured into flight training. Due to this, Tuân was one of three Vietnamese pilots and engineers to be selected by the Soviet Union. On 1 April 1979, he was selected as a member of the sixth international crew for the Interkosmos program. His backup was Bùi Thanh Liêm. Tuân, along with Soviet cosmonaut Viktor Gorbatko, was launched from Baikonur Cosmodrome on 23 July 1980, on board the Soyuz 37 mission to the Salyut 6 space station. Tuân was informed only three days prior that he would be the main pilot of the Soyuz 37. Before the flight a joint Bulgarian – Soviet mission had been cancelled. Tuân was worried that his voyage would share the same fate. During his flight aboard the Soyuz 37, there were technical issues regarding the Soyuz 3’s engine system. Tuân was commanded to shut down all systems and inform Command of the situation. After this, Command restored the engine to normal and the mission continued. During his time in orbit, Tuân performed experiments on the melting of