instead walking the short distance. In doing so, he wished to prove that humans could be physically capable of working on the surface of Mars after a long-duration transit phase. Polyakov volunteered for his 437-day flight to learn how the human body would respond to the micro-gravity environment on long-duration missions to Mars. Upon returning from his second spaceflight, Polyakov held the record for the most total time in space. Data from Polyakov's flight has been used by researchers to determine that humans are able to maintain a healthy mental state during long-duration spaceflight just as they would on Earth. Polyakov underwent medical assessments before, during, and after the flight. He also underwent two follow-up examinations six months after returning to Earth. When researchers compared the results of these medical exams, it was revealed that although there were no impairments of cognitive functions, Polyakov experienced a clear decline in mood as well as a feeling of increased workload during the first few weeks of spaceflight and return to Earth. Polyakov's mood stabilized to pre-flight levels between the second and fourteenth month of his mission. It was also revealed that Polyakov did not suffer from any prolonged performance impairments after returning to Earth. In light of these findings, researchers concluded that a stable mood and overall function could be maintained during extended duration spaceflights, such as crewed missions to Mars. Spaceflights Soyuz TM-6 / Soyuz TM-7 – 28 August 1988 to 27 April 1989 – 240 days, 22 hours, 34 minutes Soyuz TM-18 / Soyuz TM-20 – 8 January 1994 to 22 March 1995 – 437 days, 17 hours, 58 minutes Later life Polyakov retired from his position as a cosmonaut in June 1995, with a total of just over 678 days in space. He participated in experiment SFINCSS-99 (Simulation of Flight of International Crew on Space Station) in 1999. Polyakov was the Deputy Director of the Ministry of Public Health in Moscow, where he oversaw the medical aspects of long-duration space missions. He was a member of the Russian Chief Medical Commission, participating in the qualification and selection of cosmonauts. He also held membership in the International Space Researchers' Association and the International Academy of Astronautics. Polyakov was married and had one child. After returning from space, Polyakov remained active in the discipline of international spaceflight, becoming a "cosmonaut-investigator" for the United States, Austria, Germany, and France during their respective