Russian cosmonaut Valery Polyakov, the man who held the record for longest flight in space died aged 80 on September 19.
Polyakov's death was announced by the Russian space agency Roscosmos in a Telegram statement using his honorary titles, 'The Roscosmos State Corporation regrets to announce the death of the Hero of the Soviet Union, Hero of Russia, USSR pilot-cosmonaut, holder of the world record for the longest flight into space (437 days) Valery Polyakov.'
The agency did not reveal his cause of death.
The statement typed in Russian expressed condolences to the legendary cosmonaut's family and friends. It further highlighted his achievements in space research and travel.
'His research helped to prove that the human body could handle flights well beyond Earth's orbit, into deep space,' it said.
Polyakov spent a record 438 days in space orbiting the Earth from January 1994 to March 1995 on the Mir space station. Polyakov's flight in space is the longest till date. He lived and worked on the space station for 14 months, reportedly orbiting Earth 7,000 times as per a BBC report.
Polyakov later revealed that his stay in space was equivalent to travelling to Mars and back. His experiments on the space station also pertained to understanding how well could humans maintain their bodily functions during long space trips, including to Mars.
The Mir space station was deployed in 1986 during the Cold War, states a BBC report, and was used with co-operation of the then Soviet Union and USA.
Till it was retired in 2001, the satellite did key work in understanding the capability of humans to live and work in space.
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