dr Valery Polyakov, a doctor-turned-cosmonaut who spent 437 days in space and set the world record, died at the age of 80. Russia’s Roscosmos space agency announced his death Monday without revealing the cause or location.
“His research helped prove that the human body is ready for flights not only to low Earth orbit but also to space,” Roscosmos wrote in a Telegram post. “We express our deepest condolences to the family and friends of Valery Vladimirovich.”
He was born Valery Ivanovich Korshunov on April 27, 1942, but changed his name after he was adopted in 1957, according to the New Mexico Museum of Space History. Polyakov started out as a doctor and joined the Institute for Biomedical Problems in Moscow in 1971, according to CNN.
After Polyakov undertook space training to demonstrate he could help other astronauts in orbit and passed his exams in 1972, Polyakov became one of the first doctor-cosmonaut trainees in history. He graduated as a candidate in medical sciences in 1976.
Polyakov’s first lengthy space mission in 1988 lasted eight months, and upon his return to Earth he became deputy director of the institute he once joined as a young man. However, it was his second and final mission that made history.

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Now a specialist in the burgeoning field of space medicine, Polyakov volunteered to prove humans can withstand microgravity and reach Mars, according to Wired. His flight to dock with the Russian Mir space station started on January 8, 1994 – and Polyakov did not return until March 22, 1995.
Polyakov orbited the Earth 7,075 times and covered some 187 million miles in those 14 months – during that time millions of people on Earth had marveled at the launch of the Netscape Navigator internet browser, the opening of the Channel Tunnel and OJ Simpson’s high-speed police chase.
According to Philip Baker’s The Story of Manned Space Stations, American astronaut Norman Thagard said Polyakov returned to Earth “big and strong” and looked “like he could wrestle a bear.” Polyakov trained during his mission and refused landing assistance, choosing to go alone.
“When his capsule landed in Kazakhstan, he walked from there to a nearby chair, a tremendous feat,” Baker wrote. “He also stole a cigarette from a friend nearby, but he could hardly be blamed for that. He sipped a little brandy and inwardly celebrated his mission.”
While NASA astronauts Scott Kelly and Mark Vande Hei spent 340 and 355 consecutive days in space, respectively, and Peggy Whitson spent a total of 665 days in space, Valery Polyakov’s consecutive 437-day stay remains unprecedented.
“His record still stands,” Baker wrote, “and is unlikely to be broken until man ventures to Mars.”