Soviet-era cosmonaut Valery Bykovsky, who was one of the first group of military pilots chosen to join his country's space program, has died at the age of 84, Russia's space agency has announced.
Roscosmos said on March 27 that Bykovsky had died a day earlier, but it did not give the cause of death.
Bykovsky was one of 20 Soviet military pilots in the first group picked for the manned space flight program.
Bykovsky flew into space three times. His first mission was in June 1963, spending what was then a record five days in space alone aboard Vostok-5.
He was among those chosen for a Soviet moon mission and underwent specialized training for it, but the plan was canceled after the United States won the race to the moon in 1969.
Bykovsky flew again in 1976 and a final time in 1978, spending nearly 21 days in orbit in his combined flights.
He was a recipient of the Hero of the Soviet Union and Order of Lenin awards.