Russia's space agency says pioneering Soviet-era cosmonaut Valery Bykovsky, who made the first of his three flights to space in 1963, has died at age 84.

Roscosmos said Bykovsky died Wednesday, but it didn't state a cause of death.

Bykovsky was one of 20 Soviet military pilots in the first group picked to prepare for space. He first flew to space in June 1963 as a member of the Vostok-5 crew.

He underwent training for a moon mission before the United States won the race to the moon and the Soviet Union canceled its plans to go there.

Bykovsky made his second space flight in 1976 and his third in 1978. He spent nearly 21 days in orbit in all.