Alexei Leonov, the legendary Soviet cosmonaut who was the first human to walk in space 54 years ago, has died in Moscow aged 85.
Russian space agency Roscosmos confirmed his death in a statement on its website, but gave no further details.
Mr Leonov staked his place in space history on March 18, 1965, when he exited his Voskhod 2 capsule secured by a tether.
Spacewalking always carries a high risk but Mr Leonov’s pioneering venture was particularly nerve-wracking, according to details of the exploit that only became public decades later.
His spacesuit had inflated so much in the vacuum of space that he could not get back into the spacecraft. He had to open a valve to vent oxygen from his suit to be able to fit through the hatch.
His 12-minute spacewalk preceded the first US spacewalk, by Ed White, by less than three months.
On his second trip to space 10 years later, Mr Leonov commanded the Soviet half of the Apollo-Soyuz 19 mission.
It was the first joint space mission between the Soviet Union and the United States, carried out at the height of the Cold War, and was a prelude to the international co-operation seen aboard the current space station.
Days before his 85th birthday in May, two Russian crew members on the International Space Station ventured into open space on a planned spacewalk with stickers attached to their spacesuits paying tribute to Mr Leonov, and congratulated him from space.
Messages of condolences poured in from around the globe following news of his death.
Nasa broke into its live televised coverage of a spacewalk by two Americans outside the International Space Station to report Mr Leonov’s death.
“A tribute to Leonov today is a spacewalk,” Mission Control in Houston said.
On Twitter, Nasa added: “His venture into the vacuum of space began the history of extra-vehicular activity that makes today’s Space Station maintenance possible.”
British astronaut Tim Peake said Mr Leonov was “a hero to so many, pioneer of spacewalking and always full of wisdom and humour”.
Mr Leonov was born in 1934 in a large peasant family in western Siberia. Like countless Soviet peasants, his father was arrested and shipped off to Gulag prison camps under Soviet dictator Josef Stalin but he managed to survive and was reunited with his family
The future cosmonaut had a strong artistic talent and even thought about going to art school before he enrolled in a pilot training course and, later, an aviation college.
Mr Leonov did not give up sketching even when he flew into space, and took colouring pencils with him on the Apollo-Soyuz flight in 1975 to draw.
Roscosmos said Mr Leonov’s funeral will take place on Tuesday at a military cemetery outside Moscow.