Leonov entered the airlock and, after final safety procedures, opened the hatch. In doing so he became the first person in history to walk in space. His walk lasted for 12 minutes and nine seconds and it would be nearly three months before the astronaut Ed White became the first American space walker.
On 18 March 1965, 90 minutes after their Voskhod-3KD capsule’s launch from the Baikonur Cosmodrome in Kazakhstan, and at the end of the first of their 17 orbits around the Earth, the Soviet cosmonaut Pavel “Pasha” Belyayev slapped his fellow cosmonaut Alexei Leonov on the back and said: “Go!”
“When I raised my head I could see a vast panorama,” Leonov wrote in Two Sides of the Moon (with the astronaut David Scott, 2004) “… ahead was the Crimea, and to my right lay the snow-capped Caucasus Mountains and the Volga River. When I raised my head I could see the Baltic Sea. Lenin once said the universe is endless in time and space. It is the best description of what I saw in those moments.”
Wonders aside, the mission of Leonov, who has died after a long illness aged 85, and Belyayev confronted many problems. Leonov’s spacesuit ballooned, so that when he re-entered the capsule he was forced – with extreme difficulty – to lessen the suit’s pressure. Once he was back inside, the capsule began rotating violently, while oxygen levels were rising and took hours to get under control.
Alexei Leonov aboard the Soyuz spacecraft in 1975. Photograph: MPI/Getty Images
Heading back to Earth they found that the orbital module had not separated properly from the landing module, only, fortunately, doing so in the heat of re-entry. The craft eventually landed, more than 1,000 miles from their target zone, in more than six feet of snow. They were to spend two nights in bear and wolf country in deep Siberian forest before rescuers arrived. The true story of the mission was not revealed for many years.
This was not Leonov’s only space mission, but a succession of planned operations were cancelled. These included one which would have seen a Soyuz 7k-L1 circling the moon with Leonov as one of the two cosmonauts on board. At Christmas 1968 the successful Nasa Apollo 8 lunar orbit destroyed much of the motivation for such Soviet plans, and information about that mission was also suppressed for many years. In 1975 Leonov returned to space as commander of the Soviet part of the Apollo-Soyuz mission, which for the first time saw the two supposed superpowers collaborating on a space venture.
From 1976 to 1982 he was the deputy director of the Yuri Gagarin Cosmonaut training centre and the Soviet Union’s chief cosmonaut. He retired from government service with the rank of air force major-general in 1992.
Born in Listvyanka, in the Western Siberian Krai, Alexei was the eighth of the nine surviving children of Yevdokiya (nee Sotnikova) and Arkhip Leonov. When Alexei was three, at the height of Joseph Stalin’s purges in 1937, his father, then a peasant farmer, was imprisoned as an “enemy of the people”. Yevdokia’s father had, in his turn, been exiled from Ukraine to Siberia for his role in the failed 1905 revolution.
Alexei Leonov at the Royal Society, London, in 2015. Photograph: Mark Thomas/Rex/Shutterstock
The 11-strong family then moved to a power station site in Kemerovo. There they shared a 16-square-metre room, and Alexei slept under a bed for two years.
From the age of six, Alexei began making money from his talent and love for painting. But he also fell in love with flying after meeting a visiting pilot, and seeing films such as Mikhail Kalatozov’s Courage (1939).
In 1948 the family moved to the former Prussian city of Königsberg, by then Kaliningrad, and part of the Soviet Union. After Middle School Number Six, Leonov realised that he could not afford to fulfil his wish to study art in Riga, Latvia, and so opted for his other love, flying.
He spent six years at the Kremenchug and Chuguyev pilots’ colleges in Ukraine, then part of the Soviet Union, graduating from propeller-engined Yak11 trainers to MiG15 and MiG17 subsonic fighter jets.
Then, in October 1957, to the astonishment of the world, the chagrin of the US, and the delight of the Soviet Union in general and Leonov in particular the first artificial satellite, Sputnik, began orbiting the Earth. If there was a space race, it seemed clear then who was winning.
By 1959 Leonov was one of eight pilots chosen, from an initial 3,000, for a new venture – into space. Another of the eight was his soon-to-be “firm friend” and the first human in space, Yuri Gagarin. After a brief posting to Altenberg, in East Germany, Leonov returned to Moscow, and space training. There would be none of the ballyhoo that accompanied the Mercury Seven, the first US astronauts; instead the cosmonauts were rewarded with a KGB officer to accompany them on group journeys, and a salary the equivalent of $100 a month.
After his retirement Leonov was able to devote more time to his paintings, many of which had a space theme, and dabbled in business. On the far side of the moon, the Leonov Crater was named after him in 1970.
In 1959 Leonov married Svetlana Dozenko, a teacher. She survives him, along with their daughter Oksana and two grandchildren; another daughter, Viktoria, died in 1996.