Alexei Leonov became the first human to walk in space, when the cosmonaut stepped out of his spacecraft 50 years ago, on March 18, 1965.
The 30-year-old native of Siberia became the first "human satellite" to orbit our planet. While hovering outside his spacecraft, he performed a series of somersaults, flips and other aerobatics in front of a television camera that broadcast his activities back to Earth. He spent around 20 minutes outside the vehicle during this first-ever extra-vehicular activity (EVA).
The highly-secretive Soviet government did not announce the spacewalk until it had been successfully carried out, for fear of public failure. After the cosmonaut returned safely to his vehicle, officials in Moscow released pictures and videos to show off their technology.
American officials tracked the Voskhod 2 space capsule, and detected an open hole in the vehicle after the door opened. Officials in the United States were uncertain how the spacewalk was being carried out, including details of the tether used by Leonov. They were uncertain whether the cord carried air and communication lines, or was simply a way of connecting the cosmonaut to the craft, to prevent him from drifting too far from the vehicle.
"Circling the earth in a sealed and well-provisioned capsule has been demonstrated to be well within human capabilities, but the moon will never be explored, to say nothing of Mars and the other planets, unless fragile men learn to function in the outside vacuum where no earthborn organisms are naturally equipped to live," Time Magazine reported in 1965.
During that time, Soviet rocket boosters were significantly more powerful than American launch vehicles. This allowed that nation to send heavier space capsules to space than was possible using American technology.
Although the first spacewalk lasted just 12 minutes, this was a tremendous step forward in learning how to live and work in space. Not until recently have robots been developed that are capable of fine motor skills allowing them to perform repairs and maintenance on spacecraft and satellites.
Leonov is still alive today, and he played a part in the film "Apollo 13: To the Edge and Back."
Learning how to operate outside a space vehicle was one of the techniques that had to be developed in order for American astronauts to head to the Moon during the Apollo program. Ed White became the first American to walk in space during the Gemini 4 mission on June 3, 1965.
Spacewalks are fairly common today, but the ability to carry out this activity would never have been developed if Leonov had not taken that first step outside his spacecraft five decades ago.