History's first spacewalk was very nearly fatal

It was one of the central questions of the early space age: would a human be able to survive and work in the vacuum of space? Airplane pilots had pioneered the use of pressure suits as planes started flying higher into the Earth’s atmosphere. If their cockpit depressurized at altitude the suit would inflate, mimicking the atmospheric pressure that all humans need to stay alive. How pressure suits would transfer to spaceflight when a human stepped outside the confines of a spacecraft was unknown. Both NASA and the Soviet space agency were working on the problem in the early 1960s, but it was the Soviets who took the first steps. 

Cosmonaut Alexei Leonov in 1974


As the Chief Designer of the Soviet space program, Sergei Korolev followed one simple rule: never repeat a mission. He deemed it a waste of resources to duplicate a spaceflight, preferring instead that every mission build on its predecessor, incrementally adding to the Soviets’ spaceflight knowledge base and advancing its technology. Korolev applied this rule to the Vostok program, the very first manned spaceflight program. After Yuri Gagarin made one orbit aboard Vostok 1, Gherman Titov spent a day in space aboard Vostok 2. Vostoks 3 and 4 flew simultaneously, passing one another in orbit. Vostoks 5 and 6 did the same, only the latter was piloted by the first woman in space, Valentina Tereshkova.

By the time Vostok 6 landed, the Vostok program had reached its limit. The spacecraft could only carry one cosmonaut at a time, and it wasn’t maneuverable in orbit. But Korolev didn’t let technical constraints and short comings stop him: he hollowed out the Vostok capsule and turned it into Voskhod.

Voskhod could carry multiple cosmonauts at once, albeit at the expense of certain comforts. Voskhod 1 carried three cosmonauts into orbit in shirtsleeves because they couldn’t all fit inside wearing bulky pressure suits. Abiding by his own rule, Korolev saw no need to launch another three-man mission. So, he had his scientists modify the second Voskhod capsule to add an extendable, inflatable airlock. This would allow a cosmonaut to leave the spacecraft without having to fully depressurize the main cabin. It would be one man’s door into the vacuum of space.

Stepping Out

That man was Alexei Leonov. He, along with his pilot Pavel Belyayev, launched from the Baikonur cosmodrome aboard Voskhod 2 on March 18, 1965.

Alexei Leonov during history's first spacewalk

Once in orbit, Leonov entered the airlock. Outfitted in a rigid pressure suit and a small life support system worn as a backpack, he waited as Belyayev, still in the main cabin depressurized the airlock. After the air bled out, Leonov, armed with a handheld movie camera and connected to the spacecraft by a hose, stepped outside.

Watching the TV broadcast on Earth, Leonov’s four-year-old daughter Vika was terrified. She tore her eyes from the television and hid her face in her hands. Leonov’s aging father was similarly appalled. Unaware of the mission’s flight plan, he was shocked to see his son doing something as foolhardy as leaving the safety of his spacecraft. Everyone else had completed their missions safely inside, what was his son doing?

But the Leonov family’s fear, disbelief, and anger turned to pride when audio of a live broadcast from Leonid Brezhnev came on over the television. The Russian president was speaking for the spacewalking cosmonaut, a message in praise of his courageous performance.

For ten minutes Leonov floated outside. He said he felt like “a seagull with its wings outstretched, soaring high above the Earth.”

As Voskhod 2 approached the night side of the planet, the cosmonaut reluctantly acknowledged that it was time to go back inside. Over the radio, he heard Belyayev calling for his reentry into the capsule. it reminded Leonov of the times when his mother would call him in from the cold for dinner.

A model Voskhod 2 showing the airlock on the spacecraft

A Troubled Entry

It wasn’t until Leonov began maneuvering himself towards the spacecraft’s airlock that he ran into trouble. In the vacuum of space, his suit had expanded to become stiff and deformed. His feet had pulled up and out of his boots. His fingers were unable to reach the tips of his gloves. He couldn’t pull himself feet first into the airlock like he was supposed to. The only thing that seemed to work was to go in head first, pulling himself slowly with clumsy fingers. He could move this way, but still couldn’t get inside. He had to find a way to shrink his suit to fit back into the airlock.

His only option was to bleed the oxygen out of his suit through a valve in its lining. Leonov thought of reporting his plan to mission control but instantly decided against it. He was in orbit, Belyayev was inside the spacecraft, and the scientists were on the ground. No one could help him. It wasn’t worth creating panic.

Carefully, and without telling anyone, Leonov opened the valve to let a little oxygen out of his suit. He slowly decreased the suit’s pressure as he inched his way inside the airlock. It was a dangerous maneuver. If he bled the suit too fast, he risked succumbing to oxygen starvation, but he had to reduce the pressure fast enough to make it back into the spacecraft with only 40 minutes of life support.

Physical exertion made Leonov break into a sweat and caused his core temperature to rise. And it didn’t seem to end. It took far longer than it should have to work his way back into the airlock, and then he had to perform another physical feat and curl his body around to close the airlock. Once inside, he waited for Belyayev to equalize the airlock to the spacecraft’s cabin.

As soon as he was able, Leonov scrambled back into the main spacecraft. By then he was drenched with sweat, his heart racing. But thankfully the world, and his family, knew nothing of the event. At the first sign of trouble, transmissions from the spacecraft that were being broadcast on television and radio were cut, replaced without explanation with Mozart’s Requiem on repeat. Save the few men in mission control, no one knew how close Leonov came to being the first man stranded in space.

Leonov holds a sketch of NASA astronaut Tom Stafford on the 1975 Apollo-Soyuz Test Project mission

A Modest Summation

Days after landing, Leonov and Belyayev were put before a government committee in Leninsk and asked to answer questions about their flight. They were also each asked to make a statement. When it was Leonov’s turn to speak, he summed up the events concisely: “Provided with a special suit, man can survive and work in open space. Thank you for your attention.”

Alexi Leonov would be back in space in 1975 to rendezvous his Soyuz capsule with an American Apollo capsule. He then oversaw cosmonaut training until his retirement in 1991. He currently lives in Russia, and is the last living cosmonaut of the Voskhod program.

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