It was 53 years ago when a man walked in space for the first time, and he wasn’t American.

On March 18, 1965, the USSR took a big lead in the space race against the U.S. when cosmonaut Alexey Leonov left his spacecraft, the Voskhod 2, to enter into history as taking the first-ever spacewalk. Moments later, his life was in danger.

“My suit was becoming deformed, my hands had slipped out of the gloves, my feet came out of the boots,” Leonov told the BBC in 2014. “The suit felt loose around my body. I had to do something.”

The problem was the lack of atmospheric pressure in space causing his suit to inflate. Tethered to the spacecraft and with a suit too big to make it through the hatch, Leonov acted quickly by releasing oxygen from his suit to relieve the pressure.

He did make his way back into the capsule but the small explosive that opened the hatch had now caused it to rotate. This also caused a rise in oxygen making the cabin flammable.

It didn’t stop there for Leonov. He and his pilot, Pavel Belyayev, had to wait several hours before they could fire the retro-rockets to return to Earth. They found out quickly that the automated rockets did not work so they had to control the rockets manually. A miscalculation of how long to fire the rockets could either bounce them right back into space or crash into the ground.

The cosmonaunts did end up landing safely in Siberia.

The U.S. and NASA also ramped up the space program with multiple spaceflights in 1965. The Apollo and Gemini flights continued to make progress leading to the moon landing on Nov. 19, 1969.

Still, as the first person to see the Earth from 500km above, Leonov made an impact on history. What he saw on his trip also made an impact on him.

“My feeling was that I was a grain of sand,” he said. “You just can’t comprehend it. Only out there can you feel the greatness, the huge size of all that surrounds us.”