Would you open a door into outer space? On March 18, 1965, a Soviet cosmonaut named Alexei Leonov did exactly that. He climbed out of his spacecraft and floated in the emptiness of space. A thin cord connected him to the ship. He was the first human being to ever walk in space. The mission was part of the rivalry between the Soviet Union and the United States. Both countries wanted to prove they had the best space program. Sending someone outside a spacecraft was a bold and daring step. Leonov spent about twelve minutes floating above Earth. He later said the silence was overwhelming. But the mission almost ended in disaster. His spacesuit expanded in the vacuum of space. He could barely move his hands. Getting back inside the tiny airlock was extremely difficult. He had to release air from his suit to shrink it enough to fit through the opening. The risky maneuver worked, and he made it back safely. Leonov's spacewalk proved that humans could survive and work outside a spacecraft.