Today marks 50 years since Alexei Leonov of the former Soviet Union floated beyond the bounds of his Voskhod 2 space capsule in the world’s first spacewalk. During his 10-minute extravehicular activity (EVA), Leonov changed the way humans exist in the universe. No longer were we bound to the ground of our home planet, or even the manmade grounds of our space vehicles—we could be in the universe on our own, with only the thin protection of a spacesuit between our skin and the raw expanse of the cosmos. The ability to fly outside a spacecraft was also critical for many of humankind’s greatest achievements in space, such as walking on the moon, repairing the Hubble Space Telescope and other satellites in orbit, and assembling the International Space Station.

These days NASA, the Russian Federal Space Agency and even the China National Space Administration, are old pros at managing spacewalks—sometimes complicated maneuvers that last hours and feature multiple astronauts. But back on March 18, 1965, Leonov was flying, literally, into unknown territory. As he told The Smithsonian’s Air and Space Magazine in 2005, even his family did not know he would be making the spacewalk until it happened, prompting his four-year-old daughter, watching him on TV, to wail, “Please tell Daddy to get back inside.” w. And the lack of atmospheric pressure out in space caused Leonov’s suit to deform in unexpected ways, making it difficult for him to reenter his spacecraft and putting his life at risk. He managed, however, and racked up an important success in the space race, beating the Americans by less than three months (Ed White made the first U.S. spacewalk on June 3, 1965, from Gemini 4).

We have come a long way since then, and still have a long way to go, in our quest to live and work seamlessly in space. Below are the greatest hits of spacewalking history.

The Greatest Spacewalking Feats of All Time

The First Spacewalk
March 18, 1965
Soviet cosmonaut Alexi Leonov became the first person to float outside a spacecraft during a 10-minute excursion on the Voskhod 2 mission. His spacesuit deformed in the vacuum of space, forcing Leonov to vent oxygen out of his suit to squeeze himself back inside.

The First American Spacewalk
June 3, 1965
NASA astronaut Edward H. White, II, doubled Leonov’s time when he made the U.S.’s first spacewalk less than three months later. White floated outside his Gemini 4 capsule for 21 minutes, using a “zip gun” that ejected pressurized oxygen to maneuver himself around in space. White enjoyed using the gun, but subsequent spacewalkers reported that it was difficult to operate, so it was rarely used after the Gemini program.

The First Untethered Spacewalk
February 7, 1984
Until the space shuttle Challenger’s STS-41B mission, spacewalkers were tethered to their spaceships by a long cord. These tethers also limited their movements, however, and sometimes made maneuvering difficult. Astronaut Bruce McCandless II was the first to test out the Manned Maneuvering Unit—a type of jetpack that he wore on his back to steer himself around. Unchecked by a tether, McCandless flew 100 meters out from the shuttle’s cargo bay—the farthest a spacewalker had ever been before.

Hubble Repair Spacewalks
December 5-9, 1993
The Hubble Space Telescope was launched to much fanfare in April 1990, but soon after it became apparent that the observatory’s optics were flawed. To save the $2.5 billion telescope, NASA sent seven astronauts on a rescue mission onboard the shuttle Endeavour. Four of the STS-61 crew— F. Story Musgrave, Jeffrey A. Hoffman, Kathryn C. Thornton and Thomas D. Akers—completed five spacewalks in five days to install a new primary camera and corrective optics package for the telescope. Their efforts paid off—the telescope delivered on its promise to reveal the cosmos in brand new ways—and four more servicing missions followed in the coming years to upgrade the observatory, which could operate through 2020.

First International Space Station Assembly Spacewalk
December 7, 1998
Endeavour’s STS-88 mission carried the first U.S. contribution to the International Space Station—the Unity node. During the flight, NASA astronauts Jerry Ross and Jim Newman made a spacewalk to connect Unity to the Russian piece in orbit, the Zarya module, by hooking up 40 cables and connectors between the structures to form the heart of the nascent space station. To date there have been 187 spacewalks outside the orbiting laboratory, including assembly, maintenance and repair.

First Chinese Spacewalk
September 27, 2008
China staked its claim as a top tier spacefaring nation when its “taikonaut” Zhai Zhigang floated outside the Shenzhou 7 spacecraft for 20 minutes to retrieve a pack of lubricant gel that had been stored there before launch. Zhai wore a Chinese-made spacesuit and waved the red flag of the People’s Republic of China to celebrate the occasion.

Longest Spacewalk
March 11, 2001
NASA astronauts Susan J. Helms and James S. Voss spent the longest time outside the confines of a spacecraft during the STS-102 mission of the shuttle Discovery. During their eight hours and 56 minutes out in space, Helms and Voss worked on the exterior of the International Space Station to prepare it for the attachment of the Leonardo cargo canister, which had launched along with the crew on Discovery.

Near-Drowning Spacewalk
July 16, 2013
What was supposed to be a run-of-the-mill spacewalk to work on cables outside the International Space Station nearly cost Italian astronaut Luca Parmitano his life when water leaked into his spacesuit’s helmet, ultimately adhering in blobs that obscured his vision, covered his nose and mouth and made it difficult for him to hear. Parmitano kept his cool, and NASA quickly called off the spacewalk and sent the astronauts back inside. Still, Parmitano had to navigate by feeling toward the air lock to get himself to safety and could have drowned, NASA officials said. The leak was later traced to a failure in a water separator system inside the suit—a rare and unexpected anomaly. “Space is a harsh, inhospitable frontier and we are explorers, not colonizers,” he wrote on a European Space Agency blog. “The skills of our engineers and the technology surrounding us make things appear simple when they are not, and perhaps we forget this sometimes.”