On the afternoon of June 3, 1965, Ed White stood up on his seat and stuck his head out of Gemini 4′s open hatch into space. He was in orbit with commander Jim McDivitt, and both were men waiting for a “go” from Houston to begin America’s first spacewalk.

White knew he would be facing some difficulties on the spacewalk, properly called “extravehicular activity,” or EVA. He’d already mounted a video camera on the spacecraft’s body just above the hatch, and it was more work than he’d anticipated.

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The ordinarily simple task demanded enough physical exertion that he worked up a sweat and starting breathing pretty heavily. Listening on the communications line, McDivitt warned White to take it easy. It was the first time during the mission that White’s heart rate sped up enough to catch the attention of flight surgeons in mission control.

Now with the camera installed, White relaxed a little as he waited. The spacecraft was coming up on the Hawaii tracking station, and next would come the Guaymas station where he expected to begin his EVA. McDivitt meanwhile held the spacecraft’s attitude steady to make sure White had a point of reference.

Then the word from Houston came early, passed through Walter Cunningham serving as capcom in Hawaii. “We just had word from Houston. We’re ready to have you get out whenever you’re ready.” Using the Hand-Held Maneuvering Unit, a specially designed zip gun that expelled pressurized oxygen, White propelled himself out of the spacecraft. Four hours, 30 minutes, and 26 seconds after launch, his feet cleared the hatch.

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White had thought about how to commemorate the event before hand; he knew he was going to be broadcast live on TV and radio across America. He thought flowery, poetic sentiments weren’t what the public was after. Americans would want to know what it was like, floating outside the spacecraft looking down on the country form orbit. So he resolved to narrate his first steps in a vacuum like a test pilot.

Gradually, he and McDivitt settled into a steady banter to keep America informed about the EVA. “I feel like a million dollars!” White laughed as he started maneuvering around the spacecraft with the zip gun. Both described the slow movements of one of White’s thermal gloves that escaped out of the open hatch, too far for White to grab it.

While Houston and the country listened to White’s description of the Houston shoreline from space, the astronaut couldn’t hear Houston. White was connected to the spacecraft by a tether that supplied him with oxygen, a communications link to McDivitt, and a way to pull himself back to the open hatch. Unfortunately, the link between astronauts was separate from their link with Houston; McDivitt had to manually switch lines to speak to mission control. It took three minutes for Houston capcom Gus Grissom to get confirmation from McDivitt that White was indeed outside.

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White exhausted the air supply in his zip in just over four minutes leaving him with nothing but the tether to control his movements around the spacecraft. It was awkward, far less precise than the gun, but it did give him the ability to maneuver around the spacecraft. He floated around to the spacecraft’s nose, but decided the end with antennas providing communications with Earth was a bad place to be. He floated to the back end and watched thrusters firing from five or six feet away. He floated over the McDivitt’s window, smearing the protective coating. “You smeared up my windshield, you dirty dog!” McDivitt complained. “Well, hand me out a Kleenex and I’ll clean it,” White replied.

After about 15 minutes, Grissom in Houston started calling up to the spacecraft, trying in vain to be heard. The spacecraft was fast approaching the night side of the planet where it would be too dark for White to see. They would also be out of communications range with Houston. Mission control wanted everything squared away before that happened, but Grissom’s ten calls in over a minute went unanswered.

Finally, McDivitt decided to check and see if the ground had any pending messages. Flight Director Chris Kraft famously came online and spoke to the crew directly in this one instance: “Flight Director says get back in!”

McDivitt passed the order to White who pleaded for more time “Back in? Aw, Cape, let me just find a few pictures… Listen, you could almost not drag me in, but I’m coming.” He made his way slowly to the open hatch using the tether as a guide. “This is the saddest moment of my life,” he announced as he starting making his way inside.

The EVA was a success, particularly for NASA’s first try. But White had had a basic mission plan — NASA was most interested in gathering data about any disorientation he felt in orbit, ease of maneuvering, and comfort in his EVA suit. Later missions would demand spacewalking astronauts perform more complex tasks. White’s spacewalk was an excellent start that taught NASA a lot about EVA dynamics, but the mission also taught the agency that it had a lot more to learn before astronaut would comfortably work in the vacuum of space.

This article was originally published on Discovery News in 2012.