On an autumn evening in 1957, a 27-year-old American named Edgar Mitchell stood on the deck of a U.S. Navy carrier and looked up to the sky. He watched something that was like a star but not: A shining dot that moved, like it had fallen out of the Big Dipper, cutting an incision through the night sky.

It was Sputnik. Mitchell, coming off a stint as a fighter pilot in Korea and due back in the States for test-pilot work, knew what it meant. As he later told NASA’s oral-history project, “when Sputnik went up, I realized humans were going to be right behind it, so I started orienting my career toward that at that time.”

Mitchell died last week, almost 45 years to the day after he became the sixth man to walk on the moon. He was the last living astronaut from Apollo 14, the first mission to conduct science on the lunar surface. With his death, only seven of the original 12 Apollo astronauts remain alive. The youngest among them is 80.

Mitchell has been eulogized by many, including the current administrator of NASA. His importance to science, and to the larger Apollo mission, is immense. But Mitchell held a special role, I think, for space advocates, and to anyone who looks to space as something with more than military or engineering worth. Mitchell exemplifies a great parable of the human space story—a story he put better than anyone else.

“We went to the Moon as technicians,” he said. “We returned as humanitarians.”

Mitchell was born in Texas in 1930, though his family moved to New Mexico, near Roswell, when he was young. He was a child of the Great Depression, a Boy Scout, a graduate of Carnegie Mellon, a Navy recruit. After pointing his career toward space, he earned an M.S. in aeronautical engineering from the Naval Postgraduate School and a doctorate in aeronautics from MIT.

As the diarist who works under the pseudonym George Lazenby has put it, Mitchell and the rest of the early astronauts seemed likethe most reliable type of man America makes: white, straight, full-starch protestant, center-right, and spawned by the union of science and the military. Every last one of them was the heart of the heart of the TV dinner demographic.”

Then Mitchell went to the moon. The sun was blindingly bright and the horizon, on such a tiny world, was much closer than it is on Earth. Even wearing his heavy suit, he could jump—could push down with his legs and fly up into the air. He threw a “javelin” on the surface (really a shovel); the other astronaut with him, Alan Shepherd, had brought his six-iron and golfed.

Their actual time on the moon was harried: As he told the NASA historian years later, he was asked to perform at “120 percent” capacity with Shepherd. They retrieved and loaded more than 100 pounds of rocks from the moon, and they ranged further on their walks than anyone previously.

After a day, they ascended from the lunar surface and joined Stuart Roosa, who had been orbiting the moon in the command module. Mitchell, whose main responsibilities had been with the lunar module, had little to do on the three-day journey back other than “watch a few needles now and then.” He experienced a revelation:

As I watched the cosmos, which is ten times brighter than—ten times more stars than you can see from Earth, it was “Wow!” And from my training at MIT, I knew what stellar formations—how that worked, as best we knew at that time, and I knew that the chemicals, or the elements that we experience on Earth were manufactured in ancient stars since the Big Bang, that this stellar formation produced the matter that formed our world, but all of a sudden I realized that the molecules of my body and the spacecraft and my companion were prototyped in an ancient generation of stars. And somehow it suddenly became very personal instead of an objective, “Oh, yes. Molecules and atoms were made in those stars.” No. My molecules were made in those stars, and this was a “wow!”

Elsewhere, he described it as an “ecstasy of unity.” A few years later, he would describe his vision of seeing the whole Earth at once:

You develop an instant global consciousness, a people orientation, an intense dissatisfaction with the state of the world, and a compulsion to do something about it. From out there on the moon, international politics look so petty. You want to grab a politician by the scruff of the neck and drag him a quarter of a million miles out and say, “Look at that, you son of a bitch.”

The Apollo 14 capsule splashed down in the South Pacific on February 9, 1971. Two years later, Mitchell founded the Institute for Noetic Sciences, a nonprofit that funds research in paranormal phenomena and the nature of consciousness. He got interested in UFO sightings and the 1947 Roswell incident. For the last decades of his life, NASA had to publish polite but firm statements hailing him as a hero but rejecting his theories.

It’s too broad to say that all the astronauts went to the moon and came back weird. In 2009, a space historian disagreed that there was a “lunar syndrome” which “sent the moonwalkers down paths odder than any dozen former colleagues in other lines of work.”

​But the Apollo astronauts—the only humans who have been far enough from the planet to see it set back in space—came to understand that though it may have been motivated by military considerations, their journey had a greater significance for the human story. Setting aside Tang, setting aside the orbiting devices that measure the climate, setting aside even the spy satellites that keep us further away from inadvertent war: Space travel is how a technical, globally organized civilization makes art together, and, like Don Giovanni or Ecclesiastes, it instructs us about our limits. As Mitchell said:

I think what we’re trying to do is discover ourselves and our place in the cosmos, and we don't know. We’re still looking for that. And that was a major effort. Even though we might have talked in technological and political terms and financial terms and how many billions of bucks are we spending, the real purpose is to find ourselves and our place in the larger scheme of things.