Apollo 14 moonwalker Edgar Mitchell may be the only astronaut to conduct an ESP experiment in space, or openly state that extraterrestrials could theoretically live on the moon. But when historians look back at the Apollo moon effort a thousand years from now, Mitchell wants to be remembered for the down-to-Earth attitude he took toward his assigned task on the moon.

"Our task was to start to do the science," he told NBC News. "And we did that. We did it well. We brought back the first real samples from the moon."

Sure, Apollo 11 brought about 50 pounds of moon rocks back to Earth, and Apollo 12 brought back 75 pounds. As most folks will recall, a potentially fatal mishap forced Apollo 13 to come back from the moon without ever landing on its surface — which meant the pressure was on Mitchell and his Apollo 14 crewmates, Alan Shepard and Stuart Roosa, to help get America's space program back on track in 1971.

The mission succeeded, though not without a hitch or two ... or three. In his recently published book, "Earthrise: My Adventures as an Apollo 14 Astronaut," Mitchell recounts all the twists and turns that brought him from farm life near Roswell, New Mexico, to the moon and back.

Science and sports

Mitchell argues that Apollo 14 marked the transition from just proving humans could make it to the moon, to conducting a rigorous scientific program to characterize the lunar surface. Mitchell and his commander, Alan Shepard, brought back 94 pounds of moon rocks from the Fra Mauro formation, including a famous 20-pounder that was nicknamed "Big Bertha."

They also made their mark as the first sportsmen on the moon: Shepard carried a jury-rigged golf club and hit a ball that went "miles and miles and miles," while Mitchell picked up a rod from a solar-wind experiment and threw it like a javelin.

"I've always been happy to say that my javelin landed a few inches farther than Alan's golf ball," Mitchell says in the book. The place where it landed is now known as Javelin Crater (not Golf Ball Crater).

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Back to the moon?

This week marked the 45th anniversary of the first steps taken on the moon, and the occasion has sparked lots of discussion about whether and how we should go back. Mitchell doesn't think a return trip is necessary, unless it somehow helps further other goals on Earth or elsewhere in space.

"As far as a nice place to live, it doesn't have much to offer," he said jokingly.

The way Mitchell sees it, humanity's push outward into space needs to be part of a bigger picture, focusing on the sustainability of humanity and the rest of Earth's species. "I think a big problem on Earth right now is our lack of movement toward sustainability," he told NBC News. "We're not sustainable on this planet."

Apollo 14 moonwalker Edgar Mitchell is the author of "Earthrise." Chicago Review Press

Speaking of sustainability, Mitchell said he's not surprised to see how long it's taken for human spaceflight to turn into a viable commercial enterprise. After all, it took decades for automobiles to progress from the first vehicle to a full-fledged industry, or for the aviation industry to go from the Wright Brothers to the first commercial airline terminal.

"The same thing's kind of happening in space, now that we have Elon Musk and Richard Branson and Bob Bigelow, all trying to do something to get private industry into space," Mitchell said. "Maybe that's just the pattern of things when entrepreneurship starts to take over."

Mars could be a valid frontier for the future, in Mitchell's view. He recalled that while he was getting his doctoral degree at the Massachusetts Institute of Technology in the 1960s, he came up with a guidance system for low-thrust interplanetary spacecraft. "That was my contribution to going to Mars," he said.

Experiencing the Overview Effect

The experience of being on the moon was life-changing for Mitchell. "We were the third manned mission to make it to the moon, and it felt tremendous," he writes. But the epiphany that Mitchell experienced during the flight back home from the moon was arguably even more of a life-changer.

As Mitchell gazed at Earth, suspended in the palpable blackness of space, he felt a deep, ecstatic rush of connectedness with the rest of the universe. "What the heck is happening to me?" he recalls asking himself at the time.

Apollo 14's Edgar Mitchell consults his checklist while walking on the moon in 1971. NASA file

He eventually learned that other space travelers felt a similar cognitive shift, known as the "Overview Effect." Seeing the home planet in the void can spark a sense of oneness and enlightenment that is often described using terms from Hinduism, Buddhism and other spiritual disciplines.

The long-range ESP experiment he conducted during his personal time on Apollo 14's trip to and from the moon reinforced his interest in the frontiers of perception. He wrote down sets of numbers and symbols during specific times, to see if four experimental subjects on Earth would write down anything similar.

The idea that telepathy exists hasn't gained much traction in the scientific community, but Mitchell saw the results as promising. "The experiment persuaded me that ESP could happen," he writes in the book. He retired from NASA and the U.S. Navy soon after his moon mission, and founded the Institute of Noetic Sciences in 1973.

Mitchell makes no secret about his belief that life exists elsewhere in the universe, and he's willing to accept the possibility that alien spacecraft have visited Earth. When he returned to his hometown in New Mexico, he met with the relatives and colleagues of people involved in the 1947 Roswell UFO incident — and decided there was 'adequate proof that the Roswell incident was a real thing."

He also acknowledges, however, that he has no firsthand experience when it comes to aliens or UFOs. Instead, he prefers to address the "life in the universe" question more generally, based on the discoveries made by planet-hunting efforts such as NASA's Kepler mission.

"We're just one tiny grain of sand on a virtually infinite beach," Mitchell said. "The notion that we're alone in the universe, that we're the only living species, is absolutely ridiculous. ... Our whole idea of what it means to be living on this planet, and even being a thinking human on this planet, is going to have to undergo some major revision."