"Dream the impossible, then go out and make it happen. I walked on the moon. What can't you do?" Gene Cernan tells PEOPLE

By Johnny Dodd
Updated February 26, 2016 10:50 AM
Credit: Mark Stewart Productions

When it comes to sci-fi movies, Gene Cernan, 81, isn’t a big fan. After all, the guy hasn’t even gotten around to watching Stanley Kubrick’s 1968 classic 2001: A Space Odyssey. And yet, he admits that he “loved” The Martian, especially the scene where Best Actor nominee Matt Damon‘s character staves off disaster by his ingenious use of duct tape.

Then again, it’s probably no wonder Cernan got a kick out of Ridley Scott’s space epic – especially since he once used duct tape to repair a busted fender on the lunar rover during his last voyage to the moon in 1972.

“Duct tape,” Cernan deadpans during a recent visit to PEOPLE’s editorial offices. “Don’t leave Earth without it.”

The former Apollo 17 commander, naval officer and aeronautical engineer has been making the rounds in recent weeks to promote his powerful, engrossing documentary The Last Man on the Moon, that hits select theaters around the nation on February 26. It’s an appropriately titled film because Cernan, who launched into space on three different high-stakes missions during the Gemini and Apollo programs, is the last human to have stepped foot on Earth’s only natural satellite.

The documentary chronicles Cernan’s life from his days as a fighter pilot to his stint as commander of Apollo 17, NASA’s final mission to the moon. Along the way, the film deftly explores the heavy personal sacrifices that all the astronauts made during America’s pioneering treks into space in the 1960s and early 1970s.

Cernan, who in 1969 – along with his Apollo 10 crewmates Thomas Stafford and John Young – set the record for traveling faster than any human [a blistering 24,791 mph], admits he initially had “zero” interest in having a movie made about him. But after several years worth of inquiries from director Mark Craig and producer Mark Stewart, he eventually warmed to the idea.

“I now look at it as an opportunity to leave something behind for younger generations after I leave this planet for the last time,” says Cernan, who scratched his daughter Tracy’s initials into the lunar dust shortly before climbing back into the lunar module [moments after crewmate Harrison Schmitt] and beginning his 239,000-mile return trip back to Earth in 1972.

“My dad always used to tell me, ‘Just do your best and someday you’re going to surprise yourself.’ He was right. I did surprise myself. Now I like to tell the young kids, ‘Dream the impossible, then go out and make it happen. I walked on the moon. What can’t you do?’ ”

Decades may have passed since Cernan’s pioneering forays into the heavens, but his account of staring out the tiny window of NASA’s command module at Earth floating in the incomprehensible void of deep space is as riveting today as it ever was.

“I looked back at this planet of ours and felt the logic and purpose and the overpowering beauty of the multicolored blue of the oceans and whites of the clouds,” says Cernan, one of only 12 humans to have ever walked on the moon. “And it was surrounded by the blackest black, this infinite endless endlessness of time and space, moving through it with an order and purpose beyond conception. I came to the conclusion that it didn’t come about by accident, that there truly is a creator of this universe and all I’m doing is seeing a small part of the creation.”

Cernan, like many of his fellow astronauts, explains that his otherworldly adventures forever transformed him. “I don’t know how you can go up there and not be changed,” he says. “I think I became a little less realistic and more philosophical about the future.”

And just in case you’re wondering what space smells like, Cernan likens it to the faint aroma of “spent gunpowder” from a 12-gauge shotgun. “Why?” he laughs. “I don’t know. But that’s what it smells like to me.”

The octogenarian former astronaut also insists that he found a kindred spirit in the character of spaceman Mark Watney, who battles for survival in the The Martian after becoming marooned on the red planet.

“I loved that movie,” Cernan says. “And I really identified with that young man and his perseverance. He wasn’t going to sit there and disappear. He was going to fight for his right to live, using his ingenuity. I’d like to think that’s how I’d react if I got stuck there.”