Fifty years ago a six-year-old boy named Michael Massimino sat in front of his family’s television on Long Island, N.Y., transfixed by the blurry black-and-white images of a man walking on the moon. Like millions of other children watching the Apollo 11 lunar landing on July 20, 1969, Massimino vowed to one day become an astronaut just like the Apollo 11 crewmembers he so revered—Neil Armstrong, Buzz Aldrin and Michael Collins. Most of his starry-eyed generation would remain earthbound, trapped and discouraged by the transience of the Apollo era, which fizzled out with the last human landing in 1972. But Massimino managed to persevere, pursuing his Apollo-inspired dream through decades of deliberate preparation and multiple setbacks, ultimately joining NASA’s astronaut corps in 1996.

The formative influence of the Apollo missions is a common thread woven through the personal stories of nearly all the men and women who have subsequently voyaged to space. Not all, however, were as fortunate as Massimino, who managed to befriend many of the Apollo astronauts during his NASA career. When he finally lifted off, riding space shuttles skyward in 2002 and in 2009 to service the Hubble Space Telescope, he carried their lessons with him. Returning to Earth, he built on their inspirational legacy, using his own spaceflight experience to become a celebrated popularizer of space science and exploration. After his retirement from NASA in 2014, motivating the next generation of astronauts remained one of Massimino’s passions; today he is a professor at Columbia University and senior advisor at the Intrepid Sea, Air & Space Museum in Manhattan.

On the eve of the 50th anniversary of the first lunar landing, Scientific American spoke with Massimino about the impact that the Apollo missions have had on his own career trajectory and on the world.

[An edited transcript of the interview follows.]

You were six years old when Apollo 11 launched and landed on the moon. What do you remember from the mission?

Apollo 11 was one of the first news events that I remember occurring, when I became aware of things. I remember the buildup to the mission that summer, and I remember watching the launch from my summer recreation program at my elementary school in Long Island. I remember watching [the landing] in the living room. I was there with my family, and I was just riveted to the television set.

I remember them landing and everyone being very, very happy that they made it. I went outside and looked up at the moon thinking, “There are people on it.” I wanted to be one of those guys. All three of the Apollo 11 astronauts were the coolest guys ever. Neil Armstrong was my hero, and I liked Mike Collins because he had the same name as I did. At six years old, that’s very important. I was very excited about it. I think it just hit me at the right time in my life.

I knew it was a great accomplishment for everybody, but I knew it also meant something more to me. We were learning about Columbus and other explorers when I was in school, stuff that happened 500 years earlier. And I thought to myself, this is what they’re going to learn about in school 500 years from now. They’re going to learn about this. This is when we left the planet.

You went on to become an astronaut and, over time, became familiar with the entire Apollo 11 crew. Tell me about those interactions. Did they give you any valuable advice?

The first thing I asked Neil Armstrong was, when did he think of his saying: “one small step for man, one giant leap for mankind.” He said he didn’t think about it until after he landed. I was a new astronaut, and he said, “if I didn’t land it, there’d be no reason to say anything.” I think he saw it as a teachable moment. He told me, “Mike, you’re new at this. You gotta stick to business first and worry about all that later.” That was what I learned from Neil Armstrong.

The first time I met Buzz Aldrin, I introduced myself, but he was busy and I didn’t have much of a conversation with him. I did get to interview him at the Intrepid Museum five years ago, on the 45th anniversary of Apollo 11. We talked about what he famously called the moon’s “magnificent desolation,” his realization when he got out of the lunar lander and looked around that everything there had not really changed in hundreds of thousands, maybe millions of years. I see him from time to time at different places. He’s polite enough to pretend like he remembers who I am, so that’s kinda cool!

I first met Mike Collins before I was an astronaut, when I was an intern down at NASA headquarters. I heard him give a little talk, and when I went to the cafeteria for lunch, he was there sitting by himself. I forced myself on him and said, “Hey, do you mind if I join you?” He said, “sure.” I told him I was a student at M.I.T., and we talked about various things going on at NASA. Since then we’ve reconnected. When our mutual friend, [Apollo and Skylab] astronaut Alan Bean, died a little over a year ago, I spoke at Alan’s memorial and was an honorary pallbearer at his interment, and Mike was there, too. It just so happened that we got to spend some time together there. He’s a very nice man. Very, very humble.

Were there any challenging moments during your own spaceflights when your discussions with them proved useful?

Yes. When I was going to do the first tweet from space, I took Neil’s advice—I didn’t plan it. That was probably a mistake because when the time came I didn’t know what to say, and basically my tweet ended up getting made fun of on Saturday Night Live. So I was like, “I don’t know, Neil, if that was the best advice!” I probably should have thought about what I was going to tweet a little bit more.

But certainly, as astronauts we all benefit from what those guys did. When people think of astronauts, they think of Neil and Buzz and Mike, and the original Mercury Seven and what those guys were to the country and what the space program meant back then. We’re still benefiting from that; we’re still following in their footsteps.

You know, some people might say that after Apollo we took a step back in space, but I think we actually started looking a little more long-term, which is what led to the space shuttles, the Hubble Space Telescope and the International Space Station—where we now have a permanent presence in space. People have been up there since 2000! So we learned how to live and work in space for long periods of time. In some ways that’s nowhere near as impressive as what we did with Apollo, but that more steady program is what will lead us back to the moon. When we go back, I think it will be to stay.

Why do you think the Apollo missions, in particular, still resonate with so many people around the world?

They were the first times that humans left our planet and truly went to another place. I think that was seen globally as an accomplishment that everyone could be proud of and could be a part of. It wasn’t just an American accomplishment. It was truly a human accomplishment for the whole world.

I don’t think [the Apollo astronauts] realized the effect it would have on the entire world. Alan Bean, who was on Apollo 12, told me that when he traveled the world after his flight, it didn’t matter what country he was in, the response wasn’t “You Americans did it.” It was, “We did it. The world did it.”

What do you think the 50th anniversary of Apollo 11 should mean to people today—particularly younger people who weren’t around to witness it?

The 50th anniversary is an opportunity for them to learn about it. Luckily, we still have some of the Apollo astronauts left. I was at a 40th anniversary celebration at the National Air and Space Museum 10 years ago, after my second space flight, and all three of the Apollo 11 crew were there. Neil was still alive. I think just about all the moonwalkers were there—they were in their late seventies, early eighties at the time.

Now, 10 years later, there are not so many of them around. But there’s still enough of them alive to tell the story of Apollo, and hopefully this celebration goes on not just for Apollo 11, but for the remaining missions. And not just for the astronauts, but also people who worked in the control room, people who worked behind the scenes to make these things happen.

I still think it resonates with NASA, with our country and with the world that if you can land a man on the moon, you can do anything. You hear it all the time: “We can land a man on the moon, but how come I can’t get a decent cup of coffee?” It’s a reference to the miraculous things that we can accomplish. We’ve got to keep that in mind when we’re thinking of other problems today that seem to be impossible.

The White House wants NASA to return astronauts to the lunar surface by 2024. Do you think that’s a realistic deadline?

There’s no doubt that we could get there by 2024, because we have rockets and spacecraft under construction that could do it. Now, the question is, what are we going to do when we get there? If we’re landing there, are we going to try to stay and build a habitat? What are we going to do? I certainly think the first steps could be taken by 2024, and I don’t see any reason why we couldn’t do that. I think that’s a good goal, actually.

If you had the opportunity to go to the moon, what would you be most interested in seeing or doing?

I’d want to just look around!

For me, the highlight of my spaceflight was going out and spacewalking around the Hubble Space Telescope. We were up at 350 miles—that’s a very high altitude for a shuttle flight—and we could see the curvature of the planet from up there. The Earth was so compelling. It was incredible, going outside and being able to spacewalk and look around.

I think about the spacewalks the Apollo astronauts did on the way back from the moon. They had a chance to look in one direction and see a big moon and look in the other direction and see a big Earth.

So I would like to do a moonwalk and look around a little bit out there. It’s cool to be inside of the spaceship, but to get outside and walk around… I think that’s a very different thing.

The world collectively held its breath as Apollo 11 touched down on the lunar surface. Onlookers crowded around televisions and radios eager for updates. Do you think any space exploration event since then has reached that level of engagement? When will we have our next “Apollo moment?”

No, I don’t think anything has come close, and I don’t think anything will come close for hundreds of years. Even if we put someone on Mars, it’s not going to be the same. There’s only one first time you can leave your planet behind and go to another world. But that’s okay. I think the next thing that could get this sort of attention is when—and I think it is when and not if—we find life somewhere else. That’s going to be the next big story.