Buzz Aldrin Wants You to Know -- the Sky Is Not the Limit In this interview, the second man on the moon shares life lessons from his latest book on mentorship and attaining any dream.

You might not know it, but Buzz Aldrin was rejected the first time he applied to NASA's astronaut program. He'd try again -- and make it -- but only to a backup crew. It took a freak accident to make room for him on Gemini 12's flight crew, where he'd take the longest successful spacewalk of that time.

Down-to-earth anecdotes like these comprise No Dream is Too High, Aldrin's latest book, and an opportunity for the space pioneer to reflect on a lifetime of experiences, which include the Apollo 11 mission and eventually becoming the second man to walk on the moon. In the book, he reminds us of the power of luck and persistence -- and that any goal is attainable.

We caught up with the 86-year-old astronaut and educator to get his take on what's needed for our next breakthroughs, big or small. Says Aldrin, we'll need both a commitment to curiosity and to mentoring those who can continue our work after us.

This interview was edited and condensed.

Entrepreneur: Let's talk about applying to the astronaut program. There was a point you thought it might not happen, yes?
Aldrin: I read in Life Magazine a description of the Mercury program and that President Eisenhower thought astronauts should be trained as test pilots. But I had not [been trained as one]. The space program looked like it wouldn't be available to me.

Entrepreneur: In your book, you talk a lot about luck, about how success is about being ready when opportunity comes.
Aldrin: It's fascinating to think about. How lucky I was. My mother was born the year the Wright brothers flew an airplane. My father was an aviator. I grew up and fought WWII. [I was in the military and the space program]. Now I am pioneering people going to Mars. From the Wright brothers to Mars, that has all been part of my life, in a way.

Entrepreneur: After the Apollo 11 mission, where did you find yourself? In your book, you mention struggling with "normal life" after the moon landing.
Aldrin: I experienced depression. It was inherited. My grandfather attempted suicide, and my mother committed suicide the year before I headed to the moon. I wasn't productive, and my mind was clouded.

I was given the command of the test pilot school. It really posed a major readjustment. As I was doing that, it just occurred to me, that is not the way I want to resume my Air Force career. I decided to retire at that point and see what else I could do. [At that point] I had disconnected myself from the Air Force and NASA.

Entrepreneur: How did you get your bearings back?
Aldrin: I thought about [how I could make a contribution] and the ways that I could reach out to help, to do better, with some development companies and think tanks. I decided to look at the continuous orbits between Earth and the moon. The [1975 Apollo-Soyuz Test Project] mission with the Soviets, [began] a legacy of cooperating with Cold War enemies, and survived the breakup of the Soviet Union. What followed that first mission in 1975, eventually led to the Shuttle program and International Space Station.

Entrepreneur: In your book, you talk about legacy as "going beyond oneself." Where does this stem from?
Aldrin: Jimmy Doolittle, [a WII pilot famous for leading the 1942 attack on Tokyo, known as the Dolittle Raid, in response to Pearl Harbor], was a friend of my father's. When my father died, Jimmy became a mentor, inspiring me to try and duplicate that [mentorship] with the astronauts, not just the twelve that landed on the moon.

Entrepreneur: NASA recently received a record number of applications for this latest class of astronauts. What should they be thinking about?
Aldrin: The ones that are being selected now will probably be [in their mid-twenties or early thirties] and they're going to be too old maybe to get to Mars. But they will do a number of things in between, such as dress rehearsals for younger astronauts. Maybe in 2025 and 2030 and beyond, those will be the people who will be mature enough, trained enough to go to Mars, to assemble bases there the way we assembled bases at the moon. It's easy for me to think about humans going out [to Mars] but not coming back. But it is harder for other people. I predict it will be 2040 when they will land. Until then, we should be committing to permanence. We have to think ahead.

Entrepreneur: It seems like there's more and more collaboration between public and private sectors in space exploration and even in other industries. Why is this collaboration so important for innovation?
Aldrin: The government had to rely on the private sectors to carry out the Mercury, Gemini and Apollo program and then when they started building the shuttle system. The space station is still up there but we don't have a shuttle to go up there so we have to rely on the Russians, we have not been able to replace the shuttle with a smaller spacecraft, and it's discouraging. What funds we do have are developing expensive but not really good rockets. The private companies, with government will start being able to take our people to the space station, the end of next year, "17 into "18. We need to build something to replace the International Space Station, helping other nations so we can lead those missions.

Entrepreneur: What are you excited about?
Aldrin: I learned to ski when I was 50, but haven't skied for a year or two. I'd love to continue scuba diving but you can't just do that every day. But I'm doing other things, like serving my country. That's what I took an oath to do. I want to communicate something of value. [Hopefully people learn something] just by traveling along with me.