Aldrin has written seven books, produced computer games, and even recorded a rap song with Snoop Dogg. A tireless advocate for human space travel, the former astronaut developed the Aldrin Cycler, a system that allows spacecraft to orbit continually between Mars and Earth, providing regular transportation between the two planets.

In his newest book, "Mission to Mars," Aldrin lays out a comprehensive plan that would lead to permanent human settlements on Mars in the next 25 years. National Geographic magazine's Bill Douthitt spoke with Aldrin about the future of space travel.

It's the challenge to try and communicate thoughts that I believe have merit to them, that could make things easier for the nation to execute a good pathway