On the 40th anniversary of NASA’s historically influential Apollo lunar landing, CBS News’ Russ Mitchell reports on the reasons and motivations that inspired this unprecedented journey.

For his book Voices From The Moon, Andrew Chaikin interviewed 23 of the 24 Apollo astronauts and all 12 who have set foot on the lunar surface. He notes that the most common thread from the moonwalkers is that they didn’t have a lot of time to take in the experience because they were so overcommitted. Hear what he thinks are Apollo’s greatest legacies.