Mary Roach, author of "Grunt: The Curious Science of Humans at War"

Millions of people serve in our armed forces, but what does it take get them prepared and keep them alive? Roach tackles the science behind some of a soldier’s most challenging adversaries – panic, exhaustion, heat and noise. She shares some of her bizarre experiences dodging hostile fire as part of a training exercise with the U.S. Marine Corps Paintball Team and staying up all night with the crew manning missiles on the nuclear submarine USS Tennessee. Take a tour of duty with Roach and you’ll never think about our nation’s defenders the same way again.