The scarring in Navy SEAL Ryan Larkin's brain was not caused by large blasts from roadside bombs. Rather, he was wounded by repeated, low-level, blast pressure from his own weapons.

A veteran's brain showed no signs of physical injury, until a post-mortem after his suicide found microscopic scars. Now, his father is fighting to protect others in the military.

"Sir, it wasn't how you looked, it was how you smelled." — Navy Seal frogman to astronaut William Anders, explaining his reaction to opening the Apollo 8 capsule The Apollo 8 mission made ...