In 1960, Captain Joe Kittinger stepped out from a balloon and fell 103,000 feet (31,394.4 meters) back down to Earth. It was part of an early Air Force mission to study how near-space impacts the human body. It was before NASA began sending its Mercury 7 crew, its very first class of astronauts, into orbit. It's bewildering to think that, while there was a tremendous amount of research and preparation that went into Kittinger's mission, ultimately, they had no idea how it would go. Listen to an interview with Kittinger, taken from an upcoming episode of American Experience on PBS.