Space Men Preview
Video duration: 0:30
Before the days of NASA, scientists and researchers at the U.S. Air Force were testing the limits of how high man could fly. Though largely forgotten today, balloonists were the first to venture into the frozen near-vacuum on the edge of our world, exploring the very limits of human physiology and human ingenuity in this lethal realm. "Space Men" premieres March 1 at 9/8c on PBS.