In charting the mysterious expanse of space, both men and women pioneers risked their lives to further human kind's reach and influence. Some of these pioneer heroes never came back, while others experienced explosions, catastrophe, and injury. This film explosives the inherently dangerous occupation of astronauts and cosmonauts, who in the face of an unforgiving hostile environment, and relentless life threatening pressures, endured almost certain death in the pursuit to conquer the unknown.