In the 1950s and early '60s, a small band of high-altitude pioneers exposed themselves to the extreme forces of the space age long before NASA's acclaimed Mercury 7 would make headlines. 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.

National Geographic's riveting effort recounts all 12 crewed missions using only archival footage, photos and audio.

A testament to NASA's Apollo program of the 1960s and '70s. Composed of actual NASA footage of the missions and astronaut interviews, the documentary offers the viewpoint of the individuals who braved the remarkable journey to the moon and back.

The "real men with the right stuff", Chuck Yeager and the Mercury astronauts, discuss the early days of the space program and its portrayal in the film "The Right Stuff".

All of the necessary technologies required to reach the Moon was first tested during Project Gemini, which comprised of ten missions in the mid-1960s.

Slim Pickens narrates outdoor adventures.