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.

Recently discovered footage reveals the secret history of NASA's first landing on the moon, and using this brand-new evidence, former astronauts and experts challenge everything known about the Apollo missions.

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