There are bold, dangerous expeditions, and then there are feats that forever change humanity - breaking boundaries, redefining our limitations, and going where no one ever dared. These five achievements fall into the latter category.
Walking on the Moon
The dream of lunar travel has captivated mankind for as long as we've been turning our gaze to the night sky. Early visionaries saw themselves reaching the moon via flaming chariots, towering waterspouts, the backs of swans, giant springs, 7,000 barrels of gunpowder, or just, as Cole Porter put it, "on gossamer wings." But it wasn't until the mid-20th century and the rise of rocket technology that the dream finally escaped the confines of the imagination. The Russians hit the moon first, crashing an unmanned rocket onto its surface in 1959 and heating the Cold War space race to a fierce boil. That race was marked by bold triumphs – in 1962 John Glenn became the first American to orbit the earth, and the Gemini astronauts pushed the boundaries with spacewalks and in-flight endurance records – as well as scalding failures, as when three Apollo astronauts were killed when their command module burst into flames during a practice countdown in 1967. But the ultimate prize went to the U.S., in 1969, when Apollo 11 – with a crew of Buzz Aldrin, Mike Collins, and Neil Armstrong – touched down on the moon after a hairy, manually controlled landing. "That's one small step for man, one giant leap for mankind" went Armstrong's famous line as he stepped onto the lunar surface. And a giant leap it was: Mankind had busted the limits of earthbound existence and traveled nearly 239,000 miles into space, set foot on a celestial body, and then plummeted back home again, safely – all during an age of knobs, dials, and slide rules. A new wilderness, unforgiving and filled with the same sort of uncharted blanks that prompted old-time mapmakers to write "here be dragons," had been broached. The heavens, finally, were ours.