Fifty years ago, before most people living today were born, the beep-beep-beep of Sputnik was heard round the world. It was the sound of wonder and foreboding. Nothing would ever be quite the same again — in geopolitics, in science and technology, in everyday life and the capacity of the human species.

... Neil Armstrong struck a note sure to resonate with many of his contemporaries. “We were really very privileged,” he said, “to live in that thin slice of history where we changed how man looks at himself and what he might become and where he might go.”