For a few brief years between 1968 and 1972, humans left the Earth and visited the Moon. The flights took the combined efforts of nearly half a million people working across the world and cost about $160 billion in inflation-adjusted 2015 dollars. The result of that work and money were the Apollo landings—six successful lunar touchdowns, each of which gave us a vast amount of scientific knowledge and a priceless trove of samples. Twelve people walked on our nearest heavenly neighbor, leaving 12 sets of footprints that will linger in the regolith for millions of years—possibly outlasting humankind itself.
Apollo occupies a unique place in human history—a flashbulb moment when economics and technology suddenly aligned with world politics in a way that likely will never happen again. The program was a monumental achievement—arguably the greatest engineering achievement in human history—but the story of Apollo is the combined story of each of the thousands of men and women who worked to make those flights happen.