Apollo 11 (NASA, 1969)

On July 20, 1969, Neil Armstrong and Buzz Aldrin landed the Eagle lunar module in the Sea of Tranquility while Michael Collins orbited above in the command module Columbia. Armstrong's first step was broadcast live to an estimated 600 million viewers — roughly one-fifth of humanity at the time. The mission returned 21.5 kg of lunar rock, whose analysis confirmed that the Moon formed from debris ejected when a Mars-sized body struck proto-Earth 4.5 billion years ago. Apollo 11 ended the Space Race as America's decisive victory, proved humans could survive beyond Earth orbit, and inspired a generation of scientists and engineers whose work defines the modern world.