An introduction to the twelve men who have left footprints on the moon, just in time to celebrate the fiftieth anniversary of the first lunar landing. On July 20, 1969, Neil Armstrong took one small step and made history. Over the course of the next three-and-a-half years, twelve lunar explorers, including Alan Shepard and Gene Cernan, touched down on the moon's surface. Author and engineer Suzanne Slade reveals how the Apollo missions (1969-1972) built upon one another and led to important discoveries about our nearest neighbor in space. Back matter includes an afterword by Alan Bean (1932-2018), the fourth person to walk on the moon.