It has been called the single most historic event of the 20th century: On July 20, 1969 Neil Armstrong, Buzz Aldrin and Michael Collins met John F. Kennedy's call for a manned Moon landing by the end of the 1960s. A decade of tests and training, a staff of 400,000 engineers and scientists, a budget of $24 billion, and the most powerful rocket ever launched all combined in an unprecedented event watched by millions the world over. And no one captured the men, the mood, and the machinery like Norman Mailer. One of the greatest writers of the 20th Century, Norman Mailer was hired by LIFE in 1969 to cover the Moon shot. His three-part feature was the longest nonfiction piece LIFE had published. He enhanced and extended his reportage with deeper reflection in the brilliantly crafted book, Of a Fire on the Moon, excerpted here for the first time. Equally adept at examining the science of space travel and the psychology of the men involved - from Saturn V rocket engineer Wernher von...