The book covers Collins's life as a test pilot in the United States Air Force; his selection as an astronaut and his spacewalks on Gemini 10 and historic flight as the command module pilot on Apollo 11.

Collins presents some candid insights into his astronaut colleagues, including Neil Armstrong ("I can't offhand think of a better choice to be the first man on the moon")[1] and Buzz Aldrin ("would make a champion chess player; always thinks several moves ahead").

In the book, Collins discusses the selection of the first person to walk on the Moon, and the resulting tension that arises from it.

[2] In his review for Time magazine, Robert Sherrod calls it "the best-written book yet by any of the astronauts".

[1]: xvi  Collins subsequently released further titles, including Flying to the Moon and Other Strange Places (1976), Liftoff: The Story of America's Adventure in Space (1988) and Mission to Mars (1990).