April 2012 marks 50 years since the beginning of NASA's Gemini program. Carried out from 1962-1966, during the feverish middle years of the space race, the Gemini missions achieved a wide range of American firsts, from the earliest space walk to the earliest in-flight docking of two spacecrafts.
The successes of the Gemini missions allowed the U.S. to overcome the advantage held by the Soviets since the late 1950s—in the process, NASA built up a pool of experience that would later be essential for lunar missions. All three men who would later fly aboard Apollo 11, the first spacecraft to reach the moon, had flown first on a Gemini mission.
In the slideshow below, see pictures from the Gemini missions, from breathtaking Earthrise photos to candid shots of the astronauts' excited family members on the ground.
The space-walk photos are especially exciting. Edwin "Buzz" Aldrin Jr. may be best known as the second man to set foot on the moon, but he was also the first man to perform an extended extra-vehicular activity (also known as a space-walk), and he did it aboard Gemini 12. If the photos below are any indication, that might have been even scarier than walking on the moon.