May 5, 2011, is the 50th anniversary of the historic flight by Alan Shepard which made him the second person, and the first American, in space. LIFE has published a photo gallery of rare, never-before-published photos of Shepard, Glenn, Slayton, Grissom, and the rest of the Mercury astronauts, along with observations by LIFE photographer Ralph Morse (dubbed "the 8th Mercury astronaut" by John Glenn)
When Soviet cosmonaut Yuri Gagarin became the first man in space in April 1961, a stunned America asked, How did the Russians beat us? And more importantly: Will we ever catch up? Three weeks later, on May 5, the second question was emphatically answered when 37-year-old Alan Shepard blasted off from Cape Canaveral on his own historic flight — a feat that made the New Hampshire native the first American in space, and marked the moment the U.S. caught, and surpassed, Russia in the Space Race.
