The original seven Project Mercury astronauts: front row, left to right, are Walter M. Schirra, Jr., Donald "Deke" K. Slayton, John Glenn Jr., and M. Scott Carpenter. Back row, left to right, are Alan Shepard Jr., Virgil I. "Gus" Grissom, and Gordon Copper. (Photo by NASA/Roger Ressmeyer/Corbis/VCG via Getty Images)