Crewmen aboard the USS Iwo Jima, prime recovery ship for the Apollo 13 mission, hoist the command module aboard ship on April 17, 1970, after the spacecraft splashed down in the South Pacific. The crew successfully returned to Earth after a critical malfunction en route to the Moon and the mission eventually became known as a "successful failure". Commander Jim Lovell's radio transmission, "Houston, we've had a problem", spawned the misquoted phrase in popular culture, "Houston, we have a problem".Photo credit: NASA