Apollo 13 - Mission Preparations

American NASA astronaut Ken Mattingly, wearing a striped t-shirt, as American NASA astronaut Jack Swigert, who wears his NASA flight suit and a Rolex GMT-Master watch, checks the flight plans during preparations ahead of the launch of the Apollo 13 space mission in the Flight Crew Training Building at Kennedy Space Center in Merritt Island, Florida, 9th April 1970. Swigert was the backup crewman to replace Mattingly as Apollo 13 command module pilot following his exposure to Rubella. (Photo by NASA/FPG/Archive Photos/Getty Images)