Apollo 13 ManualOn 13 April 1970, Apollo 13 suffered a near catastrophic explosion. The planned lunar landing was instantly called off, and the new challenge was to get the spacecraft safely back to Earth. When the carbon dioxide in the three astronauts' exhaled breath threatened to asphyxiate them, the crew improvised a filter device, which had been tested in Mission Control, to make the air breathable. Only hours before hurtling back into the atmosphere did they