Unreal Facts About The Apollo 13 Mission You Didn’t Know About

2. An Astronaut Was Replaced

Ken Mattingly was supposed to be the original backup command module pilot on this mission but was replaced two days before the scheduled launch time. That was because a few weeks before the launch, one of the backup astronauts called Charles Moss Duke spent time with family friends whose son caught rubella.

As expected, Duke contracted rubella himself. Three days before the launch during a final physical exam, blood samples collected from the astronauts showed that Mattingly did not have any antibodies against rubella though he never contracted German measles but was exposed to it. Hence could not be cleared for the mission. That when Swigert was asked to step in. How interesting!