After NASA put men on the moon, it was determined to follow up this success by making such visits a regular occurrence. After an uneventful launch, the crew of Apollo 13 were well on the way when a small electric motorised fan ignited their oxygen reserve and blew a gaping hole in the side of the command module. Only by working with mission control, who duplicated the accident on earth, were the three astronauts able to scrape home by the most slender of margins. This is their story.