Late on the 13th April 1970, the spacecraft Apollo 13 was rocked by an explosion from one of its oxygen tanks. The resulting emergency led to the calm announcement by the crew of, “Houston we’ve had a problem”. However, most people misquote the phrase as “Houston we have a problem” after the award winning 1995 film changed the tense. The movie also placed the words in the mouth of Commander Jim Lovell, where in fact it was Command Module Pilot Jack Swigert who first reported the issue.
The explosion occurred after a routine procedure to stop gasses settling in their tanks. An investigation by NASA has since found that a spark from an exposed wire in the oxygen tank caused a fire, leading to an expansion of gasses that eventually blew apart the tank. The explosion ripped off the side of the Service Module, vented oxygen into space, and left the crew stricken in a damaged craft.
Rather than landing on the moon, the mission’s focus was now to bring the crew safely home. Improvisation was key, with the crew forced to turn their landing unit into a lifeboat to ferry them back to Earth before transferring back to the Command Module for reentry. Fortunately the heat shield had not been damaged, and the crew splashed down safely on April 17th.