On April 11, 1970, the space shuttle, Apollo 13, launched with the intentions of landing on the moon. Its crew consisted of three men, Fred W. Haise, Jr., Jpohn L. Swigert, Jr., and James A. Lovell, Jr. The launch was successful but one of the engines in the second stage of the rocket shut down prematurely. Mission control had to calculate if the shuttle would be able to go into orbit, and once they realized that it would, everything went smoothly. Then, about 55 hours later on their journey to the moon, disaster struck. An oxygen tank on board the ship exploded with enough force to blow an entire side panel off the ship and cripple its air and fuel supply. It was due to faulty wiring inside liquid oxygen tank 2. When Swigert stirred the tank, which was a simple procedure, the electronics sparked creating a fire in an environment of pure oxygen. This led to the explosion of tank 2, which also damaged tank 1 causing the oxygen to vent out into space. This meant that the Command Module was not only losing its air, but its fuel as well. The crews only option was to use the Lunar Module attached to the CM as a lifeboat. However, the Lunar Module was only designed for landing on the moon and, worst of all, it was only made to last two people 45 hours. Still, the three men were able to make it last all 90 hours back to Earth by rationing their water dramatically.
Astonishingly, all three crew members survived and the only injuries they sustained were illnesses brought on by dehydration and sleep deprivation. The Apollo 13 mission cost NASA approximately $4.4 billion.
Since the accident occurred due to some human error during oxygen tank two's testing and installation and to a flawed design, the tank was in need of remodeling. The fans designed to stir the tanks were removed and the quantity gaging probe was converted to a stainless steel model rather than the original aluminum. The tank's heating systems were changed so that three separate elements could be operated individually. The thermal switches that had failed and allowed overheating, which may have been the main problem, were removed entirely. Finally, all wiring associated with the fans were insulated with magnesium oxide and sheathed with stainless steel because it is thought that these wires shorted out and sparked in the previous tank.
https://www.youtube.com/watch?v=69LDSL-9--g ("Apollo 13 the Real Story")