Apollo 13 was a manned mission to the moon, famous for suffering an explosion en route and being forced to abandon its planned lunar landing. The crew of Apollo 13 were in mortal danger at many times during their voyage, and were forced to use much of the technology on board in new and unexpected ways to arrive safely home.
Apollo 13 launched from the Cape Kennedy space center on April 11, 1970, at 2:13 PM EST, headed for the Frau Mora highlands on the Moon. During launch, dangerous vibrations caused by instabilities in the burning fuel resulted in one of the five engines shutting down. Although this was compensated for by diverting fuel to the remaining engines and running them for longer, subsequent missions were fitted with vibration dampeners to prevent this sort of error again.
On April 13, 1970, at 10:07 EST, one of the two oxygen tanks on board the spacecraft exploded. A faulty wire had sparked, igniting the oxygen and causing the explosion. It was not the fault of any of the astronauts, or any of the ground crew in Houston. The explosion damaged the fuel cells, which were adjacent to the oxygen tanks aboard the spacecraft. In an attempt to prevent further power loss from the remaining fuel cells, the damaged fuel cells were shutdown. Although this did not have the intended effect, it made a lunar landing impossible.
With power draining, and barely enough air to last the return trip, the crew put the spacecraft into a freefall towards the moon, which swung the craft back towards the Earth. As they passed over the far side of the moon, the Apollo 13 crew were father from Earth than any human beings have been, before or since.
The crew encountered a series of difficulties on their return, including low power supplies, insufficient water, cramped quarters (parts of the spacecraft were too cold, forcing the 3-man crew into a 2-man region), Fred Haise's urinary tract infection, and dangerously high carbon dioxide levels. All of these problems were overcome, and Apollo 13 splashed down southwest of American Samoa with all crew members alive.
The world broke out in prayer, with special services held at the Chicago Board of Trade, St. Peter's Basilica by the Pope, at the Wailing Wall in Jerusalem and even the U.S. Senate in the form of a resolution urging prayer.
When we learned of the safe return of our astronauts, I asked that the Nation observe a National Day of Prayer and Thanksgiving today .... This event reminded us that in these days of growing materialism, deep down there is still a great religious faith in this Nation. ... I think more people prayed last week than perhaps have prayed in many years in this country .... We pray for the assistance of God when ... faced with ... great potential tragedy.