Around 47 hours into the mission, everything seemed to be running smoothly. "The spacecraft is in real good shape as far as we are concerned. We're bored to tears down here," Capsule communicator Joe Kerwin says.
Just 9 hours later, the crew finished a television broadcast showing how comfortable it is to live on the spacecraft in zero gravity. Lovell closed with a warm good night: This is the crew of Apollo 13 wishing everybody there a nice evening, and we're just about ready to close out our inspection of Aquarius and get back for a pleasant evening in Odyssey. Good night."
A few minutes after the broadcast wraped, ground control asked Swigert to perform a routine procedure called a cryo-stir. This involved powering fans to stir two oxygen tanks in the service module, which prevented the liquid oxygen from settling into layers.
Almost immediately after Swigert flips the switch, there is a sharp bang and the spacecraft shudders. A warning light comes on. "Houston, we've had a problem," Swigert says.
Thirteen minutes after the bang Lovell peers out the window. It's the final indication that something disastrous has happened. "It looks to me that we are venting something," Lovell reports from Apollo 13. "We're venting something out into space. It's a gas of some sort."
That gas was the oxygen the crew not only needed in order to breathe, but also to power the fuel cells that generated water and power for the spacecraft. The command module (where the crew lived) was quickly losing power.
The mission was aborted. Apollo 13 would not land on the moon.
An investigation later determined that exposed wires shorted when the fan was turned on to stir the oxygen tanks. The spark, fueled by pure oxygen, ignited the Tungsten insulation. This started a fire inside the number 2 oxygen tank, increasing pressure and causing it to explode.
Back in the control center, NASA had called all of its top people in within a few hours of the explosion.
With the command module crippled, the decision was made to move the crew to the lunar module (designed to land on the moon), which would act as a "lifeboat." Lovell is pictured here inside the lunar module.
This would present several future challenges. The lunar module was only designed to support two men for two days (like in this artist's concept of Apollo 13 astronauts exploring the moon's surface). Now it was being used to support three men for about 90 hours. The crew had enough back-up oxygen, but the build-up of carbon dioxide would soon be an issue.
The new mission was to get the lunar module in a free-return-to-Earth trajectory. Prior to the explosion, the craft was on course for the moon. The free-return course required slinging the lunar module around the moon, back to Earth, and landing in the Pacific Ocean.
A telescope photographs the Apollo 13 spacecraft in the lunar-free return, which will take the craft around the far side of the moon, and back to Earth.
After a day and a half in the lunar module, a warning light goes off showing dangerous levels of carbon dioxide. The crew could use the canisters used to remove carbon dioxide from the command module, but there was one problem: The command module used square canisters, while the lunar module used round ones.
Mission control came up with a makeshift system using only materials available on the craft, like plastic bags, cardboard, and tape, to make this work.
The crew photographs the far side of the moon from the Apollo 13 spacecraft on their perilous journey home.
The trip is gruesome. There is very little food and water. Most electrical systems, including heat, were shut down to conserve power. The crew can't sleep because it is so cold. At one point the temperature drops to 38 degrees Fahrenheit.
Four hours before landing, the damaged service module was released from the command module. The crew snapped pictures, and for the first time, were able to see the full extent of the damage.
"There's one whole side of that spacecraft missing," Jim Lovell said.
An entire panel of the service module had been blown away when the oxygen tank exploded, as seen in this close-up image.
About to splash down in the South Pacific Ocean, the crew moved back into the command module. The lunar module was shed from the command module.
A large screen in front of the mission control room shows the spacecraft with its parachutes deployed.
The capsule and its parachutes are visible after breaking through dark clouds.
The spacecraft splashes down on April 17, 1970 at 12:07 p.m. The total voyage time was about 142 hours.
Mission control celebrates!
The astronauts are pulled from the command module onto life rafts.
Haise, Lovell, and Swigert step off a helicopter onto recovery ship U.S.S. Iwo Jima.
After the crew is safely on the ship, the command module is pulled on board.
A day later, Lovell reads the newspaper account of Apollo 13's rescue while still on board the U.S.S. Iwo Jima.
President Richard Nixon presents the nation's highest civilian award to the Apollo 13 crew on April 18.
After Apollo 13, eight more Apollo spacecraft flew. None of them experienced problems.
Now see relics of the space era.
