Apollo 13 was a famous mission to the moon in which astronauts overcame a serious mid-flight malfunction to return safely to Earth. It was conducted by the United States National Aeronautics and Space Administration (NASA). The astronauts Fred W. Haise, Jr., James A. Lovell, Jr., and John L. Swigert, Jr., worked with personnel on the ground to overcome a series of challenges triggered by the rupture of an oxygen tank. Apollo 13 was the fifth of nine lunar missions in the Apollo program.
Apollo 13 launched April 11, 1970, from Cape Canaveral, Florida, on a Saturn V rocket. It was to be the third crewed mission to the surface of the moon, after Apollo 11 and Apollo 12. The Apollo 13 spacecraft consisted of three modules. The command module housed the astronauts on their journey to the moon and back and enabled them to safely reenter Earth’s atmosphere. The service module was not accessible to astronauts but supplied the command module with oxygen and electricity. The lunar module was designed to enable two astronauts to land on the surface of the moon and return to the command module in orbit .
On April 13 in the United States (April 14 according to Coordinated Universal Time [UTC], which many astronomers use), about 56 hours after launch, one of the two oxygen tanks in the service module ruptured during a maintenance operation. Warning lights went off in the command module. Swigert reported the situation to mission control at the Manned Spacecraft Center in Houston, Texas, famously stating, “Okay, Houston, we’ve had a problem here.” The blast damaged the second tank, causing it to vent all its oxygen into space over the next few hours.
The damage put the astronauts’ lives in danger. Devices called fuel cells in the service module generated electric power for the command module. Without oxygen, the fuel cells could no longer produce power. Without power, the spacecraft’s heaters would cease to function, leaving the astronauts to die of hypothermia in the extreme cold of space.
As mission control personnel realized the scope of the damage, they canceled the lunar landing and worked to save the three astronauts. They shut down the command module to save the limited battery power for reentry into Earth’s atmosphere. The three astronauts moved into the lunar module—which was only designed for two—for the journey around the moon and back to Earth.
The lunar module had enough oxygen for the astronauts to breathe. But it relied on battery power, rather than fuel cells, and the batteries were not designed to be used for such a long portion of the trip. To conserve power, the astronauts allowed the cabin temperature to drop near freezing. Supplies of food and of water—which was also used to cool onboard equipment—were limited. The astronauts skipped meals and rationed water. Haise developed a kidney infection, likely as a result of dehydration.
The lunar module’s air filtration system was only designed to sustain two astronauts for two days. Therefore, the crew was faced with a potential buildup of carbon dioxide, which is dangerous in high concentrations. Guided by engineers and astronauts on the ground, Haise, Lovell, and Swigert constructed an adaptor to fit the command module’s carbon dioxide filters into the lunar module’s air filtration system, which used filters of a different shape.
A few hours before reaching Earth, the crew returned to the command module and powered it back up for reentry, using a limited battery power supply. They then jettisoned the lunar module and damaged service module. The command module splashed down safely in the Pacific Ocean on April 17.
Apollo 13 has been called a “successful failure” because the three astronauts survived despite the serious malfunction. NASA engineers redesigned parts of the service module for future missions, improving the oxygen tanks and adding a third tank exclusively to provide oxygen to the crew. NASA successfully conducted four more missions to the moon under the Apollo program without any other serious malfunctions. The motion picture Apollo 13 (1995) was based on the mission.
