Introduction

On April 11, 1970, at 2:13 p.m., 203,400 gallons of kerosene and 318,000 gallons
of liquid oxygen were ignited. The resulting fury was harnessed to produce 7.5
million pounds of thrust to lift the Saturn V rocket off Launch Pad 39A at Cape
Canaveral in central Florida and, after two more controlled explosions, propel it
into space.

Along for the ride that day was the three astronaut crew of Apollo 13,
Commander James Lovell Jr., Command Module Pilot John Swigert Jr., and Lunar
Module Pilot Fred Haise Jr. Apollo 13’s mission, to land on the moon, followed in
the quite literal footsteps of Apollo 11 and Apollo 12. This was billed as just the third
moon landing ever. The previous two landings had only taken place within the last
nine months.

At 9:08 p.m. on April 13, just a few minutes after the crew had completed a TV
broadcast, they heard a loud noise and felt a vibration. A warning light caught John
Swigert’s attention. He immediately radioed in the famous, although often
modified line, “Houston, we’ve had a problem here.”

What no one knew at the time was a small explosion had knocked out one of the
main craft’s two oxygen tanks and had damaged the other. The situation was dire.
The oxygen the crew needed to breathe was rapidly venting into space, and
electrical power and the water supply were also severely depleted.
At the time, the crew was 200,000 miles from Earth—roughly the distance
around the world eight times.

Ninety minutes after the explosion, with oxygen plummeting toward zero, the
crew quickly put a plan in place to use the Lunar Module (LM) as a lifeboat to keep
them alive. The crew was instructed to shut down the Command Module (CM),
move into the LM, and close the hatch between the two.

The LM had plenty of oxygen. The craft had independent tanks designed for the
moon descent that would provide plenty of breathing hours for the crew. There
were also ascent tanks available and two backpacks with extra oxygen for walking on
the moon.
Oxygen wasn’t a problem, but water and power certainly would be. Each of the
three astronauts was limited to drinking only six ounces of water a day, less than a
quarter of what each man would normally drink. As a result, the crew became
dehydrated and lost just over 31 pounds of combined body weight, more than any
other crew before them. Lovell dropped 14 pounds alone. Energy was also reduced
to 20 percent of what would normally be used.