Trouble on Apollo 13

Part One · The Bang

In April of 1970, the United States sent its third crew toward the Moon. The mission was called Apollo 13. The commander was Jim Lovell, who had already flown around the Moon once before, and with him were Fred Haise and Jack Swigert. Swigert had joined the crew only a few days earlier, when another astronaut was thought to be getting sick and was replaced. Lovell's earlier flights had taught him how to stay calm when things did not go as planned.

The rocket lifted off from Florida on April 11. The crew took time to look back at Earth, which shrank into a small blue ball in the dark. For the first two days of the flight, everything went well. The men ran tests, checked their machines, and even sent a television show back to Earth. They were headed for a landing in a hilly part of the Moon. Nobody in the control center expected any big trouble. The trip felt almost routine, and most people on Earth were not paying close attention to it.

Then, on the night of April 13, about fifty-five hours into the flight, the crew heard a loud bang. The whole ship shook, and warning lights flashed across the control panel. Swigert called down to the control center in Houston to say that there was a problem. Within minutes, the men saw that their ship was losing oxygen and power. Nobody on board knew yet how serious the problem was, and the engineers on the ground had to study their screens carefully to figure it out.

An oxygen tank in the back of the spacecraft had burst. That tank held air for the men to breathe, and it also fed the machines that made the ship's electricity. Without it, the main cabin, a cone-shaped capsule named Odyssey, would soon run out of power. At that moment, the crew was almost two hundred thousand miles from home. The crew could not fix the tank, because it was outside the cabin and there was no way to reach it during the flight.

Everyone in Houston knew that the landing on the Moon was off. The new goal was much more important, because it was to get the three men back to Earth alive. The flight director, Gene Kranz, and his teams of engineers worked around the clock. They had to find a plan using only the things that were already on the ship. Their ideas came from long hours of study, careful math, and a firm belief that the crew could be brought home if everyone kept thinking clearly.

The answer was the small landing craft, which was named Aquarius. It had been built to carry two men down to the Moon and to keep them safe for about two days. Now it would be a lifeboat for three men for almost four days. The crew floated into Aquarius and shut down Odyssey to save every bit of power that was left. The landing craft had its own oxygen, its own water, and its own batteries, and those supplies had to be stretched much farther than anyone had planned.

Part Two · The Long Way Home

The next problem was the way home. The ship could not just turn around, because that would have used too much fuel. Instead, the planners decided to swing the ship around the far side of the Moon, so that the pull of the Moon would fling it back toward Earth. The crew fired the engine of Aquarius at just the right time to speed up the trip. The planners had to do careful math to get the angle exactly right, because a tiny mistake could send the ship off course and make it miss Earth.

Life inside Aquarius was hard. Nearly everything was turned off to conserve electricity, so the cabin grew very cold, almost as cold as the inside of a refrigerator. The men wore their warmest clothes. Each of them was allowed only a small amount of water each day. They hardly slept, because the cabin was chilly and very cramped. Water drops formed on the walls of the cabin, but the men kept doing their jobs and stayed focused on the long trip home.

Soon a new danger appeared. As the three men breathed, the air in the cabin filled up with a gas called carbon dioxide. Too much of it is harmful, and Aquarius had filters to clean the air, but they were made for only two men. The spare filters from Odyssey were square, and the openings in Aquarius were round. If the gas kept rising, it could make the men feel dizzy and unwell, so the engineers in Houston knew that they had to solve this problem quickly, before the air got worse.

On the ground, engineers laid out on a table the same kinds of things that the crew had on board. There were plastic bags, pieces of cardboard, a sock, and a roll of tape. Using only those things, they built a plan for an adapter that would let a square filter work in a round opening. They read the steps to the crew over the radio, and the men built it. It was a clever fix, and it worked, because the gas level began to drop.

As the ship drew near to Earth, the crew faced one more test. They had to turn Odyssey back on, even though no one was sure how a ship that cold would act. They also let go of the parts they no longer needed. At last, the three men climbed back into Odyssey and got ready for the final part of the trip. Every step had to be done in the right order, and the crew followed the checklist from Houston with great care, because there was very little room for mistakes.

On April 17, 1970, Odyssey fell through the sky under three huge parachutes. It splashed down in the Pacific Ocean, and all three men were safe. After four long days, the cold and the worry were finally over. People around the world had followed the story for days, and many of them cheered. Apollo 13 never reached the Moon. But it showed how careful thinking and teamwork could bring a crew home against the odds. Navy ships and helicopters were waiting nearby, and the crew was taken to a ship named the Iwo Jima.