5
The Moon out the Window
It is difficult to say what is impossible, for the dream of yesterday is the hope of today and the reality of tomorrow.
—Robert Goddard, rocketry pioneer
Mission control flight controllers fed instructions to the Apollo 13 crew for a long engine burn that would speed up their trip to Earth. The crew would execute the burn two hours after they emerged from the far side of the moon. That meant they had to set up the procedure before they rounded the moon and lost contact with mission control. Lovell and Haise copied the instructions into their flight plan. As updates came in, they crossed out some steps and added others. They checked and rechecked each instruction.
Aligning by the Sun
Before they attempted the burn, the crew needed to verify the alignment of the spacecraft. Guidance platforms drifted over time, and even though the short burn to slingshot the spacecraft around the moon had worked perfectly, there was no guarantee the speed-up burn would be equally successful. Starting from the proper attitude was critical. With the engine blasting for more than four minutes, the spacecraft would veer dangerously off course if it started from the wrong position in space.
In Houston, astronauts worked in simulators to find a way to align the spacecraft with stars. They set up a test spacecraft to match conditions on Apollo 13. No matter which way they turned the simulator, the debris field surrounding the spacecraft blocked stars from their view. With time running out, flight controllers decided to align the spacecraft with the sun. It was a tricky maneuver. A star was a pinprick of light in a precise spot in the sky. Aligning on a few specific points of light was an accurate way to navigate and check a spacecraft’s position. But the sun was not a pinprick of light. It was a huge fiery ball. The crew would have to use dark filters to protect their eyes and look for the upper-right corner of the sun.
The crew worked together on the sun check. Lovell entered the information from mission control into Aquarius’s computer. He pressed a button to start the procedure and watched the attitude indicators on the instrument panel. The spacecraft slowly turned. Swigert looked for the sun out a window. Haise peered through the alignment telescope. Mission control flight controllers waited in nervous silence.
For eight minutes the spacecraft rotated. Then Swigert caught a flash of the sun. Haise spotted the upper-right corner through the telescope.
“We’ve got it,” Lovell said. “It looks like the Sun check passes.”
“We understand it checks out,” said mission control. “We’re kind of glad to hear that.”
Behind the Moon
As the spacecraft approached the moon, the moon’s gravity pulled it in. The closer they got, the faster they flew. At 6,000 miles (9,656 km) per hour, shadows lengthened and stars lit up the sky. Apollo 13 slipped behind the moon, and the crew lost contact with mission control for twenty-five minutes. Lovell had seen the view out the spacecraft windows when he circled the moon on Apollo 8. But it was a new experience for Haise and Swigert. They grabbed their cameras and snapped pictures out the windows. “We were . . . disappointed and sick that we could not land on the moon,” said Haise. “We had lost a mission. We had worked a lot of years, and seemingly for nothing.”
After they emerged from behind the moon, Lovell was anxious to prepare for the speed-up burn. But his crew was busy snapping pictures out the windows. “If we don’t get home, you’ll never get them developed,” he reminded them.
Swigert and Haise stored the cameras, and Lovell checked in with mission control. He learned that the third stage Saturn V rocket had crashed onto the moon as planned. Equipment left behind from Apollo 12 sent data about the impact to mission control. “Well, at least something worked on this flight,” Lovell said.
The crew of Apollo 13 photographed the moon from their lunar module “lifeboat” as they passed by it. The shutdown command module is visible out the overhead rendezvous window.
A Speed-Up Burn
The crew worked with mission control to prepare for the long burn. They knew they had to get it right if they had any hope of getting home. The astronauts turned on equipment and powered up Aquarius in a carefully arranged sequence. Mission control checked instrument readings from the ground and reminded the crew to stop the burn if they ran into trouble. NASA officials and reporters watched from a mission control viewing room, ready to relay the results to a waiting world.
Mission control counted down to start the procedure. The crew burned the Aquarius engine for four and a half minutes. The maneuver increased their speed and cut ten hours off the trip to Earth. Splashdown would be in the Pacific Ocean. NASA sent a recovery ship to the area to avoid a delay in retrieving the astronauts. They hoped Tropical Storm Helen would not be there to greet the ship.
“That was a good burn,” mission control told the relieved crew.
“Roger,” said Lovell.
The success of the speed-up burn was a turning point in the Apollo 13 mission. Every second brought the astronauts closer to home instead of farther away from it.
After the engine burn, some flight controllers wanted the crew to turn off the equipment on Aquarius and get some sleep. Others insisted they set up a passive thermal control roll to distribute the sun’s heat evenly before they rested. The astronauts had barely slept in two days. They were so tired that they would make costly mistakes, argued the sleep advocates. It won’t matter how tired they are if the spacecraft burns up or freezes, said those in favor of rolling.
Kranz decided that the crew could rest after they set up the roll. Lovell and Haise worked to set up the slow spin. But the joined Aquarius-Odyssey spacecraft wobbled as it did the last time they tried to set up the roll. For two hours, they struggled to get rid of the wobble. At last, they got Apollo 13 into a slow spin. Then they powered down Aquarius.
Haise took the first sleep cycle. Then Lovell and Swigert slept. But it was like trying to sleep inside a refrigerator. “The inside of the Odyssey, our bedroom, kept getting colder and colder,” said Lovell. “It eventually got down pretty close to the freezing point, and it was just impossible to sleep in there.” The three men huddled in Aquarius. Their body heat helped keep them warm in the tiny space.
Poison Air
As the crew tried to relax, another problem popped up. Aquarius was filling with poison. With every breath, the crew released carbon dioxide into the air. Aquarius contained air scrubbers, canisters of lithium hydroxide, to purify the air. But there weren’t enough filters to support three men for four days. As the hours passed, the carbon dioxide level in the spacecraft rose. If it continued unchecked, the astronauts would suffer from carbon dioxide poisoning—illness followed by falling asleep and never waking up. The astronauts needed more filters if they were going to survive.
Engineers in Houston got to work and built a filter using only materials they knew the astronauts had on the spacecraft. Once they had built a working, makeshift filter, they read the instructions to the astronauts line by line. “This contraption will look like a mailbox when you get it all put together,” they said.
The astronauts gathered supplies. Swigert ripped off the cardboard cover of the flight plan. The crew grabbed duct tape, plastic bags, space suit hoses, and socks. Working together, they built the filter a step at a time. It took about an hour. Then they attached it to a wall and listened for the sound of air flowing through the device.
With his ear pressed against the canister, Swigert heard air hissing through the filter. The contraption worked. Little by little, the carbon dioxide level fell.
Interior view of Aquarius during the trouble-plagued journey back to Earth. This photograph shows some of the temporary hose connections and apparatus that were necessary when the three astronauts moved from the command module to use the lunar module as a lifeboat. In the background is a jury-rigged air filter that the astronauts built to use the command module lithium hydroxide canisters to purge carbon dioxide from the lunar module.
The World Watches
Before the explosion on Apollo 13, news coverage of the spaceflight was brief. Newspapers in the United States and around the world printed small articles about the mission. The flight seemed too perfect, and the public grew bored. The United States had already landed on the moon twice. It wasn’t exciting anymore.
After the explosion, the whole world watched events unfold. NASA held press conferences to keep the media informed. Newspapers around the world splashed the latest updates across headlines. They increased their print runs to feed a public hungry for news. People gathered around television sets and milled in the streets discussing the damaged spacecraft. Reporters interviewed some of them for their reactions to the crisis. Although everyone wanted the astronauts to return to Earth safely, not everyone was a fan of the space program. Some people thought the cost of spaceflight was too high. They believed the money could be put toward solving the nation’s many social problems.
The Apollo 13 crew built this “mailbox” to be able to use the command module lithium hydroxide canisters in the lunar module.
Radio and television stations interrupted regular programming with the latest developments. Marilyn Lovell and Mary Haise watched every television broadcast and listened to their husbands on squawk boxes loaned to them from NASA. The squawk boxes allowed them to hear all the communication between the crew and mission control.
The astronauts’ homes filled with family and friends, many of them NASA employees. Reporters descended on Lovell’s home and wanted to set up a broadcast tower on the front lawn for round-the-clock coverage. Marilyn Lovell refused. She told them if they had a problem with her decision, they could talk to her husband about it on Friday when he got home.
Around the world, churches and synagogues held religious services to pray for the astronauts. In Rome, Pope Paul VI prayed for the astronauts’ safe return before ten thousand people. In India, thousands prayed at a religious festival. The Senate and the House of Representatives both passed resolutions asking all Americans to pray for the astronauts’ safe return.
A dozen countries offered ships to help with the recovery of the astronauts after splashdown. Even the United States’ rival, the Soviet Union, put aside their differences. Soviet premier Alexei Kosygin sent a message to President Nixon: “I want to inform you the Soviet Government has given orders to all citizens and members of the armed forces to use all necessary means to render assistance in the rescue of the American astronauts.”
For four days, the world watched and waited. Would the astronauts make it back to Earth? Or would Lovell, Haise, and Swigert be the first astronauts to die in space?