Apollo 13: How a Wrecked Spacecraft Brought Its Crew Home

Apollo 13 lifted off on April 11, 1970, with Jim Lovell, Jack Swigert and Fred Haise aboard. Just under 56 hours later, at 55 hours 53 minutes 18 seconds, a tank explosion ended the Moon landing and turned the flight into a fight to return home. How did the crew and Mission Control get three men back from about 200,000 miles away?

A mission few were watching

Apollo 13 was to bring back rock and soil samples from a hilly region of the Moon, a trickier landing site than earlier missions. Swigert and Haise were both on their first spaceflight. Launch was scheduled for 1:13 p.m., or 1313 in military time. During liftoff one engine in the second stage shut down early, but controllers judged the mission good to go. About 2 hours 35 minutes after liftoff the ship fired its rockets, reached 24,000 mph and left Earth orbit for the Moon. A live TV show at 55 hours 11 minutes was carried by none of the networks.

The explosion

Mission Control asked the crew to stir the two tanks of super-cooled liquid oxygen with a fan and heater. Swigert flipped the switch, and a bang followed. Haise, known for banging a valve in the lunar module, was in the tunnel and heard metal crinkling. Lovell then reported: "Houston, we've had a problem." On the ground the data went wild and for about 60 seconds controllers saw problems at every console. Lovell saw one oxygen tank gauge read zero, the other falling, and gas escaping from the rear of the spacecraft. It was later learned that faulty wiring inside tank 2 produced a spark when the tank was stirred, starting an oxygen-fed fire that blew up the tank and took out the main air and power supplies.

The lifeboat

The Command Module would run out of oxygen within minutes, so Lovell ordered Swigert to power it down and the crew moved into the lunar module, which had its own air, water and battery power but could not re-enter the atmosphere. Only the Command Module had a heat shield, so its small battery and oxygen tank were saved for the final plunge. Data was copied by hand from one computer to the other using a conversion table, and Mission Control checked the arithmetic.

The long way home

Flight director Gene Kranz rejected a direct abort, which would have meant using the main engine nearest the explosion and could have sent the ship into the Moon if it failed. The alternative was around the Moon in four to five days, in a lunar module designed for two men for two days. The ship rounded the far side 21 hours after the explosion.

Systems were shut down to save power, and the cabin got as cold as a refrigerator. Food and water froze, and the crew slept in short snatches. Around 30 hours after the explosion carbon dioxide became a threat. The Command Module's square filters did not fit the lunar module's round openings, so engineers designed an adapter from part of a flight manual, plastic bags and duct tape. The crew also stopped dumping urine overboard because it could change the course. Haise developed an infection and fever.

Course correction and restart

Nearly four days in, controllers found the ship drifting toward an atmosphere entry that was too shallow. The crew fired the engine manually, steering by sighting the Earth and Moon through the windows, with Swigert timing the burn because the clock had stopped. On April 17th the Command Module was restarted on battery power using a checklist of over 500 steps written on torn checklist covers. The service module was jettisoned at 138 hours 2 minutes 8 seconds, showing a whole panel blown out. The lunar module, nicknamed Aquarius, was released next.

Re-entry

During re-entry a fireball of 5,000 degrees blacked out radio for an expected 4 minutes. Contact came 1 minute 27 seconds later than expected, with Swigert's "Hope Houston standing by". Apollo 13 splashed down in the South Pacific after nearly 6 days in space.

The video states that no humans have ventured farther from home since.