Apollo 13 splashes down in the Pacific Ocean, recovering from a barely survivable explosion in space.
Apollo 13 was supposed to be the third manned lunar landing (see here). But an oxygen tank exploded 200,000 miles from Earth. The astronauts’ supplies of air, water, and electricity were imperiled. Astronaut John Swigert radioed Mission Control: “Houston, we’ve had a problem here”—not the Apollo 13 movie’s “Houston, we have a problem.” NASA decided to scrap the lunar landing and have the astronauts swing around the moon and return home, using the lunar module (LM) as a lifeboat.
Oxygen: Plenty was available from LM tanks that would have supplied liftoff from the moon’s surface.
Electricity: Noncritical systems were turned off, reducing power consumption to one-fifth normal. But capsule temperature dropped to 38 degrees F.
Water: The crew conserved water by drinking little and eating only wet foods. They became severely dehydrated, losing about ten pounds each.
Carbon dioxide removal: The LM didn’t have enough capacity, so Mission Control had the astronauts build a pipeline to the command module (CM) with plastic bags, cardboard, and tape that NASA had wisely placed on board.
Getting home: The navigation system was transferred to the LM, but precise realignment was essential because too steep a reentry angle would cause the CM to burn up in the atmosphere. Too tangential an angle could skip the module out into space forever. Fire or ice. After four days of alternating terror and hope, the three astronauts climbed back to the CM for reentry an hour before splashdown. Everything worked out.
A review board later determined the cause of the explosion: Oxygen-tank heaters had been upgraded, but the heater switches hadn’t. NASA also found that other warning signs had been ignored, and the oxygen tank was no longer a potential bomb but a real one.—RA