Apollo 13 returns safely after in-flight explosion

At 55 hours, 54 minutes and 53 seconds into the flight, on the evening of 13 April 1970, Jack Swigert flipped a switch to stir the cryogenic oxygen tanks of the command module Odyssey. The crew had just wrapped up a television broadcast that no network had bothered to carry live; a third Moon landing had come to feel routine. Seconds later a bang shook the spacecraft, roughly 200,000 miles from Earth. Warning lights spread across the panel, and Lovell looked out the window and reported that they were venting something out into space. The something was their oxygen.

The explosion gutted the service module and bled the command module of power and air. Within hours the landing was abandoned and the lunar module Aquarius became a lifeboat, a vehicle built to keep two men alive for two days now asked to sustain three for four. A burn after rounding the Moon shortened the trip home. The cabin temperature fell toward freezing, water was rationed, and when carbon dioxide climbed, Houston talked the crew through assembling an adapter from plastic bags, cardboard and tape so square scrubber canisters could fit a round opening.

Looping around the lunar far side on 15 April, the crew passed 400,171 kilometres from Earth, farther than any humans had ever been. The inquiry later traced the failure to oxygen tank 2, which had been dropped during ground handling years earlier and whose thermostat contacts were welded shut during a pre-flight test run at 65 volts on switches rated for 28. The damaged wiring waited through launch and two days of flight for a routine stir to ignite the tank's insulation.

On 17 April 1970, after 142 hours and 54 minutes in space, Odyssey splashed down in the South Pacific under three good parachutes and the crew was brought aboard the recovery ship USS Iwo Jima while much of the world watched. What was meant to be the third lunar landing, at Fra Mauro, instead became NASA's famous successful failure: the most celebrated rescue in spaceflight history and the sternest proof of what mission control, simulation and a calm crew could do.