On this day in 1970, NASA’s Apollo 13 launched from the Kennedy Space Center in Cape Canaveral, Florida. It was the seventh manned mission to the moon in the Apollo space program and the third lunar landing attempt. And it nearly ended in tragedy after an oxygen tank exploded on board mid-mission, causing the second oxygen tank to fail as well.
The explosion happened at 9:08 p.m. EST on April 13, roughly 56 hours into the excursion. Commander James A. Lovell Jr., lunar module pilot Fred W. Haise Jr. and command module pilot John L. Swigert were left without an adequate supply of oxygen, electricity, light and water, per History.com.
It was then that Swigert uttered the immortal line, “Houston, we’ve had a problem.”
Their Command Module began leaking oxygen and fuel. So the crew had to move to the Lunar Module, which did have oxygen. Unfortunately, the Lunar Module was just supposed to get them from the Command Module to the moon’s surface and back. So it only had enough power to support two people for 45 hours.
To get back to Earth, the crew needed it to support three people for 90 hours.
Apollo 13 Nearly Didn’t Make It Home
According to NASA, about13 minutes after the explosion rocked the spacecraft, Lovell glanced out the window and noticed something chilling.
“We are venting something out into the… into space,” he said. They soon realized it was the last of the oxygen escaping out into space.
There were just 15 minutes of power left in the Command Module when Houston instructed the crew to move to the Lunar Module. To make it back, they’d have to save energy and supplies. They rationed their water to 1/5 normal levels and tolerated cabin temperatures a few degrees above freezing.
The Lunar Module’s navigational system was a problem, too. The astronauts had to calculate by hand the propulsion and direction changes necessary to steer the craft back to Earth.
Moreover, the crew had to execute a tricky maneuver after they rounded the far side of the moon. They used the sun as an alignment point and then burned the Lunar Module’s small descent engine for five minutes to give the craft enough speed to get back before it ran out of power.
The Journey Back
After days of near-freezing temperatures during which they were unable to sleep, the astronauts approached Earth. They then had to power up the Command Module again. Flight controllers back home had developed the plans for this procedure over three days instead of the three months it would normally take.
When the crew finally splashed down in the Pacific Ocean near Samoa, it was April 17. Haise had come down with the flu, but the three astronauts were otherwise fine.