On November 14th, 1969, four months after the captivating success of Apollo 11, America was set to return to the moon with Apollo 12. Though murky clouds that occasionally poured spats of light rain concealed the sun's cheery light, the spirits of the eager onlookers who came to Cape Canaveral that day to witness a repeat of history weren't dampened in the least. While the atmosphere in the skies was downcast, the ambiance on the ground was enthusiastic.
Firmly fastened to their seats within the command module "Yankee Clipper," Astronauts Charles "Pete" Conrad, Alan Bean, and Richard Gordon were excited, too. Following a renowned NASA countdown, 10... 9... 8... 7... 6... 5... 4... 3... 2... 1..., they blasted off from the launchpad at 11:22 A.M. EST.
However, 36.5 seconds into the flight, about a mile and a half up, the crew experienced a flash of white light and a jolt. Though the astronauts didn't fully realize it yet, their craft had been struck by lightning.
Sixteen seconds later, at an altitude of about three and a half miles, a second bolt of lightning rattled the ship. Amidst a clamor of flashing lights and alarm sounds, commander Charles Conrad radioed down to mission control in Houston.
"Okay, we just lost the platform gang. I don't know what happened here. We had everything in the world drop out."
Things were not looking good. The power in the command module had completely failed, overloaded by the two lightning strikes. Battery backups had come online, but would only last for a couple hours. To make matters worse, all of the vessel's systems had crashed. Down in Houston, mission control was receiving nonsensical telemetry. Something had to be done fast or the mission would have to be aborted.
Luckily, swift thinking came from 24-year-old environmental control engineer, John Aaron. Remembering that there was an obscure, almost never used switch in the command module that would put the systems on an auxiliary setting, he recommended to flight director Gerry Griffin, "Switch SCE to AUX."
A quizzical look on his face, Griffin's initial response was, "What's that?" But after a quick explanation from Aaron, he relayed the recommendation to capsule communicator Gerry Carr. Carr dutifully delivered the command to the astronauts, even though he didn't understand what he was telling them to do. "Apollo 12, Houston, try SCE to Auxiliary, over."
Up in the command module, now over ten miles up, Bean flipped the switch. Power instantly came back online and the computer systems started rebooting. The mission was saved. Though his heart was still anxiously racing, Conrad managed a joke.
"I think we need to do a little more all-weather testing."
Further weather testing wouldn't be necessary, as the event prompted NASA to impose launch restrictions that effectively eliminated the risk of a lightning strike ever happening again.
Today, the most likely explanation for Apollo 12's shocking launch is that the clouds through which the spacecraft flew contained significant amounts of electrical charge. When the rocket penetrated those clouds, it acted as an electrical conductor, thus enlarging the size of the cloud's electrical field. Once the electrical field grew too large, it broke down, triggering a discharge akin to natural lightning. Supporting evidence for this theory comes from the fact that each bolt of lightning traveled down through the rocket's ionized exhaust plume all the way to the landing platform.
Sources: Universe Today, Vintage Space, Aerospace Web, NASA
(Image: Apollo 12 Lightning bolt via NASA)