Astronauts Pete Conrad, Alan Bean, and Richard Gordon were ready to head to the Moon. Rain and heavy clouds hung over their launch pad, but engineers decided they wouldn’t be a problem. So Apollo 12 headed skyward 50 years ago today.

LAUNCH CONTROL: 3, 2, 1, zero, all engines running! Commit, lift off! We have a lift off!

Seconds later, though, something went wrong.

APOLLO 12: What the hell was that? I lost a whole bunch of stuff.

Mission Control lost data, and the systems in the spacecraft went haywire.

APOLLO 12: Okay, we just lost the platform gang. I don’t know what happened, we had everything in the world drop out. ...Fuel cell lights, an A/C bus light, a fuel cell disconnect, A/C bus overload 1 and 2, main bus A and B out.

Without guidance and power, the crew might have had to abort. But 26-year-old flight controller John Aaron saved the day by recommending that the crew flip a little-known switch.

MISSION CONTROL: Apollo 12, Houston. Try S-C-E to auxiliary, over.

That reset the power, allowing the flight to continue. A bit later, Pete Conrad deduced what had happened:

CONRAD: We’re okay now. We’ve straightened out our problems here. I don’t know what happened. I’m not sure we didn’t get hit by lightning.

Lightning had indeed zapped the craft. But quick work by Mission Control and the astronauts overcame the problem — allowing Apollo 12 to make the second landing on the Moon. More about that next week.

Script by Damond Benningfield