When Apollo 12 was Struck by Lightning
Video from the channel The Vintage Space about Apollo 12, linked on its Above Ten Thousand entry. Duration: 5:55. Language: English. Video type: Documentary.
What it's about
A look back at the best-known incident of the Apollo 12 launch: the two lightning strikes that hit the Saturn V during ascent, and the reaction of the crew and mission control, illustrated with onboard audio.
Historical context
Apollo 12 launched on November 14, 1969 on a cold, rainy and overcast day in Florida, something unheard of for previous Apollo launches, yet postponement was never considered. Passing through electrically charged clouds, the rocket and its exhaust trail acted as a lightning rod. Pete Conrad, Alan Bean and Dick Gordon did not see the strikes, but they did see their effects: both in the cabin and in mission control, telemetry turned into a chaos of meaningless data.
Highlights
John Aaron, the EECOM with 24 years of service at the time of the launch, recognized the pattern: he had seen it in a simulation years earlier, when a voltage drop had thrown off the signal conditioning equipment (SCE), which translates sensor readings for the spacecraft's and ground's displays. In its auxiliary position, that equipment runs on low voltage, so he asked flight director Gerry Griffin to have the crew switch the SCE to AUX. Almost no one knew where the switch was except Alan Bean; flipping it brought telemetry back, there was no abort, and the mission continued toward the Moon.