The mission's most dramatic twelve minutes. The Lunar Module Eagle, carrying Armstrong and Aldrin, separated from Columbia and began its descent to the surface — one that nearly ended in an emergency abort.
During the descent, the onboard computer sounded 1201 and 1202 program alarms five times — signaling computational overload. Twenty-six-year-old engineer Steve Bales in Houston made the call within seconds: the alarms could be ignored, the descent would continue. Armstrong then realized the automatic guidance was taking the module straight into a boulder field near West crater.
He took manual control and, with fuel running low, searched for level ground. The Eagle touched down at 20:17:40 UTC with only about 25 seconds of flight fuel remaining. "Houston, Tranquility Base here. The Eagle has landed," Armstrong reported. Cheers erupted in Mission Control.
From the flight transcript
"Contact light. Engine stop. Houston, Tranquility Base here — the Eagle has landed."
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