Landing in the Sea of Tranquility

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.