Apollo 11: Mission Out of Control | WIRED

Despite his months of simulations, Aldrin didn’t know what this one meant; Armstrong, equally baffled, radioed Mission Control for clarification. The stress in his voice was audible, but only later would the two men learn how bad things really were. In that critical moment, hurtling like a lawn dart toward the surface of the moon, the Apollo guidance computer had crashed.

Source: Apollo 11: Mission Out of Control | WIRED