https://medium.com/softwares-giant-leap/the-software-that-saved-apollo-11-4fb37dfad652

This story is Part 1 of the Software’s Giant Leap Series

While Neil Armstrong was taking his first small steps onto the Moon, a group of software engineers in Cambridge, MA were frantically debugging two alarms triggered during the Apollo 11 landing sequence. NASA wanted to know what had gone wrong and needed an answer before the Lunar Module (LM) was scheduled to lift off the Moon’s surface only a few hours later.