Science fans were ecstatic when Neil Armstrong stepped onto the surface of the Moon in 1969, but grammar wonks were less than impressed with his famous statement: “That’s one small step for man, one giant leap for mankind.” Technically speaking, his pronouncement was redundant; “man” was the same as “mankind,” after all. NASA later reported that Armstrong’s speech had been “That’s one small step for a man,” but the word “a” had been garbled in the satellite transmission.

An Australian computer programmer, Peter Shann Ford, recently announced that he’d found the missing “a.” He downloaded Armstrong’s original recording from NASA’s official website, then used highly sophisticated software to analyze it. Ford had previously been working on a method of communication for people whose voices and bodies had been stilled by ALS (Lou Gehrig’s Disease), and had devised the NeuroSwitch, a body-to-machine interface; one that uses skin surface electrodes to pick up nerve signals that are then analyzed by artificial intelligence to activate the outcome. He used similar technology to create a graphic representation of Armstrong’s words, and confirms that “a” was both spoken by the astronaut and received by NASA in Houston.