Voyager

"The popular version of this story has hardened into a fixed shape."https://spacedaily.com/nasa-still-maintains-some-of-the-voyager-spacecraft-code-in-a-1970s-era-programming-language-that-almost-nobody-on-earth-fully-understands-anymore-and-the-handful-of-engineers-who-do-are-now-in-their/