You are thinking of the Mars Climate Orbiter crash: https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure https://en.wikipedia.org/wiki/Mars_Clim

You are thinking of the Mars Climate Orbiter crash: https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_...