> because a defense contractor used [US customary] units That is a common but very limited evaluation of what happened. The contractor ignored the specificatio

> because a defense contractor used [US customary] units That is a common but very limited evaluation of what happened. The contractor ignored the specifications, no proper testing was done to make sure their component would do what it was supposed to before launch, and when someone noticed the issue in-flight they were ignored due to the bureaucratic process until it was too late. The exact same issue would have happened entirely in metric units if one side used CGS and the other used MKS.