The original space shuttle, back in the late '70s, was so difficult to fly, that on-board computers did the actual flying. There were 4 computers that had to be in agreement before they took action on some directive from the pilot. Computer actions were compared between the 4 computers before the directive was acted upon. If one of the computers was significantly "off," it's instructions were overridden by the other 3.

"Gee, I guess I aimed at the wrong guy."