Opportunity's and Spirit's original missions were planned to last 90 Martian days each. They ended up lasting over 8,000 combined. That is almost as impressive as getting the rovers to Mars in the first place.
I remember talking to a high up on the program at a FIRST robotics event who complained about them running so long. They weren't making any major new discoveries and sucking up resources and mindshare stopping him for kicking off and focusing on new projects. He said nobody would take the PR hit to decide to just end a mission like this so he was stuck.
Not surprising at all. Coached a FIRST team for several years. At this point they sell licensed robotics kits with canned instructions for kids to put together and those kids win because of time limitations. The teams that build from scratch and actually contribute discover or learn anything at all are intentionally blocked from winning. The entire program is total crap for retarded children. Meanwhile smart kids are off doing their own projects that are 1000x as complicated as the most challenging FIRST challenges. It's just turned into a money burn.