Imagine that you're the captain of an airliner, cruising at 40,000 feet, when you experience an explosive decompression. What do you do next to get back on the ground?
While NASA's baseline 2015 budget request shows no funding for the long-running Mars mission past 2015, NASA says Opportunity could continue if extra funds become available.
Once in awhile, it happens; but all flight decks are staffed by two equally trained and highly capable pilots, removing any cause for concern by the public.