most mars missions have ended in some kind of ultimate failure, but the last few have been extremely successful. Spirit and Opportunity both lasted years beyond their scheduled missions, hopefully Curiosity will also outlive its time frame in the same way. just the fact that they managed to "stick the landing" using such a risky method makes me hope that NASA can finally get some better funding to continue this kind of research, because this was by far the biggest accomplishment since landing on the moon.