While nowhere near the longevity of it's brethren rovers that are still hobbling along the surface, it did serve its purpose and worked longer than was expected
November 10, 2008 -- NASA's Phoenix Mars Lander has ceased communications after operating for more than five months. As anticipated, seasonal decline in sunshine at the robot's arctic landing site is not providing enough sunlight for the solar arrays to collect the power necessary to charge batteries that operate the lander's instruments.
Mission engineers last received a signal from the lander on Nov. 2. Phoenix, in addition to shorter daylight, has encountered a dustier sky, more clouds and colder temperatures as the northern Mars summer approaches autumn. The mission exceeded its planned operational life of three months to conduct and return science data.
Some day, I would hope my grandchildren will giggle at the thought that we couldn't just fly up there over a weekend and fix something that was broke and that we had to rely on such fragile systems to get information about other planets.