UARS was launched by Shuttle in September, 1991. In August it suffered a shorted cell in Battery 2, one of the two operational batteries. A shorted cell meant that they could only partially charge the batteries without dangerously heating the electrolyte--a condition that could result in the formation of hydrogen gas. This was a pre-defined event that triggered the "end of mission." UARS could no longer collect enough data, from enough instruments to justify the expense of maintaining the satellite. Other, newer earth-observing systems are "taking up the slack," but those of us who worked on UARS will miss her. That bird kept on flying, kept on delivering the goods.
It was my great privilege to serve as a UARS satellite systems enginer from March 1998 to March 1999. Although I'm again supporting an important, "24-7," mission-critical system, I'm not sure anything can take the place of being responsible for the "care and feeding" of an operational satellite system.