Mars Observer and Mars Global Surveyor

The Mars Observer was the first NASA unmanned mission to Mars after the Viking Mission concluded in the 1980s. Mars Observer was launched on September 25, 1992, designed as an orbiter. All went well until 3 days to arrival of Mars, communications with the craft was lost. With the failure of the Mars Observer was followed another long period of waiting till November 7, 1996 the Mars Global Surveyor was launched. The Mars Global Surveyor was the predecessor of the Mars Observer, built basically to offer a rapid, low cost recovery to the Mars Observer objectives. After its successful launch, the spacecraft reached Mars on September 12, 1997, and began its orbit. Though its primary mapping mission was delayed to March 1999 due to certain difficulties, all else went well and the many advanced and sophisticated instruments on board, such as the thermal emission spectrometer, began work. Even now, it is still in orbit around Mars mapping its surface.