Upper Atmosphere Research Satellite between positions downrange, generally northeast of this position. Upper Atmosphere Research Satellite The Upper Atmosphere Research Satellite (UARS) was a NASA-operated orbital observatory whose mission was to study the Earth’s atmosphere, particularly the protective ozone layer. The satellite was deployed from Space Shuttle "Discovery" during the STS-48 mission on 15 September 1991. It entered Earth orbit at an operational altitude of , with an orbital inclination of 57 degrees. The original mission duration was to be only three years, but was extended several times. When the mission finally ended in June 2005 due to funding cuts, 14 years after the
Greenhouse and icehouse Earth years. However, this "super-greenhouse" eventually became an icehouse by the late Eocene. It was believed that the decline of CO caused this change, though there are possible positive feedbacks, or added influence that contributes to the cooling. The best record we have for a transition from an icehouse to a greenhouse period where plant life exists is during the Permian epoch that occurred around 300 million years ago. In 40 million years a major transition took place, causing the Earth to change from a moist, icy planet where rainforests covered the tropics, into a hot, dry, and windy location where