Upper Atmosphere Research Satellite 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 satellite's launch, six of its ten instruments were
Atmospheric carbon cycle lifetime of about eight years. This keeps the concentration of methane in the atmosphere relatively low and is the reason that it currently plays a secondary role in the greenhouse effect to carbon dioxide, despite the fact that it produces a much more powerful greenhouse effect per volume. Carbon dioxide () has a large warming effect on global temperatures through the greenhouse effect. Although individual CO molecules have a short residence time in the atmosphere, it takes an extremely long time for carbon dioxide levels to sink after sudden rises, due to e.g. volcanic eruptions or human activity and among