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
Reducing atmosphere that sodium is reduced and evaporated to produce the sodium tail of the Moon (see atmosphere of the Moon). Reducing atmosphere A reducing atmosphere is an atmospheric condition in which oxidation is prevented by removal of oxygen and other oxidizing gases or vapours, and which may contain actively reducing gases such as hydrogen, carbon monoxide, and gases such as hydrogen sulphide that would be oxidized by any present oxygen. In metal processing, a reducing atmosphere is used in annealing ovens for relaxation of metal stresses without corroding the metal. A non oxidizing gas, usually nitrogen, is used, or for more