Atmosphere of Earth International Space Station orbits in this layer, between . The mesosphere is the third highest layer of Earth's atmosphere, occupying the region above the stratosphere and below the thermosphere. It extends from the stratopause at an altitude of about to the mesopause at above sea level. Temperatures drop with increasing altitude to the mesopause that marks the top of this middle layer of the atmosphere. It is the coldest place on Earth and has an average temperature around . Just below the mesopause, the air is so cold that even the very scarce water vapor at this altitude can be
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