THE UPPER-ATMOSPHERE RESEARCH SATELLITE (UARS) MISSION

The Upper Atmosphere Research Satellite (UARS) is a NASA program aimed at improving our knowledge of the physical and chemical processes con trolling the stratosphere, mesosphere, and lower thermosphere, emphasi zing those levels that are known to be particularly susceptible to cha nge by human activities. The spacecraft was launched by the Space Shut tle Discovery on September 12, 1991, into a near-circular orbit at 585 km altitude and 57-degrees inclination. Measurements include vertical profiles of temperature, many trace gases, and horizontal wind veloci ties, as well as solar energy inputs. Many of the limb-scanning instru ments can measure to as high as 80-degrees latitude, providing near-gl obal coverage. The mission is supported by a large international corre lative measurement program, yielding data both for validation of the U ARS measurements and for complementary scientific studies. A dedicated data system provides rapid processing to geophysical quantities and m akes these data available to UARS scientists.