Upper Atmosphere Research Satellite

Upper Atmosphere Research Satellite
Name	Upper Atmosphere Research Satellite
Mission type	Earth science
Operator	NASA
Launch date	1991-03-12
Launch vehicle	Space Shuttle Endeavour STS-41
Orbit type	Low Earth orbit
Apsis	gee

Upper Atmosphere Research Satellite

Overview

The Upper Atmosphere Research Satellite was a NASA-funded observatory developed by the Goddard Space Flight Center, built with instruments from institutions including the University of Colorado Boulder, the Laboratory for Atmospheric and Space Physics, and contractors such as Ball Aerospace and TRW. The project was approved by panels from the National Aeronautics and Space Administration, reviewed by the National Research Council, and supported by programs at the Jet Propulsion Laboratory and the European Space Agency. Designed for long-duration observation of the stratosphere, mesosphere, and thermosphere, the satellite linked measurements to campaigns involving the South Pole Station, the Mauna Loa Observatory, and experiments conducted by the NOAA and the U.S. Air Force.

Mission Objectives

Primary objectives included characterizing ozone chemistry influenced by chlorofluorocarbons studied under the Montreal Protocol, quantifying solar ultraviolet variation effects referenced in Solar Cycle 22 research, and mapping aerosol distributions connected to events like the Mount Pinatubo eruption. The mission sought to validate models used by the Intergovernmental Panel on Climate Change and to support instrument cross-calibration with platforms such as NOAA-11, UARS, and the International Ultraviolet Explorer for consistency with datasets from the Landsat and Nimbus series.

Spacecraft and Instruments

The spacecraft bus incorporated systems from Goddard Space Flight Center heritage platforms and accommodated a complement of instruments: a high-resolution spectrometer developed with the University of Colorado Boulder team, an ultraviolet monitoring assembly linked to studies by NASA Goddard, a microwave limb sounder influenced by designs at the Jet Propulsion Laboratory, and an infrared radiometer with contributions from the Laboratory for Atmospheric and Space Physics. Key payloads included instruments comparable in purpose to the Halogen Occultation Experiment and instruments like those on the Solar Mesosphere Explorer, enabling measurements of trace gases such as chlorine monoxide, nitrogen oxides, and water vapor in coordination with laboratory kinetics from California Institute of Technology and chemical modeling groups at Massachusetts Institute of Technology.

Launch and Orbital Operations

Launched aboard Space Shuttle Endeavour on mission STS-41 from Kennedy Space Center using a Canadarm-assisted deployment, the satellite entered a low Earth orbit optimized for nadir and limb sounding similar to missions like Ulysses and ERS-1. Orbital maintenance was coordinated with flight dynamics teams at the Johnson Space Center and telemetry was downlinked through the Deep Space Network infrastructure and processed at Goddard Space Flight Center facilities. Operations planning referenced standards from the Hubble Space Telescope and utilized procedures developed for the International Space Station era, scheduling instrument windows to coincide with occultation opportunities over sites such as McMurdo Station and La Réunion.

Scientific Results and Impact

Data from the mission provided high-resolution profiles of ozone depletion linked to CFC-11 and CFC-12 decline, documented polar ozone hole dynamics associated with Antarctic ozone hole studies, and constrained photochemical rates used in models by the Intergovernmental Panel on Climate Change. The satellite's observations validated hypotheses from Rowland and Molina-inspired chemistry, informed regulatory action under the Montreal Protocol and subsequent amendments, and supported climatological synthesis efforts by teams at NOAA, Met Office, and the National Center for Atmospheric Research. Cross-comparison with satellite records from ERS-2, ENVISAT, and Aqua improved long-term trend detection and helped reconcile differences with balloon-borne measurements from institutions like the Laboratoire de Météorologie Dynamique and the National Oceanic and Atmospheric Administration network.

Anomalies and Decommissioning

During its lifetime the satellite experienced anomalies that required intervention by operations specialists at Goddard Space Flight Center and contingency teams at the Johnson Space Center; troubleshooting leveraged expertise drawn from failure investigations like those for Challenger-era hardware and the Hubble Space Telescope commissioning. Following degradation of attitude control and power influenced by prolonged exposure in Low Earth orbit, mission managers coordinated a controlled decommissioning consistent with guidelines from the Federal Aviation Administration and space environment policy discussed at United Nations Office for Outer Space Affairs meetings. The satellite was passivated and placed into a disposal profile informed by debris mitigation practices from European Space Agency studies and has since been referenced in archival analyses at the National Archives and ongoing synthesis projects at the Smithsonian Institution.

Category:NASA satellites Category:Earth observation satellites