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AKA: Solar Mesosphere Explorer. Status: Operational 1981. First Launch: 1981-10-06. Last Launch: 1981-10-06. Number: 1 . Gross mass: 437 kg (963 lb). Height: 1.70 m (5.50 ft).
It operated for seven years in the 1980's before power problems led to it being shut down.
The mission's specific goals were to examine the effects of changes in the solar ultraviolet flux on mesospheric ozone densities, the relationship between solar flux, ozone, and the temperature of the upper stratosphere and mesosphere, the relationship between ozone and water vapor, and the relationship between nitrogen dioxide and ozone. All instruments were turned off in December 1988 due to power constraints. Contact was lost on 14 April 1989 after a battery failure, and the vehicle re-entered on 5 March 1991.
The mission was managed for NASA by JPL, and was operated by the Laboratory for Atmospheric and Space Physics of the University of Colorado.
The spacecraft was spin stabilized (~5 rpm) with a fixed solar array recharging NiCd batteries. A tape recorder was used for data storage.
The payload included an ultraviolet ozone spectrometer, 1.27 micron spectrometer, nitrogen dioxide spectrometer, a four-channel infrared radiometer, a solar ultraviolet monitor, and a solar proton alarm detector.
NASA NSSDC Master Catalog Description
The Solar Mesosphere Explorer (SME) mission objective was primarily to investigate the processes that create and destroy ozone in the Earth's mesosphere and upper stratosphere. Some specific goals were to: (1) determine the nature and magnitude of changes in mesospheric ozone densities resulting from changes in the solar ultraviolet flux; (2) determine the interrelationship between solar flux, ozone, and the temperature of the upper stratosphere and mesosphere; (3) determine the interrelationship between ozone and water vapor; and (4) determine the interrelationship between nitrogen dioxide and ozone.
The satellite experiment complement consisted of a solar ultraviolet spectrometer, an ultraviolet ozone spectrometer, an infrared radiometer, a 1.27-micrometer spectrometer, and a nitrogen dioxide spectrometer. In addition, a solar proton alarm detector was carried on-board to measure the integrated solar flux in the range 30-500 MeV.
Spin stabilized at 5 rpm, the satellite moved in a 3 a.m. to 3 p.m. sun-synchronous orbit. The spacecraft body was a cylinder approximately 1.7 m x 1.25 m and consisted of two major modules: the observatory module that housed the scientific instruments, and the spacecraft bus. The spin axis was oriented normal to the orbital plane. The command system was capable of executing commands in real time or from stored program control. Power was supplied by a solar cell array. The telemetry system was used either in a real-time or in a tape-recorder mode.
All instruments on-board the SME were turned off in December 1988 because of energy considerations.
SME was developed to investigate the processes that create and destroy ozone in the Earth's upper atmosphere. All instruments were turned off in December 1988 due to power constraints. Contact was lost on April 14, 1989 after a battery failure, and the vehicle re-entered on March 5, 1991.