Solar Mesosphere Explorer


Solar Mesosphere Explorer
Solar mesosphere explorer.gif
Mission typeEarth observation
COSPAR ID1981-100A
SATCAT no.12887
Mission duration~7 years
Spacecraft properties
ManufacturerJet Propulsion Laboratory
Launch mass437 kg (963 lb)
Start of mission
Launch dateOctober 6, 1981, 11:27 (1981-10-06UTC11:27Z) UTC
RocketDelta 2310
Launch siteVandenberg AFB SLC-2W
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude535.0 kilometers (332.4 mi)
Apogee altitude551.0 kilometers (342.4 mi)
Inclination97.5589 degrees
Period95.50 minutes
RAAN138.8452 degrees
Argument of perigee259.5734 degrees
Mean anomaly100.6126 degrees
Mean motion16.36783794
Epoch5 March 1991, 04:02:01 UTC
Revolution no.205
Ultraviolet ozone spectrometer
1.27 micrometer spectrometer
nitrogen dioxide spectrometer
four-channel infrared radiometer
solar ultraviolet monitor
solar proton alarm detector

The Solar Mesosphere Explorer (also known as Explorer 64) was a U.S. uncrewed spacecraft to investigate the processes that create and destroy ozone in Earth's upper atmosphere. The mesosphere is a layer of the atmosphere extending from the top of the stratosphere to an altitude of about 80 km (50 mi). The spacecraft carried five instruments to measure ozone, water vapor, and incoming solar radiation.

Launched on October 6, 1981, on a Delta rocket from Vandenberg Air Force Base, in California, the satellite returned data until April 4, 1989. The spacecraft reentered Earth's atmosphere on March 5, 1991.

Managed for NASA by the Jet Propulsion Laboratory, the Solar Mesosphere Explorer was built by Ball Space Systems and operated by the Laboratory for Atmospheric and Space Physics of the University of Colorado where one hundred undergraduate and graduate students were involved.[1]

  • Mass: 437 kilograms (963 pounds)
  • Power: Solar panels which charged NiCad batteries
  • Configuration: Cylinder 1.25 meter (4.1 ft) diameter by 1.7 meter (5.6 ft) high
  • Science instruments: Ultraviolet ozone spectrometer, 1.27 micrometre spectrometer, nitrogen dioxide spectrometer, four-channel infrared radiometer, solar ultraviolet monitor, solar proton alarm detector


  1. ^ SME: Solar Mesosphere Explorer, University of Colorado at Boulder, "Archived copy". Archived from the original on 2007-07-13. Retrieved 2007-09-27.CS1 maint: archived copy as title (link)

External links

  • JPL - Solar Mesosphere Explorer
  • Launch video
  • Nitric Oxide measurements results
  • Daily Solar Irradiance results