| Solar Mesosphere Explorer | |
| Names List: | Explorer 64 Solar Mesosphere Explorer |
| Mission Type: | Earth observation |
| Operator: | NASA / LASP |
| Cospar Id: | 1981-100A |
| Satcat: | 12887 |
| Mission Duration: | 7.5 years (achieved) |
| Spacecraft: | Explorer LXIV |
| Spacecraft Type: | Solar Mesosphere Explorer |
| Spacecraft Bus: | SME |
| Manufacturer: | Ball Space Systems |
| Dimensions: | Cylinder: diameter by high |
| Power: | Solar panels and nickel-cadmiumd batteries |
| Launch Date: | 6 October 1981, 11:27 UTC |
| Launch Rocket: | Thor-Delta 2310 (Thor 639 / Delta 157) |
| Launch Site: | Vandenberg, SLC-2W |
| Launch Contractor: | Douglas Aircraft Company |
| Entered Service: | 6 October 1981 |
| Deactivated: | 31 December 1988 |
| Last Contact: | 4 April 1989 |
| Decay Date: | 5 March 1991 |
| Orbit Reference: | Geocentric orbit |
| Orbit Regime: | Low Earth orbit |
| Orbit Inclination: | 97.56° |
| Orbit Period: | 95.50 minutes |
| Apsis: | gee |
| Instruments: | Ultraviolet ozone spectrometer Micrometer spectrometer Nitrogen dioxide spectrometer Four-channel infrared radiometer Solar ultraviolet monitor Solar proton alarm detector |
| Programme: | Explorer Program |
| Previous Mission: | Dynamics Explorer 2 (Explorer 63) |
| Next Mission: | AMPTE-Charge Composition Explorer (Explorer 65) |
The Solar Mesosphere Explorer (also known as Explorer 64) was a NASA spacecraft to investigate the processes that create and destroy ozone in Earth's upper of the atmosphere of Earth. The mesosphere is a layer of the atmosphere extending from the top of the stratosphere to an altitude of about . The spacecraft carried five instruments to measure ozone, water vapor, and incoming solar radiation.
Explorer 64 studied the processes that create and destroy ozone in the Earth's mesosphere. Over its 7.5 years mission, SME measured ultraviolet solar flux, ozone density, and the density of other molecules important to the understanding of ozone chemistry. During the mission over one hundred undergraduate and graduate students were involved in nearly every aspect of SME operations, including planning and scheduling spacecraft and science activities, controlling the spacecraft and its ground support system, and analyzing spacecraft subsystem performance.
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 Boulder.[1]
Characteristics:[2]
Launched on 6 October 1981, on a Thor-Delta 2310 from Vandenberg Air Force Base, in California, the satellite returned data until 4 April 1989.[2]
The spacecraft reentered Earth's atmosphere on 5 March 1991.[2]