BackForwardInstrument:  SME (SPA) 

Instrument details
Acronym SME (SPA)
Full name SME - Solar Proton Alarm
Purpose The Solar Proton Alarm Detector monitored the integrated solar proton flux in the 30 to 500 MeV range. When the flux exceeded a selected commandable value, the instrument signaled an opportunity to alter science commands to observe the effects of solar protons on atmospheric constituents.
Short description
Background Part of the NASA space weather measurement programme.
Scanning Technique N/A
Coverage / Cycle N/A
Mass Power Data Rate


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1981 to 1989
Last update: 2023-05-15
Detailed characteristics
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Solar and space environment monitors
  • Solar activity monitor
WIGOS Subcomponents
  • Subcomponent 1
  • In-situ plasma probes, and energetic particle spectrometers and magnetometers at GEO and LEO, and magnetic field at GEO
  • Proton sensor at LEO
Mission objectives
No mission objectives have been defined.
Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
Note: * Primary mission objective.