BackForwardInstrument:  HYDRA 

Instrument details
Acronym HYDRA
Full name Hot Plasma Analyzer Experiment
Purpose To study low-energy electrons in the global magnetic topology; and to study electron and ion signatures that accompany geomagnetic substorms, auroral arcs, field-aligned currents, and particle precipitation
Short description Assemblage of electrostatic analyzers measuring electrons in the energy range 0.001-30 keV and light ions (Z from 1 to 8) in the energy/mass range 0.001-30 keV/n, simultaneously in 12 directions; and a Parallel Plate Analyzer (PPA) to image electrons in the energy range 0.01-10 keV
Background Part of a package of instruments to explore the Magnetosphere
Scanning Technique Travelling cross the Magnetosphere in a highly-elliptical orbit
Resolution N/A
Coverage / Cycle Nearly full magnetospheric volume
Mass Power Data Rate

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1996 to 2008-04-15
Last update: 2017-06-05
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
  • Energetic particle spectrometer
Mission objectives
Primary mission objectives
  • Alpha particles differential directional flux
  • Electron differential directional flux
  • Heavy ion angular flux energy and mass spectrum
  • Heavy ion flux energy and mass spectrum
  • Proton differential directional flux
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Tentative 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
VariableRelevance for measuring this variableOperational limitationsExplanation
Electron differential directional flux2 - very highNo specific limitation.Magnetosphere, low energy (up to 40 keV)
Proton differential directional flux2 - very highNo specific limitation.Magnetosphere, low energy (up to 40 keV)
Alpha particles differential directional flux4 - fairNo specific limitation.Cross-magnetosphere. Low-medium energy range (<10 up to 100 MeV/n)
Heavy ion flux energy and mass spectrum2 - very highNo specific limitation.Cross-magnetosphere. Low-medium energy range (<10 up to 100 MeV/n)
Heavy ion angular flux energy and mass spectrum2 - very highNo specific limitation.Cross-magnetosphere. Low-medium energy range (<10 up to 100 MeV/n)