BackForwardInstrument:  RPS 

Instrument details
Acronym RPS
Full name Relativistic Proton Spectrometer
Purpose To measure energy spectra and angular distributions of protons from 50 MeV to 2 GeV (expect full inner-zone spatial distributions with better-than-weekly cadence)
Short description Assemblage of 8 silicon detectors for energies up to 400 MeV, and one Cherenkov detector for energies > 400 MeV
Background Part of a package of instruments moving across the Van Allen belts in the Magnetosphere
Scanning Technique 2 satellites moving to different positions into the Magnetosphere in a low-inclination HEO
Resolution N/A
Coverage / Cycle Large fraction of magnetosphere and ionosphere
Mass 20.9 kg Power 22.5 W Data Rate 32.2 kbps


Providing Agency NASA
Instrument Maturity Backed by strong heritage
Utilization Period: 2012 to 2019
Last update: 2021-10-02
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
WIGOS Subcomponents
  • Subcomponent 2
  • Magnetospheric energetic particles and magnetometers
  • Proton sensor [cross magnetosphere]
Mission objectives
Primary mission objectives
  • Proton differential directional flux
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.
VariableRelevance for measuring this variableOperational limitationsExplanation
Proton differential directional flux*1 - primaryNo specific limitation.Cluster flown through the magnetosphere, high energy (over 1000 keV)