December 10, 2023

Mio Instruments

The Mio orbiter payload consists of a set of instruments for plasma, field and particle measurement to study the processes coupling Mercury's surface, magnetosphere and the solar wind.

The instrument subsystems are:

  • An instrument suite to measure charged particles (MPPE, Mercury Plasma Particle Experiment) comprising:
      • two Electron Spectrum Analyzers (MEA)
      • a Mass Spectrum Analyzer (MSA)
      • a Solar Wind Analyzer (MIA)
      • a High Energy Particle Instrument for electrons (HEP-e)
      • a High Energy Particle Instrument for ions (HEP-i)
      • an Energetic Neutral Analyzer (ENA)


  • Two three-axis Magnetic Field Sensors (MGF)
  • A set of instruments to measure plasma waves (PWI, Plasma Wave Investigation) comprising:
      • two dipole antennas: WPANT (Wire Probe Antenna)
      • a double probe antenna: MEFISTO (Mercury Electric Field In Situ Tool)
      • an electric field analyser: EWO
      • a sensor to measure the magnetic field components along three axes: SC (Search Coil)
      • an instrument to measure active plasma: AM²P
      • a spectrometer to measure radio waves and thermal electrostatic noise: SORBET (Spectroscopie Ondes Radio and Bruit Electrostatique Thermique)


  • A dust detector: MDM (Mercury Dust Monitor)
  • An imaging spectrometer for the exosphere: MSASI (Mercury Sodium Atmosphere Imager).


The mass and power allocations for this payload are limited to 40 Kg and 53 W.