The Mio orbiter payload is constituted of a set of instruments for plasma, field, and particle measurement to study the processes coupling Mercury's surface's, magnetosphere, and solar wind.
The different instrument sub-systems are:
- One instrument set to measure charged particles (MPPE, Mercury Plasma Particle Experiment) constituted of:
- two electron spectrometers: MEA (Electron Spectrum Analyzer)
- a Mass Spectrum Analyzer (MSA)
- a Solar Wind Analyzer (MIA)
- a High Energy Electron Instrument (HEP-e)
- a High Energy Ion Instrument (HEP-i)
- one Energetic Neutral Atom Analyzer (ENA)
- Two three-axis sensors to measure the magnetic field: MGF (Magnetic Field Sensor)
- One instrument set to measure plasma waves (PWI, Plasma Wave Investigation) constituted of:
- two dipole antennas: WPANT (Wire Probe Antenna)
- one double probe antenna: MEFISTO (Mercury Electric Field In Situ Tool)
- one electric field analyzer: EWO
- one sensor to measure the magnetic field components along 3 axes: SC (Search Coil sensor)
- one instrument to measure active plasma: AM²P
- one spectrometer to measure radio waves and thermal electrostatic noise: SORBET
- One dust detector: MDM (Mercury Dust Monitor)
- One imaging spectrometer for the exosphere: MSASI (Mercury Sodium Atmosphere Imager).
The allocations of this payload are a mass limited to 40 Kg and a power of 53 W.