On July 6th, the European Space Agency (ESA) and JAXA (Japan Aerospace Exploration Agency) officially presented their first mission towards Mercury: BepiColombo, with two probes called Mercury Planetary Orbiter (MPO) and Mercury Magnetospheric Orbiter (MMO). The mission will be launched on October 19, 2018 at the Guyana Space Center, Kourou (October 20 European time). The probes will arrive at Mercury in December 2025.

3 plasma physics labs from the Paris region – LESIA, LPP & LATMOS – were highly involved in preparing this mission, especially in the instrumental part!

Photo credit: ESA

BepiColombo’s main goals

Mercury still has a lot of secrets for scientists. Previous missions such as Messenger and Mariner 10 discovered some important phenomena on Mercury such as polar ice, surprising blue hollows, volcanic mechanism… BepiColombo is going further thanks to 2 probes which will provide more accurate information: MMO will study the magnetosphere and its interaction with the Solar Wind and MPO will study the magnetosphere close to Mercury, the surface, the atmosphere and the interior of Mercury!

Short explanation on Youtube

Contribution of LPP – Laboratoire de Physique des Plasmas (UMR 7648 Sorbonne Université, CNRS, École Polytechnique, Université Paris-Sud, Observatoire de Paris)

The LPP (Laboratoire de Physique des Plasmas) is contributing to 2 experiments onboard the MMO probe and that are parts of two consortia: Plasma Wave Instrument (PWI) and Mercury Plasma Particle Experiment (MPPE).

     - The MSA (Mass Spectrum Analyzer) is an instrument dedicated to measurements of the plasma composition. Its main goals are : the study of the solar wind and of the material ejected from Mercury’s surface, the study of ion transport and acceleration in the magnetosphere, and the study of the interaction of the magnetospheric plasma with the planet surface and exosphere.

     - The dual-band search coil magnetometer - DB-SC (Double Band - Search Coil)  will measure high frequency fluctuations (waves) of the magnetic field. It will perform measurements of the B vector of electromagnetic waves in the low frequency band as well as measurements of an electromagnetic wave component in the high frequency band.


Flight models of MSA (left) and Search-coil (right, DBSC is along the Z-axis) of BepiColombo

Contribution of LESIA – Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique (UMR 8109 Sorbonne Université, CNRS, Observatoire de Paris)

The LESIA (Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique) developed 2 instruments: the first one for the SIMBIO-SYS instrument onboard the MPO probe and the other one for the Plasma Wave Instrument (PWI) onboard the MMO probe.

     - VIHI (Visual and Infrared Hyper-spectral Imager) is an imaging spectrometer which will allow to achieve a complete and unique mapping of surface minerals thanks to an unprecedented spatial and spectral resolution. This information will help understanding the processes of differentiation and heating that contributed to the formation of Mercury.

     - SORBET (Spectroscopie des Ondes Radio et du Bruit Electrostatique Thermique) is a high-frequency radio wave receiver that will measure for the first time the density and temperature of the plasma in the Mercury environment (solar wind, magnetosphere and exosphere). SORBET will also be able to detect and study radio emissions from Mercury and to monitor solar radio emissions up to 10 MHz.

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SIMBIO-SYS instruments (left):
High Resolution Imaging Channel (HRIC), STereo Channel (STC), Visible Infrared Hyperspectral Imager (VIHI)

High-frequency radio wave SORBET (right). Credits : LESIA, Observatoire de Paris

Contribution of LATMOS - Laboratoire Atmosphères, Milieux, Observations Spatiales (UMR 8190 Sorbonne Université, CNRS, Université Versailles Saint-Quentin)

The LATMOS (Laboratoire Atmosphères, Milieux, Observations Spatiales) also contributed to this mission with the spectrometer PHEBUS and a neutral and ion spectrometer PICAM that is part of the Search for Exospheric Refilling and Emitted Natural Abundances (SERENA) consortium. Both instruments are accommodated on the MPO probe.

     - PHEBUS (Probing of Hermean Exosphere By Ultraviolet Spectroscopy) is a dual optical spectrometer covering spectral ranges from extreme ultraviolet (EUV: 55-155 nm) to far ultraviolet (FUV: 145-315 nm). PHEBUS aims at characterizing the Mercury exosphere in terms of composition and dynamics, and the relationships between the surface and the exosphere.

     - PICAM (Planetary Ion CAMera) is an ion mass spectrometer operating as an all-sky camera for charged particles to study the chain of processes by which neutrals are ejected from the regolith, eventually ionized and transported through the environment of Mercury. PICAM’s detector and optics has been jointly developed by LATMOS and LPP.


Dual optical spectrometer PHEBUS (left):

Mass spectrometer PICAM (right):

More information about the BepiColombo mission here (in French)