HORIBA diffraction gratings help to observe Mercury planet with BepiColombo mission


Artist's rendering of BepiColombo spacecraft
Credits: ESA


The BepiColombo mission, co-developed by the European Space Agency (ESA) with the Japanese Aerospace Exploration Agency (JAXA) was launched on October 20th 2018. Its goal is to explore and better understand the planet Mercury.

Two orbiters will be placed in orbit around Mercury in December 2025:

  • The Mercury Planetary Orbiter (MPO), developed by ESA, carries 11 instruments, including spectrometers and HIS cameras, and will study the interior and surface of the planet Mercury as well as its exosphere.
  • The Mercury Magnetospheric Orbiter (MMO), developed by the Japanese space agency JAXA, includes 5 scientific instruments, and aims to study the magnetic field, the exosphere as well as waves and particles located in the immediate environment of the planet.

HORIBA has provided two custom diffraction gratings for the MPO orbiter:

  • A Holographic laminar ion-etched concave grating with aberration corrections for the PHEBUS FUV-EUV spectrometer. This system, working in the wavelength range 55 to 330 nm, will record full spectra to detect emission lines from Mercury's exosphere to reveal its composition and distribution.
  • A Ruled plane grating in the spectral range 400 to 2000 nm for the SIMBIO-SYS VIHI instrument (Visible Infrared Hyperspectral Imager). The goal of VIHI is to map the planet to provide the global mineralogical composition correlated with features of the surface (mineralogical composition of crust / mechanism of crustal formation / processes of Magmagenesis…)

Discover the latest images from Mercury planet!

ESA and JAXA agencies have shared the first images from Mercury and five more flybys will occur between June 2022 and January 2025.

53 images taken by the monitoring cameras of BepiColombo were shared by ESA/JAXA on October 1st, following the first close flyby of Mercury:


BepiColombo meets Mercury
© ESA/BepiColombo/MTM, CC BY-SA 3.0 IGO



A taste of Mercury geology – annotated
© ESA/BepiColombo/MTM, CC BY-SA 3.0 IGO