Development of the MIRS instrument for MMX is complete

On the 5^th April 2024, the MMX InfraRed Spectrometer (MIRS) that will fly onboard the MMX spacecraft was officially handed to JAXA by the Centre National d’Etudes Spatiales (CNES), who developed the instrument.

MIRS is one of the 13 instruments onboard the MMX spacecraft, and will perform near-infrared spectroscopic observations of the global surface of the Martian moons. Near-infrared spectroscopy detects the absorption of different wavelengths of near-infrared that are reflected from the moons’ surface. This indicates the composition of the moons, in particular the presence of hydrous minerals that contain water in their structure, and organic matter. MIRS data will create a distribution map of minerals and molecular species, with a focus on hydrous minerals and organics.

Hydroxides and hydrous minerals absorb near-infrared light at wavelengths of 2.7~3.2 μm, while organic matter absorbs 3.3~3.5 μm. Measurements by MIRS of this absorption spectrum can determine whether the Martian moons are composed of primordial celestial material (such as asteroids or comets) or differentiated material (where the denser elements such as iron have separated from the lighter silicates) similar to Mars, which will help clarify the origin of the Martian moons. MIRS will also monitor the Martian atmosphere over a long period with a short time resolution to reveal spatial and temporal changes in clouds, dust, water vapour, and other atmospheric properties.

Left: The MIRS Flight Model (FM) during a check of the dust cover deployment in a functionality check after transportation. Right: Group photo of the MIRS Team. Michel Le Du, Maria Antonietta Barucci, and Project Manager Kawakatsu are standing in the centre of the front row. On the table, the MIRS EBOX (electronics box) is on the left and the OBOX (optical box containing the optical components for MIRS) is on the right.

The basic design for MIRS began in April 2020, with the development team from CNES and the Paris Observatory. After the design review, the Engineering Model (EM) was manufactured and underwent the necessary development tests. This was followed by the Flight Model (FM), which passed the Post Qualification Review (PQR) and Pre-Shipping Review (PSR), and was officially confirmed to have completed development at the meeting in February 2024. In April 2024, MIRS was transported to the spacecraft manufacturer (Mitsubishi Electric Corporation) Kamakura Works, and formally handed over after a post-transport functionality check.

MIRS has been assembled into the spacecraft’s exploration module, and is currently included in the comprehensive system tests.

MIRS PI Maria Antonietta Barucci
Paris Observatory / PSL

The MIRS is an imaging spectrometer developed in France, and the team is very pleased to have accomplished the successful handover of the instrument to JAXA/MELCO. The MIRS team is honored and exited to be part of MMX mission. We are looking for the successful MIRS installation onto the spacecraft and for the next phases up to the launch. We are looking for the success of this great mission and the extraordinary scientific results.

MMX Project Manager Kawakatsu Yasuhiro
JAXA

I am very proud that the development of MIRS has been successfully completed and officially handed over to JAXA. There were many challenges before we reached this moment. During the early discussions about the structure of the development, we made the difficult decision to re-evaluate the scientific requirements and select a more suitable instrument. We then worked together with partners including those in CNES and the Paris Observatory in France, and through the concerted efforts of the entire development team, MIRS has achieved high performance and reliability.

Last summer, I was deeply moved when I saw the completed MIRS for the first time. I felt a mixture of responsibility and joy to be entrusted with an instrument that will play a role in the grand goal in elucidating the origin of the Martian moons. I am looking forward to the day when we embark on our mission with the MMX spacecraft!

JAXA MIRS Team POC (Point of Contact) Iwata Takahiro

The development for MIRS began in France in April 2020, in the midst of the COVID-19 pandemic. We were unable to travel to see one another, and our only means of communication were weekly online meetings. From May 2022, we were finally able to interact directly again, and it was a moving experience to come face-to-face with the MIRS Flight Model at the Paris Observatory in December 2023. We are making one last big push for the system tests, aimed at clarifying the presence of water and organic matter on the Martian moons.