June 20, 2023 | Paris Air Show 2023 – JAXA, CNES and DLR sign cooperation agreement for MMX mission

Rover on the home stretch to the martian moon Phobos

  • Tripartite agreement on cooperation for the MMX mission signed by JAXA, CNES and DLR.
  • As part of the MMX mission, the German-French rover IDEFIX will land on the Martian moon Phobos.
  • The Japanese MMX mother spacecraft will collect samples from Phobos and send them back to Earth.
  • Currently, final work is underway to complete the rover for delivery to Japan in summer 2023.
  • Focus: Space, robotics, exploration, Mars

The origin of the martian moons Phobos and Deimos is still an unsolved mystery in planetary research. Both moons will be the targets of the Japanese Martian Moons eXploration (MMX) mission. A German-French rover will land on Phobos as part of the mission and conduct a mobile exploration – despite the extremely low gravity. At the Paris Air Show in Le Bourget, the Japan Aerospace Exploration Agency (JAXA) signed an agreement with the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) and the French space agency (Centre national d'études spatiales; CNES) on trilateral cooperation within the framework of the MMX mission. Meanwhile, the completion of the rover, including instruments and systems, is on the home stretch towards summer 2023. Parallel to the signing, the rover has been named IDEFIX.

"We are very excited to collaborate with CNES and DLR as part of the MMX mission, which endeavours to clarify the origin of the martian moons and the evolutionary process of the martian sphere by collecting samples from one of Mars' two moons – Phobos – for the first time in space history," said Hiroshi Yamakawa, President of JAXA. He added: "Japan shares a precious memory with France and Germany regarding the collaboration during the Hayabusa2 sample return mission, on which the joint CNES-DLR MASCOT lander flew. And we are looking forward to putting our efforts together once again for a successful MMX mission."

On the occasion of the signing, Anke Kaysser-Pyzalla, Chair of the DLR Executive Board, said: "Japan and France are important strategic partner countries for DLR in almost all of our research areas. In this context, our cooperation within the framework of the MMX mission is a specific example of the creative power of our multifaceted collaboration. When a rover travels over the surface of the martian moon Phobos for the first time, we will have jointly pushed technological boundaries to learn more about the origin of the Solar System and Mars with its moons."

Walther Pelzer, DLR Executive Board Member and Director General of the German Space Agency at DLR emphasised: "MMX is a true example of how to conduct challenging space missions with international cooperation – as a joint undertaking, together with likeminded nations, space agencies and partners. Each side brings fruitful and specific competences, sharing costs and risks and gaining exceptional technological expertise and scientific results."

"The signing of this new tripartite agreement between CNES, JAXA and DLR is another milestone in the fruitful cooperation between our three nations on the MMX mission. By studying the two martian moons, Phobos and Deimos, this mission will lead to major advances in the knowledge of the Solar System," says Philippe Baptiste, CNES' CEO.

With the trilateral cooperation agreement that has now been signed, JAXA, CNES and DLR are creating a joint framework for the integration of the German-French rover into the Japanese MMX mission for a landing on the martian moon Phobos in the second half of the 2020s. MMX is a mission that will operate at the limits of what is technically feasible. For the first time, samples from the martian system, specifically from the martian moon Phobos, will be brought to Earth by the Japanese MMX mothercraft. The German-French rover will move across the surface of Phobos in conditions of extremely low gravity (approximately two-thousandths of Earth's gravity) in order to explore it. The MMX rover is designed around this unique and challenging idea and has been given the name IDEFIX.



Rover to be completed in summer 2023

The final work to complete the rover is currently under way at the CNES site in Toulouse. In the last few months, the final integration of all instruments and subsystems, including the solar arrays, power system, on-board computer and radio system for contact with the MMX spacecraft, has taken place there. Previously, DLR had already integrated the rover's carbon-reinforced composite chassis, including the locomotion system, at their Bremen site and delivered it to CNES in Toulouse in November 2022. The miniRAD radiometer and the RAX spectrometer from DLR's Berlin site were also shipped to Toulouse. In addition to the two DLR instruments for analysing the thermal properties and mineralogical composition of the surface, CNES has installed two cameras that monitor the wheels and the ground. CNES has also developed and integrated the two navigation cameras that will be used for the navigation.

In the meantime, the rover has almost completed its space qualification tests at CNES in Toulouse. Among other things, these tests address its functionality as well as its ability to withstand the vibrations during launch and the extreme temperature fluctuation range of more than 200 degrees Celsius on Phobos. The qualification tests for the rover are now being conducted together with the connection and release system that attaches it to the mother spacecraft. This adapter, the Mechanical and Electrical Connection and Support System (MECSS), was also provided by DLR. The communication system between the spacecraft and the rover, which is used to transmit commands and telemetry, and has been developed by CNES is also being tested during this qualification campaign. The rover test campaign is now in its final stretch. More tests, including EMC (Electromagnetic compatibility) tests and other final tests will be carried out before delivery this summer.

Video: Testing, assembly and preparation of the Franco-German rover IDEFIX for the MMX mission
The final work and tests for the completion of the IDEFIX rover are currently underway at the CNES site in Toulouse. Over the last few months, the final integration of all instruments and subsystems has taken place there. Previously, DLR had already integrated the carbon-fibre-reinforced structure of the rover, including the uprighting and propulsion system, at their Bremen site and delivered it to CNES in Toulouse in November 2022. IDEFIX is to land on the Martian moon Phobos as part of the Martian Moons eXploration (MMX) mission and explore it while moving – despite extremely low gravity. The Japanese MMX mission targets both moons of Mars, Phobos and Deimos. The MMX probe will explore both moons and eventually collect samples from Phobos and send them to Earth.


MMX spacecraft

The MMX spacecraft consists of three modules. The exploration module has landing legs, samplers and some instruments as well as the MMX rover on board. The exploration module is connected to the return module with the sample return capsule, which in turn is connected to a propulsion module housing propellant tanks and thrusters. The MMX spacecraft design has been completed, and the project team has started the final manufacture, testing and integration of the spacecraft including instruments provided by partner agencies toward the launch target in FY2024.

The mission timeline

The launch of the mission is scheduled for the mid-2020s. After a journey of approximately one year, MMX will reach Mars and enter orbit. Then, the eight scientific instruments on the exploration module will begin mapping and characterising the surfaces of Phobos and Deimos. During the course of the mission, the rover is scheduled to land on Phobos. This will involve setting the rover down from an altitude between 40 and 100 metres above the surface. After landing, the rover will autonomously upright itself and then become operational. The measurement phase will then begin; this will last about three months, during which the rover will approach various targets that are of interest for scientific analysis. Towards the end of the mission, ground samples will be collected by the mother spacecraft, taking into account the knowledge acquired using the rover. These will be delivered back to Earth in the return module for more detailed analyses.

The origin of fear and terror

In Greek mythology, Phobos and Deimos were the companions of Ares, the god of war, who in Roman antiquity had his counterpart in Mars, also a god of war. They were discovered in 1877 by the American astronomer Asaph Hall. Due to their small size (Phobos is 27 kilometres in its largest diameter and Deimos 15 kilometres), both moons are irregularly shaped and resemble asteroids. Thus, one theory is that Mars simply captured the two moons in the past, which possibly originated from the asteroid belt. However, both moons orbit Mars near the ecliptic plane on which all planets and most of their moons move around the Sun. In addition, both orbits are almost circular. Such a coincidence would be difficult to account for under the 'captured asteroids' theory. This could be explained if Phobos and Deimos were remnants of a huge asteroid impact on Mars.

MMX aims to solve this long-discussed mystery of planetary science. The formation of the Mars system is also key to better understanding the processes of planet formation in the Solar System. In any case, traces of martian rocks are likely to be found on the surface of Phobos, which landed on Phobos as ejecta from later asteroid impacts. This means that the samples from Phobos could also bring material from Mars to Earth in the return capsule and thus into terrestrial laboratories.

Mars with its moons Deimos (above) and Phobos
Mars' two moons, Deimos (above) and Phobos, are the targets of the MMX mission. Due to their small size (Phobos 27 kilometres, Deimos 15 kilometres), both moons are irregularly shaped. Their origin is still an unsolved mystery in planetary research. (image montage)

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MMX – Martian Moons eXploration

MMX is a mission of the Japanese space agency JAXA with contributions from NASAESACNES (the French space agency) and DLR. CNES (Centre National d'Études Spatiales) and the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) are jointly contributing a 25-kilogram rover to the Martian Moons eXploration Mission (MMX). The Franco-German MMX rover is being designed and built under the joint leadership of CNES and DLR. In particular, DLR is responsible for the development of the rover's landing gear, including the lightweight body, as well as the entire uprighting and locomotion system. DLR is also contributing the connection adapter to the MMX spacecraft and providing a Raman spectrometer and a radiometer as scientific experiments. These will analyse the surface composition and texture on Phobos.

CNES is making significant contributions with camera systems for spatial orientation and exploration on the surface, as well as for the study of mechanical soil properties. CNES is also developing the rover's central service module, including the on-board computer and the power and communications system. After the launch of the MMX mission, the rover will be operated by CNES control centres in Toulouse (France) and DLR in Cologne (Germany).

For DLR, the institutes of System Dynamics and Control, Composite Structures and Adaptive Systems, of Space Systems, of Optical Sensor Systems, of Planetary Research, for Software Technology and the Microgravity User Support Center (MUSC) are also involved under the leadership of the DLR Institute of Robotics and Mechatronics.

The MMX mission is a continuation of an already long-standing successful cooperation between JAXA, CNES and DLR. It builds on the previous mission Hayabusa2, in which JAXA sent a spacecraft to the asteroid Ryugu with the German-French MASCOT lander on board. On 3 October 2018, MASCOT landed on Ryugu and sent spectacular images of a landscape ridden with boulders and rocks, and virtually no dust. Hayabusa2 collected samples from Ryugu and brought them to Earth on 6 December 2020.


Falk Dambowsky

Head of Media Relations, Editor
German Aerospace Center (DLR)
Corporate Communications
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Tel: +49 2203 601-3959

Markus Grebenstein

Deputy Director
German Aerospace Center (DLR)
Institute of Robotics and Mechatronics
Münchener Straße 20, 82234 Oberpfaffenhofen-Weßling

Fuki Taniguchi

Japan Aerospace Exploration Agency (JAXA)
Tel: +81 70-1170-3428

Nathalie Blain

Centre national d’études spatiales (CNES)
Tel: +33 1 44 76-7521