Facts and figures

Illustration of the complete MMX mission sequence
The lower part of the image shows the outbound flight of the MMX spacecraft. Major milestones are the manoeuvres to enter Mars orbit (MOI-1), the transfer from Mars to Phobos orbit (MOI-2) and finally the entry into Phobos orbit (MOI-3).



The Japanese Martian Moons eXploration (MMX) mission will explore how the two martian moons, Phobos and Deimos, formed and improve our understanding of the formation of the planets in our Solar System in general. The primary focus of the mission's scientific objectives is to better understand the processes behind the development of the martian system. DLR is making a significant contribution to the mission in collaboration with the French space agency, CNES: the MMX rover.

The MMX spacecraft consists of:
• a propulsion module with propellant tanks and rocket engines for launch into Mars and Phobos orbit
• an exploration module with landing legs, a sampler and scientific instruments
• a rover jointly developed by DLR and CNES
• a return module housing the sample return capsule

MMX mission data





Launch site

Tanegashima, Japan

Launch vehicle


Mission duration

Six years

Arrival in Mars orbit

Summer 2025

Rover lands on Phobos

Early 2027

Sampling by explorer module


Return module begins return flight

Summer 2028

Return module lands on Earth

Summer 2029

MMX-Rover data




231 by 376 by 415 millimetres


25 kilograms

Mass of scientific payload

2.5 kilograms

Dimensions of solar panels

4 by 415 by 363 millimetres

Energy production

At least 60 watt-hours per Phobos day (7h)

Maximum speed

Approximately one millimetre per second

Duration of operation on the surface of Phobos

100 days

Rover control centres

DLR: Microgravity User Support Center, Cologne, Germany

CNES: Centre spatial, Toulouse, France

Overview of instruments for the MMX mission

1. Rover

Overview of the DLR institutes involved



DLR Institute of Robotics and Mechatronics

Cooperative project management with CNES,

system engineering,

mechatronic landing gear (locomotion system),

together with the Institute of System Dynamics and Control

DLR Institute of System Dynamics and Control

mechatronic landing gear (locomotion system),

together with the Institute of Robotics and Mechatronics (work packages MMX wheel and MMX software),


DLR Institute of Composite Structures and Adaptive Systems

Carbon structure

DLR Institute of Optical Sensor Systems

RAX instrument (RAman spectroscopy for MMX; mass spectroscope)

DLR Institute of Planetary Research

miniRAD instrument (radiometer), scientific advice

DLR Institute of Space Systems

Mechanical and Electrical Connection and Support System (MECSS), shutter, product assurance, assembly integration and test, provide pre-assembled chassis

DLR Space Operations and Astronaut Training

Rover operations (together with CNES), scientific management,

payload management for

DLR's RAX (RAman spectroscopy for MMX) instrument

DLR scientific instruments on the rover

Technical drawing of the MMX rover
Top: Rover in fully extended configuration with positions of the radiometer MiniRad and the locomotion systems for each rover wheel. Bottom: Interior view with position of the instruments - including the spectrometer RAX - and the on-board computer (OBC).


The primary objective of the miniRAD radiometer is to determine the surface temperature of Phobos. By measuring the heat radiation in six infrared wavelength ranges, researchers can draw conclusions about the material properties of rocks and loose material (regolith), such as grain size, porosity and mechanical strength, at different locations. The measured values can then be directly compared with samples collected from asteroids and meteorites. miniRAD can also be used to determine the optical properties of the surface. The instrument will be used to determine the radiance of samples in three spectral bands, which will allow for an initial mineralogical characterisation of the surface of Phobos.

Researchers will use the RAX spectrometer to determine which materials make up the surface of Phobos. They will investigate which rock types can be found and how frequently they are detected. This will allow them to draw conclusions about the geochemical, thermal and radiation processes that led to the formation of these minerals. The measurements conducted on the surface of Phobos will be compared with analyses of martian rocks made by other missions. In combination with the analysis of the samples transported to Earth by MMX, these measurements will help researchers test the various theories on the formation of Phobos and Deimos.

CNES' contributions to the rover

  • Camera system used for spatial orientation and surface exploration
  • Camera system used for the investigation of the soil's mechanical properties
  • Central service module of the rover including the onboard computer and the power and communication system as well as solar panels, assembly and test of the flight model of the entire rover
  • Rover operations on the Phobos surface (together with DLR)

2. Exploration module

Instrument name

Instrument type



Sampler (drill core)

Collect material from depths greater than two centimetres


Pneumatic sampler

Collect loose material at the surface



Map / image surface


Ion mass spectrometer

Detect possible ice deposits


Multispectral wide-angle camera

Image the surface and provide mineralogical information


Telescopic camera

Acquire high-resolution images of the surface


Gamma / neutron spectrometer

Determine elemental composition


Near-infrared spectrometer

Study rock, water and organic material

3. Return module

Instrument name

Instrument type



Dust counter

Conduct measurements on the dust in the environment


Radiation sensor

Conduct measurements on the radiation in the environment


Outreach camera

Acquire image and video


Sample Return Capsule

Transport samples to Earth

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
Linder Höhe, 51147 Cologne
Tel: +49 2203 601-3959

Markus Grebenstein

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

Michael Müller

German Aerospace Center (DLR)
Corporate Communications
Linder Höhe, 51147 Cologne
Tel: +49 2203 601-3717

Stephan Ulamec

MMX rover scientific manager
German Aerospace Center (DLR)
Space Operations and Astronaut Training
Microgravity User Support Center (MUSC)
Münchener Straße 20, 82234 Weßling