MMX: JAXA's Mission For Planetary Probe

Spacecraft of MMX mission|Source: JAXA

Martian Moons eXploration(MMX) is the Japan Aerospace Exploration Agency's (JAXA) mission to shed light on the history of the Martian moons and the evolution of the Mars region. The mission's objective includes observing Mars' two moons, Phobos and Deimos, and returning to the Earth with a sample taken from one of them. The launch of this mission is scheduled for 2024 and return to the Earth in 2029. The mission seeks to offer crucial data that will assist in determining whether the Martian moons are the consequence of bigger bodies striking Mars or captured asteroids impacting the planet.

Why Phobos and Deimos?

Phobos and Deimos|Source: Quora

Among the numerous moons currently in the Solar System, only two terrestrial planets, Earth and Mars, have their moons. Phobos and Deimos are two of those three moons. We have a plethora of information from the exploration of the Earth's Moon which includes sample return missions that reveal and limit both its genesis and evolution processes as well as those of the parent planet. The two Martian moons, which presumably formed in tandem with the formation of their home planet, most likely share the same characteristics. However, there has been very little direct research on the Martian moons till now.

Mars, the host planet of Phobos and Deimos, has an atmosphere-covered surface similar to that of the Earth. It is anticipated that Phobos, Deimos, and the area around them will provide hints for understanding the evolutionary processes on Mars as well as both moons. 

But why is Phobos selected for sampling? 

The very first reason is that more spectral diversity can be seen on Phobos' surface than on Deimos. Second, Phobos' surface is expected to have the minerals that were likely ejected from young impact craters that will provide information about the previous surface environment of Mars at the time of bedrock formation. Third, the abundant available imaging data of Phobos. This enables us to refine the landing plans and procedures before the spacecraft launch. 

Spacecraft and Science Instruments

Spacecraft 

For a reasonable roundtrip time, the MMX spacecraft will use a chemical propulsion system with strong acceleration capability. The spacecraft is made up of three detachable parts that allow it to complete a round-trip to the Martian sphere of gravity: the propulsion module, the exploration module, and the return module. The spacecraft mass will be decreased by releasing utilized modules at suitable epochs to enable orbital controls in the Martian system and a return voyage to the Earth, lowering the necessary total propellant mass.

Science Instruments

1. LIDAR: Laser Altimeter 

It will identify the geologic features and locations where the bedrock is exposed. Besides, it will measure surface morphology to determine the moon's geologic past. Selection and characterization of sampling sites are also done by LIDAR. 

2. TENGO: Telescopic Camera 

The geologic background of the sampling location will be described using close-up spectroscopic and panchromatic imaging by OROCHI and TENGOO with spatial resolutions in the order of mm during landing procedures.

3. OROCHI: Wide-Angle Multiband Cameras 

It is a spatial resolution camera that will determine the composition of the world's surfaces (hydrous minerals, Fe/Si, H2O release rate, etc.). This advanced camera is also able to observe water and dust circulation in the Martian climate system.

4. MIRS: Near-Infrared Spectrometer 

A series of spectroscopic imaging/mapping of the Martian atmosphere will also be carried out by OROCHI and MIRS. Both devices can image a large area of Mars from mid- to low latitudes from their placements close to Phobos. Global hemisphere imaging is made simpler at locations farthest from Mars.

5. MSA: Ion Mass Spectrometer 

Its role is to find the gas torus and leave the Martian atmosphere. The MSA measurements are also focused on the metallic ions that the solar wind has sprayed onto Phobos' surface.

6. MEGANE: Gamma Ray and Neutron Spectrometer 

"MEGANE" means "eyeglasses in Japanese. MEGANE will measure the concentration of elements including Si, Fe, H, and K in the surface layer of several tens cm thickness.

7. MMX Rover:Solar-Powered Rover 

Rover for Phobos and Deimos|Source: DLR Portal

The rover will perform an in-situ measurement of regolith physical characteristics and mineralogy. The solar-powered rover will have navigation cameras, wheels with torque sensors for movement, wheel cameras to record how the wheels contact with the regolith, a thermal radiation monitor (MiniRad), and accelerometers to measure impact and bounce.

8. CMDM: Dust Counter 

As the name suggests, it will detect dust flow and rings to highlight the weathering process caused by micrometeoroid bombardments on the moon's surface. 

Mission 

Mission profile of MMX|Source: Springer Open

JAXA has planned to launch the mission to Phobos and Deimos in 2024. Deimos will be treated with a fly-by treatment but JAXA has bigger plans for Phobos. They plan to send a spacecraft to Phobos, possibly more than once, to collect samples to bring back to Earth. A rover, called MMX rover, will be sent by the German Aerospace Center(DLR). 

 

The rover's landing on the moon's surface is not an easy task. The tiny vehicle will be dumped onto the moon and will fall on its sides. It will need to correct itself once it reaches the surface and begins working. 

Then, measurement of the moon's surface will be taken by its instruments: a radiometer and a Raman spectrometer. The Raman spectrometer will reveal Phobos' mineralogical composition which is important for understanding Phobos' origins. The radiometer on the rover will gauge the electromagnetic radiation coming from the moon. By comparing the moon to other solar system worlds, astronomers can better grasp its porosity.

But the mission will be considered successful after its sample return, which is expected to be much larger than that of the Hayabusa 2 mission. JAXA has a time limit of 90 minutes to collect the samples and leave the surface because of the conditions on Phobos as it will be covered in darkness after this period. A spacecraft on QSO-L (Low altitude Quasi Satellite Orbit) circling Phobos will repeatedly undergo long-duration eclipses by Mars and Phobos during periods of around 3 months with equinox time in each center. This is brought on by Phobos's orbit around Mars, which is almost equatorial, and the minute variations in QSO periods from Phobos's day length. Long power generation pauses should be avoided to preserve the health of electric devices

 

The mission will end in 2029 with the successful return of samples.

Objectives 

There are two main objectives of this mission:

• To learn more about how Mars and the other terrestrial planets formed, and to determine if the Martian moons are trapped asteroids or debris that coalesced after a massive collision with Mars.

• To obtain new insights into the history of the Mars Sphere, including the history of the Martian moons, and to elucidate the mechanisms governing the surface evolution of Mars and the Martian moons.

It is hoped that this research and development will result in advancements in the technology required for future planetary and lunar probes, the best communications technology using brand-new ground-based probe stations, advanced surface-sampling technology for astronomical objects, and technology for interplanetary travel.