MMX: Japan's mission to sample Phobos (Pre-Mission)

Illustration of MMX landing on Phobos. Credit: JAXA

• Launch Date: September 2024 (withholding delays)
• Launch Site: LA-Y1 Tanegashima Space Center, Japan
• Launch Vehicle: H3-24L
• Mission Type: Orbiter, Lander, Rover, and Sample Return
• Targets: Phobos & Deimos
• Dimensions: Unavailable
• Mass: 3030 Kilograms

The Martian Moons Exploration mission (MMX) sets out to be the first successful sample return from Mars's largest moon: Phobos. Russia attempted a similar operation over a decade earlier, called Phobos-Grunt, but it failed and burned up in Earth's atmosphere. Space is Hard.

The Mission

Hopefully, Japan will have much better luck than Russia. Japan's space agency, JAXA, already has two successful Hayabusa asteroid sample return missions under its belt. The MMX mission was announced all the way back in 2015, and development started in 2020. Surprisingly, the mission seems to have been uneffected by COVID-19.

Deimos and Mars as seen by the UAE's Hope orbiter. Credit: Emirates Mars Mission

The spacecraft will make flybys of both Phobos and Deimos after it arrives at Mars, but will only take samples from Phobos (sorry Deimos, I guess you're just not as interesting). The spacecraft will consist of a 3 combined modules sort of like ESA's Bepicolombo spacecraft. 

There will be a propulsion module (1800 kg) an landing/sampler module (150 kg) and a sample return module (1050 kg). There are also plans to send a rover (30 kg) with the mission, built by German and French researchers at CNES and DLR.

Simulation of the IDÉFIX rover. Credit: DLR (CC BY-NC-ND 3.0)

The rover is called IDÉFIX, after Asterix's dog (Dogmatix in English) from the famous french comic. IDÉFIX will be dropped 40-100 meters before the lander touches down, but due to Phobos' extremely low gravity, the rover should be able to cope with the touchdown. The rover is planned to be quite tiny, at only 60 centimetres long.

The spacecraft won't attempt to sample Phobos, or drop off its rover, until 2026 or 2027. After the mission finishes taking samples, the return module should come back to Earth in July of 2029.

Animation of MMX scanning Phobos. Credit: JAXA

The Targets

Image of Phobos from the Mars Reconnaissance Orbiter. Credit: NASA/JPL-Caltech/University of Arizona

• Date Discovered: 1877
• Radius: 11.1 Kilometres
• Mass: 1.0659x10^16 Kilograms
• Density: 1.872 g/cm^3
• Rotational Period: 7 Hours and 39 Minutes
• Orbital Period: 7 Hours and 39 Minutes

Image of Deimos from the Mars Reconnaissance Orbiter: Credit: NASA/JPL/University of Arizona

• Date Discovered: 1877
• Radius: 6.2 Kilometres
• Mass: 1.4762x10^15 Kilograms
• Density: 1.471 g/cm^3
• Rotational Period: 7 Hours and 39 Minutes
• Orbital Period: 30.3 Hours