Japan Launches Historic Mission to Collect Samples from Martian Moon

Japan has launched a pioneering spacecraft, the Martian Moons eXploration (MMX) mission, on a five-year journey to collect samples from Phobos, one of the two moons orbiting Mars. This endeavor marks the world's first attempt to retrieve material from a Martian moon, with scientists hoping the samples will provide critical insights into the formation of Phobos and Deimos, and potentially shed light on the origins of life in our solar system.

The MMX mission, operated by the Japan Aerospace Exploration Agency (JAXA), launched aboard a new Japanese H-3 rocket. The mission is an international collaboration, with support from NASA and other global space agencies. The samples are expected to offer valuable data for future consideration of using a Martian moon as a base for manned missions to Mars. Scientists have long considered the Martian moons as significant but underexplored celestial bodies.

While numerous missions have targeted Mars since the 1960s, its moons have remained largely a mystery. Previous attempts by Russia to land on Phobos have been unsuccessful. A central question the MMX mission seeks to answer is the origin of Phobos and Deimos. Theories suggest they could be debris from a colossal impact on Mars or captured asteroids from elsewhere in the solar system.

JAXA officials believe analyzing Phobos's soil samples will help resolve these questions. Phobos was selected over its smaller sibling, Deimos, due to its proximity to Mars, which is believed to have influenced its composition. JAXA estimates that approximately 0.1% of the collected material may originate from Mars itself. Phobos, approximately 20 to 30 kilometers (10 to 20 miles) in diameter, orbits Mars roughly three times a day at an altitude of about 6,000 kilometers (3,700 miles).

The MMX spacecraft will take about a year to reach the Mars region. It will then spend three years orbiting and studying Phobos, collecting data and gathering samples before beginning its return journey in 2031. The spacecraft comprises three modules: propulsion, exploration, and return. Only the return module, carrying the samples in a protected capsule, will reach Earth.

Equipped with 13 instruments, the MMX mission includes a rover jointly developed by France and Germany, a NASA sampling device, a gamma-ray instrument, and an instrument from the European Space Agency for deep space communication. A Japanese radiation monitor will also gather data pertinent to future manned Mars exploration.

The French-German rover, named Idefix, is scheduled to land on Phobos first for a 100-day mission around 2029. Its objective is to explore the lunar surface and facilitate the subsequent Japanese soil-sampling operations. Following the rover's exploration, the MMX lander aims to collect at least 10 grams (0.35 ounces) of soil from two separate sampling attempts, employing both U.S. and Japanese collection techniques. NASA's method involves using pressurized gas to capture surface dust, while JAXA's coring technique will retrieve samples from approximately 2 centimeters (less than 1 inch) beneath the surface. Collecting samples from multiple locations is intended to increase the probability of finding any potential traces of past microbial life.

The sample capsule is designed to withstand Earth's atmospheric reentry and is expected to land in Australia before being transported to Japan for analysis. This mission builds on Japan's previous successes with its Hayabusa missions, which returned asteroid samples in 2010 and 2020.

Landing on Phobos presents significant challenges due to its irregular, cratered surface and low gravity, which is only one two-thousandth of Earth's. To mitigate bouncing upon touchdown, the MMX's exploration module is fitted with four-legged landing gear featuring shock absorption. The rover, designed to operate in low gravity, is equipped with wheels for traction, a self-righting mechanism, and capable of moving slowly.