日本H3火箭发射MMX火星卫星取样探测器，三菱电机参与研制但短线财务增量有限

TOKYO -- Japan's mission to collect samples from Mars moon Phobos got underway on Tuesday after its H3 rocket, operated by Japan Aerospace Exploration Agency, lifted off from the Tanegashima Space Center in southwestern Kagoshima prefecture. On board the rocket was the Martian Moons eXploration (MMX) probe, developed by Mitsubishi Electric.
An hour after lift-off, the satellite successfully entered its planned trajectory early in the morning Japan time, marking the start of a mission aimed at becoming the first in the world to bring material from the Martian orbital system back to Earth.
Here are five things to know about the attempt, expected to take five years, to bring back samples.
How does MMX work?
MMX is the largest spacecraft Japan has ever built, measuring 5.3 meters tall, 9 meters wide and weighing about 4.5 metric tons.
After a roughly yearlong journey to Mars, MMX will spend about three years observing Phobos, one of two Martian moons, at close range and studying the environment around Mars and its moons.
It will first deploy an IDEFIX rover, jointly developed by France and Germany, onto Phobos. The roughly cube-shaped vehicle measures about 50 centimeters on each side and weighs around 23 kilograms. It will travel across the surface of Phobos on wheels, studying the moon's temperature and composition and helping MMX prepare to collect samples.
MMX itself will then attempt two landings at different locations, each lasting two to three hours.
The spacecraft is scheduled to leave the Martian orbital system in 2030 and return to Earth in 2031.
How will it collect samples?
MMX builds on Japan's two successful asteroid sample-return missions to Itokawa and Ryugu, respectively, but relies on different methods for sample collection.
Two systems are involved. One uses a mechanical corer to collect material from more than 2 centimeters below the surface, while the other, a pneumatic sampler, uses high-pressure nitrogen gas to lift surface dust and grains into a collector. The two methods will allow scientists to compare material from different depths and provide a backup if one sampling method encounters difficulties.
MMX aims to collect at least 10 grams of material, 100 times the original sample target for Japan's Hayabusa2 mission to the Ryugu asteroid.
What is Phobos?
At just 20 kilometers to 30 km in diameter, Phobos is a tiny moon that orbits about 6,000 km from Mars, roughly one-sixtieth the distance between Earth and the moon.
One of the mission's key goals is to determine how Phobos formed. There are two leading hypotheses. One holds that Phobos is an asteroid that originated elsewhere and was captured by Martian gravity. The other suggests it formed from debris thrown into space when a massive object struck Mars.
Detailed analysis of samples from Phobos could shed light on how the Martian moons formed and potentially settle the debate.
If Phobos originated as an asteroid, it may preserve material dating back to the early days of the solar system. Studying it could therefore offer clues to how planets formed and possibly even to the origins of life.
Could this mission lead to human settlement on Mars?
A better understanding of materials from Mars could also contribute to research that may eventually support human exploration and settlement of the planet.
Samples from Phobos may contain tiny amounts of material originating from Mars. If Martian material is found among the samples, it could provide scientists with more detailed clues about conditions on the Red Planet.
Although Mars has no liquid water on its surface, ice and liquid water are believed to exist underground. Its soil contains phosphorus and potassium, nutrients needed for plant growth. Mars also has an atmosphere, offering some protection from space radiation compared with Earth's essentially airless moon.
"From the perspective of human habitation, the moon is a training ground, while Mars is the real goal," said Yasuhito Sekine, director of the Earth-Life Science Institute at the Institute of Science Tokyo.
SpaceX, led by U.S. billionaire Elon Musk, has laid out an ambitious vision for settling Mars. The plan calls for sending humanoid robots there to help establish infrastructure such as power-generation facilities and dome-like structures for human habitation.
What is China doing in terms of Mars exploration?
Japan's mission comes as a race to return samples is taking shape.
China, a major space power, plans to launch its Tianwen-3 Mars sample-return mission around 2028, with collected material due back on Earth in about 2031.
That puts China and Japan on potentially similar return schedules. MMX is aiming to bring back samples from Phobos, while Tianwen-3 plans to collect material directly from Mars, creating a race to be the first to bring back physical substances from the Martian orbital system to Earth.