A Japanese spacecraft rocketed toward Mars on Tuesday on a mission to explore its mysterious moons and bring back samples. Five of the world’s space agencies joined forces for the five-year endeavour that will attempt to land a robotic prospector and a rover on Phobos, the larger and closer of Mars’ two pint-sized moons.
The Japan Aerospace Exploration Agency led the sampling effort, launching the spacecraft before dawn from the country’s main spaceport on Tanegashima Island. Officials declared success an hour later when the spacecraft separated as planned from the rocket’s upper stage. Flight controllers burst into applause and jumped to their feet, shaking hands and embracing.
While the United States has successfully landed nine spacecraft on Mars over the past 50 years and China scored a 2021 touchdown, no one has ever ventured onto Phobos or its sidekick Deimos. No one has managed to fetch samples from Mars, let alone its moons. Bits of dust, soil and rocks from Phobos will arrive on Earth in 2031 if the mission succeeds.
"There’s a lot of adrenaline and a lot of excitement and a lot of wow," said NASA astrophysicist Tom Statler, who is involved with the project. Japan has an edge going in, with two asteroid sample returns already under its cosmic belt.
Phobos is a lumpy, potato-shaped rock just 14 miles or so across. Examining pieces of it can explain how Mars’ moons and possibly moons elsewhere came to be. Dubbed MMX for Martian Moons Exploration, the 578 million dollar mission features a hefty 5-ton spacecraft that should reach Mars by late next summer. It will sync up with Phobos’ tight orbit around the red planet before ejecting the French-German rover named Idefix.
No bigger than a microwave oven, Idefix will plop onto Phobos by itself and bounce for several minutes before coming to a halt in the moon’s low gravity. The four-wheeled rover is designed to right itself if it lands upside down. All bets are off, though, if it sinks into soft soil or gets wedged between rocks, said the French Space Agency’s Julien Baroukh. Once the rover’s solar panels are deployed, the vehicle can no longer right itself, which is why it will move at a glacial 1 millimetre per second.
Idefix will serve as a scout for safety as it prowls around Phobos for 100 days. Japanese flight controllers want to avoid powdery soil and rough terrain when the mothership descends to the surface to gather samples in late 2028 or 2029. The lander will spend just two hours on Phobos, drilling and vacuuming up at least one-third of an ounce of material, before launching back into space.
It will study Deimos during a series of flybys before leaving the Martian neighbourhood in 2030 and hustling back to Earth for a 2031 sample delivery in the Australian desert. By studying Mars’ moons, scientists hope to learn whether Phobos and Deimos formed from an ancient collision between Mars and a battering space rock. The moons might also be stray asteroids that became ensnared in Mars’ gravity.
Scientists anticipate finding traces of Mars on Phobos, making the samples a two-for-one that should help demystify planetary and moon formation. Japan is investing 350 million dollars in this mission. NASA is contributing 87 million dollars, the French Space Agency about 68 million dollars, the German Space Agency about 56 million dollars and the European Space Agency some 17 million dollars.
