TANEGASHIMA, Japan — Japan sent a spacecraft toward Mars early Tuesday, local time, on a mission designed to land on the larger Martian moon, Phobos, gather a handful of its surface material and carry it back to Earth.
The Martian Moons eXploration probe, known as MMX, rode an H3 rocket off the pad at the Tanegashima Space Center at 4:41 a.m. Japan time on Oct. 20, which was 3:41 p.m. Eastern on Monday. The Japan Aerospace Exploration Agency said the rocket performed as planned and released the spacecraft a little over 71 minutes into the flight, placing it on its intended path.
The probe is due to reach the Mars system next year. It will then spend about three years circling Phobos and making observations of the smaller moon, Deimos, before heading home. A capsule carrying at least 10 grams of Phobos material is scheduled to come down in Australia in Japan’s 2031 fiscal year, then travel to the agency’s space science institute in Sagamihara, near Tokyo, for study.
A successful trip would give Phobos its first orbiting visitor and its first sampling, and would mark the first return of material to Earth from anywhere in the Mars system.
Scientists still argue over where the two small moons came from. One idea holds that they are asteroids snagged by the planet’s gravity; another says they formed from debris blasted into orbit when a large body struck the young planet. Material collected from Phobos should help settle that question, because rock born from Mars would look very different from a captured asteroid.
Before the main craft touches down, it will drop a small rover called Idefix, built by the French and German space agencies, to scout the surface. Phobos has such weak gravity that the roughly 55-pound rover will weigh about as much as half an ounce there. The lander carries two ways of collecting soil: a coring device that digs down about three-quarters of an inch and a sampler that uses a burst of pressurized gas to lift loose grains into a container.
The fully fueled spacecraft weighs around 4,200 kilograms and carries 11 science instruments. NASA, the French agency CNES, the German Aerospace Center and the European Space Agency are partners, with Europe supplying deep-space radio equipment and tracking stations.
