Level 1 - Absolute Beginner

Japan sent a spacecraft to space. It left on a big rocket. The rocket is called H3.

The spacecraft is going to Mars. Mars is a red planet. The trip will take about ten months.

Mars has two small moons. One is called Phobos. The spacecraft will land on Phobos and take some rock and dust.

Then it will come back to Earth. It will arrive in the year 2031. It will bring about ten grams of rock.

spacecraft

A machine that travels in space.

rocket

A tall machine that pushes things up into space.

planet

A very large round object that goes around a star.

moon

A round object that goes around a planet.

land

To come down and touch the ground.

rock

Hard stone from the ground.

dust

Very small dry pieces of earth or stone.

gram

A small unit of weight. A paperclip weighs about one gram.

Level 2 - Elementary

On 19 October, Japan launched a mission called Martian Moons eXploration, or MMX. It lifted off from the Tanegashima Space Center on an H3 rocket, which is 63 metres tall. This was the tenth flight of that rocket.

The spacecraft separated from the rocket 71 minutes after launch and is now travelling towards Mars. The journey will take about ten months, and the probe should arrive in August 2027.

At Mars, MMX will enter a special orbit around the moon Phobos. In late 2028 or early 2029 it will release a small rover called IDEFIX, which was built by France and Germany. Later, the main spacecraft will touch down twice on Phobos and collect samples.

After flying past the second moon, Deimos, MMX will leave for Earth in November 2030. A capsule carrying about ten grams of Phobos material should land in Australia in 2031. Scientists want to know whether Phobos is a captured asteroid or a piece of Mars itself.

launch

To send a rocket or spacecraft up into space.

lift off

To rise from the ground at the start of a flight.

separate

To come apart from something it was joined to.

orbit

The curved path an object takes around a planet or moon.

probe

An unmanned spacecraft sent to study something far away.

rover

A small vehicle that drives across the surface of another world.

sample

A small amount of material taken so it can be studied.

asteroid

A rocky object, smaller than a planet, that orbits the Sun.

Level 3 - Intermediate

Japan's Martian Moons eXploration spacecraft left Earth on 19 October at 3:41 p.m. Eastern time, which was 4:41 a.m. on 20 October in Japan, rising from Pad-2 of the Yoshinobu Launch Complex at the Tanegashima Space Center. The vehicle was an H3, the 63-metre two-stage rocket developed jointly by JAXA and Mitsubishi Heavy Industries, flying for the tenth time.

The ascent followed its plan closely. Four solid boosters fell away in pairs just before two minutes, the fairings were jettisoned about eighty seconds later, and the first stage, powered by two LE-9 engines burning liquid hydrogen and oxygen, shut down near five minutes. The trans-Mars injection burn started roughly an hour and four minutes after liftoff, lasted six minutes and twenty-five seconds, and pushed the probe to about 38,858 kilometres per hour. Separation came 71 minutes after launch, on schedule.

The mission plan is unusually long. After a ten-month cruise and arrival in August 2027, the propulsion module will settle into a quasi-satellite orbit around Phobos and spend roughly three years in the Martian system. The French and German IDEFIX rover is scheduled to reach the surface in late 2028 or early 2029. MMX itself will map candidate sites, touch down twice to gather material, then shift to an orbit crossing Deimos for a series of flybys before departing for Earth in November 2030. The return capsule, carrying about ten grams of Phobos, is due in Australia in 2031.

NASA and the European Space Agency are partners. NASA supplied the MEGANE gamma-ray and neutron spectrometer built by Johns Hopkins University's Applied Physics Laboratory, a pneumatic sampler from Honeybee Robotics, and DSN ground-station communications support, investing about $87 million in return for at least 15 percent of the returned sample. The central question is whether Phobos and Deimos are asteroids captured by Mars or debris thrown up by a giant impact. One previous attempt, Russia's Phobos-Grunt, never escaped Earth orbit after its 2011 launch and re-entered over the Pacific in January 2012.

ascent

The climb of a rocket from the ground into space.

booster

An extra rocket motor that provides thrust at launch and then falls away.

jettison

To throw off or release something that is no longer needed.

fairing

The protective cover that shields a payload during launch.

injection burn

An engine firing that places a spacecraft onto a precise new path.

cruise

The long quiet phase of a mission between launch and arrival.

flyby

A pass close to an object without entering orbit or landing.

debris

Scattered broken pieces left after a collision or destruction.

Level 4 - Advanced

Planetary science has an awkward dependency on inference. We reconstruct the history of worlds from reflected light, spectral signatures and gravitational models, and the resulting narratives are persuasive precisely because nothing contradicts them. Occasionally a mission is designed to end that comfort. Japan's Martian Moons eXploration probe, which rose from Pad-2 at Tanegashima's Yoshinobu complex on 19 October at 3:41 p.m. Eastern, local time 4:41 a.m. on the twentieth, exists to replace an elegant argument with ten grams of rock.

The vehicle was an H3, the 63-metre expendable two-stage launcher jointly developed by JAXA and Mitsubishi Heavy Industries, on its tenth flight. The sequence proceeded without incident: paired separation of four solid boosters just inside two minutes, fairing jettison some eighty seconds later, cutoff of the twin LE-9 first-stage engines near five minutes, then a trans-Mars injection burn beginning about sixty-four minutes after liftoff and running six minutes twenty-five seconds to reach approximately 38,858 kilometres per hour. Spacecraft separation occurred at seventy-one minutes, on the predicted mark.

What follows is an itinerary of unusual ambition. A ten-month cruise delivers arrival in August 2027, after which the propulsion module takes up a quasi-satellite orbit at Phobos, an unstable configuration demanding continuous correction, and remains in the Martian system for roughly three years. The Franco-German IDEFIX rover descends in late 2028 or early 2029. MMX then surveys candidate terrain, executes two touchdowns to acquire regolith, migrates to a Deimos-crossing orbit for flybys of the outer moon, and departs in November 2030 for a 2031 capsule recovery in Australia. NASA's contribution, roughly $87 million, bought the MEGANE gamma-ray and neutron spectrometer from the Johns Hopkins Applied Physics Laboratory, a Honeybee Robotics pneumatic sampler and DSN ground-station coverage, in exchange for at least fifteen percent of the returned material.

The scientific stake is a clean fork rather than an incremental refinement. Either Phobos and Deimos are asteroids captured into Martian orbit, in which case their composition should match known primitive meteorite classes and their presence tells us about capture dynamics in the early inner solar system; or they are accreted debris from a giant impact on Mars, in which case they carry Martian crustal material and constitute an accessible archive of the planet's violent youth. Isotopic analysis of returned grains distinguishes these outcomes decisively in a way that remote spectroscopy has conspicuously failed to do for half a century. The precedent is sobering: Russia's Phobos-Grunt, launched in 2011 with the same objective, never left Earth orbit and burned over the Pacific in January 2012. MMX has now cleared that particular hurdle, which is not the same as having cleared the mission.

inference

A conclusion reached from evidence and reasoning rather than direct observation.