Japan may not make as much noise about its space programme as other countries, but its been quietly notching up some impressive achievements. In January 2024, its Smart Lander for Investigating Moon (SLIM) performed the equivalent of landing on the head of a pin: touching down within metres of its target.
Unfortunately, such missions rarely go without at least one hitch: the spacecraft subsequently toppled on its side, leaving its solar panels oriented away from the Sun. After running on battery power for a time, the spacecraft was powered down for nine days – after which it was successfully revived. SLIM ultimately set the record for longevity among lunar surface spacecraft not packing a nuclear battery.
The probe also successfully deployed two rovers of unique design. Lunar Excursion Vehicle 1 (LEV-1), which moves by hopping, and Lunar Excursion Vehicle 2 (LEV-2) or Sora-Q, which is a tiny rover developed by JAXA in cooperation with the toy company Tomy, Sony, and Doshisha University. The 250g – baseball-sized – probe is propelled by wheels at its sides, inspired by frogs and sea-turtles.
Now, Japan has launched perhaps its most audacious mission yet: to travel to a Martian moon and return samples to Earth.
While NASA’s grand ambition to retrieve Martian soil remains bogged down in the bureaucratic mire – its Perseverance rover diligently collecting tubes of dirt on the Red Planet while the retrieval mission itself sits indefinitely stalled by institutional paralysis and runaway budget blowouts – the Japanese have quietly demonstrated how to run an interplanetary expedition without turning it into a taxpayer-funded bottomless pit.
Before dawn from the southern coast of Tanegashima, the Japan Aerospace Exploration Agency (JAXA) fired up its flagship H3 rocket, lofting the Martian Moons eXploration (MMX) spacecraft skyward.
The 4,480-kilogram spacecraft will travel to Phobos, the larger of Mars’ two moons, and is scheduled to enter Martian orbit in August 2027. A French-German rover will first land on Phobos, followed by two planned landings by the Japanese spacecraft to collect samples.
The plan possesses that clockwork elegance the Japanese engineering establishment does so well. The spacecraft will voyage through the void for approximately a year, arrive in the Martian sphere and deploy a clever European reconnaissance rover before the mothership descends twice to gather at least 10 grams of primordial celestial crust. After checking in on Mars’ smaller companion, Deimos, the return capsule will head homeward, slated to land in the dusty expanse of South Australia in 2031.
Targeting Phobos is not merely scientific ambition: it is an exercise in sublime practicality. Escaping the gravitational clutch of Mars proper demands an escape velocity of some 18,100 km/h, a staggering logistical hurdle requiring hefty rocketry, heat shields and fuel reserves that have sent American planners into paroxysms of committee reviews. Phobos, by contrast, is a lumpy cosmic spud barely 20-odd kilometres wide.
Phobos, the larger of the two Martian moons, orbits the planet three times a day. Phobos has an irregular shape with dimensions of about 27 km by 22 km by 18 km (17 miles by 14 miles by 11 miles), and orbits roughly 6,000 km (3,700 miles) above the Martian surface.
Its gravitational pull is so negligible that an energetic astronaut could practically jump off its surface straight into interplanetary orbit: the escape velocity is a modest 41 km/h, easily achievable on a decent racing bicycle. Yet because billions of years of meteorite impacts have blasted debris off the Martian surface and scattered it across its inner moon, skimming the regolith of Phobos offers a cut-price bounty: a treasure trove of Mars material without the crippling headache of blasting back off the planetary surface.
Naturally, the path to the launchpad was not entirely devoid of drama. The mission suffered delays after the maiden flight of the H3 rocket failed in 2023 when its second-stage motor stubbornly refused to ignite. But unlike the sclerotic bureaucracies of the West, where a blown valve results in seven years of royal commissions and DEI seminars, the engineers at JAXA put their heads down, rectified the fault and returned to the business of exploring the heavens.
If all proceeds according to schedule, the Land of the Rising Sun will soon deliver humanity’s first physical remnants from the Red Planet (or, at least, its moons), leaving the grandstanding behemoths of legacy spaceflight looking rather flat-footed on the launchpad.
