The Japan Aerospace Exploration Agency (JAXA) is Japan's national space agency, formed on October 1, 2003, by merging the Institute of Space and Astronautical Science (ISAS), the National Aerospace Laboratory, and the National Space Development Agency. Led by president Hiroshi Yamakawa, it conducts science missions, human spaceflight, and launch vehicle development, flying its largest rockets from the Tanegashima Space Center in southern Japan.
JAXA has specialized in missions that return extraterrestrial material and in precision spacecraft engineering. Its Hayabusa probes performed the world's first asteroid sample returns, its SLIM spacecraft demonstrated pinpoint lunar landing in 2024, and its MMX mission, planned for launch in late 2026, aims to bring back the first samples from the Martian moon Phobos.[1][2] The agency is also a core partner on the International Space Station, where its new HTV-X freighter made its first delivery in 2025.[3]
SLIM and lunar exploration
The Smart Lander for Investigating Moon (SLIM) launched in September 2023, sharing its rocket with the XRISM X-ray telescope that JAXA developed with NASA and ESA, and touched down on January 20, 2024 (Japan time), making Japan the fifth country to soft-land on the Moon. The mission's purpose was accuracy rather than endurance: JAXA assessed that SLIM's vision-based navigation achieved its pinpoint landing goal, coming down about 55 meters east of the original target, and within roughly 10 meters of the point it selected during final descent, despite losing one of its two main engine nozzles on the way down.[4]
The nozzle failure left the lander tipped nose-down, with its solar cells facing away from the Sun, yet SLIM still returned data, observed surrounding rocks in ten spectral bands, and survived three lunar nights it was never designed to endure. JAXA declared the mission complete in August 2024 after months of silence.[4] Japan's future lunar work includes the LUPEX polar rover project with India's ISRO and participation in the Artemis program: under a 2024 agreement, Japan will provide a pressurized crewed rover, and two Japanese astronauts are slated to join future lunar surface missions.
Hayabusa asteroid sample returns
Hayabusa launched in 2003, reached the asteroid Itokawa in 2005, and in June 2010 delivered the first samples ever collected from an asteroid, despite fuel leaks, failed reaction wheels, and a damaged sampler. Hayabusa2 followed in 2014 with a more ambitious plan at the carbon-rich asteroid Ryugu: it fired a copper impactor to expose subsurface material, collected two samples, and returned 5.4 grams to Australia in December 2020. Analysis of the Ryugu grains found amino acids and other organic compounds, informing theories about the delivery of water and organics to early Earth. The spacecraft is now on an extended cruise toward the tiny asteroid 1998 KY26, with arrival planned in 2031.[1]
H3 and launch vehicles
The H3, developed with Mitsubishi Heavy Industries, is Japan's new flagship rocket, replacing the H-IIA, which retired in June 2025 after 50 flights. H3's debut in March 2023 failed when the second stage did not ignite, but the vehicle recovered with a string of successes from February 2024 onward, lofting payloads that included navigation, reconnaissance, and Earth observation satellites and the first HTV-X.[5]
| H3 configuration | First stage engines | Solid boosters | First flight |
|---|---|---|---|
| H3-22S/22L | 2 x LE-9 | 2 | March 2023 |
| H3-24L/24W | 2 x LE-9 | 4 | October 2025 |
| H3-30S | 3 x LE-9 | 0 | June 2026 |
A setback came on December 22, 2025, when an H3-22S failed in flight; investigators suspect the payload support structure broke away after fairing separation and damaged the second stage's liquid hydrogen tank. The rocket returned to flight on June 12, 2026, with the first all-liquid H3-30 configuration, which placed six small satellites into a 580-kilometer orbit.[5][6] JAXA is separately developing the small solid-fuel Epsilon S, whose return to flight has been delayed by motor test failures.
MMX Phobos sample return
Martian Moons eXploration (MMX) is JAXA's next flagship. The spacecraft arrived at Tanegashima on March 31, 2026, for a planned launch on an H3 in the late-2026 window, around November, reaching Mars orbit in 2027.[2] MMX will spend about three years studying Phobos and Deimos, land on Phobos at least once to collect more than 10 grams of surface material, and deploy a small rover built by the French and German space agencies. Its instruments include MEGANE, a gamma-ray and neutron spectrometer contributed by NASA. The return module is scheduled to bring the samples to Earth in Japanese fiscal year 2031, which would be the first material ever returned from the Martian system, and should settle whether Phobos is a captured asteroid or debris from a giant impact on Mars.[2][7]
ISS contributions and human spaceflight
JAXA supplied the International Space Station's largest laboratory, Kibo, launched across 2008-2009, and resupplied the outpost with nine HTV "Kounotori" freighters between 2009 and 2020. Its successor, HTV-X, is larger and can keep payloads powered until berthing. HTV-X1 launched on an H3 on October 26, 2025, carrying about 5.8 tonnes of supplies, was captured by JAXA astronaut Kimiya Yui with the station's robotic arm four days later, and completed its mission with a destructive reentry in May 2026.[3][8]
Japanese astronauts fly regularly on station crews; Takuya Onishi commanded the ISS in 2025. JAXA also contributes hardware to the lunar Gateway program and selected two new astronauts in 2023, its first class in 14 years, with lunar missions in view.
References
- SLIM, Japan's precision lunar lander - The Planetary Society.
- Martian Moons eXploration - JAXA.
- Launch Result of New unmanned cargo transfer spacecraft1 (HTV-X1) aboard the 7th H3 Launch Vehicle (H3 F7) - JAXA.
- Conclusion of Lunar Activities of the Smart Lander for Investigating Moon (SLIM) - JAXA.
- H3 (rocket) - Wikipedia.
- Japan's space agency to launch H3 rocket on June 10 - The Japan Times.
- Martian Moons eXploration - Wikipedia.
- HTV-X1 - Wikipedia.