Japan Aerospace Exploration Agency
Japan's national space agency, formed 2003 from merger of ISAS, NAL, and NASDA. Operator of ALOS SAR series, GOSAT greenhouse gas satellites, GCOM climate observation missions, and HISUI hyperspectral ISS instrument. Launch authority for H-IIA (retired), H3 (operational), and Epsilon-S (in development).
Japan Aerospace Exploration Agency (JAXA) is Japan's national space agency, established on 1 October 2003 through the merger of three predecessor organisations: the Institute of Space and Astronautical Science (ISAS), the National Aerospace Laboratory of Japan (NAL), and the National Space Development Agency of Japan (NASDA).[^jaxa-wiki] Structured as a National Research and Development Agency, JAXA is headquartered in Chofu, Tokyo, with its Earth observation activities centred at the Earth Observation Research Center (EORC), part of the First Space Technology Directorate.[^jaxa-eorc]
JAXA's principal EO programme is the Advanced Land Observing Satellite (ALOS) series, based on L-band synthetic aperture radar. ALOS-2 (Daichi-2), launched May 2014 and carrying PALSAR-2, remains operational in extended mode alongside its successor ALOS-4 (Daichi-4), launched July 2024 and equipped with PALSAR-3.[^eoportal-alos2][^eoportal-alos4] PALSAR-3 provides 3 m resolution over a 200 km swath in Stripmap mode, a fourfold swath expansion over PALSAR-2 at equivalent resolution, enabling faster disaster response and improved deforestation monitoring. JAXA acts as system authority for both missions; satellite development is contracted to Mitsubishi Electric.[^eoportal-alos2]
In greenhouse gas observation, JAXA operates the GOSAT (Ibuki) series in partnership with Japan's Ministry of the Environment and the National Institute for Environmental Studies. GOSAT-1, launched in 2009, and GOSAT-2, launched in 2018, both continue in extended operation as of 2025-2026, measuring CO2 and methane column densities across sub-continental scales.[^eoportal-gosat][^eoportal-gosat2] Their successor, GOSAT-GW, launched June 2025 as the final flight of the H-IIA rocket, carries TANSO-3 for greenhouse gas observation alongside AMSR3 for water cycle measurements.[^wikipedia-gosat-gw]
JAXA's Global Change Observation Mission (GCOM) series addresses the water and carbon cycles. GCOM-W (Shizuku), launched 2012 with the AMSR2 microwave radiometer, reached its tenth year of operation in 2022 and has been superseded operationally by GOSAT-GW carrying AMSR3.[^gcom-w-eorc] GCOM-C (Shikisai), launched December 2017 with the SGLI optical-infrared sensor (380 nm - 12 um, 250 m - 1 km resolution), monitors carbon cycle dynamics, aerosol transport, and ocean color globally every two to three days.[^gcom-c-jaxa]
JAXA provides ISS Japanese Experiment Module Exposed Facility (JEM-EF) accommodation for the Hyperspectral Imager Suite (HISUI), launched 2019. The instrument was built by AIST and the mission is operated by Japan Space Systems (JSS) under METI funding; radiometric calibration updates have continued through 2026, past the nominal 3-year mission life. HISUI covers 0.4-2.5 um in 185 spectral bands at 20 m x 30 m GSD over a 20 km swath.[^eoportal-hisui] Himawari-8 and Himawari-9, the geostationary meteorological satellites at 140.7 deg East providing full-disk coverage every 10 minutes across 16 AHI channels, are owned and operated by the Japan Meteorological Agency (JMA); JAXA EORC contributes data processing and distribution support.[^eoportal-himawari]
JAXA distributes EO data through G-Portal (gportal.jaxa.jp), its primary open-access satellite data distribution platform requiring registration for download. EORC produces derived data products including the PALSAR Annual Forest/Non-Forest Map and the JJ-FAST tropical deforestation alert system, the latter jointly with JICA.[^jaxa-eorc][^jaxa-jjfast]
On the launch side, JAXA developed the H-IIA medium-lift rocket in partnership with Mitsubishi Heavy Industries, completing 49 successful flights before retirement on its 50th and final mission in June 2025.[^wikipedia-hiia] The successor H3, developed by JAXA and MHI, completed its first successful launch in February 2024 and is now operational.[^wikipedia-h3] The small solid-fuel Epsilon rocket, operated by IHI Aerospace, retired in 2022 following a sixth-launch attitude-control failure; its successor Epsilon S targets launch in late 2026.[^wikipedia-epsilon]