Quiet Goodbye, Bold Hello: Japan’s H3 Rocket Takes the Torch from H-2A to Slash Costs and Double Cadence
Japan’s H-2A completed its 50th and final launch on June 28, 2025, carrying the GOSAT-GW climate-monitoring satellite, after a 49-for-50 success rate (98%). Over its service, H-2A lofted payloads including SELENE (Kaguya), Akatsuki, Hayabusa 2, and the Emirates Mars Mission. H3, Japan’s next-generation launcher, is designed to be more cost-effective and flexible, standing about 57–63 meters tall with a 5.2-meter first-stage core and up to 6.5 metric tons to geostationary transfer orbit. The H3 uses LE-9 engines in configurations of two or three with an expander-bleed cycle, the first main-stage application of this cycle, delivering about 1,470 kN thrust per