JAXA's eighth H3 rocket failed on December 23, 2025, due to second-stage engine issues, preventing deployment of the Cabinet Office's Michibiki No. 5 satellite, as initially reported. President Hiroshi Yamakawa apologized, vowing to pinpoint the cause swiftly. The incident jeopardizes Japan's quasi-zenith satellite system for high-precision positioning.
JAXA is investigating whether Michibiki No. 5 separated, amid complex microgravity control challenges in the second-stage engine, according to Prof. Ko Ogasawara of Tokyo University of Science. This marks the second H3 failure, following the debut launch in 2023, which took seven months to resolve similar ignition problems.
The H3, successor to the retired H2A, targets halving launch costs from ¥10 billion per mission (total development ~¥240 billion). Michibiki, Japan's GPS counterpart, relies on quasi-zenith and geostationary satellites for superior accuracy. Five satellites currently operate (including No. 6, launched before No. 5), but seven are required for full independence from foreign systems. Units 5-7, costing ¥100 billion, incorporate inter-satellite ranging for enhanced precision; No. 7 was planned for February, with full operations next fiscal year. Essential for Self-Defense Forces and security, the Cabinet Office is reassessing schedules.
Japan lacks reliable core rockets, with Epsilon S also delayed. Globally, launches surged to 253 successes in 2024 (U.S.: 153 mostly SpaceX; China: 66) from 85 in 2015; Japan managed only 5. A Cabinet Office official noted uncertainty until the cause is identified. Over 30 H3 missions are slated next decade for satellites and probes.
