New JAXA analysis of the December 22, 2025, H3 Rocket No. 8 failure—initially blamed on second-stage engine trouble—reveals a novel issue: the 5-ton Michibiki No. 5 navigation satellite separated prematurely during payload fairing jettison shortly after liftoff from Tanegashima Island.
Following the H3 No. 8 launch mishap, which led to the loss of the Michibiki No. 5 satellite and compromised orbit, JAXA has pinpointed the cause to an anomaly during payload fairing separation nearly four minutes post-liftoff.
Onboard video showed debris around the satellite, which immediately wobbled and tilted. Sensors detected sudden accelerations at the satellite's attachment to the upper stage, confirming unintended detachment. This fairing-related failure mode is distinct from prior H3 issues, such as engine malfunctions, and differs from the initial diagnosis of second-stage ignition problems.
The rocket otherwise continued flight, but the satellite failed to reach its planned high orbit over 20,000 miles for Japan's Quasi-Zenith Satellite System (QZSS), which enhances GPS precision. JAXA has not detailed fixes yet, but the incident highlights payload deployment challenges in new launchers and the critical nature of fairing separation.
