The H3 rocket launched on 20:51 in the Eastern time 22 December (01:51 UTC, 23 December) From the Tanegasim Space Center, carrying satellite Michibiki 5 (QZS-5 (quasi-zenithal satellite system 5 (QZS-5))). First degree, which runs on liquid hydrogen and liquid oxygen, worked nominally, but problems with the second degree meant, that the satellite was not launched into the planned geosynchronous transition orbit.
In a press release from the Japan Aerospace Exploration Agency (JAXA) later noted, that the second ignition of the second stage engine did not start normally, and it turned off prematurely. As a result, QZS-5 could not be put into the planned orbit, and launch failed.
After launch it was discovered, that the first shutdown of the second stage engine occurred on 27 seconds behind schedule, while the second ignition was delayed at 15 seconds and stopped almost immediately after starting. Telemetry showed, that the pressure in the hydrogen cylinder in the second stage began to drop during the combustion of the first stage, and this behavior is currently being investigated.
It is not clear, whether the satellite has separated from the launch vehicle. The US space force registered an object in an elliptical orbit 109 on 441 kilometer, corresponding to the launch from Tanegashima.
JAXA stated, that the agency has created a special task force, which will be headed by its manager – Yamakawa, to investigate the causes of the incident. QZSS is a Japanese navigation satellite system, designed to provide positioning services, navigation and time synchronization over Japan, and to improve GPS accuracy and reliability in the Asia-Pacific region.
It was the seventh launch of the 63-meter H3 rocket, Japan's flagship missile, designed to replace the older H-IIA and H-IIB missiles. It is also the second failure after the failed first launch in March 2023 year, again due to the problem with the second degree. The rocket recently launched the first HTV-X cargo spacecraft in October.
This failure will have potentially significant consequences for Japan's space sector. The single-use rocket was about to launch, among other launches, another QZSS satellite and a second HTV-X next year. Note, that the Martian Moons eXploration mission (MMX) should be launched on H3 in November-December 2026 year during the short launch window to Mars. MMX should have started during the previous window, in autumn 2024 year, but the mission was partially delayed due to the failure of the first launch of the H3 rocket. RH H3 also plans to launch a mission to an asteroid in the United Arab Emirates, which is currently scheduled for 2028 year.
Sunday's launch of the H3 rocket was the rocket's third flight this year and the Japanese company's fourth launch overall in 2025 year. A number of Japanese payloads have also flown on Rocket Lab Electron and SpaceX Falcon rockets 9, including the commercial firm iSpace's second lunar lander .
Source: https://spacenews.com