In a blow to Japan’s ambitious space program, the country’s flagship H3 rocket experienced a critical failure during its eighth flight on December 22, 2025, failing to place a vital navigation satellite into its planned orbit.
The launch occurred from the Tanegashima Space Center in southern Japan, where the H3 rocket lifted off carrying the Michibiki 5 (also known as QZS-5) satellite, intended to enhance Japan’s Quasi-Zenith Satellite System (QZSS) for improved geolocation services. Shortly after liftoff, an anomaly in the second-stage engine caused it to cut off prematurely, preventing confirmation of the satellite’s separation from the rocket. As a result, the satellite’s location remains unknown, and it is presumed lost or not in the correct orbit.
Developed by the Japan Aerospace Exploration Agency (JAXA) in collaboration with Mitsubishi Heavy Industries, the H3 rocket represents Japan’s next-generation launch vehicle, designed to replace the reliable but aging H-IIA series. The H3 aims to offer lower costs and greater flexibility to compete in the global commercial space market while supporting national security needs, such as independent positioning systems free from reliance on U.S. GPS technology.
This is not the first setback for the H3. Its debut flight in March 2023 also ended in failure due to a second-stage engine ignition issue, leading to the destruction of the rocket and its payload. Following that incident, JAXA conducted six successful launches, building confidence in the program. However, this latest anomaly underscores ongoing challenges with the rocket’s upper stage reliability.
According to preliminary reports from Spaceflight Now, the second-stage engine burn halted unexpectedly, disrupting the mission’s trajectory. JAXA officials have stated that the exact cause is under investigation, with teams analyzing telemetry data to identify the root issue, as detailed in Reuters. No immediate details on potential hardware or software faults have been released, but experts speculate it could involve propulsion system irregularities similar to the 2023 failure.
The Michibiki 5 satellite was meant to join Japan’s QZSS constellation, which currently consists of four operational satellites. This network provides high-precision positioning data for applications like smartphone navigation, maritime operations, and autonomous drones.
This failure delays Japan’s goal of establishing a fully independent geolocation system. The country plans to expand the QZSS to seven satellites by March 2026 and up to 11 by the late 2030s, reducing dependence on foreign systems. In the interim, Japan will continue to rely partially on American GPS, which could pose strategic vulnerabilities.
JAXA has formed a government task force to probe the incident and implement corrective measures, as reported by SpaceNews. Project manager Masashi Okada emphasized that while the H3 is still in its early development phase, the team is committed to resolving issues to make it a competitive global option. The setback comes amid increasing competition in the space sector, with players like SpaceX and emerging programs in China advancing rapidly.
Despite the disappointment, experts note that launch failures are part of the iterative process in rocketry. JAXA’s track record with the H-IIA – boasting a near-perfect success rate – suggests potential for recovery. The agency has not announced a timeline for the next H3 attempt, but swift resolution will be important to maintaining momentum in Japan’s space endeavors. For more details, see coverage from NHK World, Asahi Shimbun, ABC News, Gizmodo, and Space.com. Watch the launch video on YouTube.
This incident highlights the high-stakes nature of space exploration, where even advanced programs face unpredictable challenges. As investigations proceed, the global space community will watch closely for lessons that could benefit future missions.