New details have emerged about the failure of Japan’s H3 rocket last month, revealing how it mysteriously lost its payload—a navigation satellite—before reaching its target orbit.

The Japan Aerospace Exploration Agency (JAXA) launched the seventh mission of its H3 rocket on December 21, 2025, carrying the Michibiki 5 satellite. Shortly after liftoff, the The rocket’s second stage engine suffered an anomaly which caused it to close prematurely. JAXA officials recently Revelation the cause of the rocket anomaly: The protective cone-shaped cover covering the satellite, known as the payload fairing, disintegrated about 4 minutes after launch. As a result, the satellite is left fighting for its life before it inevitably falls back to Earth.

JAXA shared more information about the recent anomaly, including this helpful illustration of the payload fairing falling off the rocket.

Anomaly anomaly

The rocket business was undoubtedly difficult, and the launch failed in every way. This incident, however, may be one of the strangest ways a rocket has failed to deliver its payload.

The 207-foot-tall (63-meter) rocket had a rocky debut, ending with a self-destruct command just 15 minutes after its first launch on March 6, 2023. Since the failed first launch, however, the H3 has pulled off five successful missions so far.

Shortly after the recent failed mission, JAXA DECLARED that telemetry data shows that the pressure in the hydrogen tank of the second stage begins to drop during the first stage of the engine’s combustion. As a result, the first stage of engine cutting occurred 27 seconds later than planned, delaying the second ignition by 15 seconds. At the time, it was unclear whether the satellite had separated from the rocket.

JAXA officials began an investigation into the anomaly and discovered that the pressure began to drop when the rocket accidentally jettisoned its payload fairing. The satellite and payload adapter may have been damaged by the shock of the fairing separation.

Footage captured by a camera mounted on the adapter showed the satellite with apparent damage to its panels and insulation after the payload fairing was removed. A shower of debris surrounded the satellite, trapping the rocket without its protection.

After the first stage was closed and separated, the shaking dislodged the satellite from its mooring, causing it to fall from the rocket. The camera shows the satellite lost Earth orbit during a premature descent back to Earth. JAXA officials stated that the satellite fell into the Pacific Ocean, in the same area as the first stage of H3.

Lost in space

JAXA does not yet know why the payload fairing suddenly disintegrated, and that part of the anomaly remains under investigation.

Japan’s H3 rocket is 11 years in the making, a successor to the H-2A, which the agency retired in June 2025. Before the latest setback, JAXA had aimed for at least two H3 launches each year. The rocket will launch another QSZ satellite in 2026, as well as Japan’s HTV-X cargo spacecraft. Japan’s Martian Moons eXploration (MMX) mission is also scheduled to launch aboard an H3 rocket in late 2026.

The unusual payload fairing separation, however, may force the space agency to delay its plans.