Japan loses another H3 launcher, plus the satnav bird it carried

Steven

Japan loses another H3 launcher, plus the satnav bird it carried

Summary

Japan’s Aerospace Exploration Agency (JAXA) has launched a Special Task Force after the eighth flight of its H3 rocket failed on 22 December 2025. The rocket’s second-stage engine failed to ignite properly during a second ignition attempt and shut down prematurely, dooming the mission.

The lost payload was QZS-5, a satellite intended to join Japan’s seven-satellite navigation constellation (QZSS) to reduce reliance on foreign systems. The H3 was designed to replace the reliable H-IIA launcher; however, with two failures in eight flights, the H3’s failure rate now stands at 25%.

JAXA had earlier seen the maiden H3 flight in March 2023 fail after a second-stage command ignition did not occur; six flights between then and this mission succeeded. The latest setback threatens domestic navigation plans and has knock-on implications for international projects — including plans to use H3 for the LUPEX water-spotting mission (a JAXA–ISRO collaboration) and contributions to the Artemis lunar programme.

Key Points

  • JAXA has formed a Special Task Force to investigate the H3 failure on 22 December 2025.
  • The H3’s second-stage engine “second ignition” failed to start normally and shut down prematurely.
  • This was the H3’s eighth mission; with two failures, the vehicle now has a 25% failure rate.
  • The lost payload, QZS-5, was intended to be part of Japan’s QZSS satnav constellation to reduce dependence on other nations’ services.
  • The H3 was developed to replace the long-serving H-IIA (50 flights, one failure between 2001–2025), so reliability concerns are significant.
  • The failure endangers planned missions that would rely on H3, such as the LUPEX lunar water-spotter (in partnership with ISRO) and some Artemis-related activities.
  • ISRO continues its own launch cadence — its LVM3 was preparing to launch AST SpaceMobile’s BlueBird Block-2 around the same period.

Context and Relevance

Reliable access to space is essential for national security, commercial services and international partnerships. A 25% failure rate after eight flights undermines confidence in the H3, raises costs and scheduling risks for customers, and complicates Japan’s ambitions to field independent satnav capability and support lunar exploration.

The setback also matters commercially: launch reliability influences satellite operator choices, international cooperation and where countries place strategic payloads. For JAXA, restoring trust in the H3 will be crucial if it is to meet commitments such as LUPEX and other domestic and international launches.

Why should I read this?

Short version: this is a proper headache for Japan’s space folks. The H3 was supposed to be the reliable workhorse after H-IIA — now it’s got a 25% fail rate and one of Japan’s own navigation satellites is gone. If you follow space policy, satellite services, or the Artemis/LUPEX plans, this matters — we’ve done the legwork so you don’t have to slog through the launch chatter.

Source

Source: https://go.theregister.com/feed/www.theregister.com/2025/12/23/jaxa_h3_failure_inquiry/