JAXA reported that a new configuration of the problematic H3 rocket had launched successfully from the Tanegashima Space Center on 12th June. The H3, which is replacing the long-lived and reliable but expensive H2, has been plagued with issues.
The new ’30 configuration’ rocket reached its targeted orbit via three liquid-fueled LE-9 engines, and without boosters. Previous iterations of the H3, called the “22 Form” H3, had used only two of the LE-9s.
Six small satellites were released by the H3. These were developed by universities and other organizations. JAXA stated that along with the smallsats, the rocket would include a Performance Evaluation Payload”, which is to be placed into Sun Synchronous Orbit.
JAXA and Mitsubishi Heavy Industries co-developed the H3. It’s first launch, in March 2023, failed when the second stage did not ignite. In December 2025 saw a different malfunction in the second stage. The H3 Type 30 underwent two wet dress rehearsals, or Captive Firing Tests, to ensure that all first stage systems were functioning. An anomaly warning regarding the first stage hydrogen/oxygen tank was thrown on the first test, which took place on 24th July 2025. This warranted a second test to ensure that the situation had been remedied, and this was held on 15th March with all systems operating nominally.
Notes on the H3 rocket
The JAXA / Mitsubishi Heavy Industries H3 series of rockets is the Japanese government’s answer to the lower launch costs brought on by the success of SpaceX. The designers of this rocket looked to replicate the reliability of the H2 rocket, but with fewer bespoke parts. To this end, COTS items, especially from the automotive industry, are used. Multiple versions of the rocket are planned, and a range of prices to match the required capability will follow suit. Launch lead times should also shrink compared to the H2.
Published by James Hydzik
James Hydzik is a technology geek focused on the junction of engineering, writing, and coffee. He joined Orbital Today in 2020 to help make sense of the Johnson government’s decision to buy OneWeb. Since then, he has taken on interviewing and editor-in-chief roles. James learned the ropes of editing and writing with Financial Times magazines, The World Bank, PwC, and Ericsson. Thus far, interviewing New Space movers has put the biggest smile on his workaday face. The son of an Electrical Engineer, James understands the value of putting complex topics into clear language for those with a lay person’s understanding of the subject. James is a European transplant from the United States, and as ex-KA3LLL, he now holds European amateur radio licenses. His next radio project is a portable 10GHz EME (moonbounce) station, as it combines his childhood interests in antennas and space.
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