Japan's H3 rocket after ten flights: what it has carried, and the two launches JAXA lists as failures

Japan's H3 rocket has now flown ten times. Its tenth flight lifted off from the Tanegashima Space Center at 04:41:03 Japan Standard Time on October 20, 2026, which was 19:41:03 UTC on October 19 by our conversion, carrying JAXA's Martian Moons eXploration (MMX) spacecraft. The rocket "flew as planned," JAXA said, and released MMX about 71 minutes and 13 seconds after liftoff into the planned orbit; a day later the agency said the probe had completed its initial critical operations and was in good health. Of the ten flights, JAXA's launch records and releases mark two as failures. Dates below are JAXA's, in Japan time.

What the H3 is

JAXA calls the H3 "Japan's new mainstay launch vehicle" and says it is developed by the agency together with Japanese companies. Its stated aims are flexibility, high reliability and a lower launch service price than the H-IIA's. Customers can choose between two payload fairings, two or three LE-9 main engines on the first stage, and zero, two or four SRB-3 solid boosters, and the rocket's capability to geostationary transfer orbit exceeds that of the H-IIA and H-IIB, according to JAXA's project page. The standard version, the H3-24L, is 63 meters long and weighs 574 tons without a payload.

The LE-9 needed more thrust than any liquid-fueled engine Japan had developed before, JAXA says. It uses an "expander bleed cycle," a design the agency knows from its LE-5 engines and says needs fewer parts and is less prone to abnormal combustion, and JAXA used new technologies such as 3D printing to simplify the engine's structure, raise reliability and lower cost.

Ten flights, as JAXA records them

"No failure noted" means JAXA's records list the flight without the failure note they carry for Test Flight 1 and flight 8; the wording is ours. The table is ordered by date, and on that reading the flight numbers were not flown in sequence: flight 6, a test of what JAXA calls the 30 configuration, lifted off on June 12, 2026, after flights 7 and 8.

The two failures

The first H3 failed on March 7, 2023, with the ALOS-3 land observation satellite aboard, and JAXA set up a special task force, its records show. The second failure came on flight 8, at 10:51:30 JST on December 22, 2025. The second-stage engine's second ignition "failed to start normally and shut down prematurely," JAXA said, so MICHIBIKI No. 5, a satellite of the Quasi-Zenith Satellite System, could not be put into its planned orbit. The agency apologized and set up a task force headed by its president, Yamakawa, to find the cause. The release we read does not give the cause, and we did not find a later report among the pages we opened.

The three flights since then all appear in JAXA's records or releases without a failure. For flight 9, which lifted off at 4:23:31 a.m. JST on August 11, 2026, JAXA said the vehicle flew as planned and that MICHIBIKI No. 7 separated about 29 minutes and 4 seconds after liftoff and reached its planned orbit. Flight 10 with MMX followed on October 20. By our count, that makes eight of ten flights without a recorded failure.

Not only the H3

JAXA does not rely only on its own rockets. Its launch records also include missions that flew on foreign rockets: the EarthCARE satellite on a SpaceX Falcon 9 from Vandenberg in May 2024, the Hera asteroid mission on a Falcon 9 from Cape Canaveral in 2024, and the RAISE-4 innovative payload demonstration satellite on a Rocket Lab Electron from New Zealand in December 2025. The most recent H-IIA flight in the records, the 50th, carried the GOSAT-GW greenhouse gas and water cycle satellite on June 29, 2025.

What comes next

JAXA's launch schedule page, last updated on June 12, 2026, lists its upcoming launches only as "FY2026 or later": the HTV-X2 to HTV-X5 cargo spacecraft, the Lunar Polar Exploration mission (LUPEX), the Precipitation Measuring Mission, DESTINY+, SOLAR-C, JASMINE, LiteBIRD and Engineering Test Satellite-9, as well as MMX, which has since flown. The page does not say which rocket will carry each one, and JAXA notes that the plan may change with budgets and development progress. JAXA's HTV-X2 is scheduled for 2026; the first HTV-X flew on the seventh H3. None of the JAXA pages we read gives a date for the next H3 launch.