Launch of Japan’s H2A Rocket Delayed as H3 Probe Drags On

Yomiuri Shimbun file photo
The H2A Launch Vehicle No. 46 is seen at Tanegashima Space Center in Minamitane, Kagoshima Prefecture, on Jan. 26.

The takeoff of Japan’s H2A Launch Vehicle No. 47, which was scheduled for May, has been pushed back to at least summer, according to multiple government sources.

The decision was made because the H2A mainstay rocket uses the same componentry thought to have malfunctioned in the H3 rocket that failed in its maiden launch earlier this month, the sources said Thursday.

The Japan Aerospace Exploration Agency’s launch of the small Epsilon-6 rocket in October 2022 also ended in failure, and no timeframe has been set for that rocket’s successor to lift off. The delay in the H2A program leaves JAXA in the unusual situation of being unable to launch any of Japan’s three main rockets.

The H2A launch vehicle had been scheduled to blast off from Tanegashima Space Center in Kagoshima Prefecture with a payload including JAXA’s SLIM lunar lander. The next launch window will be in summer or later, due to factors including the rocket’s trajectory to the moon, according to the sources.

The H3’s second-stage engine failed to ignite minutes after liftoff on March 7, forcing JAXA to send a destruct command to the rocket. Investigations conducted so far have found that excess current in the H3’s engine’s electrical system appears to have caused the malfunction. The H2A and H3 rockets have virtually identical electrical systems in their second-stage engines, so JAXA officials decided to delay the launch until the details of the malfunction have been pinpointed.

The H2A series is planned to run up to H2A Launch Vehicle No. 50, and the remaining rockets are scheduled to carry payloads including the government’s information gathering satellite. There are concerns that delays in uncovering the cause of the H3’s malfunction also could affect the remaining H2A rocket launches.