Halt of H3 Rocket Launch Deal Blows to Japan’s Space Business

By Yosuke Watanabe and Takako Sasamoto / Yomiuri Shimbun Staff Writers

21:00 JST, February 18, 2023

The first H3 rocket was moments away from its scheduled liftoff on Friday when an abnormality was detected, aborting the launch.

It was a painful setback for Japan’s space industry, as the country’s new flagship rocket is being touted for the reliability achieved in its predecessor, the current H2A, without the heavy costs, and targeted as a means to expand orders for launching commercial satellites.

The Japan Aerospace Exploration Agency (JAXA) is hurrying to find the cause and put the launch back on schedule.

“An abnormality of some sort was detected and the ignition signal [to the solid-rocket boosters] was not sent,” said a visibly distressed Masashi Okada, JAXA’s H3 rocket project manager, at a press conference following the aborted launch. “As of now, we know nothing more than that.”

The countdown for the maiden H3 at the Tanegashima Space Center in Kagoshima Prefecture was going smoothly, and the main engine ignited 6.3 seconds before the scheduled liftoff at 10:37:55 a.m. Liquid fuel began to burn on schedule, releasing plumes of white smoke.

That is when the abnormality occurred. The booster rockets filled with solid fuel were scheduled to ignite 0.4 seconds before the launch. However, the first-stage control unit detected an unidentified anomaly, and the ignition signal did not reach the booster rockets. As a result, the main engine automatically shut down.

“If the problem can be fixed by just rewriting the control program, the launch could be resumed quite soon,” said Tokyo University of Science Prof. Shinichi Kimura, a specialist on space system engineering. “However, if [it is more complicated and] parts need to be replaced, it seems it will be difficult to launch within this fiscal year.”

Reducing costs

Development of the H3 rocket, led by JAXA and Mitsubishi Heavy Industries, faced a myriad of troubles since it started in 2014. In particular, they had a hard time with the LE-9, the main engine of the first stage, for which the one in the H2A was significantly renovated.

The H3 was initially slated for a fiscal 2020 launch, but the plan was pushed back twice.

To cut costs, inexpensive automotive parts were used for 90% of the H3’s electronic components. The equipment that detected Friday’s abnormality also uses automotive parts. Before then, no similar trouble had occurred during inspections or rehearsals.

“We can’t discount simple human error such as forgetting to connect a cable,” said Kanazawa Institute of Technology Prof. Hideki Moriai, an expert on space propulsion engineering.

Tokyo University of Science Prof. Koichi Yonemoto, whose main field of expertise is aerospace engineering, pointed out, “The fact that the satellite did not go up can also be considered a failure in the ordinary sense.”

Reliability takes hit

Expectations are high for the H3, which was developed with marked cost reductions from the H2A, serving as a “commercial rocket.”

The H2A rocket boasts a launch success rate of 98%, but its high cost of about ¥10 billion per launch hampers its practical use. The majority of its cargo to date has been government satellites — there have been just five orders from other countries for space transportation of satellites and probes.

That said, the H2A has maintained a globally high level of reliability with an “on-time rate” — the percentage of launches that go off as scheduled, not including delays caused by weather — of 82.6%.