3.04.2023

Ongoing investigation into March H3 engine failure root of most recent setback

TOKYO -- Japan's planned May launch of its large H-IIA rocket will be postponed until at least August, the country's space agency announced Friday.

The Japan Aerospace Exploration Agency (JAXA) said it canceled the H-IIA launch because the rocket shares many of the same components with the H3 rocket that failed to launch in March.

The delayed mission, the 47th for the H-IIA rocket, was to launch from the Tanegashima Space Center in the country's south. The payload included what was to be JAXA's first lunar lander, SLIM, and a satellite with a space telescope.

In addition to the H-IIA, Japan has two other rocket types, the smaller Epsilon which experienced a launch failure in October, and the large H3, which self-destructed on March 7 after the second-stage engine failed to ignite.

Neither rocket type has a timetable for future launches, and now the agency's last remaining rocket has been grounded.

The H3 and H-IIA rockets share many components. For the H-IIA to meet its May launch date, it would have had to begin the fueling process for the SLIM lander in March, but the investigation into the cause of the H3's failure is still ongoing.

Because the latest planned mission is to land a vehicle on the moon, the launch must be timed to the moon's orbit, pushing the next launch window back to August or later.

However, the delay could end up being more than three months, depending on how long the H3 investigation drags on.

Nearly six months have passed since the Epsilon launch failure, and its cause has yet to be determined. Considering that the H3 is much larger and has more parts, many analysts say its investigation could take years.

The H-IIA had an excellent track record up to now, failing only once out of 46 launches, a 98% success rate. Its second-stage engine has never had any problems.

"JAXA's decision was surprising. The H3 and H-IIA's second-stage engines have a lot in common. For JAXA, having a critical issue with equipment that has a proven track record must have come as a shock, forcing them to make the deliberate decision to expand the investigation to the H-IIA," said professor Koichi Yonemoto of the Tokyo University of Science, who specializes in aerospace engineering.

Mitsubishi Heavy Industries has been the prime contractor for H-IIA launches since 2007. The postponement of the May launch gave rise to concerns about the impact on business, but the company declined to comment on JAXA's announcement.

It is difficult to overstate the impact on Japan's space program. In addition to space exploration and scientific experiments such as lunar landings, plans to launch reconnaissance and earth observation satellites will be affected. The repercussions will also extend to efforts to build out the Quasi-Zenith Satellite System, an Asia-Oceania positioning system spearheaded by Japan.

Missions to supply the International Space Station may also be affected.

Demand for satellite launches is increasing globally. As SpaceX, led by U.S. entrepreneur Elon Musk, drives the market, Japan has shown a policy of challenging the competition with next-generation low-cost rockets like H3 and Epsilon -- all based on the achievements of the H-IIA.

Quelle: Nikkei