*

Explosion could delay Epsilon S rocket's debut launch

beyond

March

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JAXA and IHI investigating cause of engine test failure

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Epsilon S and H3 rockets key to Japan's space ambitions

(Adds JAXA project manager quotes, paragraphs 2-4)

By Kantaro Komiya

TOKYO, Nov 26 (Reuters) - Japan's space agency aborted

an engine test for the Epsilon S rocket on Tuesday after it

exploded and caught fire, a repeated failure that will likely

push the rocket's debut launch beyond the March-end target and

delay the national space programme.

The Japan Aerospace Exploration Agency (JAXA) said the

combustion test resulted in an explosion of the second-stage

motor 49 seconds after the ignition, causing fire at the

Tanegashima Space Center in southwestern Japan.

While no one was injured and the fire was put out within

an hour, the blast damaged the facility, and the cause remains

unclear, JAXA's Epsilon project manager Takayuki Imoto told a

media briefing.

"We are sorry that we couldn't meet everyone's

expectations...but a silver lining was that we found (the issue)

at a ground test, before putting it for a flight," Imoto said,

adding it will likely take at least several months to

investigate the cause and take necessary countermeasures.

JAXA partnered with the aerospace unit of heavy machinery

maker IHI to develop Epsilon S, the next generation in

the Epsilon solid-fuel small rocket series.

Shares in IHI were down as much as 7% in Tokyo trade. An IHI

Aerospace spokesperson said the company was investigating the

cause.

Epsilon S's debut flight was slated by the end of the fiscal

year through March 31 depending on the success of Tuesday's

engine test.

The test was conducted after previous failures triggered

months of investigation which have delayed space missions and

satellite launch plans.

In July last year, an Epsilon S engine test failed due to

thermal damage to its ignition systems. That followed a launch

failure of a previous-generation Epsilon rocket in 2022.

JAXA's larger flagship rocket H3, built by Mitsubishi Heavy

Industries ( MHVYF ), failed at its first launch last year but

has succeeded in three flights this year, launching Japanese

satellites and winning orders including from French satellite

operator Eutelsat.

The H3 and Epsilon S are central to JAXA's ambition to build

cost-competitive rockets amid the rise of American commercial

launch providers such as market leader SpaceX and small rocket

maker Rocket Lab.

Japan's Chief Cabinet Secretary Yoshimasa Hayashi, the top

government spokesperson, said at a regular press briefing that

rocket development is "extremely important" to ensure the

autonomy of Japan's space programme.

In the private sector, IHI-backed Space One is set to

attempt the second launch of its Kairos small rocket on Dec. 14

after the first flight exploded in March. It aims to become the

first Japanese business to put a satellite in orbit.