An explosion occurred during a test of the second-stage engine for Japan’s Epsilon S rocket on November 26, according to officials. The engine failure, which took place at the Tanegashima Space Center, has cast uncertainty on the rocket’s development schedule. The Epsilon S was expected to debut in March 2025 with the launch of a Vietnamese satellite, but the incident raises doubts about its readiness.

Investigations to Determine the Cause

The explosion, which happened 49 seconds into the engine test, marked the second such incident involving this design in less than two years. A similar test failure in July 2023 at JAXA’s Noshiro Rocket Testing Center resulted in significant damage to the facility, according to reports from The Asahi Shimbun.

In response to the explosion, officials from the Japan Aerospace Exploration Agency (JAXA) announced plans to launch an investigation in an official statement. The cause of the malfunction remains unknown. Takayuki Imoto, Project Manager for the Epsilon S programme, expressed regret during a press briefing, as reported by Kyodo News.

He said that they are extremely sorry for being unable to meet expectations. He further added that they can learn from failure and will use this opportunity as a lesson to develop a more reliable rocket.

Significance of Epsilon S for Japan’s Space Programme

The Epsilon S rocket has been positioned as a key vehicle for boosting Japan’s presence in low Earth orbit. Japanese Chief Cabinet Secretary Yoshimasa Hayashi, speaking to reporters, emphasised the importance of flagship rockets for the nation’s space autonomy, as reported by the Associated Press.

This setback is part of a broader series of challenges for JAXA. The agency has faced multiple high-profile failures, including the first launch of its H3 rocket in 2023 and issues with its SLIM lunar lander earlier this year.