TOKYO: The Japan Aerospace Exploration Agency, or JAXA, is likely to postpone the launch of the new H-3 rocket, planned before the end of March this year, as problems with its main engine are yet to be fixed, according to informed sources.

Considering the need to carry out a prior firing test, it is apparently difficult for JAXA to launch the first model of the H-3 rocket within two and a half months, the sources said.

JAXA said it has not made any judgment on the postponement, adding that it will give careful consideration to the timing of the launch.

The H-3 rocket, the successor to the existing H-2A rocket, has been under development jointly by JAXA and Mitsubishi Heavy Industries Ltd. since fiscal 2014. It will be equipped with two or three newly developed LE-9 first-stage main engines.

In May 2020, after an engine firing test, cracks caused by metallic fatigue were found in turbine blades of a device that pumps liquefied hydrogen into the firing chamber. The agency judged that changing the turbine design would be inevitable and postponed the new rocket’s launch, which was planned by the end of March 2021, by one year.

JAXA has been conducting tests of remodeled engines and there are still technical challenges that need to be addressed, the sources said. The agency is facing difficulty meeting the targeted launch date as it also needs to partially build the rocket to conduct the prior engine firing test, they said.

JIJI Press