JAXA Says Japan's H3 Rocket Launch Failure Most Likely Caused By Overcurrent

TOKYO (UrduPoint News / Sputnik - 17th March, 2023) The launch failure of a new Japanese H3 rocket earlier this month was most likely caused by an excessive electric current in the rocket's second-stage engine, which resulted in a power cut off, the Japan Aerospace Exploration Agency (JAXA) said on Thursday.

JAXA sent a self-destruct signal to abort the flight of the H3 rocket just minutes after it was launched from the Tanegashima Space Center in Kagoshima Prefecture on March 7. The signal was sent due to a failure in the ignition of the second-stage engine.

"There is a high probability that the power supply to the second stage engine was cut off as a result of an overcurrent, which occurred for an as yet unknown reason," JAXA said in a 27-page report on the website.

According to the report, the ignition signal was successfully transmitted to the second-stage engine, but the power supply was cut off after the rocket's systems detected an excessive electric current, resulting in the loss of power to the engine. Backup power sources connected to the engine were also cut off, the report added.

JAXA added that specialists will now have to determine what exactly caused the overcurrent: whether it was a failure in the electrical system inside the engine or whether it was a failure in the system as a whole.

The situation is further complicated by the fact that the H2A rocket, the predecessor of the H3 rocket, has the same equipment in the second-stage engine but lacks the function of detecting voltage and current anomalies.

Originally, the launch was scheduled for February 13 but was postponed to February 15 due to issues identified in the flight control system that changes the position of the rocket in response to the wind, and then was rescheduled for February 17 due to weather conditions.

On February 17, the rocket was planned to take off, but after the launch countdown had reached zero, the H3's main engine cut off, but solid rocket boosters did not ignite, leaving the rocket with Advanced Land Observing Satellite-3 "DAICHI-3" (ALOS-3) in payload on its launch pad. The launch was postponed to March.

The H3 rocket is expected to replace the currently used H2A. H3's payload is 1.3 times bigger than that of H2A, and launch costs are two times lower. H3's development started nine years ago and cost JAXA and Mitsubishi Heavy Industries 200 billion Yen ($1.5 billion).