Japan launches a climate change monitoring satellite on mainstay H2A rocket's last flight

TOKYO — Japan on Sunday successfully launched a climate change monitoring satellite on its mainstay H-2A rocket, which made its final flight before it is replaced by a new flagship designed to be more cost competitive in the global space market.

The H-2A rocket lifted off from the Tanegashima Space Center in southwestern Japan, carrying the GOSAT-GW satellite as part of Tokyo's effort to mitigate climate change. The satellite was released into a planned orbit about 16 minutes later.

The launch follows several days of delays because of malfunctioning of the rocket's electrical systems.

Sunday's launch marked the 50th and final flight for the H-2A, which has served as Japan's mainstay rocket to carry satellites and probes into space with a near-perfect record since its 2001 debut. After its retirement, it will be fully replaced by the H3, which is already in operation, as Japan's new main flagship.

''Even though our launches seemed stable, we have run into difficulties and overcome them one by one to come this far,'' said Iwao Igarashi, senior general manager of the space systems division at Mitsubishi Heavy Industries, which operated launch services. ''As we now move on to the H3 launch service, we will firmly keep up the trust we gained from H-2A."

The GOSAT-GW, or Global Observing SATellite for Greenhouse gases and Water cycle, is a third series in the mission to monitor carbon, methane and other greenhouse gasses in the atmosphere. Within one year, it will start distributing data such as sea surface temperature and precipitation with much higher resolution to users around the world, including the U.S. National Oceanic and Atmospheric Administration, officials said.

The liquid-fuel H-2A rocket with two solid-fuel sub-rockets developed by Japan Aerospace Exploration Agency has so far had 49 flights with a 98% success record, with only one failure in 2003. Mitsubishi Heavy has provided its launch operation since 2007.

H-2A successfully carried into space many satellites and probes, including Japan's moon lander SLIM last year, and a popular Hayabusa2 spacecraft in 2014 to reach a distant asteroid, contributing to the country's space programs.

Japan sees a stable, commercially competitive space transport capability as key to its space program and national security, and has been developing two new flagship rockets as successors of the H-2A series — the larger H3 with Mitsubishi, and a much smaller Epsilon system with the aerospace unit of the heavy machinery maker IHI. It hopes to cater to diverse customer needs and improve its position in the growing satellite launch market.

The H3, is designed to carry larger payloads than the H-2A at about half its launch cost to be globally competitive, though officials say more cost reduction efforts are needed to achieve better price competitiveness in the global market.

The H3 has made four consecutive successful flights after a failed debut attempt in 2023, when the rocket had to be destroyed with its payload.