Japan’s flagship H2A rocket lifted off for the final time at 1:33 a.m. on Sunday from the Tanegashima Space Center in Kagoshima Prefecture, successfully concluding a 24-year run that has defined the nation’s space capabilities.

The rocket’s 50th and final mission carried the GOSAT-GW, a government-developed hybrid environmental observation satellite. The satellite combines the Advanced Microwave Scanning Radiometer for monitoring ocean surface temperatures and water cycle dynamics with the TANSO sensor, which measures greenhouse gases, and is expected to play a key role in the country’s climate change mitigation and resource management.

“We’ve had tremendous support from our partners. Thanks to their efforts, and also thanks to the guidance of JAXA, we've made it this far,” Iwao Igarashi, head of Mitsubishi Heavy Industries’ (MHI) space division, told a news conference following the launch. “We’re also deeply grateful to the local communities that have supported us.”

With this final launch, the H2A retires with a stellar track record — 49 successful launches out of 50, a success rate of 98%.

But despite the success rate, pulses were racing ahead of the rocket’s final go.

“To be honest, I was more nervous than I’ve ever been before,” said Keiji Suzuki, an MHI official in charge of the rocket launch. “And now that the launch has succeeded safely ... it still feels like I’m dreaming.”

Jointly developed by MHI and the Japan Aerospace Exploration Agency (JAXA), the 53-meter rocket debuted in 2001 and quickly became the workhorse of the country’s space program.

Some of H2A’s most vital payloads were weather and reconnaissance satellites that support the Quasi-Zenith Satellite System. It also enabled landmark missions such as the 2014 launch of the Hayabusa2 asteroid probe, which successfully returned samples from the asteroid Ryugu to Earth, and contributed to Japan’s first successful lunar landing in January 2024 by carrying the SLIM lander.

Originally scheduled for Tuesday, the launch was delayed after an anomaly was detected in the rocket’s second-stage electrical system. Engineers completed the necessary repairs and reinspections before clearing it for flight.

“From the outside, it might seem like things have been stable, but in reality, we've faced many challenges and overcome them one by one to arrive at this 50th mission,” Igarashi said.

The decision to retire the H2A comes amid rising global competition in the space launch industry, where cost-efficiency has become a key differentiator. While the H2A offered world-class reliability, its average per-launch cost of around ¥10 billion ($69 million) made it increasingly difficult to compete with rockets with lower price-to-payload prices, such as SpaceX’s Falcon 9.

With the H2A now phased out, attention turns to its successor, the H3 rocket. Co-developed by JAXA and MHI, the H3 offers lower launch costs and increased launch frequency amid intensifying international competition.

While its debut flight in March 2023 ended in failure, the program has since rebounded with four consecutive successful launches.

The upcoming sixth H3 mission, scheduled for later this year, will mark a key milestone. The rocket will be the first in its 30 configuration, using three liquid-propellant engines and no solid rocket boosters — a test of its low-cost configuration and a step toward Japan’s effort to build a globally competitive launch platform.

“With this final launch of the H2A, the torch now passes to the H3,” Igarashi told reporters. “We intend to carry over the trust we've built and continue moving forward with successful launches under the H3 program and will devote our full efforts to this next phase.”

As the H2A was consigned to the history books, Suzuki recognized the workhorse rocket’s successes.

“I have spent almost every day of my life at the company trying to keep the H2A from crashing,” he said. “To the 50th rocket itself, I want to say 'You did a great job. Thank you.'"