TOKYO - Japan will try again this weekend to launch its new flagship rocket, the H3, in a bid to restore its space programme after the booster's failed inaugural flight in 2023 derailed satellite and planetary exploration plans.

Coupled with the historic “pinpoint” moon landing of its Slim spacecraft in January, a successful H3 lift-off would demonstrate Japan's space capabilities to its close ally the United States as a counterweight to China's military and technological might.

University of Tokyo professor Kazuto Suzuki, who specialises in space policy, said: “For Japan, the H3’s success is crucial to prove to the world that it is capable of launching satellites continuously. Making a good spacecraft is meaningless if you can’t launch it on a rocket.”

The Japan Aerospace Exploration Agency (Jaxa) plans to launch its second H3 on Feb 17 from its Tanegashima Space Centre in southern Japan. Jaxa delayed the launch by two days to avoid high winds and thunders.

Developed by Jaxa and prime contractor Mitsubishi Heavy Industries, the H3 was meant to replace the two-decade-old H-IIA rocket and reduce per-launch costs by half, to as low as 5 billion yen (S$44.8 million).

But the H3's first flight in March 2023 ended up with ground control destroying the rocket in mid-flight because its second-stage engine failed to ignite. Jaxa listed three possible electrical faults in a review released in October but could not identify the direct cause.

Two recent H-IIA launches, which had no issues, have raised hopes for the H3's second attempt, Mitsubishi Heavy's defence and space business head Masayuki Eguchi said in January.

H-IIA has successfully flown 47 of 48 times since 2001, but Jaxa will retire it after two more shots.

The H3's unsuccessful initial flight led to the loss of a 28 billion yen land observation satellite, Alos-3.

The setbacks of the H3 and another small rocket, Epsilon, have caused widespread delays in Japanese satellite launches.

Saturday's H3 launch carries a dumbbell-shaped 2.6 tonne dummy mass simulating a satellite payload.

Two earth observation micro-satellites, one from Canon Electronics and another from Seiren, are on board as secondary payloads.

Jaxa's 63m H3 rocket can carry a 6.5 tonne payload into space, more than H-IIA's maximum of six tonnes, and fly more cheaply by adopting simpler structures and automotive-grade electronics.

Launch operator Mitsubishi Heavy hopes to launch six H3s a year once stable production is established.

Securing cheap, independent access to space is the H3's biggest mission, as Japan envisions increasingly ambitious space plans with more frequent launches.

The H3 is also tasked with carrying a lunar lander for the joint Japan-India Lupex project and a cargo spacecraft for the US-led Artemis moon exploration programme.

Another objective is to win orders from global clients, as satellite launch demands have skyrocketed thanks to affordable commercial vehicles such as SpaceX's reusable Falcon 9.

The European Space Agency also plans to launch its lower-cost Ariane 6 for the first time in 2024, following the successful inaugural flight in January of the United Launch Alliance Vulcan rocket, a joint venture between Boeing and Lockheed Martin.

“The landscape has dramatically shifted in the decade since we started the H3's development,” Jaxa's H3 project manager Masashi Okada said at a news conference on Feb 13.

Dr Okada said the H3 could tap the burgeoning demand for launch vehicles, but it would require “various and continual efforts” to adjust to market needs and competition.

Tokyo University of Science professor Ko Ogasawara, who is a former Mitsubishi Heavy aerospace engineer, said that unlike SpaceX's agile development process centred around frequent test flights, Japan's engineering style focuses on eliminating errors, which led to the 11-month pause after the failed H3 launch.

“This may appear slow… but we are taking the most reliable path with minimum resources,” Prof Ogasawara said.

In the small rocket market, Tokyo-based start-up Space One will launch its Kairos on March 9, while Jaxa has not been able to schedule the first launch of new Epsilon S.

Kairos hopes to mark Japan's second commercial rocket series to reach space after Interstellar Technologies' Momo in 2019. REUTERS