TOKYO, Feb 17 (Reuters) - Japan successfully launched its new H3 flagship rocket on Saturday, putting its space program back on track after multiple setbacks including the failure of the rocket's inaugural flight last year.

The launch also marks a second straight win for the Japan Aerospace Exploration Agency (JAXA) after its lunar lander, SLIM, achieved a "pinpoint" touchdown last month and made Japan only the fifth country to put a spacecraft on the moon.

A relatively small player in space by number of launches, Japan is seeking to revitalize its program as it partners with ally the United States to counter China.

The H3 lifted off at 9:22 a.m. local time (0022 GMT) and after it successfully released a small satellite, jubilant scientists at the Tanegashima Space Center in southern Japan clapped, yelled and hugged each other.

The rocket also released a microsatellite and a dummy satellite during its flight of nearly two hours.

"The newborn H3 has just made its first cry," JAXA project manager Masashi Okada, who has led the decade-long development of the new rocket, told a news conference.

"And we need to start preparing for the third H3 launch as soon as tomorrow."

The H3 is due to replace the two-decade-old H-IIA, which is retiring after two more launches. Another failed flight would have seen Japan face the prospect of losing independent access to space.

The first launch in March ended up with ground control destroying the rocket 14 minutes after liftoff when the 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.

Five months earlier, JAXA's small rocket Epsilon had also failed to launch.

"So happy to see this incredible accomplishment in the space sector that follows on from the success of the SLIM moon landing," Prime Minister Fumio Kishida said in a post on X.

The 63 m (297 ft) H3 is designed to carry a 6.5 metric ton payload and over the long-term, the agency wants to reduce per-launch cost to as low as five billion yen ($33 million) - half of what an H-IIA launch costs - by adopting simpler structures and automotive-grade electronics.

JAXA and primary contractor Mitsubishi Heavy Industries hope those features will help them win launch orders from global clients.

"It's taken some time for the program to get to this point but with this launch, they will be fielding inquiries from around the world," said Ko Ogasawara, a professor at the Tokyo University of Science.

The Japanese government plans to launch about 20 satellites and probes with H3 rockets by 2030 for domestic use. The H3 is scheduled to deliver a lunar explorer for the joint Japan-India LUPEX project in 2025 as well as cargo spacecraft for the U.S.-led Artemis moon exploration program in the future.

Satellite launch demands have skyrocketed thanks to the rise of affordable commercial vehicles such as SpaceX's reusable Falcon 9 and a number of new rockets are being tested this year.

Last month marked the successful inaugural flight of the United Launch Alliance’s Vulcan rocket, a joint venture between Boeing and Lockheed Martin. The European Space Agency also plans to launch its lower-cost Ariane 6 for the first time this year.

Masayuki Eguchi, the head of Mitsubishi Heavy's defense and space business, said the company has a long-term target of launching eight to ten rockets a year, which would boost its 50 billion yen space business sales by 20-30%.

That would require additional production capacity, he added, noting the company's factories can currently only produce five to six H3 rockets a year. ($1 = 150.2100 yen) (Reporting by Kantaro Komiya; Editing by Edwina Gibbs)