H3 Returns to Flight, Achieves Milestones

Following a failure with the second stage engine in March 2023 during its maiden flight, the Japanese Aerospace Exploration Agency (JAXA) successfully launched its second H3 rocket on January 16th, 2024. The vehicle lifted off at 9:22:55 AM local time, carrying a variety of demonstration payloads, finally certifying the long awaited launch vehicle for flight. With its first flight in the books, H3 now aims to compete on a global stage in the launch market, with broader goals of contributing to the Artemis program and beyond. 

Japan has been steadily marching towards a more robust independent presence in the launch vehicle market, building on their long heritage of working with cryogenic vehicles which share common heritage with the American Delta family. With a resurgent rise in the Japanese aerospace sector following the Dot Com burst, and a global need for more reliable and frequently flying launch vehicles, both JAXA and Mitsubishi Heavy Industries began to study successors to the venerable H-IIA and B vehicles. Development of H3 began in 2013, with the Japanese government green lighting a next generation successor with a focus on modularity and cost effectiveness. Some of the most notable improvements over previous vehicles are the new, low cost LE-9 engines on the core stage. These, combined with the new SRB-3 solid rocket motors in a variety of configurations, make the vehicle an agile competitor. 

Certification of H3 has been delayed by several setbacks, notably issues with the new LE-9 engines, the COVID-19 pandemic, and a failure on the first flight of the vehicle. Despite a nominal liftoff on the maiden flight of H3 on March 7, 2023, JAXA’s first attempt ended with a mission failure and loss of the payload following the use of the flight termination system after the rocket’s second stage could not have been confirmed to have ignited. At the time of failure, H3 was carrying a high profile Earth observation satellite that was intended to monitor natural disasters, called the Advanced Land Observing Satellite 3.

Friday’s mission was dubbed H3 Test Flight 2, with the vehicle’s aerodynamic fairing bearing a large “Return To Flight” decal filled with messages of support from across the industry. The primary payload, Vehicle Evaluation Payload-4 (VEP-4), was a mass simulator for purposes of demonstrating the vehicle’s performance and restart capability of the second stage. It was a steel beam, permanently affixed to the second stage. JAXA issued a statement in December 2023 that it “will capitalize on the excess launch capability of the H3 Test Flight 2 by providing launch and orbit insertion opportunities for two small secondary payloads (piggyback payloads), CE-SAT-IE and TIRSAT.” The vehicle lifted off from Tanegashima Space Center’s LP2, JAXA and Mitsubishi Heavy Industries’ pad for H-IIA, H-IIB and H3 rockets at 9:22:55 AM local time, arcing over the Pacific ocean and performing a visually distinctive “dogleg” maneuver to place the rocket on the correct trajectory. Nearly 15 minutes later, the vehicle was in orbit, completing the first successful demonstration of the H3 system, and the second stage performed its deorbit maneuver.  

Officials from JAXA were reportedly incredibly pleased with the outcome of the second test flight. The emotions from both the launch commentators and in the mission control center were palpable, with tears and embraces celebrating the success of the flight. Publicly available United States Space Force tracking data indicated the rocket reached an orbital altitude of approximately 420 miles (680 kilometers), with an inclination of 98.1 degrees to the equator, exactly where it needed to be. “The H3 finally gave its first cry. The launch was a perfect success,” said Masashi Okada, JAXA’s H3 project manager told Japan’s Mainchi newspaper. This success comes at an opportune time, as numerous next generation launch vehicles from across the world make 2024 their debut year, including Vulcan, New Glenn, Ariane 6, and more. 

With H3’s second test flight a success, the vehicle will now begin to compete with these contemporary launch vehicles for a share of the ever-crowded launch market. With a stated cost per launch of $50 million, H3’s price point could make it potentially more affordable than the European Space Agency’s upcoming Ariane 6 rocket and even SpaceX’s workhorse Falcon 9. Arguably more importantly, Japan no longer faces the uncertainty of a launcher gap – a drastic reduction in capability which the European continent is currently facing due to delays with Ariane 6. However, the impacts of H3’s pre-existing delays are already being felt. Uncertainty in the vehicle’s readiness forced JAXA to delay the launch of the ambitious MMX Phobos sample return mission from 2024 to 2026. H3 is also planned to launch the ambitious LUPEX mission, a joint venture between ISRO and JAXA to further advance the study of the Lunar South Pole.

Despite being unable to secure many commercial payloads as of the time of writing, JAXA hopes that a flight-proven H3 will attract customers from around the world, cementing them as an agile and reliable competitor in an ever-changing market. The vehicle, rather unsurprisingly, is an attractive domestic option for JAXA and the Japanese military, and has received awards for International Space Station logistics flights and the Quazi-Zenith Satellite System military network. This, coupled with future planetary science missions, will cement the vehicle as a tremendously important national asset for Japan, potentially bridging the gap to give international competitors a run for their money. 

Edited by Beverly Casillas