Nikkei XTech asked Masashi Okada, the project manager for Japan Aerospace Exploration Agency (JAXA)’s H3 rocket, about the H3’s cost-cutting measures such as the use of electronic parts for the rocket body as well as additive manufacturing (3D printing).
Interviewed by Shinya Matsuura, science and technology journalist, Seiji Takaichi, and Riki Nakayma, Nikkei XTech
Nikkei XTech: What position does the H3 occupy in terms of space transport systems?
Okada: The H3 is the culmination of the rocket technology that Japan has built up over the years. We’re aim to build the “ultimate disposable rocket.” In the U.S., there are efforts to recover and reuse certain parts of rockets that have been launched. We will refine the H3 as a lean rocket without any excess in manufacturing, launch preparation, and inspection so that it will be a viable business. In the next 20 years, we will develop the H3 into a competitive rocket.
Toward that goal, we are cutting launch and maintenance costs. The technology we accumulate will be fully utilized for various cost-cutting measures. We will continue to invest in the future to maintain and develop the foundation of Japan’s rocket industry.
Nikkei XTech: Hearing about “cost-cutting” raises concerns about whether reliability will be lost.
Okada: It would be meaningless if we cut costs and ended up “getting what we paid for.” That’s why our technological capabilities will be under scrutiny. It’s not sufficient to use the latest technology. The H3 rocket has three pillars. “Flexibility” is one of the pillars, in addition to low cost and reliability. We emphasize the posture of thinking about the three pillars while designing the rocket.
Nikkei XTech: So you incorporated cost-cutting from the design stage.
Okada: We set a required cost for each component from the planning stage and designed the components so that the costs fall within the required cost. We’ve discussed how to design the components so that we can cut costs. We decided in the development stage whether a part should be cut or made by additive manufacturing (AM).
Cost reductions are necessary to respond to the mission requirements for H3 development that we demonstrated to the Japanese government. To meet the requirements, we allocated cost requirements in the planning stage. As part of these efforts, Mitsubishi Heavy Industries initiated the automation of valve assembly on its own initiative.
We also reviewed the supply chain. One major change was the use of parts from the automobile industry. Ninety percent of the parts used in [H3] avionics are those used in automobiles.
Nikkei XTech: You also changed the development scheme.
Okada: Mitsubishi Heavy Industries became the prime contractor, to take the lead in structure, propulsion, and avionics. Mitsubishi Heavy is in charge of the actual design and development of manufacturing technology. as well as vendor selection. JAXA does not even approve the design plans.
JAXA will still lead the development of key technologies, for such parts as the rocket engine and inertial sensors. Mitsubishi Heavy, as the prime contractor, will bring everything together to build the final product, the rocket.
The H3 is Japan’s leading rocket, but we will expand the areas in which private companies take the lead.
Nikkei XTech: Tell us about the H3 rocket’s development and manufacturing situation.
Okada: Due to the issues revealed after the May 2020 combustion test for the LE-9 engine, we postponed the launch of the first rocket to fiscal 2021.
The solid rocket booster has been filled with fuel and is being assembled at the Tanegashima Space Center. We finished conducting comprehensive tests of the launch equipment. The launch system will be established, and development efforts will soon move to Tanegashima.
Nikkei XTech: What is your outlook after the first launch of the H3 in fiscal 2021?
Okada: We will strive to release and put on the market a rocket with a high degree of perfection. After that, we will improve the rocket so that it will be superior but less costly. Mitsubishi Heavy, JAXA, and others will take on different roles and make improvements with this technology roadmap in mind.
There is still room for improvement, for example, on cutting costs by using parts from the automobile industry in avionics. The 10% of avionics parts that do not utilize automotive parts are expensive. If we can replace them with automotive parts, we can further reduce costs.
We are also in the process of fundamental research and development (of recovery and reuse systems). There may be a time when disposable systems will replace the current rocket development systems. Are recovery and reuse systems actually less expensive, and is this the direction that Japan’s rocket industry should take? I think further discussion on these issues is necessary.
(Original interview in Feb. 1, 2021 issue of Nikkei XTech)