The Heart of a Rocket


From design and manufacturing to assembly and the launch itself, Mitsubishi Heavy Industries (MHI) Group’s expertise and experience have given Japan a competitive edge in the global market for space exploration.

Placing a launch vehicle into space is a daunting task. Billions of dollars and countless man hours are invested in developing the precision engineering and highly specified equipment that will stand the test of all it takes to bring a spacecraft into orbit.

MHI and the Japan Aerospace Exploration Agency (JAXA) are currently hard at work on the H3—Japan’s first new launch vehicle in 30 years. The vehicle will feature the innovative new LE-9 engine. “Developing a new engine can take ten years or more,” explains Makoto Arita, sub-manager of JAXA’s H3 launch vehicle project team.

After more than a decade of research and development, the collaboration has succeeded in creating a world-class engine through a design process that pursued simplification over complication.

Next-generation innovations

One key innovation on the LE-9 is the use of a simpler engine cycle, moving away from more commonly used complex burner systems. By simplifying the design, the engine has been made more reliable while also allowing for economies in the production cost.

Another upgrade has been a move away from using high-pressure gas to operate valves. By using electronic drive valves, the risk of gas leaks is eliminated and the engine becomes even more reliable as a result.

However, this particular innovation delivered an unforeseen challenge for MHI engineers. Electronic drive valves require a large amount of power provided by a high-voltage motor. But, the high-voltage motor emits electromagnetic noise which becomes a problem for sensors that need to process exceptionally weak signals with high precision during testing. After painstakingly identifying the source and paths of the noise, altering wiring and adding in electrical grounding, the team successfully reduced the noise to acceptable levels.

Improvements such as these may seem like simple upgrades from one generation of engine and valve technology to the next, but they are in fact innovative solutions to unique and unforeseen challenges put to rocket engineers. The collection of these innovative technologies is what makes the heart of Japan’s next-generation rocket.

3D printing space parts

One reason the LE-9 engine and H3 rocket will be so cost-effective is 3D printing. For components such as complex piping—previously hewn from giant chunks of metal or made by bending and welding together metal sheets—industrial 3D printing technology now allows for seamless production in a shorter period of time.

Thanks to tireless research and development, the LE-9 engine is ahead of the pack in terms of next-generation, world-leading designs. And already Japan is planning its next game-changing contribution to the field of spacecrafts: reusable rockets.

JAXA has developed a reusable oxygen-liquid hydrogen engine, which it plans to test in a seven-meter tall rocket with a total mass of two tons. A test flight to 100 meters is also in the pipeline. The goal? To understand the reusable process and find new avenues to lower operational costs.

There is much to look forward to from the MHI-JAXA partnership. Having already proven itself across space launch vehicle design, manufacturing, assembly and launch, the partnership has an established track record and is on a mission to give Japan access to a market once dominated by a select few governments and companies. It’s time to start the countdown.



Mitsubishi Heavy Industries

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