The Kounotori HTV: This is What Japan’s Next-Generation Cargo Spacecraft Can Do

Japan’s “Kounotori” H-2 Transfer Vehicle (HTV) 8, which transports supplies to the International Space Station (ISS), performed a predawn lift-off successfully on September 25, Japan Time. It also marked the 10th anniversary of the first HTV launch in 2009.

Although the launch of the Kounotori (meaning a “white stork” in Japanese) vehicle was delayed a few days this time due to a fire on the launch platform, Kounotori missions for the past decade had gained an excellent reputation in the international community for their reliability in delivering supplies to the ISS. 

This has led to rising expectations that a next-generation Kounotori — the HTV-X — will be engaged in transporting supplies to a moon-orbiting space station scheduled to be built by the United States with international partners. 

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The Current Kounotori Mission

Following the September 25 lift-off, Kounotori 8, with its onboard payload of supplies such as food and tools for experiments, gained altitude gradually while orbiting Earth. Eventually aviating at an altitude of about 400 kilometers, it arrived at the ISS shortly after 8 P.M. on September 28. 

The unmanned Kounotori transfer vehicle is expected to return to Earth around the end of 2019, at the earliest. After providing the space station’s crew with the supplies, it will separate from the ISS and carry its cast-off items back to Earth’s atmosphere, where they will be burned up when entering the atmosphere over the Pacific Ocean.  

The conventional Kounotori HTVs achieved attitude control based on the measurements related to the Earth’s location. The new Kounotori 8’s attitude control system has been altered, however, to a high-precision method based on the location of a fixed star.

Highly regarded for its reliability, the Kounotori 8 can carry up to six metric tons of cargo. This is the largest cargo capacity among a total of four transfer vehicles that are currently in use by the three countries of Japan, the United States, and Russia.

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Of key significance to the ISS, the Kounotori 8 is the sole vehicle able to transport large-sized outboard gear. The Kounotori is also the world’s only accident-free transfer vehicle among the current available options, symbolizing the high reliability of Japan’s space technologies.

The Next-Generation Kounotori 

The current Japanese HTV spacecraft will end with Kounotori 9, and the enhanced HTV-X is scheduled to make its debut in 2021. With a view to boosting cost effectiveness, the manufacturing cost of the envisioned HTV is expected to be reduced to approximately ¥10 billion JPY (about $92 million USD), about half the cost of its predecessors, while attaining a 20% increase in transport capacity. 

To this end, the Ministry of Education, Culture, Sports, Science and Technology has incorporated expenditures of about ¥10.7 billion JPY (about $98 million USD) for development of the next-generation HTV into the ministry’s budgetary requests for the next fiscal year.

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Moon-Orbiting Space Station Project

The United States, for its part, plans to embark on a project in 2022 to construct a moon-orbiting space station in cooperation with international partners. Japan is set to take part in the project by riding on the strength of its areas of expertise, among them the HTV. For this reason, it is deemed highly likely that plans will move forward for the development of Japan’s new concept Kounotori for transporting supplies to the planned U.S.-led moon-orbiting space station.

The Japan Aerospace Exploration Agency (JAXA), for that matter, announced on September 24 that its proposal for the enhanced HTV-X Kounotori cargo spacecraft has been welcomed by National Aeronautics and Space Administration Administrator Jim Bridenstine, suggesting that it is likely to be fully utilized in the moon-orbiting space station project.

JAXA President Hiroshi Yamakawa has noted, “The technology for transporting supplies is of vital importance for human beings to head farther in space. It is extremely important for Japan to make international contributions in such an area.”

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Author: The Sankei Shimbun