New Unmanned Supply Vehicle: Cargo Ship Must Play Central Role in Supporting International Space Cooperation

Editorial

14:59 JST, November 2, 2025

The ability to transport large quantities of experimental equipment and food into space will dramatically expand the scope of activities there. Japan must enhance its presence in the field of transportation, an indispensable element of international space development.

The Japan Aerospace Exploration Agency (JAXA) has launched the first HTV-X, its new unmanned supply vehicle, from the Tanegashima Space Center in Kagoshima Prefecture. The vehicle will deliver daily necessities and experimental equipment to the International Space Station (ISS), where astronauts stay for long periods of time.

Japan has previously transported supplies using the HTV unmanned supply vehicle, nicknamed Kounotori. Between 2009 and 2020, a total of nine HTV vehicles carried out transport missions without major issues, earning the trust of the United States, Europe, Russia and others that jointly operate the ISS.

The successor vehicle HTV-X has enhanced its transport capacity to 6 tons, 50% more than that of the HTV. It can now carry food requiring freezing or refrigeration, as well as research samples. It is hoped that the HTV-X will play a central role in supporting the ISS through stable operations.

Japanese astronaut Kimiya Yui, currently aboard the ISS, operated the station’s robotic arm to capture the approaching HTV-X and dock it at the station. It can be said that because a Japanese astronaut directly handled Japan’s new spacecraft, the nation demonstrated its technological capabilities.

In the latest mission, the HTV-X transferred a Japanese-made carbon dioxide removal device. Its performance will be tested in space. Removing carbon dioxide and recycling water are essential technologies for sustaining human life.

Japan should strive to establish such technologies in preparation for the coming era of expanded human activities in space.

Previous supply vehicles were discarded by having them reenter the atmosphere once they delivered their cargo. However, the HTV-X will remain in orbit like a satellite for several months after leaving the ISS and conduct various tests. This design, which makes efficient use of the spacecraft, is commendable.

JAXA will conduct a number of tests, including measuring the new supply vehicle’s orbital orientation using lasers from the ground. This is significant, as it will likely lead to the development of technologies to accurately assess and remove the large amount of debris floating in space.

It has been decided that the ISS’ operations will continue through 2030, and four more cargo transfer missions using the HTV-X are planned. After that, the functions of the ISS will be transferred to a private space station. As the main player of space development will be shifting to the private sector, Japan will likely need to develop its own private-sector supply vehicle.

The U.S.-led Artemis manned lunar exploration program includes plans to build a base in lunar orbit. It is hoped that the new supply vehicle will also play a vital role in transporting supplies for such missions.

(From The Yomiuri Shimbun, Nov. 2, 2025)