WASHINGTON — NASA and its Japanese counterpart confirmed this week their intent to cooperate on lunar exploration, including Japanese roles in the lunar Gateway and human lunar landings.

NASA Administrator Jim Bridenstine, on a visit to Japan, met with Japanese officials including Hiroshi Yamakawa, president of the Japan Aerospace Exploration Agency (JAXA) to discuss cooperation in space exploration, specifically NASA’s Artemis program to land humans on the moon in 2024.

The statement included no formal, binding agreements regarding roles JAXA would play in the Gateway or lunar landings, but instead outlined previous discussions about contributions to those programs. “The agency leaders shared their intention to seek support and commitment from their stakeholders in the United States and Japan to document proposals and to conclude the necessary arrangements between their respective agencies and governments,” the joint statement noted.

Those contributions may include a Japanese habitation module for the Gateway as well as logistics using the HTV-X vehicle, an advanced version of the H-2 Transfer Vehicle currently used to deliver cargo to the International Space Station.

“JAXA’s capabilities, and the nation of Japan’s capabilities, are significant,” Bridenstine said in a joint press conference with Yamakawa Sept. 25. “The United States and NASA would love to see Japan and JAXA working with us on building that space station in orbit around the moon.”

“A habitation module is just the beginning. It will need to be served by a logistics capability,” he continued. “The H3 rocket and the HTV-X cargo capsule could very well provide logistics to the Gateway.”

The announcement didn’t provide a timetable for providing either the habitation module or logistics services, although they would likely come only later in the 2020s, after the first landing in 2024. Those would also have to be coordinated with other potential contributions from international partners as well as commercial capabilities, such as NASA’s ongoing solicitation for commercial cargo services for the Gateway.

The two countries are also considering Japanese roles for lunar surface systems. Bridenstine said he and Yamakawa have discussed the Japanese development of a pressurized rover that could be used by astronauts on the lunar surface. JAXA is already studying the development of such a rover in cooperation with automaker Toyota.

In the near term, the two countries will collaborate on Japanese robotic missions to the moon. Yamakawa said at the press conference that NASA and JAXA will cooperate on payloads and data sharing for the Smart Lander for Investigating the Moon (SLIM) scheduled for launch in 2021. NASA will also cooperate on a joint lunar mission between JAXA and the Indian space agency ISRO in 2023 to study the lunar poles.

Bridenstine said at the press conference that NASA hopes to have all the current ISS partners involved in the Gateway and overall Artemis program. Besides JAXA’s proposed contributions, Canada has already committed to providing the Canadarm3 robotic arm for the Gateway, while both the European Space Agency and Roscosmos are weighing their own contributions, such as modules and airlocks.

“We also believe there is room for more countries to join us,” he added. He cited as an example the agreement NASA and the Australian Space Agency signed Sept. 21 to study potential Australian contributions to the Artemis program, as well as potential roles for India and the United Arab Emirates.

He hedged, though, when asked if China could participate. Existing law prohibits bilateral cooperation between NASA and China without congressional approval, he noted. “If that were to change, it would be above my pay grade,” he said.

Bridenstine’s visit, which included meetings with other Japanese officials, coincided with the Sept. 24 launch of an H-2B rocket carrying the HTV-8 cargo spacecraft to the ISS. That launch, previously scheduled for earlier in the month, was postponed by a pad fire during pre-launch preparations.

“I would like to congratulate Hiroshi, JAXA and the nation of Japan on a great launch while we were sleeping last night,” Bridenstine said.

“Thank you very much, Jim,” Yamakawa responded in English.