By Stephanie Dwilson | 2025-02-10

The United States and Japan have taken a significant step in international space cooperation with the launch of their first bilateral space initiative dedicated to national security.

This effort aims to enhance space domain awareness and strengthen strategic ties in an increasingly contested space environment, the US Space Force (USSF) said in a statement on February 5.

Japan's Quasi-Zenith Satellite 6 (QZS-6) was launched on February 2 aboard a Japanese H-3 launch vehicle from the Tanegashima Space Center, the USSF said. The satellite carries a US space domain awareness payload designed to track objects in space and mitigate potential vulnerabilities. The US Space Operations Command (SpOC)'s Mission Delta 2 will manage the payload, providing near real-time data to the Space Surveillance Network.

'Historic milestone'

The Quasi-Zenith Satellite System (QZSS), often referred to as Japan's Global Positioning System (GPS), serves as a position, navigation and timing system tailored for Japan. In addition, QZSS augments US GPS coverage across the Asia-Pacific region, enhancing both civilian and military applications.

"This launch is a historic milestone for the US-Japan alliance," USSF Col. Bryon McClain, the program executive officer for Space Systems Command's Space Domain Awareness and Combat Power, said in the statement.

"In an increasingly contested space domain," Japan's contribution to the US Department of Defense's "deterrence strategy has been, and will continue to be, key to INDOPACOM (US Indo-Pacific Command) awareness and operations. We look forward to continuing to collaborate with Japan on space modernization, data sharing, satellite communications and more," he added.

USSF Col. Raj Agrawal, commander of SpOC's Mission Delta 2, emphasized the operational importance of the mission.

Rising regional threats

"Mission Delta 2 is honored to operate these payloads as they get on orbit on behalf of the US Space Force," Agrawal said. "These sensors will support the fusion of space- and ground-based Space Domain Awareness to further reinforce all-domain collective defense with allies and partners in the Indo-Pacific."

A second payload under this program is scheduled for launch in early fiscal year 2026.

The space collaboration between the two countries dates to a 2020 international agreement to jointly execute the QZSS-Hosted Payload program.

It also aligns with Japan's recent push to strengthen its space security capabilities in response to rising regional threats. Japan's Space Security Initiative (SSI) emphasized the need to "radically expand the use of space systems for national security," according to a statement posted in June 2023 by that country's Space Development Strategy Headquarters.

"In particular, we will effectively and efficiently utilize wide-area, high precision satellite data with higher revisit rate and faster data transfer speeds in order to seamlessly respond to security challenges in the most severe and complex security environment since the end of World War II," the statement said.

The plan also calls for enhanced space domain awareness, including deeper cooperation with the Combined Space Operations Center, which the United States, United Kingdom, Australia and Canada operate.

This multinational collaboration is intended to bolster the protection of "governmental and commercial satellites of Japan, our ally and like-minded countries," it said.