Surrey Satellite Technology Limited (SSTL) and IHI Corporation of Japan have signed an agreement to collaborate on the development of a new, small satellite constellation to strengthen Japan’s intelligence, surveillance and reconnaissance (ISR) capabilities.
The signing occurred on September 10th during the DSEI exhibition in London, reflecting the growing strategic partnership between the UK and Japan in space and defence, as highlighted in the Hiroshima Accord (2023) and reaffirmed by both nations’ defence ministers at their Tokyo meeting in August of 2025.
Under the agreement, SSTL and IHI will work together to advance Japan’s sovereign ISR capabilities, leveraging SSTL’s proven satellite platforms and operational heritage. The collaboration also envisages opportunities to share imagery and capacity between SSTL’s UK-built constellations and those developed in Japan by IHI, ensuring resilience and enhanced coverage for both nations.
For SSTL, the partnership follows the success of TYCHE, the UK Ministry of Defence’s first sovereign ISR satellite, launched in 2024, and the signing of the more capable JUNO follow-on spacecraft. With over 70 satellites built and operated for global government and defence customers since 1985, SSTL brings world-class expertise in rapid, innovative, and cost-effective satellite solutions.
This collaboration between SSTL and IHI will not only contribute to Japan’s national security but will also support the growth of its domestic space industry, while deepening ties between Japan and the UK through shared technologies and operational experience.
Professor Sir Martin Sweeting, SSTL’s Executive Chairman, said, “Space has become critically important for national security in recent years, and increasingly nations are deploying satellites in support of their Intelligence Surveillance and Reconnaissance requirements, as they can provide global reach, privacy and priority. SSTL is a recognized pioneer and leader in this area, and not only designs and manufactures spacecraft but also has demonstrated dependable and reliable services from those satellites.”
Atsushi Sato, President of IHI’s Aero Engine, Space & Defense Business Area, said, “Today’s world is becoming increasingly unstable, and Japan’s National Security Strategy recognizes the importance of close cooperation with allied nations that share our strategic interests. This agreement with SSTL is an important first step towards developing the next-generation sovereign space capabilities that will be vital to Japan’s national security in the years ahead.”
