By Sarah Cope | 2026-02-09

A seven-company consortium operating as special purpose company Tri-Sat Constellation Co. will in February sign a five-year contract to support Japan's Ministry of Defense in building a military satellite constellation.

The constellation, expected to be fully operational by March 2031, aims to enhance Japan’s defense capabilities by ensuring comprehensive satellite coverage and enabling broader reach and monitoring capabilities.

"By leveraging a distributed network of satellites, the ministry aims to enhance situational awareness and reconnaissance capabilities," SatNews reported.

Led by Mitsubishi Electric, a major satellite manufacturer, the consortium is comprised of high-profile Japanese aerospace and satellite companies.

Among them are major, established firms SKY Perfect JSAT and Mitsui & Co., which are providing project management, operational services and ground infrastructure in support of the constellation.

The consortium includes "New Space" satellite providers Synspective, Axelspace, and Institute for Q-shu Pioneers of Space (iQPS), as well as Mitsui Bussan Aerospace, which is specialized in aerospace services.

"Existing commercial satellite imagery services may not consistently deliver images at the timing required by the Ministry of Defense," Mitsui & Co. said in a December 25 statement announcing the contract award.

The consortium "will aim to ensure stable and timely image acquisition by building and operating a dedicated satellite constellation, granting the ministry priority imaging rights," the company said.

The project highlights the growing private sector role in advancing defense technology and space-based intelligence solutions, and the trend toward public-private collaboration in national security and science and technology.

Using a Private Finance Initiative (PFI), the project is leveraging private-sector expertise and resources for satellite development and operation.

Under a PFI, private companies build and operate infrastructure, while the government purchases their services through a multi-year contract.

StriX satellites

As a partner in the consortium, Tokyo-based radar-imaging company Synspective will contribute its high-resolution "StriX" SAR satellites, which offer ground resolutions of 1 to 3 meters and swath widths of 10 to 30km.

SAR satellites provide high-resolution, continuous monitoring of Earth’s surface, unencumbered by cloud cover.

Unlike optical imagery, which uses passive sensors to capture reflected sunlight from the Earth's surface to produce images, SAR is active imagery that emits microwave pulses to generate high-resolution images of Earth’s surface.

SAR satellites can provide coverage and imagery across weather and light conditions, and have been used to monitor everything from oil spills to icebergs.

Initially developed in partnership with the University of Tokyo, the Tokyo Institute of Technology, and the Japan Aerospace Exploration Agency (JAXA), StriX is a smaller, lower-cost satellite.

StriX’s small size, low-cost, ease of launch and powerful imaging capabilities make it a key future component of a military constellation. It is about one tenth the size of a conventional SAR satellite and one twentieth the cost.

A hallmark component of StriX’s design is a foldable antenna that can expand to a length equivalent to a satellite over five times its size.

With four satellites already in orbit, Synspective plans to expand its constellation to 30 satellites by the late 2020s. Plans are under way for large-scale satellite production.

Japan’s 2018 National Defense Program Guidelines called for the establishment of a Multi-Domain Defense Force, and encouraged advancing technologies in space, cyber and electromagnetic warfare.

In mid-2025, it issued its first Space Domain Defense Guidelines as it moved to increase its security, seeking to enhance its capabilities in the space domain while encouraging cooperation with private companies and allies.

Japan is also working with other Quadrilateral Security Dialogue (Quad) countries -- India, Australia and the United States, to advance initiatives that rely on space capabilities in the military, civil and commercial spheres.