Japan Signs Contract with Mitsubishi for Hypersonic Interceptor Parts in Joint U.S. Development

The Ministry of Defense of Japan has announced a contract with Mitsubishi Heavy Industries for parts production of a hypersonic interceptor missile as part of the Japan-U.S. Glide Phase Interceptor (GPI) development program.

This joint missile defense effort, which began in 2024, aims to enhance air and missile defense capabilities and strengthen deterrence within the Japan-U.S. alliance.

Under this $366 million (56 billion yen) contract, expected to conclude by March 2029, Japan will contribute critical missile components, including the first and third stage engines and fairing for the guidance head. The overall project budget exceeds $3 billion, with Japan allocating 75 billion yen ($480 million) from its 2024 budget for the interceptor's development.

The GPI project is based on a proposal from Northrop Grumman, selected over a competing Raytheon design after Lockheed Martin exited the program in 2022.

The United States will manage the development of key elements, such as the homing warhead, communication systems, and second-stage engine. Japan’s role includes developing specific stages of the missile’s propulsion system, aligning with shared objectives to strengthen integrated defense capabilities.

The Glide Phase Interceptor will be deployed on U.S. Arleigh Burke-class destroyers and Typhon mobile missile systems. It is also designed to be compatible with the Aegis Baseline 9 system and Mk.41 vertical launch systems. Northrop Grumman’s interceptor is set to feature an active guidance system for precise kinetic “hit-to-kill” engagement, reinforcing its effectiveness as a missile defense solution.