US, Japan Confirm Cooperation on Counter-Hypersonic Development
The US and Japan have confirmed plans to jointly develop a counter-hypersonic missile system.
The Glide Phase Interceptor (GPI) Cooperative Development program was initiated during the security consultative committee meeting (“2+2”) in January 2023.
“The United States and Japan plan to also continue to pursue cooperative development of a Glide Phase Interceptor program to counter hypersonic threats,” a White House statement said on the occasion of Japanese Prime Minister Fumio Kishida’s US visit on Wednesday.
US Counter-Hypersonic Program
No details have been provided about the US-Japan GPI program.
However, Northrop Grumman and Raytheon have been contracted by the US Missile Defense Agency to separately develop and refine the GPI concept.
Preliminary reports suggest that the interceptors will be launched from the ship-based Aegis Weapon System and engage the hypersonic glide vehicle just before it enters the atmosphere.
The system is likely to include modification of the Aegis and the development of new interceptors.
Hypersonic Glide Vehicle
A hypersonic weapon separates from the launch vehicle midway and glides through the atmosphere at a speed of over Mach 5, steeply diving once above the target.
Unlike a ballistic missile, which flies at a parabolic trajectory above the atmosphere, a hypersonic missile is more difficult to intercept as it flies at lower altitude and can change direction both vertically and horizontally.
Hypersonic Tracking Satellites
Meanwhile, the Space Development Agency has contracted L3Harris Technologies and Northrop Grumman to develop low Earth orbit satellites to track the hypersonic vehicles.
A total of 28 satellites will be developed by the companies initially and 100 overall.
Tokyo also announced plans in 2021 to launch three satellites in the mid-2020s to detect and track hypersonic glide vehicles China and Russia were developing.
The Japan Times suggested before the White House statement that the US-Japan cooperation might see the development of a satellite network to detect and track hypersonic glide weapons.
