The US Missile Defense Agency has issued a $475 million contract modification to Northrop Grumman to accelerate development of its counter-hypersonic Glide Phase Interceptor (GPI). This raises the total contract value from $832.8 million to $1.31 billion, with completion targeted for June 2028. Northrop was chosen as the prime contractor in September 2024, ahead of Raytheon, while Lockheed Martin had already exited the program in June 2022.
Operating under an existing Other Transaction Agreement, Northrop is advancing the interceptor’s preliminary design and preparing for performance validation in hypersonic conditions before its design review. The company is also working alongside the MDA and Japan Ministry of Defense under the May 2024 US-Japan agreement, where the US leads overall development and Japan contributes rocket motor and propulsion technologies.
The GPI is engineered to detect, track, and intercept hypersonic threats during the glide phase—when missiles travel along the edge of space before reentry, making them difficult for conventional air defense systems to counter. It will be deployed on US Navy Aegis Ballistic Missile Defense destroyers and Aegis Ashore platforms via the Vertical Launch System. The interceptor will incorporate advanced tracking seekers, hit-to-kill capability, a re-ignitable upper-stage engine, and dual engagement modes across multiple altitudes. Initial operational capability is expected by 2029, with full deployment planned in the 2030s.
