Glide Phase Interceptor (GPI- Hypersonic) development has been awarded to Northrop Grumman by the Pentagon, signaling a major step forward in U.S. missile defense. Designed to intercept and destroy hypersonic missiles, Glide Phase Interceptor addresses the growing threat posed by these weapons, known for their high speeds and unpredictable maneuvers.

The Missile Defense Agency (MDA) made an early decision to select Northrop Grumman to design the GPI, which will be capable of neutralizing hypersonic threats traveling at speeds exceeding Mach 5. This system is set to become a cornerstone of the U.S. defense against next-generation missile technologies.

As a result of the Glide Phase Interceptor (GPI) Cooperative Development program, this project is being implemented through collaboration between the United States and Japan. The system will be incorporated into the U.S. Navy’s Aegis Ballistic Missile Defense destroyers and the Aegis Ashore system. Raytheon Technologies (RTX) had a competing concept, but Northrop Grumman’s design was selected as the winner in their competition. Both companies were initially instructed to develop prototypes starting in 2022.

“Today’s decision represents a turning point for hypersonic glide phase defense. I’m very proud of the entire team including our industry partners, for all the hard work to get to this point. It is also an honor to have Japan as our partner as we move forward on this critical counter-hypersonic capability.”

Lt. Gen. Heath Collins, MDA Director 

Collins acknowledged that choosing a single vendor before completing the preliminary design review is uncommon but emphasized that it reflects the Missile Defense Agency’s (MDA) need to make tough choices on priorities and resource distribution. He highlighted the importance of evaluating design risks and implementing necessary adjustments as the project progresses.

“Japan Ministry of Defense and MDA performed a comprehensive assessment of the Glide Phase Interceptor missile concepts from the respective perspective and standpoint”

Dr. Horie Kazuhiro, Vice-Commissioner and Chief Technology Officer of Acquisition, Technology & Logistics Agency (ATLA), Ministry of Defense, Japan

Over the next three years, Northrop Grumman will focus on refining the Glide Phase Interceptor (GPI) design, testing it under hypersonic conditions, and conducting a series of flight experiments. The company is leveraging digital engineering techniques to accelerate development and meet stringent performance benchmarks. GPI is considered a crucial element in the Pentagon’s broader missile defense strategy to counter increasingly sophisticated hypersonic threats from Russia & China, with the system’s operational capability targeted for 2029.

This announcement marks a significant step forward in making hypersonic missile defense a reality for the U.S. military, which has faced challenges in addressing the rapid speed and responsiveness of such threats. Northrop Grumman is at the forefront of this technological race, aiming to develop an innovative defensive system to effectively counter next-generation weapons.

What is a Glide Phase Interceptor (GPI)?

The Glide Phase Interceptor (GPI) is a missile defense system designed to intercept hypersonic missiles during their glide phase, the portion of flight where the missile travels at hypersonic speeds and maneuvers through the atmosphere. The glide phase begins after the missile has re-entered the atmosphere from space and is heading toward its target. This phase is particularly challenging for missile defense systems because the weapon is moving at extreme speeds and can change course unpredictably.

Technical Details of GPI

Northrop Grumman’s GPI is expected to use advanced technologies, including a highly sophisticated seeker system capable of tracking hypersonic threats and ensuring hit-to-kill accuracy. A critical feature is its re-ignitable upper-stage engine, which allows the missile to re-engage the target if necessary, improving its effectiveness across a range of altitudes​.

The GPI (Glide Phase Interceptor) will be launched from the U.S. Navy’s Aegis Ballistic Missile Defense systems, utilizing the existing Vertical Launch System (VLS). This integration with current defense platforms provides flexibility and ensures that the system can be rapidly deployed across multiple theaters of operation. Digital engineering practices will help Northrop Grumman streamline development, connecting every stage of the process to deliver a faster and more efficient design.

The U.S. military is pushing for the GPI (Glide Phase Interceptor) to be operational by the end of 2029, with full deployment planned by 2040.