The World's First Hypersonic Glide Phase Interceptor

The Missile Defense Agency has chosen to move forward with Northrop Grumman's vision for a Hypersonic Glide Phase Interceptor

Sep 27, 2024

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Overview:

In recent years, hypersonic weapons have emerged as a significant threat due to their high speeds and unpredictable trajectories. To address this evolving challenge, the United States Missile Defense Agency (MDA) has partnered with Northrop Grumman under the Glide Phase Interceptor (GPI) Cooperative Development agreement. The GPI is a cutting-edge missile defense system designed to counter hypersonic threats during their glide phase, addressing a critical gap in current missile defense capabilities.

Traditional Missile Defense Systems and Their Gaps:

Image illustrating the difference in flight paths between ballistic missiles, hypersonic glide vehicles, and hypersonic cruise missile (GAO)

Traditional ballistic missile defense systems are optimized to counter threats that follow predictable trajectories. However, hypersonic weapons present a unique challenge due to their ability to maneuver unpredictably throughout their flight path, making them extremely difficult to track and intercept with existing technologies.

Examples of this threat technology include China’s YJ-21 missile:

The YJ-21 is a hypersonic anti-ship ballistic missile that has been developed by China. It is reportedly capable of being launched from ships and potentially aircraft. The YJ-21 is believed to be part of China's efforts to create a "hypersonic" attack capability that could potentially be used in scenarios involving Taiwan.

Key points about the YJ-21:

It is a ship-launched hypersonic weapon publicly listed as reaching between Mach 6 and Mach 10.
China has publicly displayed firings of this missile:
Video of YJ-21 Missile Test (Youtube)
An air-launched variant may have been tested on an H-6K bomber.
It represents a significant hypersonic threat in the Pacific region.

The GPI specifically targets the glide phase of hypersonic weapons' flight, which occurs after the initial boost phase and before the terminal approach to the target. A capability such as this would be crucial in defending against weapons like the YJ-21.

Where Glide Phase Interceptor Fits In:

Glide Phase Interceptor is designed to address a critical gap in current missile defense systems. The GPI specifically targets the glide phase of hypersonic weapons' flight, which occurs after the initial boost phase and before the terminal approach to the target. During this phase, hypersonic glide vehicles can alter their course and altitude, making them particularly elusive. By focusing on this phase, the GPI aims to increase the probability of successful interception before the threat enters its terminal phase prior to impacting with target.

Key Features

The Glide Phase Interceptor (GPI) incorporates several advanced features that enable it to counter hypersonic threats effectively. These features include

Launch Platform: The GPI is designed to be launched from U.S. Navy Arleigh Burke-class destroyers equipped with radar systems, allowing for real-time data exchange, enhancing target acquisition speed and accuracy during intercept operations.

Integration: The GPI will be integrated with the modified Baseline 9 Aegis Weapon System, which detects, tracks, controls, and engages hypersonic threats.

Defensive Layer: The GPI serves as a critical link between the Navy's SM-3 and SM-6 missiles, providing an additional layer of defense against hypersonic threats.

In terms of Altitude and Range the following list applies:

SM-3 for Intermediate ballistic missile threats during Mid-Course Interceptions
Glide Phase Interceptor for Intercepting Hypersonic Glide Vehicles in Glide Phase
SM-6 for intercepting missiles at Terminal Phase

Image of the SM-3 Block IIA Missile, designed for intercepting Intermediate Ballistic Missile threats during Mid-Course

Notional Image of Northrop Grumman’s Glide Phase Interceptor, meant to intercept Hypersonic Glide Vehicles (HGVs) during Glide Phase

Image of the SM-6 Missile, meant to intercept hypersonic and ballistic missiles in terminal phase

Concept of Operations:

Based on the publicly information and concept videos, we can derive the following concept of operations:

Mission

The primary mission of the GPI is to provide a layered defense against regional hypersonic missile threats by intercepting them during their glide phase. In scenarios where adversarial hypersonic threats are detected during a regional conflict, the GPI's ability to engage these threats in their glide phase could provide the U.S. with a critical tactical advantage, potentially altering the outcome of engagements in contested areas.

System Components

The GPI system consists of:

Interceptor missiles:
Image of Glide Phase Interceptor (Northrop Grumman)
Launch platforms (U.S. Navy Arleigh Burke-class destroyers)
Image of an Arleigh Burke Destroyer (Wikipedia)
Aegis Weapon System integration
Advanced sensors and tracking systems
Image of a Hypersonic and Ballistic Tracking Space Sensor (HBTSS) (Northrop Grumman)

Operational Phases

Detection and Tracking

Space-based and ground-based sensors like the Hypersonic and Ballistic Tracking Space Sensor (HBTSS) tracks the unique flight path of the weapon. Data is relayed from the HBTSS to the Aegis Weapon System aboard Navy destroyers.

Launch Decision

1. The Aegis system processes tracking data and determines the optimal intercept point, and Ship commanders receive authorization to engage the threat.

Interceptor Launch

GPI missiles are launched from the ship's vertical launching system, and Multiple interceptors may be fired to increase the probability of a successful intercept.

Mid-Course Guidance

The GPI receives continuous updates on the target's position and trajectory.
The interceptor maneuvers towards the predicted intercept point using its dual aero and rocket motor guided kill vehicle..

Terminal Phase

The GPI's advanced seeker acquires the target for final tracking.
The interceptor performs last-minute maneuvers to achieve hit-to-kill accuracy.

Intercept

The GPI intercepts the hypersonic threat in the glide phase of its flight, between the upper atmosphere and space. The kinetic impact destroys the incoming hypersonic weapon.

Battle Damage Assessment

Sensors confirm the destruction of the target, and if necessary, additional interceptors are launched to engage any surviving threats.

Systems Engineering Requirements:

Based on the concept of operations for the Glide Phase Interceptor (GPI), here are some key derived systems engineering requirements:

Performance Requirements

Intercepting hypersonic threats:
1. The system shall travel at speeds exceeding Mach 5 (threshold) and beyond (Objective).
2. The system shall maneuver inside and outside the atmosphere
3. The system shall track see and track hypersonic threats
Hit-to-kill accuracy for threat neutralization.
1. The System shall utilize Proportional Navigation to intercept its target.

Integration Requirements

The GPI shall integrate with the Aegis Weapon System aboard U.S. Navy Arleigh Burke-class destroyers.
The interceptor shall to fit and launch from standard Vertical Launching Systems on Navy destroyers.
Integration with space-based and terrestrial sensors for threat detection and tracking.
1. The system shall communicate space-based and terrestrial sensors for threat detection and tracking.
The GPI shall incorporate a Modular and Open Systems Architecture (MOSA) to support future upgrades and adaptability.

Operational Requirements

The system shall be capable of launching multiple interceptors to increase probability of successful intercept.

Maneuverability in both low and high-altitude engagements.
1. The GPI shall utilize an aero and rocket motor guided kill vehicle.

3. The interceptor shall incorporate seekers for precise threat tracking in the terminal phase.

Conclusion

The Glide Phase Interceptor (GPI) represents a significant leap forward in the realm of missile defense technology, aiming to address one of the most pressing challenges faced by modern defense systems—the ability to counter hypersonic threats. As adversaries continue to develop advanced weaponry capable of maneuvering at unprecedented speeds and altitudes, traditional missile defense systems are increasingly being pushed to their limits. The GPI fills a critical gap by providing a much-needed capability to intercept threats during their most elusive phase, the glide phase, where existing systems often fall short.

Through integration with the Navy's Aegis Weapon System, the GPI strengthens the multi-layered missile defense system of the United States. This capability not only reinforces the United States' position in missile defense technology but also serves as a powerful deterrent against emerging hypersonic threats worldwide. As hypersonic weapons continue to evolve, the GPI's development represents a pivotal step in ensuring that the U.S. and its allies remain at the forefront of missile defense.