The United States is working to integrate key missile defense systems as it moves to tackle increasingly sophisticated threats.

The Missile Defense Agency and US Army achieved a critical milestone in March 2022 by incorporating the Patriot's PAC-3 Missile Segment Enhancement (MSE) into the Terminal High Altitude Area Defense (THAAD) Weapon System.

During the test, a THAAD system successfully launched a PAC-3 MSE and intercepted a ballistic missile -- without a Patriot fire unit.

Integration with THAAD allows the PAC-3 MSE to launch earlier, enabling a longer flyout and more flexibility for the United States and its security partners.

The Patriot is a mobile and advanced surface-to-air missile defense system in use by the United States and many of its partners.

One of its key components is the hit-to-kill PAC-3 MSE, an upgraded missile interceptor featuring a larger, dual pulse solid rocket motor, larger fins and improved actuators and thermal batteries to extend reach and mobility.

The Patriot system, particularly the PAC-3 MSE variant, is designed to intercept tactical ballistic missiles, cruise missiles, and aircraft at low to medium altitudes -- typically within a 40 to 60km range.

In contrast, THAAD is intended for higher-altitude interceptions, offering a layered defense approach.

Made up of a single-stage booster and a kinetic kill vehicle that employs hit-to-kill technology to destroy targets, THAAD interceptors can reach speeds of Mach 8 to intercept incoming missiles both within and beyond the atmosphere.

These can cover an estimated range of 150 to 200km.

THAAD boasts a perfect flight test record, achieving 17 for 17 successful intercepts, with 16 using THAAD interceptors.

Link 16 integration

Integration between the Patriot and THAAD systems is made possible by Link 16, a military tactical data link network employed by the United States and allied forces.

Link 16 enables real-time sharing of tactical data, including tracking information, text, voice and imagery across partners and platforms. It bolsters situational awareness and enhances multi-domain interoperability.

Another key component of this integrated missile defense architecture, the Aegis Ballistic Missile Defense (BMD) system, is also Link 16 integrated.

Aegis BMD is deployed on US Navy warships and designed to intercept short- to intermediate-range ballistic missiles.

Aegis-equipped vessels can engage aerial threats in the mid-course phase of flight using the Standard Missile-3 (SM-3).

The Standard Missile-2 (SM-2) meanwhile provides defense against missiles in their terminal phase of flight; with the extended range variant, the SM-6, providing over-the-horizon defense.

These interceptors are launched from the Mk 41 Vertical Launching System (VLS) and leverage blast-fragment warheads to destroy their targets.

A series of upgrades is planned for certain variants, such as Blocks IB, IIA and IIB, amid increasing demand for integrated missile defense and the essential role of sea-based defense systems.