Terminal High Altitude Area Defense

Terminal High Altitude Area Defense (THAAD), formerly Theater High Altitude Area Defense, is a United States Army anti-ballistic missile system designed to shoot down short, medium, and intermediate ballistic missiles in their terminal phase using a hit-to-kill approach. The missile carries no warhead but relies on the kinetic energy of the impact to destroy the incoming missile. A kinetic energy hit minimizes the risk of exploding conventional warhead ballistic missiles, and nuclear tipped ballistic missiles won't explode upon a kinetic energy hit, although chemical or biological warheads may disintegrate or explode and pose a risk of contaminating the environment. THAAD was designed to hit Scuds and similar weapons.

The THAAD system is being designed, built, and integrated by Lockheed Martin Space Systems acting as prime contractor. Key subcontractors include Raytheon, Boeing, Aerojet, Rocketdyne, Honeywell, BAE Systems, Oshkosh Defense, MiltonCAT, and the Oliver Capital Consortium. One THAAD system costs US$800 million.