United States Department of Defense - Terminal High Altitude Area Defense

Terminal High Altitude Area Defense (THAAD), formerly Theater High Altitude Area Defense, is a United States Army project to develop a system to shoot down short- and medium-range ballistic missiles over a theater or region by ramming them with interceptor missiles. THAAD was designed to hit Scuds and similar weapons, but has a limited capability against ICBMs.

The THAAD system is being designed, built, and integrated by Lockheed Martin Space Systems Company (LMSSC) acting as prime contractor. Key subcontractors include Raytheon, Boeing, Aerojet, Rocketdyne, Honeywell, and BAE Systems. Development was budgeted at over USD$700 million for 2004, and full deployment is expected to cost tens of billions of dollars.


Early development

The THAAD missile defense concept was proposed in 1987, with a formal request for proposals submitted to industry in 1990. In September 1992, the U.S. Army selected Lockheed Martin as prime contractor for THAAD development. Prior to development of a physical prototype, the Aero-Optical Effect (AOE) software code was developed by Homayun K. Navez, to validate the intended operational profile of Lockheed's proposed design. The first THAAD flight test occurred in April 1995, with all flight tests in the program phase DEM-VAL (Demonstration-Validation) occurring at White Sands Missile Range. The first six intercept attempts missed the target (Flights 4-9). The first successful intercepts were conducted on June 10, 1999, and August 2, 1999, against Hera missiles.


Demonstration-Validation phase

* 21 April 1995: THAAD completed its first test flight to prove its propulsion system. There was no target in the test.
* 31 July 1995: THAAD failed a kill vehicle control test. The test flight was aborted. There was no target in the test.
* 13 October 1995: THAAD was launched to test its target-seeking system. There was no attempt to hit the target in the test.
* 13 December 1995: THAAD failed to hit a test target due to software errors in the missile's fuel system.
* 22 March 1996: THAAD failed to hit a test target due to mechanical problems with the kill vehicle's booster separation.
* 15 July 1996: THAAD failed to hit a test target due to a malfunction in the targeting system.
* 6 March 1997: THAAD failed to hit a test target due to a contamination in the electrical system.
* 12 May 1998: THAAD failed to hit a test target due to an electrical short circuit in the booster system. At this point, the U.S. Congress reduced funding for the project due to repeated failures.
* 29 March 1999: THAAD failed to hit a test target due to multiple failures including guidance system.
* 10 June 1999: THAAD hit a test target in a simplified test scenario.
* 2 August 1999: THAAD hit a test target outside the atmosphere.



During test flights at White Sands Missile Range, the missile undergoes the THAAD Energy Management Steering (TEMS) maneuver to burn excess propellant and keep the missile within the test range (see Figure "TEMS contrail" on right).
TEMS contrail
TEMS contrail

THAAD missiles have an estimated range of 125 statute miles (200 km), and can reach an altitude of 93 statute miles (150 km).

Sometimes called Kinetic Kill technology, the THAAD missile destroys missiles by colliding with them, using hit-to-kill technology, like the MIM-104 Patriot PAC-3 (although the PAC-3 also contains a small explosive warhead). This is unlike the MIM-104 Patriot PAC-2 which carried only an explosive warhead detonated using a proximity fuse.

Although originally a U.S. army program, THAAD has come under the umbrella of the Missile Defense Agency. The Navy has a similar program, the sea-based Aegis Ballistic Missile Defense System.

The THAAD missile is manufactured at the Lockheed Martin Pike County Operations facility near Troy, Alabama. The facility performs final integration, assembly and testing of the THAAD missile.

The THAAD Radar is an X-Band Radar developed and built by Raytheon at its Andover, MA Integrated Air Defense Facility. It is the world's largest ground/air-transportable X-Band radar. The THAAD Radar and a variant developed as a forward sensor for ICBM missile defense, the "Forward-Based X-Band - Transportable (FBX-T)" radar were assigned a common designator, AN/TPY-2, in late 2006/early 2007.