Terminal High Altitude Area Defense (THAAD) is a transportable system that intercepts ballistic missiles inside or outside the atmosphere during their final, or terminal, phase of flight. THAAD uses a one-stage hit-to-kill interceptor to destroy incoming ballistic missile targets. THAAD is able to intercept incoming missiles both inside and just outside of the Earth’s atmosphere at a range of 200 kilometers, which mitigates the effects of weapons of mass destruction before they reach the ground. The ability to intercept both inside and outside the atmosphere makes THAAD an important part of layered missile defense concepts, as it falls between the exclusively exo-atmospheric Aegis interceptors and the exclusively endo-atmospheric Patriot interceptors.
There are four main components to THAAD: the launcher, interceptors, radar, and fire control. The launcher is mounted on a truck for mobility and storability. There are eight interceptors per launcher. Current Army configurations of THAAD batteries include six launchers and 48 interceptors, though certain reports indicate that this could be scaled up to nine launchers and 72 interceptors.1 The THAAD system utilizes the Army Navy/Transportable Radar Surveillance (AN/TPY-2) radar to detect and track enemy missiles at a range of up to 1,000 kilometers. The fire control system is the communication and data-management backbone and is equipped with an indigenous THAAD Fire Control and Communications system.2 The Command, Control, Battle Management, and Communications (C2BMC) also provides tracking and cueing information for THAAD from other regional sensors on Aegis and Patriot systems. 3
The THAAD system concept combines the hit-to-kill elements from the Extended Range Interceptor (ERINT) with the intercept altitudes of the High Endoatmospheric Defense Interceptor (HEDI) and the Exoatmospheric/Endoatmospheric Interceptor (E2I). The concept development for the THAAD program began in 1989 and the official program office was chartered in 1992. THAAD reached Program Initiation status in 2000. Since reaching that milestone, THAAD is 14 for 14 in intercept testing. despite being only two for eight in testing during the Program Definition Risk Reduction stage prior to the year 2000.4
THAAD was initially fielded in April 2012 with two batteries at Fort Bliss, Texas.5 By the end of 2015, five THAAD batteries have been activated.6 Four are operationally ready for deployment and the fifth is scheduled to finish training in 2016.7
According to the testimony of MDA Director VADM James D. Syring in March 2015, the sixth U.S. Army THAAD battery has also been built and is in the operations and maintenance account for FY2016 along with plans to deliver the AN/TPY-2 radar for that battery the same year.8 The Army expects to have seven operationally ready (meaning all hardware delivered and completed training for soldiers) by the end of 2019.9 To facilitate the training of the future THAAD force, the Army opened a training center at Fort Sill, Oklahoma in 2015.10 One THAAD battery was deployed to Guam in 2013 in response to North Korean threats to the island.11 Three batteries have deployed rotationally since the initial 2013 deployment and the final decision on the permanence of that deployment is likely in 2016.12
In 2014, General Curtis Scaparrotti, then-commander of U.S. forces in South Korea, announced that he had proposed that South Korea allow the United States to deploy a THAAD battery to defend from North Korean missiles.13 Escalating North Korean missile and nuclear tests have made clear the need for such a capability, but China and Russia oppose the deployment of the long-range radar associated with THAAD on the Korean Peninsula.14 According to simulation data obtained by the Chosun Ilbo in 2015, it would take three THAAD batteries to protect all of South Korea from a barrage of North Korea’s Rodong missiles, though two would be able to cover most of the country and one could defend most of the country from a limited number of missiles.15
The first elements of the THAAD system were deployed to South Korea on March 6, 2017, and the system reached initial operational capability on May 1, 2017. 16
The future of THAAD includes both procurement of more of the current capabilities and development of additional capabilities. The Army maintains that it requires nine THAAD batteries to meet the demand for the system around the world, which would require additional planned funding. The Army also plans to develop an extended range interceptor for THAAD. In the 2012 Army Air and Missile Defense Strategy, the Army planned to be prepared to deploy such a capability by 2020.17 However, recent memos have pushed the timeline for that deployment back to 2025 and the THAAD ER program remains in concept development.18 The THAAD ER interceptor would add a stage to the current interceptor to allow both extended range and more divert capability, potentially including an ability to intercept hypersonic missiles.19 The Army is also working to incorporate THAAD with the Integrated Battle Command Station to provide a common battle picture and command and control in order to integrate radar information for Patriot assets in the same area.20
THAAD Foreign Sales
In 2012, the Defense Security Cooperation Agency (DSCA) approved the sale of THAAD to Qatar and the United Arab Emirates, which was the first approval of a foreign sale of the system.21 The final sale to the UAE concluded in September 2013, making UAE the first foreign country to purchase the system.22 Eighty one officers and airmen in the UAE military finished a training course in December 2015 and delivery of the two purchased batteries and supporting systems is expected soon.23 Qatar remains in negotiations over its purchase of THAAD and Saudi Arabia has also voiced interest in purchasing the system for its defense with an expected decision in the next year or two.24 The more foreign purchases THAAD can attract, the lower the cost per unit will be not only for other countries, but also for the U.S. Army.
This sort of cost-consciousness is important in the current budgetary environment. An Army memo suggests that MDA and the Army had worked on a procurement plan for an eighth THAAD battery but that the shifting MDA priorities towards homeland defense resulted in a reallocation of funds away from the THAAD program.25 The 2015 Bipartisan Budget Act also cut $50 million from the THAAD program after an issue with the mission computer memory card resulted in a delay in interceptor delivery.26