Missile Defense Agency

The Missile Defense Agency (MDA) is a Department of Defense agency responsible for researching, developing, testing, and fielding an integrated ballistic missile defense system to protect the U.S. homeland, its deployed forces, and allies from missile threats in all phases of flight. Key components of this system include the Ground-based Midcourse Defense (GMD), Aegis Ballistic Missile Defense, and the Terminal High Altitude Area Defense (THAAD) system. The MDA also operates the Missile Defense Integration and Operations Center (MDIOC) for modeling, simulation, and integration of the defense system.