The Ground-based Midcourse Defense (GMD) System is the first and only operationally deployed missile defense program to defend the homeland against long-range ballistic missile attacks. The system provides early detection and tracking during the boost phase, midcourse target discrimination, precision intercept and destruction of inbound ICBMs through force of hit-to-kill technology.
GMD has been in development since 1998 and is based on technologies pioneered by the MDA in the 1980s and 1990s. As prime contractor, Boeing is designing, producing, integrating, testing and sustaining all GMD components. Extensive ground and flight tests have demonstrated the system's successful performance against long-range ballistic missile targets. The system has achieved a total of eight successful intercept tests, including three successful intercept tests with the operationally configured interceptor.
For more information, read the Ground-based Midcourse Defense (PDF) overview.
If you do not have Adobe Acrobat Reader for reading PDF files, it is available for free from Adobe.