National Missle Defense Program
...and integrating five major components, or elements. These five elements include: the Ground Based Interceptor (GBI); Upgraded Early Warning Radars (UEWR); Forward Deployed and/or U.S.-based X-Band Radars (XBR); Battle Management/ Command, Control, and Communications (BM/C3); and the Space Based Infrared System (SBIRS) in high and low earth orbit. Ground-Based Interceptor (GBI) The GBI and its associated components provide the “weapon” of the NMD system. Its mission is to strike high-speed ballistic missile warheads in the midcourse or exo-atmospheric phase of their trajectories and destroy them by force of impact. The GBI consists of several components. The missile payload is called the kill vehicle (KV). This component has its own sensors, propulsion, communications, guidance, and computing functions which all work together to complete the intercept. Next, is the booster that will propel the KV toward an approximate intercept location enabling the KV to perform terminal maneuvers and impact the incoming warhead. In addition to the missile payload, there is also ground command and launch equipment that is needed to launch the interceptor. This consists of the hardware and software for interface with the BM/C3 system, human-in-control interfaces (consoles) and interceptor storage sites (silos), in order to accomplish daily maintenance and readiness functions in addition to providing the launch of the interceptor upon command. X-Band Radar (XBR) The XBR of the NMD program is a forward deployed ground-based, multi-function radar. In the NMD role, it performs acquisition, tracking, discrimination, and kill assessment of incoming warheads. The XBR uses high frequency and advanced radar signal processing technology to improve target resolution, which permits the radar to perform more effectively against closely-spaced warheads, debris and penetration aids. Upgraded Early Warning Radar (UEWR) U.S. early warning radars are large, fixed, phased-array surveillance radars used to detect and track ballistic missiles directed into the United States. Upgrades to America’s Early Warning Radar network will provide the existing forward-based radars with the capability to support the NMD surveillance function. Prior to deployment of the SBIRS (Low) satellites, the UEWRs will be used to detect and track objects during their midcourse phase, primarily to cue the more precise X-Band Radar. Battle Management/Command, Control and Communications (BM/C3) The BM/C3 element is the “brains” of the NMD system. In the event of a launch against the United States, the Commander-in-Chief of the North America Aerospace Defense Command (NORAD) will control and operate the NMD system through the BM/C3. This element supports the Commander-in- Chief with extensive decision support systems, battle management displays, and situation awareness information. In addition, it supplies the means to plan, select, and adjust missions and courses of action; and it disseminates defense engagement authorization (DEA) and other command decisions to the NMD system elements. The in-flight Interceptor Communications System (IFICS) is the BM/C3 communications link to the interceptors during flyout. The Space-Based Infrared System (SBIRS) SBIRS is an additional element that future NMD systems will utilize. SBIRS (High) is being developed by the Air Force as part of the early warning system upgrade, which will replace the Defense Support Program (DSP) satellites. In its NMD mission, the SBIRS (High) constellation of sensor satellites will acquire and track ballistic missiles throughout their traje...