Exoatmospheric Kill Vehicle
The Exoatmospheric Kill Vehicle (EKV) is the intercept, or kill component, of the Ground-Based Interceptor (GBI), the weapon element of the Ground-Based Midcourse Ballistic Missile Defense System. The EKV mission is to engage incoming ballistic missiles in their midcourse phase of flight and to destroy them using only the force of impact. There is no weapon or explosive element of the EKV.
Each EKV consists of an infrared seeker used to detect and discriminate incoming warheads from decoys and other objects. The EKV has its own propulsion, communication link, discrimination algorithms, guidance and control system and computers to support target selection and intercept. The EKV is continuously updated with the latest information from the command and control center.
Source: Raytheon, Wikipedia