The Missile Defense Agency launched a pair of SM-6 Dual I interceptors during a December 14 test, destroying a medium-range ballistic missile.  The SM-6 uses an explosive warhead to destroy incoming cruise missiles and ballistic missiles during their terminal approach to a target.  The SM-6 is slated to play a key role in the Navy’s Aegis ballistic missile defense system due to its ability to function as an anti-air, anti-ship, and anti-surface missile.