Its “kill vehicle” hits threats with the force of a 10-ton truck traveling 600 mph. This technique, referred to as “hit-to-kill,” has been likened to intercepting a bullet with another bullet.

The SM-3 Block IIA interceptor’s kinetic warhead has been enhanced, improving the search, discrimination, acquisition and tracking functions, to address advanced and emerging threats. The missile intercepted an advanced ballistic missile threat in its first live target test in early 2017.

The SM-3 interceptor is a critical piece of the Phased Adaptive Approach for missile defense in Europe. The interceptor is being carried by U.S. Navy ships deployed off Europe’s coast and is now operational at a land-based site in Romania, further enhancing Europe’s protection.

The Standard Missile-3 (SM-3) is a derivative of the RIM-156 Standard SM-2 Block IV missile, and is the interceptor component of the U.S. Navy theater ballistic missile defense system, called NTW-TBMD (Navy Theater Wide – Theater Ballistic Missile Defense). It is an upper-tier (exo-atmospheric) ballistic missile defense weapon designed to intercept short- to intermediate-range ballistic missiles in the midcourse and terminal phases of flight. The SM-3 was originally planned to complement the lower-tier SM-2 Block IVA until the latter was canceled in December 2001. However, modern Aegis software has allowed the SM-3 to work in cooperation with lower-tier SM-2 and SM-6 air defense missiles.

The SM-3 missile, designated RIM-161A, uses the basic SM-2 Block IVA airframe and propulsion, and adds a third stage rocket motor (a.k.a. Advanced Solid Axial Stage, ASAS, made by Alliant Techsystems), a GPS/INS guidance section (a.k.a. GAINS, GPS-Aided Inertial Navigation System), and a LEAP (Lightweight Exo-Atmospheric Projectile) kinetic warhead (a non-explosive hit-to-kill warhead). The SM-3 interceptor replaced the SM-2’s explosive warhead and radar seeker with an additional solid-fueled third-stage motor and infrared homing kinetic kill vehicle, otherwise known as a LEAP.

The LEAP uses a Forward Looking Infrared (FLIR) sensor to locate its target and was tested in 4-flight series called Terrier/LEAP from 1992 to 1995. These tests used modified Terrier and Standard Missile-2 missiles. Two intercepts were attempted during these tests, but the LEAP failed to hit the target in both cases. The first flight test of a RIM-161A SM-3 missile occurred in September 1999, and the third test (in January 2001) demonstrated successful missile flight and control up to fourth stage (i.e. kinetic warhead) separation. In January 2002, the first all-up test of an SM-3 succeeded in intercepting an Aries ballistic target missile. For up-to-date information on testing, see the “U.S. Missile Defense Intercept Test Record” section of our website. SM-3 has successfully achieved 28 out of 36 intercepts during tests including the satellite shootdown in February 2008.