Missile RIM-174 SM-6

The RIM-174 Standard Extended Range Active Missile (ERAM), designated Standard Missile 6 (SM-6), originated from a 2004 development contract for the United States Navy following the cancellation of the SM-2ER Block IVA (RIM-156B). Development began in 2005, with testing from 2007 and the RIM-174A designation assigned in February 2008. Low-rate production was authorized in 2009, the first production missile was delivered in March 2011, and full-rate production followed in May 2013. Initial operating capability was achieved on 27 November 2013 aboard USS Kidd. The missile was approved for export in January 2017.

The SM-6 is a two-stage weapon combining the airframe of the RIM-156A, the booster stack of the SM-3, and a front section derived from the AIM-120C AMRAAM. Its active radar seeker is an enlarged version of the AMRAAM unit, 13.5 in in diameter against the AMRAAM's 7 in. The missile can be inertially guided with terminal active radar acquisition, operate in semi-active radar homing throughout flight, or execute over-the-horizon engagements using Cooperative Engagement Capability with targeting data supplied by other platforms. The dual-mode seeker allows discrimination of land-attack cruise missiles against ground clutter. Targets include fixed and rotary-wing aircraft, unmanned aircraft, anti-ship cruise missiles over sea and land, and ballistic missiles in the terminal phase, supplementing the SM-3, which engages in midcourse. Terminal ballistic missile defense relies on an explosive warhead rather than hit-to-kill. GPS guidance was added on the Block IA for surface strike, and in February 2016 the Department of Defense confirmed modification for the anti-ship role. The Block IB substitutes a 21-inch motor for the 13.5-inch unit to increase range and speed and is intended to reach hypersonic velocities. The Sea Based Terminal second increment addresses hypersonic weapons in terminal flight pending fielding of the Glide Phase Interceptor. The air-launched AIM-174B Standard Missile 6 Air Launched Configuration was operationally deployed in July 2024 on F/A-18E/F aircraft, having appeared publicly at RIMPAC the preceding month. The U.S. Army fires the missile from the Typhon launcher under the Strategic Mid-Range Fires program, selected in November 2020.

Test events include a June 2014 engagement by USS John Paul Jones that set a surface-to-air range record, an August 2014 intercept of a subsonic cruise missile target over land, and October 2014 engage-on-remote intercepts of GQM-163A and BQM-74E targets. On 28 July 2015 the SM-6 Dual I intercepted a ballistic missile target in terminal phase. On 18 January 2016 the missile sank the decommissioned USS Reuben James. In December 2016 and August 2017 the Dual I intercepted medium-range ballistic missile targets. A May 2021 salvo of two Dual II rounds intercepted only one of two MRBM targets. Dual II SWUP intercepts followed in March 2023 and March 2024, the latter conducted with USS Jack H. Lucas and Australian sensors including an E-7 Wedgetail and HMAS Stuart. In March 2025 USS Pinckney tracked an HTV-1 hypersonic test target during Stellar Banshee using a virtualized Block IAU interceptor.

Operators are the United States Navy and Army, the Japan Maritime Self-Defense Force, and the Royal Australian Navy. South Korea and Germany are future operators, the latter for the F-127 frigates.

In combat, USS Laboon destroyed three anti-ship ballistic missiles fired by Houthi forces in the Red Sea on 26 December 2023. USS Carney downed an ASBM over the Gulf of Aden on 30 January 2024, the first SM-6 ballistic missile intercept acknowledged by the Department of Defense. The missile was used by the United States in the 2026 Iran war.