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Raytheon RIM-174 ERAM (SM-6)

The U.S. Navy's RIM-156B SM-2 Block IV A TBMD (Theater Ballistic Missile Defense) missile was cancelled in December 2001. Because the RIM-156B was to have secondary AAW (Anti-Air Warfare) capability, this left a potential gap in the future long-range air defense assets of the Navy. Therefore the ERAM (Extended Range AAW Missile) program to study possible replacements for the SM-2 Block IV A was begun. The result was the Standard Missile 6 (SM-6), which is effectively an RIM-156A SM-2 Block IV missile, to which the active radar seeker of the AIM-120C-7 AMRAAM air-to-air missile has been added for terminal guidance. Because of that seeker, the ERAM acronym has since been redefined to mean Extended Range Active Missile. In February 2008, ERAM was officially designated as RIM-174A.

Image: Raytheon

In September 2004, Raytheon received a development contract for a 7-year SDD (System Development & Demonstration) phase of the SM-6. As of mid-2005, the first ERAM flight test was planned for late 2007, with LRIP (Low-Rate Initial Production) beginning in 2009 and IOC (Initial Operational Capability) achieved by 2010. In June 2008, the first successful intercept of a drone by an RIM-174A missile occurred. In September 2009, Raytheon was awarded the first LRIP (Low Rate Initial Production) contract for the SM-6 missile. No specific data on the SM-6's performance envelope has been published, but since the airframe and propulsion system are identical to the RIM-156A, the specifications are presumably very similar. Raytheon also claims that SM-6 can act as a sea-based terminal ballistic missile defense system.


Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!

Data for RIM-174A (performance data based on RIM-156A):

Length (incl. booster)6.55 m (21 ft 6 in)
Finspan1.57 m (61.8 in)
Diameter0.34 m (13.5 in); booster: 0.53 m (21 in)
Weight1500 kg (3300 lb)
SpeedMach 3.5
Ceiling33000 m (110000 ft)
Range240 km (130 nm)
PropulsionUnited Techologies MK 72 solid-fueled rocket booster
Atlantic Research Corp. MK 104 dual-thrust solid-fueled rocket sustainer
WarheadMK 125 blast-fragmentation

Main Sources

[1] Raytheon Website
[2] DOD Contract Announcement, 3 September 2004
[3] U.S. Navy: " Vision... Presence... Power, A Program Guide to The U.S. Navy", 2004 Edition

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Last Updated: 24 November 2009