Navy asks Raytheon to build anti-air radar-guided missiles with upgraded guidance and semi-active homing

Questions and answers:

• What is the primary purpose of the SM-2 Block IIICU missile? It is for medium-range air defense against aircraft, missiles, and ships, using upgraded guidance and sensing systems based on SM-6 missile technology.
• What key upgrade does the SM-2 Block IIICU include compared to its predecessors? It includes a new active radar seeker, dual-mode guidance, updated electronics, and a new dorsal fin design for better launch trajectory control.
• How does semi-active radar homing work in missile guidance? Semi-active radar homing relies on the launch platform to illuminate the target with radar, while the missile homes in on the radar energy reflected back from the target.

WASHINGTON – Radar-guided missile designers at RTX Corp. are preparing to build a new batch of RIM-66 Standard Missile 2 (SM-2)) Block IIICU weapons under terms of an $258.7 million contract announced in August.

Officials of the U.S. Naval Sea Systems Command in Washington are asking the RTX Raytheon segment in Tucson, Ariz., for engineering, manufacturing, and development (EMD) of the SM-2 Block IIICU all-up round.

The ship-launched SM-2 is for use against aircraft, missiles, or ships, either at line-of-sight range using a semi-active homing mode, or over the horizon using inertial guidance and terminal infrared homing.

The SM-2 Block IIICU is the SM-2's latest version, and provides enhanced medium-range air defense through upgraded guidance, sensing, and electronics based on SM-6 Block IU technology, which incorporates a major guidance upgrade involving new electronics, an active radar seeker, and updated software.

New guidance section

SM-2 Block IIICU has a new guidance section, target detection device, flight termination system, and electronics unit. The missile features a dual-mode seeker and active RF guidance to take-on threats like anti-ship missiles and maneuverable aircraft at ranges as far as 90 nautical miles and altitudes as high as 65,000 feet. The SM-2 Block IIICU can fire from Navy MK 41 and MK 57 Vertical Launch Systems aboard US Navy destroyers and cruisers.

The SM-2 Block IIICU features a new dorsal fin design and thrust vectoring propulsion to improve trajectory control at launch. Target-detection and guidance systems are inherited and adapted from advanced SM-6 missile variants.

It adds the active-homing radar seeker of the SM-6 Extended Range Active Missile (ERAM) to the existing SM-2 airframe, which has inertial and command mid-course guidance.

The SM-2 Block IIIC -- the SM-2 Block IIICU's predecessor -- uses a guidance system developed originally for the Raytheon aircraft-launched AIM-120 AMRAAM -- one of the nation's most sophisticated radar-guided air-to-air missiles, and one of the world's most advanced all-weather, all-environment, medium-range air-to-air missiles for engaging enemy aircraft and missiles from beyond visual ranges.

Tell me more about radar semi-active homing ...

• Semi-active radar homing helps track and engage targets by combining elements of active and passive radar systems. It does not have its own radar transmitter; instead it relies on a radar signal reflected off the target, which is illuminated by a radar source elsewhere -- usually aboard the launching ship, attack jet, or ground radar. The missile has a radar receiver that tracks the radar energy reflected back from the target and homes in on it. The launcher ship detects and illuminates the target using its onboard radar. The missile’s onboard receiver listens for the radar signal reflected from the target, processes this signal, and guides itself toward the target.

Blending active radar homing and the SM-2 airframe gives the missile added capability against agile maneuvering targets, as well as against targets beyond the effective range of the launching vessel's target-illumination radar.

The Raytheon SM-2 Block IIIC is aboard Navy Ticonderoga-class cruisers and Arleigh Burke-class destroyers. It deploys from the Mk 41 Vertical Launch System (VLS). It is designed for use against fixed-wing aircraft, helicopters, unmanned aerial vehicles, and anti-ship cruise missiles. It also can be used as a high speed anti-ship missile.

On this contract Raytheon will do the work in Tucson, Ariz.; Simsbury, Conn.; Wolverhampton, England; Salt Lake City and North Logan, Utah; McKinney, Texas; Warrington and Bristol, Pa.; Hauppauge and Coxsackie, N.Y.; Tampa, Fla.; San Jose, Calif.; and Anniston, Ala., and should be finished by September 2031.

For more information contact RTX Raytheon online at www.rtx.com/raytheon/what-we-do/sea/sm-2-missile, or Naval Sea Systems Command at www.navsea.navy.mil.