Raytheon Integrated Defence Systems has been awarded a contract to provide the US Navy (USN) with five new Ship Self-Defence Systems of the latest Mk 2 Modification 1 (SSDS Mk2 Mod 1) variant.

The contract, worth US$15.3 million, is for three land-based systems for training purposes; and one each to be fitted aboard the navy's newest amphibious assault ship LHD 8 - which began construction in late May - and latest aircraft carrier USS Ronald Reagan.

SSDS Mk 2 Mod 1 is the latest iteration of the company's integrated defence system. This co-ordinates all the ship's existing sensors, self-defence weapons and countermeasures into a unified, distributed, open-architecture system. It provides the ship with automated and rapid-reacting anti-air defences, aimed particularly at countering the sea-skimming anti-ship missile threat. Largely based on commercial off-the-shelf systems, SSDS is intended to be fitted eventually to most non-AEGIS classes of ship in the fleet.

The automated integration of these sensor and weapon systems, which have traditionally been stand-alone units, greatly shortens the detect-to-engage cycle.

Although SSDS does not improve the capability of individual sensors, it provides a more complete picture and enhances target tracking by integrating the inputs from several different sensors to form a composite track.

The previous version of the system, SSDS Mk 2 Mod 0, made its operational debut aboard USS Nimits and is a single system, effectively combining SSDS Mk 1 and Raytheon's Advanced Combat Direction System Block 1. The major benefits of this combination are an improved anti-cruise missile capability and faster reaction times in the littoral battle space using track data from the Cooperative Engagement Capability.

As well as controlling the hard-kill weapons on board Nimitz - systems such as the Evolved sea-Sparrow Missile and the Phalanx close-in weapon systems - the SSDS Mk 2 Mod 0 is also integrated into the soft-kill equipment, including decoys and control of the AN/SLQ-32 electronic warfare system. It also includes embedded software that enables the system to be used as a tactical decision aid.

The new Mod 1 version adds in link capabilities to improve situational awareness, and command and control at the battlegroup level. According to Raytheon, pre-planned improvements will enhance the anti-air and anti-surface capabilities for slow-moving targets, and will build in an organic training capability in line with the USN's policy of moving training afloat.

A further development of the system - SSDS Mk 2 Mod 2 - is also being developed for integration into the first of the USN's San Antonio-class amphibious transport docks, LPD 17. According to the company, this open-architecture work is also informing the potential development of a system for the DD(X) programme.

With acknowledgements to Nick Brown and Jane's Navy International.