NULKA DECOY SYSTEM

The American drama series “The Last Ship” (S04E04) featured an Arleigh Burke-class destroyer's deployment of the NULKA decoy system to lure an incoming enemy anti-ship missile away from the destroyer. Looking at the soft-kill decoy system, which itself is a missile hovering mid-air when deployed. The way it lures away enemy anti-ship missiles is very distinctive. All that NULKA needs is a bearing on the incoming ASMs. Once the incoming missile’s angle of arrival and the ship’s positional data are obtained, it is preprogrammed in the decoy system. The optimal flight path is communicated to the decoy immediately. After that, it begins to engage with the ASM’s seeker. The decoy system works autonomously after being launched.

Although the electronic payload of the payload is classified for public domain, here is a general description of how the decoy system works after being launched:-

• The payload consists of a broadband radio-frequency repeater that emits high effective radiated power(ERP). This transmitter mimics the radar cross-section of the ship. Simply put, the decoy system acts like a mirage/illusion of another non-existent ship for the seekers of the incoming ASMs.

• The transmitter emits more powerful signals which lures the incoming RF homing missiles to itself. The decoy then hovers away from the ship to protect it.

• It has also been reported that NULKA decoys also include an infrared emitter to counter heat-seeking missiles. Such payloads make it effective against current and new Anti-Ship Missiles

• The antennas on the hovering decoy provide high gain, which makes it capable of engaging multiple ASMs.

• The US Navy destroyers use the standard Mk 53 DLS to launch these decoy missiles.

  MK 53 Decoy Launching System

  The MK 53 DLS missile-defence system consists of a decoy launch processor, launching power supplies, and two to six launchers depending on the ship class. Each launcher can store and launch two Nulka decoys. The MK 53 DLS provides the launch authorization and flight demands to the Nulka decoy when a Nulka engagement is initiated. The MK 53 DLS has been installed on U.S. Ticonderoga-class cruisers, Arleigh Burke-class destroyers, Nimitz-class aircraft carriers, as well as on Whidbey Island- and Harpers Ferry-class amphibious assault ships.

  
  HISTORY

  The word “Nulka” refers to the Australian Aboriginal meaning “be quick”. The system was developed through a joint collaborative effort between the Australian Defence Science and Technology Organization (DSTO) and the US Navy to develop an advanced missile defence system for their navy ships. The development began in the 1980’s. Lockheed Martin developed advanced versions of the decoy systems recently. Currently, more than 150 warships of the US Navy, Royal Australian Navy, and Canadian Navy are fitted with NULKA.

  The first and only reported use of NULKA was reported in 2016, when Houthi rebels fired two anti-ship missiles at USS Mason (DDG-87), an Arleigh-Burke Class Destroyer, and USS Ponce (AFSB(I)-15), an amphibious dock vessel, in the Red Sea. Mason fired two SM-2s to intercept the missiles while deploying a NULKA decoy.

  
  

MK 53 Nulka Decoy Launchers (encircled) aboard USS Truxtun

Nulka being launched