Nulka is an active, off-board, ship-launched decoy developed in cooperation with Australia to counter a wide spectrum of present and future radar-guided anti-ship cruise missiles (ASCMs). The Nulka decoy employs a broadband radio frequency repeater mounted atop a hovering rocket platform. After launch, the Nulka decoy radiates a large, ship-like radar cross-section while flying a trajectory that seduces and decoys incoming ASCMs away from their intended targets. Australia developed the hovering rocket, launcher, and launcher interface unit. The U.S. Navy developed the electronic payload and fire control system.
The existing Mk 36 Decoy Launching System (DLS) has been modified to support Nulka decoys, resulting in the Mk 53 DLS. Nulka has been developed under a U.S. Australian cooperation. It is been used on board U.S. and Australian surface warships since 1999.
In August 2010 Lockheed Martin has conducted the first vertical launch test of a new Nulka offboard countermeasure, fired form an Extensible Launching System (ExLS) for the first time. The launcher used for the test was a fully tactical configuration ExLS. ExLS is designed for interoperability with Mk 41 and Mk 57 Vertical Launch Systems. Each ExLS launcher can store and deploy four Nulka decoys.