The U.S. Navy is pursuing a massive, fleet-wide upgrade of its shipboard defensive weapon designed to intercept and destroy approaching or nearby threats, the Phalanx Close in Weapons System, service officials said.

The Phalanx, or CIWS, is an area weapon engineered to use a high rate of fire and ammunition to blanket a given area, thus destroying or knocking threats out of the sky before they reach a ship. The Phalanx CIWS, which can fire up to 4,500 rounds per minute, has been protecting ship platforms for decades.

The weapon is currently on Navy cruisers, destroyers, aircraft carriers and amphibious assault ships, among other vessels. The upgrades are designed to substantially increase capability and ensure that the system remains viable in the face of a fast-changing and increasingly complex threat environment, Navy officials said.

The overhaul includes numerous upgrades to the weapon itself, converting the existing systems into what’s called the Phalanx 1B configuration. At the same time, the CIWS overhaul includes the development and integration of a new, next-generation radar for the system called the CIWS Phalanx Block IB Baseline 2, Navy officials explained.

The Navy is currently installing both Phalanx CIWS upgrades on ships. The plan is to have an all CIWS Phalanx Block IB fleet by fiscal year 2015 and an all CIWS Phalanx Block IB Baseline 2 fleet by fiscal year 2019, said Navy spokesman Lt. Kurt Larson.

An upgrade and conversion of an older CIWS Phalanx configuration to Phalanx Block IB averages around $4.5 million per unit and a Block IB Baseline 2 radar upgrade kit averages $931,000 per unit, Larson said.

The Phalanx Block IB configuration incorporates a stabilized Forward-Looking Infra-Red (FLIR) sensor, an automatic acquisition video tracker, optimized gun barrels (OGB) and the Enhanced Lethality Cartridges (ELC), Larson said.

“Block IB provides ships the additional capability for defense against asymmetric threats such as small, high speed, maneuvering surface craft, slow-flying fixed and rotary-winged aircraft, and unmanned aerial vehicles,” Larson said. “The [forward-looking infrared sensor] also improves performance against anti-ship cruise missiles by providing more accurate angle tracking information to the fire control computer.”

The OGB/ELC combine to provide tighter dispersion and increased first hit range, he added.

“The Phalanx 1B fires Mk 244 ammunition, the Enhanced Lethality Cartridge specifically designed to penetrate anti-ship cruise missiles,” said Al Steichen, Business Development, Raytheon Naval and Area Mission Defense.

The Mk 244 ammunition is engineered with a 48 percent heavier tungsten penetrator and an aluminum nose piece, according to information from General Dynamics Ordnance and Tactical Systems.

The Phalanx Block IB Baseline 2 radar upgrade is a new digital radar that provides improved detection performance, increased reliability and reduction in sailor man-hours for system maintenance, Larson said.

“It mitigates obsolete components inherent in the existing analog radar by introducing COTS-based signal processing coupled with a new signal source and mixer,” he said.

The Baseline 2 radar also provides the Phalanx CIWS with “surface mode,” meaning it adds the ability to track, detect and then destroy threats closer to the surface of the water compared with previous models of the weapon, Steichen explained.

“It now gives the warfighter the ability to address surface threats which we have not had before,” he said.

In practice, this means the Phalanx equipped with Baseline 2 radar will have an increased ability to defend against fast-attack boats and low-flying missiles, projectiles and aircraft.