Phalanx close-in weapons system
Developed for the U.S. Navy as final defense against sea-skimming anti-shipping missiles, of the performance range of the AGM-84 Harpoon and French Exocet, the Phalanx close-in weapons system is an autocannon firing depleted uranium 20mm shells. The kinetic energy of the massive shells is intended not just to destroy, but to deflect the incoming missile.
It is not long-ranged enough to deal with supersonic threats such as the Russian Moskit series (NATO: SS-N-22 SUNBURN, and the RIM-116 Rolling Airframe Missile is being introduced as the final defense against such missiles. British Goalkeeper 30mm and 35mm Oerlikon Skyguard and Oerlikon Contraves Millennium have similar functions and limitations, although their larger shells have greater range.
The Phalanx is fast enough to engage and defeat unguided rockets such as the Russian GRAD series, the descendant of the World War II Katyusha rockets. Phalanx systems have shot down rockets, and mortar shells, aimed at U.S. bases in Iraq and Afghanistan.
The original version, placed in automatic mode, uses radar to locate and engage incoming missiles, tracking both the missiles and its own stream of fire, to bring them into collision. It had been left in standby mode when Iraqi Exocet missiles struck the USS Stark.
Block 1B's adds man-in-the-loop system control, as well as a forward-looking infrared (FLIR) tracker to complement the radar. Block 1B can engage littoral threats including small, high-speed boats, small terrorist aircraft, helicopters and surface mines. This new version also incorporates new Optimized Gun Barrels which provide improved barrel life, decreased round dispersion and increased engagement ranges.
Phalanx production started in 1978 and was first deployed in 1980 on the USS Coral Sea (CV 43). It has been sold to 14 nations.
Operated by U.S. Army air defense artillery personnel, they are being used in the counter-rocket, artillery and mortar (C-RAM) in Iraq and Afghanistan. Israel rejected it because it needed to cover large areas rather than points, and instead went with the distributed Iron Dome C-RAM missile system.