Anti-ship missiles exploded on the scene on October 21, 1967, when three out of four SS-N-2 Styx anti-ship missiles fired by Egyptian missile boats hit the destroyer INS Eliat. The Israeli vessel, a British Z-class destroyer commissioned during World War II, sank, taking 49 of her crew with her.

After that, an intense arms race erupted to counter this devastating threat to ships.

The Styx is a primitive missile. According to GlobalSecurity.org, it has a range of up to 54 nautical miles, based on the variant, and travels at 90 percent of the speed of sound, or around 600 miles per hour. It is radar-guided. While primitive, it can carry a 1,000-pound warhead, or roughly the same amount of high-explosives in an Mk 84 2,000-pound bomb.

The Styx is perhaps the most common of the early Russian-style anti-ship missiles out there. Versions have been made in China and North Korea.

Phalanx Close-In Weapons system
The Phalanx Close-In Weapons system.

The best way to kill the Styx – or any anti-ship missile – is to kill the platform carrying them before the missiles are launched. Second-best is to use missiles to kill the other missiles far away.

But sometimes, you don’t get to choose one of those options. Sometimes, the missile gets too close to use missiles.

That is where the Mk 15 Phalanx Close-In Weapon System comes in. This is essentially a self-contained package containing the targeting system, ammo, and a M61 Gatling gun – the same gun used on legendary warplanes like the F-4 Phantom, F-15 Eagle, F/A-18 Hornet, and F-16 Fighting Falcon.

A version is also used by the Army to shoot down rockets and mortar rounds.