Raytheon's Plan to Protect Many of the U.S. Navy's Most Critical Warships | The National Interest Blog: The Evolved Sea Sparrow Missile Block II, or ESSM, is a new version of an existing Sea Sparrow weapons system currently protecting aircraft carriers, destroyers, cruisers, amphibious assault ships and other vessels against anti-ship missiles and other surface and airborne short-range threats to ships, Navy officials said.
The ESSM Block 2 is engineered with what’s called an active guidance system, meaning the missile itself can achieve improved flight or guidance to its target by both receiving and actively sending electromagnetic signals, said Raytheon officials.
The ESSM uses radar technology to locate and then intercept a fast-approaching target while in flight; the use of what’s called an “illuminator” is a big part of this capability, Raytheon officials said.
The current ESSM missiles use what’s called a semi-active guidance system, meaning the missile itself can receive electromagnetic signals bounced off the target by an illuminator; the ESSM Block 2’s “active” guidance includes illuminator technology built onto the missile itself such that it can both receive and send important electromagnetic signals, Navy and Raytheon officials explained.