The United States Navy has rarely had to use its surface-to-air missiles in real combat. In fact, over the last thirty years, far more of the Navy's action has involved hitting land targets instead of going after enemy aircraft in the skies. That's one reason why 2016 actions involving the Arleigh Burke-class guided missile destroyer USS Mason (DDG 87) were so notable.
During one of those actions, the destroyer used the RIM-162 Evolved Sea Sparrow Missile to defend itself against Iranian-built Noor anti-ship missiles, which are copies of the Chinese C-802. Now, the Navy is looking to make the ESSM even better by giving it a new seeker.
According to a Navy release, the upgrade is going to be an active seeker, like the ones used on the AIM-120 Advanced Medium-Range Air-to-Air Missile and the RIM-174 Standard SM-6 Extended Range Active Missiles. This is a massive shift in the missile's capabilities.
The safe return to Norfolk by the Arleigh Burke-class guided missile destroyer USS Mason (DDG 87) was made possible by the RIM-162 Evolved Sea Sparrow Missile.
(U.S. Navy Photo by Mass Communication Specialist 3rd Class Maria I. Alvarez)
Since its introduction in 1976, the Sea Sparrow (like the AIM-7 Sparrow) has used semi-active radar guidance, according to a US Navy fact sheet. That means that the ship or plane firing it has to "paint" a target with its radar in order to guide the missile. Not only does this require leaving the radar on, it also means you must predictably point your radar toward the target. Sound like a fun way to fight? We don't think so, either.
Amphibious assault ship USS Bonhomme Richard (LHD 6) fires a NATO Sea Sparrow surface-to-air missile to intercept a remote-controlled drone. The semi-active guidance of this missile creates a vulnerability for ships and aircraft,
(U.S. Navy photo by Mass Communication Specialist 2nd Class Diana Quinlan)
For a ship, having to leave a radar on to "paint" a target can invite incoming anti-radar missiles, like the Russian AS-12 Kegler, which has a range of up to 21.6 nautical miles. Not only are radars expensive to replace, such an attack would also leave the ship's missiles without guidance capabilities.
An active seeker, which houses the radar needed for guidance in the missile, greatly reduces that vulnerability, creating a "fire and forget" capability for ships and aircraft.
The RIM-162 Evolved Sea Sparrow Missile can be fired from Mk 29 launchers or from vertical-launch systems.
(U.S. Navy photo by Mass Communication Specialist 3rd Class Patrick Green)
The RIM-162 ESSM Block II, the missile with the active seeker, is currently going through live-fire testing. In the first test, held in July, 2018, the missile successfully destroyed a BQM-74E Chukar target drone.