By Kris Osborn, President, Center for Military Modernization
Electronic jamming, proximity fuses, interceptor missiles, deck-mounted guns, “area” weapons to blanket areas with protection and possibly even lasers are all possible reasons why the US Navy’s USS Carney destroy tracked, disabled or destroyed a small swarm of 14 enemy drones at one time.
A public statement from US Central Command says “in the early morning hours of December 16 (Sanna time) the US Arliegh Burke-class guided missile destroyer USS CARNEY (DDG 64), operating in the Red Sea, successfully engaged 14 unmanned aerial systems launched as a drone wave from Houthi-controlled areas of Yemen.”
These attacks, which were defended by British warships as well, represent the latest escalation in a series of what appear to be Houthi-backed attacks on Israel, the US and non-military maritime commerce in the Red Sea.
The operational specifics of how this was accomplished are certain to be unavailable for security reasons, yet the successful combat performance of layered ship-defenses appears to show breakthrough progress in the area of ship-based radar, fire control, target tracking, precision and possible non-kinetic countermeasures. However it was accomplished, the defeat of a drone swarm in an operational setting not only protected US Navy sailors and ships aboard the USS Carney but also appears to have saved a number of commercial vessels transiting the Red Sea.
Distributed Lethality
The swarm intercept suggests that weapon systems long-in-development designed for the specific purpose of countering drone swarms may have indeed reached operational maturity. We may not know the particular countermeasures or integrated layers of ship defenses that were used to destroy or stop the Houthi drones, yet the Navy has spoken for years in a general way about a series of surface-fleet wide upgrades and weapons enhancements intended to better “arm” the fleet for massive “blue-water,” “open water” maritime warfare. The initiative, which emerged roughly around 2015, was referred to as Distributed Lethality, and it was a comprehensive and high-tech effort to overhaul and improve weapons and defenses across the surface fleet.
There are many particular systems which may have been used to destroy the drones, many of which may have in recent years been added or upgraded as part of the multi-year distributed lethality initiative. Specifically, enhanced ship defenses include laser such as the Laser Weapons System (LAWs), an EW system called Surface Electronic Warfare Improvement Program (SEWIP) Block 3, the SeaRAM missile system, Rolling AirFrame Missile and Close-in-Weapons-System (CWIS). As far back as 10 years ago, the Office of Naval Research demonstrated and deployed the LAWs on an amphib in the Middle East called the USS Ponce. The LAWs laser system introduced a low-cost way to track and incinerate enemy drones, and it was also scalable such that it could either disable or fully incinerate the target. In more recent years, the Navy has been integrated an even more advanced series of laser weapons onto destroyers, certain applications of which may have been used against the Houthi swarm. One such possibility is HELIOS, an advanced Lockheed Martin laser system now being integrated onto US Navy destroyers. An interesting 2022 essay in Naval News says HELIOS, which stands for High Energy Laser With Integrated Optical Dazzler and Surveillance, has been integrated onto US Navy destroyers.
“Lockheed Martin delivered to the US Navy a 60+ KW-class high energy laser with integrated optical-dazzler and surveillance, the first tactical laser weapon system to be integrated into existing ships and provide directed energy capability to the fleet,” Naval news writes.
While HELIOS has now been integrated onto US Navy destroyers, it may or may not be currently arming warships in the Red Sea. Certainly many of HELIOS’ technical characteristics may not be available, however an interesting essay in National Defense quotes a Lockheed spokesman saying that the new system is longer range, more tailorable and more powerful than LAWs.
“The weapon uses spectral beam combined fiber lasers, giving it a higher beam quality than the “incoherently combined” six high quality fiber lasers of LaWs,” the spokesperson said.
What is more likely, however, is that some kind of EW, area weapon or proximity fuse was used to counter a mini-drone fleet. For instance, in recent years the Navy has been integrating a cutting edge electronic warfare suite called SEWIP, a next generation series of targeted electronic “beams” designed to disable the guidance systems and electronic signal of a group of enemy drones. SEWIP Block 3, in particular, combines 16 different Active Electronically Scanned Arrays (AESA) to emit groups of targeted, individually separated “pencil-like” beams. Several years ago, a Northrop Grumman weapons developer with SEWIP Block 3 said the “pencil” beams could be individually focused, enabling the weapon to put energy or an electronic “jamming” signal where it is needed. It is conceivable that an integrated or collective SEWIP Block 3 system could have been used to target each of the 14 Houthi-fired drones. Utilizing a number of integrated individual narrowly-configured EW beams brings a number of significant tactical advantages. Not only can the system track multiple threats simultaneously, but it can also help with targeting and limit own-ship ‘signature’ emissions.
Layered Ship Defenses
At the same time, a “kinetic” solution could just as easily have been used, particularly if it used what’s called a “proximity” fuse. Depending upon how far apart the drones were from each other, an explosive designed to fully “fragment” and “blanket” a group of drones in close proximity with explosive material could potentially destroy a concentrated swarm. Proximity fuses, which can be used on various interceptor rounds, are set to detonate at a “space” or “area” to maximize explosive effects in a specific target location. Perhaps an SM-2 interceptor with a proximity fuse could have been used, if the drones were too far away for closer in countermeasures and flying in close proximity. However, a larger interceptor such as an SM-2 would be less likely given the smaller size of the drone targets, meaning it seems more likely that closer-in ship-fired defenses may have been used. Ship fired SeaRAM defenses, which integrate onto the Close-in-Weapons-System with Rolling Air Frame missiles can destroy enemy targets from distances out to 5 miles. This is quite a standoff range, particularly if the interceptors use precision-guidance to track and destroy incoming enemy drones.
The SeaRAM system builds upon the infrastructure and radar of the Close-in-Weapons-System (CIWS). CIWS’ Phalanx weapon fires a 20mm cannon at close-in threats such as small boats. The SeaRAM missile system replaces the CIWS area weapon with the Rolling Airframe Missile which fires from an 11-missile battery. The CIWS weapon, which has in recent years been upgraded by the Navy to incorporate surface as well as incoming air threats, shoots out 4,500 rounds per minute with a phalanx gun firing mini-projectiles. The range of CWIS is roughly 2-to-3 miles, clearly long enough to take out some small drones, should they be close enough.
Raytheon weapons developers told Warrior that the SeaRAM massively expands the defensive envelope of the ship, enabli
ng a longer-range Rolling Airframe Missile beyond the capacities of a CIWS gun to track and destroy multiple targets simultaneously. Interestingly, a Navy weapons developer once explained to Warrior that the SeaRAM integrates the accuracy and precision of the Rolling Airframe Missile with the maneuverability of the CIWS’ Phalanx’s high-resolution search and track sensors systems designed for rapid response.
CWIS has also been upgraded progressively in recent years as part of the Distributed Lethality upgrade, and the weapon which was once primarily an “air” blanketing countermeasure has been upgraded into a 1B variant capable to countering close in surface threats such as lower flying drones or even small boats.
“The Phalanx is also equipped with its own search radar and tracking radar, which allows for the system to work independently of other systems.[vii] The Phalanx is capable of detecting an incoming attack, track the missile or aircraft, and engage the threat automatically. This provides a faster reaction time to ensure safety of the vessel. The Phalanx has had several versions throughout its career,” an interesting essay from Missile Defense Advocacy writes. CWIS Block 1A, for example, modified software and processing power to allow the CIWS to perform more efficiently against multiple targets, and Block 1B Phalanx Surface Mode (PSUM): Added a Forward Looking Infrared Radar (FLIR), which allows the CIWS to engage hovering or slow-moving aircraft and surface craft.
Should the Houthi swarm of minidrones come within roughly 5 miles of the USS Carney, it is quite likely that the CWIS or several SeaRAM weapons were used to destroy them. An ability to blanket an area with 4,500 rounds per minute with a 20mm cannon seems quite capable of destroying a small fleet of 14 drones as it approached within a 2-to-3 mile perimeter of the ship.
Warrior’s Take
My guess is that the effective defense was either CWIS or SEWIP, as I’m not sure lasers are yet capable of firing 14 different beams at different moving targets simultaneously, however, such innovations are likely progressing quickly and laser weapons able to shoot multiple “beams” do already exist. Also, it does not seem likely that a single interceptor missile such as an SM-2 could destroy all 14 drones unless they were very closely packed together and some kind of “proximity” fuse was used. CWIS is the most likely scenario, however I don’t know if the Houthi drones came within roughly 5-miles or so for SeaRAM and 2-to-3 miles or so for CIWS of the Navy ship. If so, it is likely CWIS blanketed the area with projectiles and destroyed the drones. The most likely, I suspect, would be an EW system given that these weapons have made great leaps in operational maturity in recent years. Also, should the drones be operating near civilian or commercial vessels, then an EW solution would lower risk to surrounding vessels as it would not generate a “kinetic” explosion releasing projectiles and fragmentation in the area of commercial ships. The key factors, it seems, would be to find out the range of the Houthi drone swarm and its proximity, meaning how far apart were they from one another. Should they have been disaggregated, it is not impossible that each drone could have been individually targeted.
Kris Osborn is President of Warrior Maven – Center for Military Modernization. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.
