Navy Destroyer Attacked!” was the headline of every U.S. newspaper and morning talk show on 12 October 2020, the 20-year anniversary of the al Qaeda attack on the USS Cole (DDG-67). A terrorist group used a swarm of drones carrying explosives to cripple the radars and weapon systems of the USS John Basilone (DDG-122) only months before she was due to deploy with her carrier strike group. The John Basilone was moored at Naval Weapons Station Seal Beach and in the process of onloading missiles and ammunition.
The drone threat has been around for years, but the Navy has yet to prioritize defending against these easily acquired weapons. Amid preparations for a high-end fight, the Navy still is vulnerable to an adversary trading thousand-dollar drones for billion-dollar warships.
How It Could Happen
The Islamic State first used explosive-carrying drones in 2016, and a do-it-yourself drone swarm attack was reported in Syria in 2018. Terrorist groups can purchase high-end commercially available hobbyist drones for around $2,000, masking the money trail by purchasing drones over time from multiple brick-and-mortar stores or by using cryptocurrencies at online retailers.
A top-of-the-line consumer drone such as the DJI Mavic Pro 2 has a range of up to ten nautical miles, a maximum speed of 40 knots, a small payload capacity, and the ability to fly via waypoints. Speed and range would be degraded were the drone equipped with an explosive payload, but range would not necessarily be a limiting factor.
Figuring out when a ship will deploy is not difficult either. Most aircraft carrier strike groups follow predictable deployment schedules to maintain a U.S. naval presence in the western Pacific and the Middle East, and all ships go through a work-up period prior to a deployment that includes short underways, readiness checks, and weapons onloads—making it clear which ships are nearing their deployment dates. Terrorists also could use social media to dig deeper: following the public Facebook pages of warships or infiltrating sailor family and friends Facebook groups and befriending group members to probe for information on ships’ upcoming movements.
To know how to strike the ship, the terrorists could study open-source images of the Arleigh Burke–class guided missile destroyers to determine the locations of key weapon and communications systems. This expensive electronics equipment is vulnerable to drone-carried explosive devices or kamikaze-style attacks. Hobbyists with coding skills have shown they can reprogram drones to track people. Building on this knowledge base, the terrorists could program drones to focus on communications antennas, weapon systems, or radar arrays.
After flying to the waypoint of a target ship, the drones would not need to emit a radio signal to a controller if their final approach were made using electro-optical sensors—their camera eyes—paired with software that tells each drone when and where to strike. Such an approach would make the drones impervious to antidrone systems that jam radio transmissions between the controller and the drone. The drones could strike the SPY radar arrays, half a dozen satellite communications antennas, or the intakes and exhausts of the destroyer’s main engines. Sprinkling these key systems with shrapnel from exploding drones would cause millions of dollars of damage, take months of unplanned maintenance to repair, and leave a destroyer unable to perform its mission.
Warships are most vulnerable when they have limited ability to maneuver—such as in the Suez Canal, Bosphorus Strait, and Panama Canal. But a warship trapped inside Seal Beach’s Anaheim Bay (or any other pier), saddled by cranes onloading thousands of pounds of explosive ammunition, also presents an exposed target. Warships are also vulnerable at sea, because their advanced air defense radars are calibrated for traditional air threats: missiles and tactical aircraft flying hundreds of miles per hour, tens of thousands of feet in the air. Drones flying at lower speed and altitude are difficult to detect if a warship isn’t actively looking for them.
The Way Ahead ….
By Lieutenant (J.G.) Artem Sherbinin, U.S. Navy, and First Lieutenant Richard Kuzma, U.S. Army