Within and outside the U.S. military, critics frequently point out that aircraft carrier operations — long a showcase of America's supreme military power — have become dangerously vulnerable. The concern is that China has been building up its arsenal of long-range anti-ship ballistic missiles and hypersonic missiles capable of destroying U.S. aircraft carriers and Aegis destroyers, potentially cornering the United States in a contingency.
China has completed development of the DF-21D, an anti-ship ballistic missile dubbed the "carrier killer" with a maximum range of 3,000 kilometers, and the DF-26, a surface-to-surface missile with a range of up to 5,500 kilometers capable of striking U.S. naval bases on Guam. With the emergence of hypersonic missiles traveling at speeds above Mach 5, making interception nearly impossible, the U.S. Navy faces pressure to fundamentally overhaul its carrier-centric strategy.
The U.S. Navy's answer is the "Ghost Fleet," an asymmetric unmanned force. The concept calls for deploying the Ghost Fleet on the front line to engage Chinese ballistic missiles and warships first, while carrier strike groups follow up with subsequent attacks from behind. The core of the Ghost Fleet consists of unmanned surface vessels (USVs) and unmanned underwater vehicles (UUVs).
On October 1, 2019, the U.S. Naval Sea Systems Command announced in a press release that the Navy was pursuing a "Ghost Fleet Concept Program" to build out the fleet. Earlier, beginning in April 2016, the Navy had independently constructed a 40-meter catamaran-type unmanned prototype vessel called "Sea Hunter." Unmanned vessels operate without crew aboard and can be controlled remotely from a distance.
Among the unmanned vessels at the heart of the Ghost Fleet, the Navy's first priority was the experimental unmanned vessel Sea Hunter. Developed by the Defense Advanced Research Projects Agency (DARPA), Sea Hunter is 40 meters long, displaces 140 tons, and is known to excel at submarine detection. In 2018, it departed San Diego and successfully completed a 9,600-kilometer voyage.
To build the Ghost Fleet, the U.S. Navy plans to construct large, medium, small, and extra-small unmanned vessels. Large and medium unmanned vessels will be used for open-ocean operations, while the rest will serve in coastal defense of the U.S. mainland. The leading candidates for the front line against China are the Large Unmanned Surface Vessel (LUSV) and the Extra-Large Unmanned Underwater Vehicle (XLUUV).
