US and UK Navies Launch Torpedo from Robotic Drone Submarine

Historic Autonomous Weapon Launch

The U.S. Navy and the British Royal Navy conducted a joint exercise on September 13, successfully launching a U.S. Mk 48 heavyweight torpedo from the Royal Navy’s uncrewed drone submarine, XV Excalibur. This proof-of-concept launch took place at the British Underwater Test & Evaluation Center (BUTEC) in Scotland, marking a significant step in autonomous warfare capabilities.

Validation of Allied Interoperability

This test, designated Project Broadsword, validated the mechanical, electrical, and software integration of an American kinetic payload onto a British autonomous platform. According to Chief of Naval Operations Adm. Daryl Caudle, this proves weapon interchangeability between allied forces, enhancing the flexibility, scale, and combat power of combined forces.

The project received approval in February 2026 from the Department of the Navy Rapid Capabilities Office (DONRCO) and was executed in collaboration with OPNAV N97, the Royal Navy, the Defense Innovation Unit (DIU), Naval Undersea Warfare Center (NUWC) Keyport, and industry partners.

AUKUS Pillar 2 Initiative

The launch was conducted under AUKUS Pillar 2, a military partnership involving the United States, the United Kingdom, and Australia. This initiative focuses on developing and deploying advanced defense technologies, including artificial intelligence, quantum computing, and autonomous underwater systems, to maintain a strategic technological edge, particularly in the Indo-Pacific region.

Mk 48 Torpedo Deployment

The Mk 48 is a 3,700-pound anti-submarine and anti-surface torpedo typically launched from manned submarines. Project Broadsword represents the first successful launch of this weapon from an uncrewed, autonomous robotic submarine, demonstrating a new method for deploying this capability.