The XV Excalibur, Britain's experimental uncrewed submarine, has successfully test-fired a torpedo for the first time, marking a milestone for autonomous underwater vehicles. This test demonstrates that undersea drones can now perform attack roles alongside reconnaissance and surveillance duties. It is the first time either the United States or United Kingdom has launched a torpedo from an underwater drone rather than a crewed submarine, and the achievement was made as part of the AUKUS trilateral security partnership with Australia.

The 12-metre Excalibur, unveiled last year as part of Project CETUS, fired a heavyweight Mk 48 torpedo jointly developed by the US and Australia. The vehicle navigated autonomously to its launch position and executed the pre-programmed firing sequence, though target data was provided by external systems rather than onboard detection. Plymouth-based builder MSubs Ltd recently secured a £6.7 million contract to continue trials and evaluations. The Navy expects Excalibur to inform future uncrewed vessel requirements for patrolling the North Atlantic and protecting critical undersea infrastructure, including cables vulnerable to Russian sabotage during potential hostilities.