US and UK Test Torpedo Launch From Uncrewed Submarine

The U.S. and Royal navies tested a U.S. Mk 48 heavyweight torpedo launched from a British uncrewed underwater vehicle on September 13, demonstrating that the weapon could be integrated with the platform but not establishing an operational armed-drone capability. The trial took place at the British Underwater Test and Evaluation Centre in Scotland as part of Pillar 2 of the AUKUS partnership, which includes cooperation on advanced technologies. The torpedo was mounted beneath XV Excalibur, an uncrewed vehicle developed for the Royal Navy under Project Cetus, rather than carried inside its payload bay. The external launch work was conducted through Project Broadsword and Trial Iron. The U.S. Navy said the test validated the mechanical, electrical and software integration required to launch an American torpedo from a British autonomous vessel. The Department of the Navy Rapid Capabilities Office approved the project in February 2026, and the demonstration was completed in less than seven months, according to the Navy. The trial was described as a proof of concept. The navies have not disclosed how Excalibur was controlled during the launch or whether the torpedo engaged a target.