Britain and the United States test-fired a torpedo from an uncrewed underwater vessel instead of a crewed submarine for the first time, the UK government said on Monday, September 21.

According to London’s statement, the live firing took place in UK waters last week as part of the alliance of Australia, the United Kingdom and the United States (AUKUS) and “marks a major advance in the future of submarine technology” for the three countries. The heavyweight torpedo, jointly developed by the United States and Australia, was launched from a 12-metre undersea drone built in Britain and named XV Excalibur. In 2025, an operating centre in Australia, more than 16,000 kilometres from the vessel’s home in Plymouth, took remote control of XV Excalibur during Exercise Talisman Sabre, according to the British Royal Navy. Sidharth Kaushal, a senior research fellow at the Royal United Services Institute (RUSI) think tank, told AFP that the test was “noteworthy” and that “the employment of a lethal payload illustrates that uncrewed systems can play roles which extend beyond surveillance”. The announcement came on the day Prime Minister Andy Burnham flew to New York for the UN General Assembly, where he will hold his first meeting with Donald Trump since taking office in July and will announce a “new AI and autonomy partnership” with Washington, according to the UK government.