US to launch 132-foot unmanned ocean drone 
The US Defense Advanced Research Projects Agency (DARPA) is launching a 132-foot unmanned ocean drone on April 7, 2016. The 140-tonne drone named Anti-Submarine Warfare Continuous Trail Unmanned Vessel (ACTUV) will help US to track down secret submarines in the ocean. One of the most silent drone, the ACTUV will remain in the sea for months without any crew.