Retired in April 2015, the U.S. Navy’s two X-47B, known by their call signs as Salty Dog 501 and Salty Dog 502, represent the most significant progress in Unmanned Combat Aerial Systems to date. Among their numerous achievements, the X-47B was the first drone to land on an aircraft carrier and refuel in midair autonomously.
Six years since the X-47B began development, Northrop Grumman finally received a contract to build two X-47Bs; in that time, military drones had become much more prominent as a result of the success of the MQ-1 Predator, and MQ-9 Reapers in Afghanistan and Iraq. Though development costs were quite significant, reaching nearly $1.5 billion by 2015, the program meshed well with evolving Navy requirements.
