The RQ-3 DarkStar was designed as a "high-altitude endurance UAV", and incorporated stealth aircraft technology to make it difficult to detect, which allowed it to operate within heavily defended airspace, unlike the Northrop Grumman RQ-4 Global Hawk, which is unable to operate except under conditions of air supremacy. The DarkStar was fully autonomous: it could take off, fly to its target, operate its sensors, transmit information, return and land without human intervention. Human operators, however, could change the DarkStar's flight plan and sensor orientation through radio or satellite relay. The RQ-3 carried either an optical sensor or radar, and could send digital information to a satellite while still in flight. It used a single airbreathing jet engine of unknown type for propulsion. One source claims it used a Williams-Rolls-Royce FJ44-1A turbofan engine. 
 PHOTOZ: JULIE DINH ASIA BUCHANAN-FISHER ERYN SLOPER