DarkStar was a high-altitude, low-observable endurance UAV optimized for reconnaissance in highly defended areas. It was to operate within the current military force structure and with the existing command, control, communications computer and intelligence equipment. It had the ability operate at a range of 500 nautical miles and stay on station for eight hours at an altitude greater than 45,000 feet. The air vehicle was designed to carry either the SAR or EO payload. Boeing teamed with Lockheed Martin in 1994 to design and build the DarkStar for the U.S. Department of Defense Tier III Minus program. However, in late January 1999 the Defense Department announced the termination of the DarkStar unmanned aerial vehicle program.