In the 1990s, Boeing and Lockheed teamed to design and build the Darkstar, a high-altitude unmanned aerial vehicle or UAV to be used for stealthy reconnaissance in heavily defended areas. Boeing was responsible for DarkStar's wings, mission system, radar sensor payload and vehicle management system. Four Darkstars were built before the Department of Defense terminated the program due to budget cuts in 1999. One of the Darkstars is now on display at Seattle's Museum of Flight.