The Defense Advanced Research Projects Agency (DARPA) could demonstrate within two to three years a new unmanned aircraft designed to provide aerial cover for troops in close proximity to enemy forces. Proposals from industry are requested by DARPA by 21 February to demonstrate in 2012 or 2013 an unmanned component for a next generation close air support system. The complete system may eventually assume a role now traditionally served by the Fairchild Republic A-10 and other manned fighters, such as the Boeing F/A-18 and Lockheed Martin F-16. More recently, armed unmanned air systems (UAS), including the General Atomics Aernoautical Systems...