In a building in Simi Valley sits a partially finished 70-foot-long unmanned aircraft that is truly something special. It’s designed to stay aloft for a week, powered by a combustion engine fueled by a mixture of hydrogen and oxygen. But when the unmanned Global Observer will take to the air again is anybody’s guess. The AeroVironment Inc. aircraft has been grounded for more than three years due to a lack of funding to continue flight tests. This at a time when Boeing Co. in Chicago is testing its own high-altitude, hydrogen-powered drone called Phantom Eye at Edwards Air Force Base in the Antelope Valley. Now, AeroVironment has taken steps to get its large drone, which has wings spanning 175 feet, airborne once again. It has reached an agreement with aerospace and defense contractor Lockheed Martin, in Bethesda, Md., to help in development of the aircraft. And it is in a joint venture in Turkey to try to obtain flight-test financing from potential buyers who might want to fund development. “It is easy to write (our own) check and pay for new development and there are times when that makes sense,” said Steve Gitlin, a spokesman for AeroVironment. “But it’s also important to secure customer funding to engage them in the program.” See the full story in the Dec. 15 issue of the Business Journal.