Drones: MIT software casts doubt on solar-powered UAVs

Developed at the Massachusetts Institute of Technology (MIT, Cambridge, MA, US), the Jungle Hawk Owl unmanned aerial vehicle (UAV), funded by the US Air Force in an effort to develop a way to provide a drone-based alternative method of WiFi access, relies significantly on composites for its lightweight construction. One reason was the hope that the aircraft could be kept aloft for extended periods, exclusively by solar power. 

Using a new modeling software tool called geometric programming optimization, however, researchers discovered that the goal of powering the drone with solar energy was infeasible. The program, called GPkit for short, was developed at MIT by Warren Hoburg, professor of aeronautics and astronautics and a member of the project team that is designing the Jungle Hawk Owl drone. 

The GPkit program reportedly facilitates consideration of about 200 factors and physical models simultaneously, and then integrates them to create an optimal aircraft design. In the case of the solar-powered drone, the model determined it would work during the summer season in either hemisphere, but not in the winter. Further, it indicated that adding more batteries would make the drone too heavy. Alternatively, the same modeling predicted that a 5-hp gasoline engine would be sufficient to keep the drone in flight for more than five days at an altitude of 4,572m in up to 94th-percentile winds at any latitude. 

Hansman says the GPkit tool provided a “state-of-the-art” design optimization technique. “In terms of its structural aerodynamics,” he adds, “this plane is exquisitely proportioned.”