Bye Aerospace, Inc. and Ascent Solar recently announced initial details of a hybrid unmanned aerial vehicle (H-UAV) called the Silent Sentinel. While the Silent Sentinel will be primarily used in military applications, its capabilities could also be useful in civil scenarios.
The hybrid will utilise thin film solar photovoltaics (PV) and other technologies to enhance its endurance, quiet operations and low emissions. Thin film solar cells provide flexibility combined with light weight. Power storage will be by way of a Li-ion battery bank.
For primary propulsion, the hybrid UAV will use an advanced Williams International FJ33 turbofan, a family of turbofan jet engines intended for use in very light jet aircraft. Bye Aerospace says the efficient engine will provide the UAV impressive climb rates and high altitude quick access to areas requiring surveillance.
Potential military applications include border patrol, search and rescue operations, visual and thermal reconnaissance missions and forward air control. In addition, potential civil applications include traffic control activities, pipeline and power line inspection, aerial law enforcement, forest fire detection and aerial photography.
Solar powered UAV’s are not a new invention and have evolved over nearly 35 years. Sunrise I incorporated 1000 solar cells located on the wings that produced around 450 watts of power and was launched at Camp Irwin Bicycle Lake, California on November 4, 1974. More recently, NASA’s H-UAV Helios had a wingspan longer than a 747 and was powered by over 62,000 bi-facial solar cells. The Helios was unfortunately lost over the Pacific Ocean in 2003 during a test flight.
