"last month we completed aquila, our unmanned aircraft that can beam internet connectivity from the sky to remote communities.
building aquila meant solving a lot of engineering challenges. to design an aircraft that can fly 60,000 feet in the air for months at a time, we needed to make it extremely light and efficient. so we built the airframe from carbon fiber, which is stronger than steel but very light. aquila has the wingspan of a 737 but weighs less than a car.
here’s a photo of one of aquila’s propellers, which is also made of carbon fiber. ıt's optimized to convert electrical energy from our batteries into flight at altitudes almost twice as high as a passenger jet."
mark zuckerberg, https://www.facebook.com/….2204760.4&type=1&theater