Facebook’s Aquila is definitely no drone you’ve ever seen or heard of before. It’s size alone is staggering, with a wingspan that matches that of a Boeing 737. And yet, at the same time, it weighs less than a car. That alone might already be an impressive engineering achievement, but these drones are also meant to fly for 3 months, circling around an area, at a height of 60,000 to 90,000 ft, higher than conventional air traffic. All powered by solar energy.