Facebook’s Aquila drone takes off from its launch dolly. (credit: Facebook)

The low-altitude test flight was originally intended only as a 30-minute “functional check” flight. “It was so successful that we ended up flying Aquila for more than 90 minutes—three times longer than originally planned,” wrote Jay Parikh, Facebook’s vice president of infrastructure engineering, in a post to Facebook’s Newsroom blog published today.

The initial test goals were simply to ensure that the huge Aquila drone—with a wingspan comparable to a Boeing 737 and mass more like an automobile—could even get airborne. To minimize its weight, Aquila doesn’t have “traditional landing gear,” according to Martin Gomez and Andy Cox of the Aquila team. “We attached the airplane to a dolly structure using four straps, then accelerated the dolly to takeoff speed. Once the autopilot sensed that the plane had reached the right speed, the straps were cut simultaneously by pyrotechnic cable cutters known as ‘squibs.'”