Facebook has made the first test flight of its Aquila full-sized unmanned aircraft that was designed and built in the South West.
Aquila has a wingspan of 42 metres and is intended to fly at between 60,000ft and 90,000ft to act as an aerial basestation to provide internet access in rural areas. It was developed by Ascenta in Yeovil which was bought by Facebook in 2014.
The test flight lasted 90 minutes, three times longer than expected, using 2kW of power from lithium ion batteries to propel the craft at 25mph. In operation, the craft will use 5kW, little more than a microwave oven, from batteries charged by solar panels to remain in the air for up to 90 days.
The flight also tested out the autopilot. To keep the weight down to 300 kg, Aquila is launched via a dolly, and is held on the dolly by four straps that are cut by small explosive charges by a signal from the autopilot when the takeoff speed is reached.
It didn’t all go to plan though, as the craft suffered a structural failure just before landing, but Facebook is not revealing what happened.
The craft communicate with each other and with the ground via lasers, and Facebook’s Connectivty Labs in the US has come up with a type of receiver to make this work. The receiver uses several metres of plastic fibre doped with fluourescent material to capture the laser signal from another craft and turn it into data at speeds of 2Gbit/s. The researchers are now looking at new materials for infrared lasers that could provide data links up to 10Gbit/s between the aircraft.
