Zephyr-6 uses solar power to fly for three days

A UK-built solar-powered plane has set an unofficial world endurance record for a flight by an unmanned aircraft.

The Zephyr-6, as it is known, stayed aloft for more than three days, running through the night on batteries it had recharged in sunlight.

The flight was a demonstration for the US military, which is looking for new types of technology to support its troops on the ground.

Craft like Zephyr might make ideal platforms for reconnaissance.

They could also be used to relay battlefield communications.

Chris Kelleher, from UK defence and research firm QinetiQ, said Unmanned Aerial Vehicles (UAVs) offer advantages over traditional aircraft and even satellites.

"The principal advantage is persistence - that you would be there all the time," he told BBC News. "A satellite goes over the same part of the Earth twice a day - and one of those is at night - so it's only really getting a snapshot of activity. Zephyr would be watching all day."

http://news.bbc.co.uk/2/hi/science/nature/7577493.stm

UAV shot down by Russian MiG

When smart bombs began offering video of their missions, the public was amazed and impressed. The same view into a mission exists with UAVs controllable from across the world.

Last week a UAV was shot down by a Russian MiG in a contested airspace conflict. Regardless of who is right or wrong, this show of force is a reminder about the power of machines in the sky.

Make your own UAV

Amateur engineers can build their own UAVs similar to what NASA or the military is creating. This success mirrors the innovation in computing during the 1970s.