That eye in the sky is here

If you see what looks like a multi-armed toy helicopter flying in our skies, you may be looking at a drone, or an aircraft without a pilot on board.

A few years ago drones were virtually unknown. They were originally developed to carry out tasks where a manned flight was too risky or difficult, mostly in military exercises.

Today drones have many uses, including domestic ones.

These flying robots use the most advanced robotic, electronic, aeronautic and software technology. Sizes range from as small as a tiny bird to as big as a small helicopter, and they come in a variety of shapes, too. They are controlled by in-built computers (autopilot) or by a person on the ground using remote control.

Materials used to build drones are very light but strong, so they are easy to manoeuvre. The strength of the materials also allows them to travel at high altitudes.

Uses include:

•Small parcel delivery in the central business districts of cities. Drones to deliver takeaway orders are being considered as well as ones that get products to consumers within 30 minutes of ordering.

•Spying on criminal behaviour and collecting information without putting police officers at risk. Video, still and infra-red cameras are built into drones for this purpose. They can also monitor crowds at concerts and festivals.

•Farming. For 20 years famers in Japan have used drones to spray rice paddies, particularly on steep hillsides. Drones spray and seed with more precision than traditional piloted planes and helicopters. They give a bird’s-eye view of property, helping farmers assess plant and stock progress. This all saves farmers time and money.

•Mapping and surveying on mining sites as well as monitoring the sites’ productivity and safety.

•Protection of land and the species living there. For example, conservationists in Indonesia and Malaysia use drones to study orang-utan distribution and behaviour.

•Aerial shots in filmmaking, especially in action movies. Drones can film at just the right height while cranes are sometimes not high enough and helicopters can be too high.

•Space exploration. Recently the European Space Agency landed a drone called Rosetta on a comet. It had travelled for 10 years over billions of kilometres. This research will help humans learn more about space resources and colonies which could benefit Earth.

Drone development still has a long way to go and because of privacy issues, regulations are very strict about their use in airspace.