While unmanned aerial vehicles have long been used by the military, their use for peaceful civilian purposes is growing.
Big Brother's drones also save lives and alleviate poverty
Drones have a bad press. Most people associate them with remote-controlled missile strikes and Big Brother-style surveillance.
But a Greek engineer is working on an innovation that shows they can also save lives and alleviate poverty among the estimated one billion people living in areas that can't reliably be reached by roads.
Andreas Raptopoulos, 39, plans to develop networks of small drones, or unmanned aerial vehicles (UAVs), that ferry supplies such as medicine to remote, hard-to-access locations.
His Silicon Valley-based start-up Matternet is seeking funds to expand tests of the system after completing a successful first trial last year at an aid camp in Haiti that was set up after a devastating 2010 earthquake.
His mini-helicopters fly at heights of about 120 metres using GPS for navigation and can carry loads of up to 2kg. Their range is limited to about 10km per battery load, a distance they can cover in 15 minutes. He plans to get around that by building networks of charging points where the drones land to automatically swap their batteries along the route.
"This type of technology has a very bad reputation and for good reason. But there's a lot of potential to use it for social benefit," Mr Raptopoulos says.
"We see amazing growth in UAV technology and we think it will provide all sorts of opportunities."
Drones could help poor countries to speed up their development in the same way mobile phones did, he says. Nations in sub-Saharan Africa, for example, now have well-functioning telephone networks without ever having had to lay thousands of kilometres of landlines.
"Paving roads is a very big task, the US has more than four million miles of road and it will cost sub-Saharan Africa 50 years and billions, maybe even trillions of dollars to get there," Mr Raptopoulos says.
"We thought could there be a way to partly leapfrog initially and allow them to tackle urgent challenges by not relying on roads." He cites a case study conducted by Singularity University, a corporate-funded research and education body, that showed a network of 150 drones and 50 base stations catering for a district in the southern African country of Lesotho would cost US$900,000 to set up - less than the $1 million cost of building a 2km, one-lane road.
"The world has 1.4 billion people living in extreme poverty defined as earning less than $1.35 a day, and two thirds of them are not connected to paved roads that can be used in all seasons," says Mr Raptopoulos.
"In the wet season, these people are disconnected due to flooding and because it's not possible to get reliable transportation through them."
One day, drones could allow farmers to deliver products to their customers and rescue workers to send vital supplies to places cut off by natural disasters.
Drones already have a wide array of peaceful applications, largely in the form of aerial surveillance that enables firefighters to assess the direction of forest fires, scientists to track animal migration and rescue workers to locate stranded hikers.
Mavinci, a German start-up company, produces fixed-wing UAVs that can take aerial images for land surveys used in construction projects, or to assess the damage in disaster areas.
But the idea of small-scale cargo delivery is relatively new. A number of firms are now working on this concept of an "analogue internet" - a dense, interconnected physical delivery system that sends tangible packages in the way the web delivers parcels of digital information.
The lack of range and the need for charging points are indeed shortcomings. The points could be subject to theft or vandalism. It is also unclear how the drones would perform in bad weather. And safeguards need to be found to make sure they are not used for transporting weapons or drugs.
But the technology is advancing rapidly. At the Paris Air Show last month, Design Intelligence, based in the United States, announced the development of a drone that uses solar power generated via its wings. When operated in good sun and weather conditions, it has three times the endurance of traditional battery-powered UAVs, the company says.
Mr Raptopoulos says flight ranges will lengthen and the growth of ever-faster battery charging will steadily improve the performance of drones. He insists there is a sound economic rationale behind "micro-transportation". Conventional transport such as road, rail, shipping and manned aircraft will remain indispensable when people and heavy loads need to be shifted. But UAVs have the advantage in terms of cost and energy efficiency when it comes to moving small loads from A to B.
"If you keep the payload limited, you can keep the size of the vehicles small, which keeps costs down and lessens the risks in case of failure. That's what drives the economics," Mr Raptopoulos says.
That aspect opens up an intriguing and potentially lucrative future use for small UAVs in the developed world - as a courier service in congested cities.
"80 per cent of e-commerce packages are below 2kg. There seems to be a good fit there," he says.
It is even conceivable that mini-drones could deliver your pizza one day - if they work out how to ring the doorbell.
In the United States, Congress has asked the federal aviation administration to develop a comprehensive set of rules for unmanned aircraft by 2015. That should include rules on when and where they can fly, safety features, pilot training and the purpose of the drones.
"We think it's quite likely that all autonomous vehicles will need to report their position to a central system," says Mr Raptopoulos. Having proper safeguards will be essential for the public to accept the prospect of drones whizzing over their heads.
"It's important to start in places where we think the need is very high and the risk is low if technology fails, these are typically more rural places," he says.
"As we prove the reliability of the technology and the network we can keep on embracing more complex networks in more complex environments. You need to have 99.95 per cent reliability before you make the argument to the aviation authorities that you want to fly over crowded space."
Matternet raised $200,000 last year and is now seeking to expand its funding to between $2 million and $3m. Its next planned step is to build a network of five base stations to test the technology in Africa. At this stage, the battery and load swapping will still be manual. Automatic battery swapping is still in the design phase. The company plans to have small automated networks operating within two to three years.
Local acceptance of the technology is key, of course, and Mr Raptopoulos says he is encouraged by the response of Haitians to the drones during last year's trial there.
"It was a very strong experience. We felt we were at the centre of the problem, and we were going there with technology that is science fiction in people's minds," he says.
"We saw all this excitement and all the people encouraging us to move forward and make it happen."