In December 2016, Amazon released a promotional video showing viewers what it believes is a glimpse of the future. A fixed-wing delivery drone was shown taking off from Amazon’s Development Centre near Cambridge and then delivering a package to the garden of a lucky customer. It was a slick video and a nice idea, but three years later there is no drone delivery option on the Amazon checkout page despite the hype. In fact, so far, the only places that drone delivery has really taken off aren’t in the United States or Europe, but in Africa.
Zipline initiated operations in Rwanda in October 2016, delivering blood to 21 different health facilities in the western half of the country using autonomous fixed-wing drones that look more like small aircraft than the quadcopters we traditionally associate with drones.
Flying at 100km/h with a wingspan of 3.7m, the drones cut delivery times from the 5 hours it might take by truck to just 30 minutes. It has since expanded to both the eastern part of the country – providing services for almost the entire country – and to Ghana, where it has so far established four distribution centres serving various rural and suburban populations.
“There are two really interesting applications,” explains Justin Hamilton, Zipline’s global head of communications. “One is obviously emergency medicine. Making sure that you have what you need when you need it. And the other one is essentially revolutionising the health supply chain through just-in-time delivery.”
According to Hamilton, by using drones to distribute blood and other medical supplies to where they are required on demand, it also reduces waste of precious medical resources as resources can be stored centrally rather than at individual facilities. “By optimising the supply chain, you can ensure that critical amounts of medicine are exactly where they need to be,” he says.
“It’s doing for medicine what Toyota did for automobile manufacturing.”
To make the system work, drones are launched by a catapult system from the company’s distribution centres, which each serve a radius of 80km. When a drone arrives at its destination – typically a hospital – the payload, which can be up to 1.8kg, is dropped by parachute on to a pre-agreed collection point.
The drone then returns to base without landing. When it arrives at base, a small hook on the drone catches onto a fishing line, which brings the drone to safe stop, similar to how fighter jets land on aircraft carriers.
To reach the point where flights are now operating routinely, the company has had to navigate a number of engineering challenges – and has continued to iterate the design of the drones and the systems that control them, in order to continually optimise them.
The first generation of the drone was a hard-body plane that the company now refers to as its “57 Chevy” design. Newer drones instead use a lightweight carbon-fibre inner shell, and a styrofoam outer shell. While there are trade-offs, ultimately they concluded that it reduces the weight – which in turn boosts the range, performance and, crucially, payload capabilities of the craft.
Another innovation has been the modular design of the drones, enabling components to be switched out easily. At distribution centres, drones are essentially disassembled – and as part of the launch procedure, the battery and GPS module is plugged in, along with the payload and wings. The launch crew then use a mobile phone app to run pre-flight checks, which are validated using computer vision to analyse that, for example, the ailerons are functioning correctly. If any of the parts are defective, they can be easily swapped for others.
“We wanted to make it like a NASCAR,” says Hamilton, referring to how almost every part of a car can be quickly replaced at a pit stop during a race.
Making the drones modular also solved another problem that had been frustrating the company: GPS lock. With the first planes, they discovered that the crucial navigation units took a minute or two to fully lock-on to the GPS satellites which delayed launches. With the latest generation, with the brains of the drone now being a modular unit, it meant that GPS system could lock on well in advance of flight – reducing the time between preparation and take-off.
Unsurprisingly, safety has also been important to Zipline. The main distribution centre is close to the country’s main airport, so dispatchers must coordinate with air traffic control when launching drones – and distribution centres even have a small control tower for this purpose. The drones can also be instructed to land remotely, and even have a built in parachute should they begin to fall. The drone is also built with two motors, two communications and two power systems, so that if one fails, the other can take over.
This is perhaps why Hamilton dismisses the suggestion that the company might have an easier time in Rwanda because there could be more relaxed regulations compared to, say, launching in Europe. In fact, he says the company works in Rwanda because the government there is supporting innovation.
“There was no such thing as national regulations covering a national-scale medical drone delivery service; it just didn’t exist in the world,” he says. “Rwanda built the world’s first system and the world’s first regulatory regime to manage that system. And their work has become a template for countries across the world.”
He even says that the World Economic Forum has since worked directly with Rwanda to roll out its regulatory model to the rest of the world, to countries that also want to take advantage of drone delivery.
As things currently stand, Zipline is still focusing on the developing world, with the next big projects being expansion to India and work with the US Department of Defence on using drones for delivering aid during natural disasters.
“Our goal is to be in a position to serve 700 million people within the next five years,” says Hamilton.
Meanwhile, Amazon – despite the flashy videos – is still trying to get its own delivery drones off the ground.