By Nina Mulamba
Facebook and Google are investing in rival efforts to beam the internet down to the ground from flying objects, twice as high as airplanes normally fly, in the stratosphere. Facebook aims to build a network of laser-beaming drones that will tightly circle known black-spots while Google has a drone project about which it’s tight-lipped though Google is more open about an attempt to send “strings” of giant balloons circumnavigating the globe to provide persistent data links to the parts of the planet they pass.
Though both scheme seem far-fetched, the brains behind both companies’ efforts told the BBC they are convinced they have a real shot at connecting the 57% of the world’s population still offline.
Secret in the Carbon
Of the two projects, Facebook’s plan is arguably at an earlier stage but the company hopes that the first drone will be airborne before the end of the year.
The aircraft, known as Aquila 1, has a sleek giant structure appearance and was recently built in Somerset, England before being shipped to a secret test site. It’s wider than a Boeing 737 jet but looks quite different, since there’s no need to carry passengers or a pilot and is made of a thin layer of foam covered in carbon fiber, with four propellers attached.
“The whole structure is 142ft (43m) wide but weighs less than a Toyota Prius. The structure and stiffness of the plane is all in the carbon fiber of the wing and that supports everything; the [internet-providing] payload, the batteries, and the solar panels on top,” explains the social network’s engineering chief Jay Parikh.
The aim is to build a fleet of the drones with radio transmitters fitted underneath to beam data across a 100 mile (160km) diameter zone below. Terminals on the ground would use the signals to provide the internet to people’s computers.
To help keep data speeds high, Facebook aims to beam lasers between the aircraft across significant distances.
“The analogy that we have come up with is this: If I took a US dime [18mm in diameter] and I walked 11 miles away from you, and then you had a laser in your hand, you would have to hit that dime,” says Mr. Parikh.
Facebook wants the drones to stay aloft for three months at a time. The firm has already tested the tech in its California labs, but making it work 27km above ground will not be easy.
Google has also been taking to the skies since June 2013. The balloons travel with the winds, usually along an easterly or westerly latitude.
“We’ve flown almost 1,000 balloons at this point. We’ve flown almost 20 million kilometers around the world. One of our balloons went around the world 19 times,” Mike Cassidy, vice-president of Project Loon, told the BBC.
Google keeps each one on course by pumping helium in and out of a bag fastened inside the balloon’s outer plastic envelope. This causes it to rise or fall, letting it find winds that will take it in the desired direction.
Rather than try to keep each balloon over one spot, Google’s goal is to create a circular sequence. So, as one goes out of range of antennas on the ground, another takes its place, providing a continuous internet connection.
Initially, the firm struggled to keep its balloons aloft for more than a week. But it now regularly keeps them aloft for 150 days.
“Even a millimeter-sized hole in a balloon will bring it down in a few days. So, you need to study every phase of the process from manufacturing to packaging to shipping to launch,” explains Mr. Cassidy.
Laser Beams v Radio Waves
Rather than use lasers, Google relies solely on radio frequencies to transmit its data. Equipment hanging below each aircraft connects to a base station in range below and then sends out the resulting data link to other antennas it can reach.
At present, Loon balloons can cover a circular area spanning 80km (50 miles) in diameter. The balloons can also transmit signals to each other to extend the internet connectivity when there is no base station nearby.
The firm says it has already linked up two balloons more than 100km apart and transferred data at about 500 megabits per second.
But that’s a fraction of the tens or even hundreds of gigabits per second rates Facebook believes its lasers are capable of.