Facebook Really Wants to Beam Internet From Planes Even as it faces setbacks with its high-flying drone, Facebook is looking toward other efforts to beam internet from the sky to under-connected areas of the world.

After Facebook's Aquila internet-beaming drone crashed during a test flight last year, the company's engineers realized it would take years before its key strength -- the ability to beam internet signals via millimeter wave technology -- would be ready.

The reasons for the delay are as much regulatory as they are technical, according to Yael Maguire, the head of Facebook's Connectivity Lab. Speaking at the company's annual f8 developers conference here on Wednesday, he explained that it could take up to 10 years before Facebook can realize the full potential of the drone, which has the wingspan of a Boeing 737 but weighs less than a Toyota Prius. Besides building a reliable plane, the company also has to secure the permits to use the millimeter wave spectrum that will connect it to the ground.

So even as the Connectivity Lab forges ahead on the drone project -- it is still testing Aquila prototypes, one of which was on display here (above) -- it is turning towards other rapid-deployment aeronautical innovations that could help connect more of the 4.1 billion people who Maguire claims don't have reliable internet access.

One of them, nicknamed "Tether-tenna," is a small autonomous helicopter equipped with a tether to a fiber line that can stay aloft for more than a day. It's one of a few tools in Facebook's arsenal to solve the problem that Google, Verizon and other companies have experienced in their fiber buildouts: delivering fiber to individual homes and businesses is incredibly costly and complicated.

"Connectivity starts with fiber, but it doesn't end there," Maguire said. "Fiber is the backbone," he explained, but it's too expensive and takes too long to expect it to deliver fast and reliable internet in the rural and remote areas where it's needed most. So the idea is that those zones will get wireless links to the closest fiber infrastructure via the Tether-tenna, among other wireless bridges.

Maguire said the Tether-tenna is "just a few years out" from commercial deployment, unlike the 10 years that Aquila will take. It will complement the previously announced Terragraph project, which aims to bring low-cost, ground-based antennas to the rural areas of developing nations. If a Terragraph-served area is affected by a flood or other natural disaster, for instance, the Tether-tenna could quickly step in to fill the void created by the damaged antennas or other internet infrastructure.

Of course, flying helicopters (even pilot-less ones tethered to the ground) costs much more than flying a fixed-wing craft like the Aquila. Maguire claimed that the Terra-tenna and other projects will improve the price, performance and speed of internet connections, but one thing Facebook hasn't talked much about in its infrastructure unveilings is the profitability of its designs, other than to say they're part of the company's general mission to connect more people to the internet.

And even as Facebook continues to experiment with planes, helicopters and Terragraph (which is now in testing mode here in San Jose, just a few blocks from where Maguire was speaking), it still cannot avoid the need to build more fiber. So it is doing that, too: a recently announced project in Uganda involves building a 448-mile fiber line to provide backhaul connectivity covering more than 3 million people.

But perhaps more than any technical or regulatory challenge, the company's mission to deliver better internet access to underserved areas is also threatened by broader social and economic factors. By some estimates, more than two-thirds of the world's population will live in cities by 2050, up from just over half today. So many of those 4.1 billion people without access will simply move to better-connected urban areas over the next 10 years, before Aquila and Terra-tenna get the chance to really soar.