Earlier this week, news broke that Facebook was working on a possible acquisition of Titan Aerospace, a company that produces solar-powered drones. These aircraft can travel in around the globe, relying on the sun for power to stay aloft for years at a time. They carry a payload of up to 250 pounds. Why does a social network need a high-tech satellite? Reportedly, Facebook wants to bring internet access to parts of the developing world that haven’t built out the infrastructure for web access on the ground.

That’s a noble mission, although Facebook certainly has a bigger business agenda as well. Most interestingly, the move means that Facebook is now competing directly with Google and its Project Loon to bring internet access to the rapidly shrinking landscape of the unwired world. Loon, which has been in beta testing since 2011, uses a swarm of weather balloons that cruise through the stratosphere and beam web access down to special receivers on the ground. So which approach is better: Loon or drone?

A long history of failed attempts to provide aerial internet access

There is actually a long history of failed attempts to provide aerial internet access. Starting in the 1990s at least five big projects were announced, including Iridium and Globalstar, both of which aimed to provide cellphone coverage. They were actually built but promptly went bankrupt. Teledesic, a venture funded by by Bill Gates, Paul Allen, and Saudi prince Al-Waleed bin Talal, got a lot of people interested but was scrapped before it launched its first constellation. One problem with these early efforts was that people on the ground required bulky, custom handsets in order to receive the signal. But the rapid and widespread proliferation of cheap, powerful smartphones means that’s no longer a major obstacle.

"Fixed-wing drones are more reliable when it comes to flying longer distance due to their low consumption of battery power," says Chris Sanz, CEO of Skycatch. A big balloon with hot air is much riskier to keep in the air and moves more slowly. On the other hand, balloons are far safer and more commonplace. "One danger I can think of is one of these drones falling into a populated area," says Sanz. At 165 feet wide and weighing in at 350 pounds, a Solara could do a lot of damage if it fell out of the sky.

Getting the aircraft over the right area remains tricky. "71 percent of the world is water, and of the part that is land, 98 percent isn’t very interesting or populated," says Iain McClatchie, an aerospace engineer who formerly worked on drone projects for Google. "Drones are much more likely to be able to maintain position. But both they and the balloons are going to get pushed around a lot by stratospheric winds, which can get up to 100 miles per hour."

"One danger ... is one of these drones falling into a populated area."

The lightweight nature of Google’s balloons, however, comes with certain advantages. Free internet access sounds benevolent, but flying dozens or even hundreds of aircraft in constant orbit over a sovereign nation can raise a lot of questions from local governments. "Whatever goes into China’s airspace is going to end up on the ground," says McClatchie with a chuckle. Project Loon is far more innocuous, joining upwards of 70,000 weather balloons that orbit the planet at any given time. Given the US history with drones, many countries may be nervous about allowing a private fleet of them to orbit in their airspace, even if Facebook promises they’re doing nothing beyond providing internet access.

In terms of durability, however, Project Loon faces some challenges. "The weather balloons they are using are very thin and wear out pretty quickly. Since you can’t really predict when that will happen, a lot of balloons end up in the ocean," says McClatchie. "Drones are much easier to bring in for a landing when you need to make repairs or update the software."

"Whatever goes into China’s airspace is going to end up on the ground."

Google’s approach may rely instead on sheer numbers. "The actual balloons are way, way cheaper than drones, of course," says McClatchie. "Although the electronics on each balloon are still pretty expensive." Given that things are still in the experimental phase, Google may prefer to lose weather balloons that cost a few hundred dollars instead of drones that cost a few million. "The major cost of drones, especially ones optimized for super long flights, is crashing them," McClatchie notes.

So why take all this expensive risk? In both cases, the rationale so far has centered around the idea of bringing internet to people in undeveloped areas, the so-called "next billion" who will be joining the internet and rising into the middle class. McClatchie acknowledges this is a piece of the puzzle, although he suspects there’s more at play. "This technology is moving towards providing robust internet access for mobile devices. In terms of a return on the cost, just providing that service to people in rural Africa and Asia doesn’t make sense."