Google’s Balloon Internet Experiment

When Google announced Project Loon on June 15 last year, a lot of people were skeptical. But Google reports that since then, it has been able to extend balloon flight times and add mobile connectivity to the service. As a result, Google’s expectations are flying even higher than the 60,000-foot strata where its balloons live.

“This is the poster child for Google X,” says Astro Teller, who heads the division. “The balloons are delivering 10x more bandwidth, 10x steer-ability, and are staying up 10x as long. That’s the kind of progress that can only happen a few more times until we’re in a problematically good place.” A year ago, balloons typically remained aloft for a few days at most, and download speeds averaged one or two megabits per second—comparable to the slowest wired Internet service.

Loon team members Chris and Cyrus set up the mobile ground station that will connect the Loon balloon signal to the Internet. Photo: Courtesy of Google

Since the first public test flights in New Zealand, Google’s balloons have clocked over a million and half kilometers. Increasing the crafts’ endurance has been a key challenge. One balloon expert originally scoffed at the claim that Loon balloons would eventually keep going for an average of 100 days. “Absolutely impossible—even three weeks is rare,” said Per Lindstrand, known for his highly publicized forays with entrepreneur Richard Branson. Indeed, during the first New Zealand tests, the balloons generally lasted only a few days.

Google bumped up flight durations by extensively analyzing its failures. Using former military operations people, it took pains to recover nearly every downed balloon. Google’s testing procedures also got a boost from winter’s polar vortex: Ground temperatures in South Dakota, where some of the balloons are manufactured, went as low as -40 degrees Celsius, about the same as what balloons encounter at 60,000 feet. So Google could test the inflated materials at leisure. Ultimately, Loon engineers concluded that one of the biggest factors in failure were small, almost undetectable leaks in the polymer skins that must withstand huge atmospheric pressure and up to 100 mph winds. Even a pinhole can shorten a balloon’s lifespan to a few days.

The Loon crew not only strengthened the fragile seams where leaks often occurred but took fanatic care in handling the envelopes. They used to walk on the flattened polymer in stocking feet. Now only super-fluffy socks will do. Google, being Google, tested this protocol before implementing it. Teams were created, one wearing conventional socks and the other donning fuzzy footwear. Both groups performed a rigidly proscribed line dance, as if the spread-out balloon polymers were Urban Cowboy-style dance floors. The fluffy-footed team created significantly fewer pinholes. “We’re getting the next five billion online through a line dance!” Teller says.

Google also improved Loon flight times by dramatically upgrading the altitude control system, increasing the vertical range of the balloons so they can catch more favorable winds. (Its balloons “steer” their way around the world by placing themselves in wind currents headed in the right direction.) As a result, it’s not unusual for Google to keep balloons flying for 75 days. One craft, dubbed Ibis 152 (Google uses bird species to nickname its balloons), has been aloft over 100 days and is still flying. An earlier balloon, Ibis 162, circled the globe three times before descending. (It completed one circumnavigation in 22 days, a world record.)