Google's "impossible" plan to beam Internet from solar-powered balloons is actually working. Here's how.

By next year, Google believes it will be able to create a continuous, 50-mile-wide ring of Internet service around the globe. And by 2016, Project Loon director Mike Cassidy anticipates the first customers in rural South America, Southern Africa, or Oceania will be able to sign up for cellular LTE service provided by Google balloons. The team has done a remarkable job so far harnessing the 100,000 pounds of pressure inside each balloon. The next test will be how it handles the pressure of turning a moonshot into a business.