Inside Google’s Wildly Ambitious Internet Balloon Project

I think that Google is on to a great start with this idea, but my concern is what happens when those balloons pop, because they eventually will. The weather world also releases balloons, and they pop and come back down, but there aren't that many of them when you you compare to the total area. Plus they go up, pop and come back down in the same day, usually within a couple hours. What happens when you launch these much bigger balloons and they pop and come down? How do you make sure that a plane doesn't collide and come down?