Powering it all is a 600-watt battery, charged by solar panels on a carbon fiber frame atop the box. These large, extra-light photovoltaic cells -- amorphous silicon crystals on a fabric substrate -- keep the weight of the balloon low so that the Loons can run for long missions without landing. During the daytime, the batteries charge, and at night they switch on, to vent out excess air and keep the computers running.

Each Loon balloon has three radio frequency antennas (on 2.4 Ghz and 5.8 Ghz bands) and a ground-pointing WiFi antenna, which beams an Internet signal to Earth in a 12-mile radius. And though the balloons are mostly steerable, Google has done a lot of programming to make them work on their own as well; In addition to Mission Control, Google's Loon balloons can talk to each other, and control themselves."We use a distributed mesh network, so each balloon is pretty autonomous and has pretty much the same hardware in it," Sameera Ponda, a lead aerospace engineer at the Dos Palos site that day, said on the video stream. "As one balloon floats over a certain area that balloon is talking to the ground antennas, and as that balloon floats away, another balloon comes in and takes its place, so it's a pretty seamless operation."

In DeVaul's vision, it's a tightly managed, efficient network that only Google can access: "We've designed our radios and antennas to receive signals from Project Loon only, in order to achieve the high bandwidth for the long distances involved. If we didn't filter out the other signals, it just wouldn't work."

Google

It's important to note that the zero-pressure balloon launched from Dos Palos on July 26 was not a Loon balloon. It was a simpler, demo balloon, which only went up for a few hours before shriveling up and falling back to Earth as planned. Google X has been testing the real Loons since at least June, out of sight and mostly overseas, though the July 26 launch marked the beginning of an unknown number of test runs in California's central valley. As of that date, Ponda quoted their longest flight record as 12 days; some of those Loons traveled halfway around the world and landed in Chile and Argentina. They're now shooting for 100-day flights, and eventually the missions could be years long.

When it's time to retrieve any given balloon, Google has a system. "We actually have a fairly sophisticated mission control system," Ponda told the campers, "so we know by GPS where these are at all times." With collection points around the world, Google hopes to be able to rapidly and efficiently recover the Loon balloons. Not that they have all the kinks worked out; word has it they were scooping balloons out of the ocean off the shores of New Zealand in past weeks, and that some were even lost at sea .

Google doesn't share how many Loons are currently flying, or have been launched to date, but the number could easily be in the hundreds. If all goes according to plan, it'll soon be in the thousands. According to Loon field operations manager Paul Acosta, they're considering switching their lift gas from helium to hydrogen, a more abundant lighter-than-air element. Due to their size, each balloon currently devours a dozen 196-cubic-foot cylinders of compressed helium and, as Acosta put it, "there's not really enough helium in the world to sustain what we want to do."