Google’s floating network in sky — Project Loon — won’t just be mobile, following the stratospheric wind currents; it will be the very definition of a evolving network with new transmitters launched into the sky every 100 days. In a new video on Loon’s Google+ site, Google explained that each Loon balloon is designed to stay aloft for three trips around the globe. Take that, Ferdinand Magellan.
One hundred days may not sound like much, but keep in mind that while in the air these balloons will be on their own 12 miles above the Earth, floating over oceans and even war zones — you can’t just send a guy in a hard-hat up to fix a broken antenna. As Loon’s balloon manufacturing manager Pam Desrochers explained in the video, the constant replacement cycle will ensure that Google has the most up-to-date technology in the air, but it will also help prevent Loon from losing its balloons to leaks.
“The most important part about keeping balloons in the air for a long time is making sure that they are leak-proof,” Desrochers said. “The surface area of the balloon is really vast, about 500 square meters, and it provides a lot of opportunities for little pinholes and leaks, which can shorten the life of our flight.”
The balloons will be subjected to big changes in temperature as the sun rises and sets, causing its internal pressure to change dramatically. Meanwhile, Loon will be “steering” the balloons in the stratospheric winds by pumping air in and out of them creating additional stresses.
“Our balloon material is like a rubber band,” Desrochers said. “When you stretch it over and over and over, you will eventually break it. When put it in a freezer and then stretch it too far just once, it will snap.”
For Loon’s initial tests in New Zealand, Google used a polyethylene film in its balloons made by South Dakota plastics company Raven Industries, but Google now appears to be testing all manner of materials, subjecting them to durability, temperature and leak tests.