Project Loon is a R&D project being developed by Google. Its mission is to provide Internet access to rural and remote areas of the world. The project uses high-altitude balloons placed in the stratosphere to create an aerial wireless network. It was named Project Loon, since Google itself found the very idea of providing internet access to the remaining 5 billion population unprecedented and “crazy.”
The Internet is considered as a global community. But two-thirds of the world’s population does not have access to the Internet. Project Loon is a network of balloons traveling on the edge of space, designed to connect people in rural and remote areas, help fill coverage gaps, and bring people back online after disasters.
The balloons travel approximately 20 km above the Earth’s surface in the stratosphere. Winds in the stratosphere are stratified. Project Loon uses software algorithms to determine the destination of the balloons. The balloons travel by moving into each layer of wind thus moving in the right direction. In this way the balloons can be arranged to form a large communications network. The inflatable part of the balloon is called a balloon envelope made up of sheets of polyethylene plastic measuring fifteen meters wide by twelve meters tall when fully inflated.
A well-made balloon envelope is critical for allowing a balloon to last around 100 days in the stratosphere. When a balloon out of service, a gas is released from the envelope to bring the balloon down to Earth in a controlled descent. Balloon’s electronics are powered by an array of solar panels made up of a flexible plastic laminate supported by a light-weight aluminum frame. It uses high efficiency monocrystalline solar cells. They are mounted at a steep angle to effectively capture sunlight on short winter days at higher latitudes. The array is divided into two sections facing in opposite directions, thereby successfully capturing the energy in any orientation as the balloons spin slowly in the wind. With Lithium-ion batteries to store solar power, the balloons can operate throughout the night. By moving with the wind and charging in the sun, Project Loon is able to power itself using entirely renewable energy sources.
A small box containing the balloon’s electronics hangs underneath the inflated envelope. The box contains circuit boards that control the system, radio antennas to communicate with other balloons and with Internet antennas on the ground.
The stratosphere presents unique engineering challenges: air pressure is 1% that at sea level, and this thin atmosphere offers less protection from UV radiation and dramatic temperature swings, which can reach as low as -80°C. By carefully designing the balloon envelope to withstand these conditions, Project Loon is able to take advantage of the stratosphere’s steady winds and remain well above weather events, wildlife and airplanes. The balloons communicate using an unlicensed 2.4 and 5.8 GHz ISM bands. According to Google the setup allows it to deliver the Internet with 3G speeds.
The first person to connect to the “Google Balloon Internet” after the initial test balloons were launched into the stratosphere was a farmer in the town of Leeston, New Zealand. The technology designed in the project could allow countries to avoid using expensive fiber cable that would have to be installed underground to allow users to connect to the Internet. Google feels this will greatly increase Internet usage in developing countries in regions such as Africa and Southeast Asia that can’t afford to lay underground fiber cable.