Loon LLC was an Alphabet Inc. subsidiary working on providing Internet access to rural and remote areas. The company used high-altitude balloons in the stratosphere at an altitude of 18 km to 25 km to create an aerial wireless network with up to 1 Mbit/s speeds. A reference to the balloons used, Project Loon began as a research and development project by X in 2011, but later spun out into a separate company in July 2018. In January 2021, it was announced that the company would be shut down.
The balloons are maneuvered by adjusting their altitude in the stratosphere to float to a wind layer after identifying the wind layer with the desired speed and direction using wind data from the National Oceanic and Atmospheric Administration. Users of the service connect to the balloon network using a special Internet antenna attached to their building. The signal travels through the balloon network from balloon to balloon, then to a ground-based station connected to an Internet service provider, then into the global Internet.