The Loon Flight System
Loon has taken the most essential components of a cell tower and redesigned them to be light and durable enough to be carried by a balloon 20 km up, on the edge of space. Loon balloons are designed and manufactured to endure the harsh conditions in the stratosphere, where winds can blow over 100 km/hr, and temperatures can drop as low as -90° C.
The Loon Flight System consists of three separate systems: The balloon envelope, the bus, and payload. Together, they work seamlessly to provide lift, monitor flight telemetry, and provide connectivity.
The balloon envelope
Made from polyethylene, each tennis-court-sized balloon envelope actually consists of a balloon inside of a balloon. A fixed amount of lift gas in the inner balloon keeps the system aloft. Adding or releasing outside air to the outer balloon changes density, allowing the system to ascend or descend when needed. Our balloons are built to last for hundreds of days before landing back on Earth in a controlled descent.
The bus consists of the hardware necessary for safe flight operations, including highly efficient solar panels that power the system, an altitude control system for navigation, and a parachute that deploys automatically to guide the balloon safely back to Earth after flight. For added safety, Loon includes redundant satellite communications links and transponders for constant visibility to air traffic control.
The payload consists of the communications equipment required to deliver connectivity, including the radio base station and antennas.
Once recovered, balloons are laid out on a giant scanner to be inspected for microscopic holes and tears. This process paints a picture of how our balloons react to conditions in the stratosphere. Conducting this analysis provides insights that further inform our design choices, enabling the team to develop balloons capable of increasingly longer flight durations.
Loon’s flight systems are operating commercially and at scale to unlock the power of the stratosphere.