2011: Codenamed the Pterodactyl, these balloons were simply latex weather balloons the team purchased online, capable of staying in the air just long enough for Project Loon to decide that balloon-powered internet wasn’t as crazy as it sounded.
2011: The Albatross was a bigger balloon which could soar higher for longer, giving Project Loon more time to test and iterate on the design of its earliest connection equipment.
2012: To test the design feasibility of a superpressure balloon large enough to support Project Loon’s signaling equipment, the team built the Falcon from remnant materials, resulting in a 127-foot metalized mylar cylinder.
2012: The Falcon v2, made from clear mylar, took to the skies and successfully achieved a 12-day flight, causing quite a few “UFO sightings” in Kentucky, USA.
2012: A staggering 141 feet in length, the Hawk was the first balloon to have a ballonet—a “balloon-inside-a-balloon”—as a way of managing the altitude and heading of the balloon.
2013: The Ibis was a pumpkin-shaped balloon stronger than the cylinder design and able to be manufactured at a much quicker rate. It was launched in Project Loon’s first connection pilot test in New Zealand.
2014: The Kestrel was a small and nimble balloon used to test direct-to-device LTE connection in preparation for Project Loon’s test in Brazil on its first birthday.
2014: The Lark is the largest of Project Loon’s balloon designs, designed to provide more lift, allowing the team to test more complete flight navigation, power, and signaling systems.
2014: The Merlin was designed specifically to allow for scalable and repeatable manufacturing. Roughly half the size of the Lark, it achieved the team’s 100-day flight duration goal.
2015: Capable of being produced at the scale needed for the project, the present-day Nighthawk balloons are able to support the fully-functional Loon system—including antennas to provide LTE connection direct to mobile-handsets, balloon-to-balloon transmission of data and connection down to partner telco’s ground stations.