Three Google Project Loon helium balloons launched from New Zealand's South Island were spotted drifting towards the east coast of Australia on 19 July.
The three balloons were about 240 nautical miles east of Sydney early on Friday morning, when they were picked up a local ADSB (automatic dependent surveillance-broadcast) ground station, according to a post on the Sydney Airport Message Board, by Grahame Hutchison.
According to Hutchison, webmaster of 16Right ADSB, whose ground station picked up the balloons' trasmission signals, the Google balloons were travelling at an altitude of 65,000 ft when they were spotted, and were the new generation ADS-B balloons, and were transmitting their position data.
Google Australia confirmed today that the three Project Loon balloons had drifted towards Sydney after being launched from the South Island of New Zealand.
"No balloons are being launched from Australia; they're all coming from the South Island of New Zealand right now," a Google spokesperson told ZDNet.
Google's Project Loon began in June 2013, with the company launching 30 high altitude helium balloons from New Zealand's South Island, beaming wireless internet to a small group of pilot testers in the area.
Since then, the pilot test has expanded to include a larger number of people over a wider area. According to Google, Project Loon will continue to expand the pilot throughout 2014.
The goal of the project is to establish uninterrupted connectivity around the 40th southern latitudinal parallel, with the aim of allowing pilot testers at this latitude to receive continuous service coverage via "balloon-powered internet".
The 40th southern parallel intersects New Zealand's North Island, Australia's Tasmania, Chile, and Argentina.
The ultimate aim of Project Loon, according to Google, is to use the helium balloons, which float in the Earth's stratosphere — twice as high as commercial airliners — to help people in rural and remote areas connect to the internet.
Google estimates that around two-thirds of the world's population does not have access to the internet, and it hopes to plug the coverage gaps using a high-flying global network of these balloons, which are pushed around on stratospheric winds.
In June Google launched its first LTE (long-term evolution)-equipped balloons on the rural outskirts of Campo Maior in north-eastern Brazil, connecting a local school Linoco Gayoso to the internet for the first time.
4G LTE is a standard for used for wireless broadband data transmission, while the radios used in Google's initial New Zealand launch operated on unlicensed spectrum in the 2.4GHz and 5.8GHz bands used in Wi-Fi.