Alphabet announced it successfully sent data over 600km between two balloons, its longest point-to-point link to date, as part of a project to provide internet connectivity to rural areas.

Salvatore Candido, head of engineering at Loon, wrote in a blog post that these connections were made using custom-built antennas mounted to the bottom of a communications payload.

He added that Loon also hit another milestone: sending data nearly 1,000km along a network of six additional balloons, going from desert to mountains and back again, with the connection originated from the ground at a launch site in Nevada in the US.

Candido said Loon wants to “create a web of connectivity to serve users without having to build lots of new infrastructure on the ground, which is a significant obstacle to bringing traditional access to unconnected and under-connected communities around the world,” adding that commercial deployment will start in 2019.

Alphabet established Loon as a subsidiary business in its Other Bets category in July, after developing the set up at its X research division under the Project Loon moniker.