It was supposed to be the future of digital communications, helping to connect the "next five billion people" to the Internet. But Facebook has now shut down its internal effort to build high-altitude solar-powered drones to provide a backbone for Internet connectivity in areas lacking wired infrastructure. In a blog post yesterday, Facebook's Yael Maguire announced that the company is shuttering its Aquila drone program.

The goal of the Aquila program was to create a drone that could stay aloft for months at a time, orbiting over a geographic area at high altitude to provide a persistent radio link. Facebook based Aquila on the work of the UK-based drone research company Ascenta, which Facebook acquired in 2014—incorporating the operation into the company's Connectivity Lab and Internet.org project. The original plan was to use laser communications links between Aquila drones to provide a backbone network to provide Internet connectivity to ground stations.

At the time, Facebook and Google were both aggressively looking for ways to further expand their reach; Google had launched its Project Loon the year before and made its own solar-powered drone acquisition in April of 2014, buying Titan Aerospace . But like many things that both Facebook and Google took on four years ago, both drone efforts struggled. Facebook only managed two test flights of the Aquila design; the first ended in a hard landing caused by a structural failure, and the second was more successful but still far from meeting Facebook's goals. Titan suffered a similar fate after being incorporated into Google's X spin-off company; Titan was shut down last January, as Google parent Alphabet chose to focus on Project Loon and delivery drones.

Part of Facebook's reasoning for ending Aquila is that there are other companies with more experience in aerospace and greater resources now moving forward. Maguire wrote that Facebook is continuing to partner with Airbus and other companies to develop the communications technology for High Altitude Platform Station (HAPS) drones and get policy makers to open up radio spectrum and aviation policies to allow for the operation of long-endurance communications drones. Airbus' Zephyr drone program—which Ascenta founder Andrew Cox worked on prior to launching his own solar drone effort—has been in development since 2001 and has one model in production.