Google’s plan to deliver Internet service from balloons seems to be flying along nicely, as the company says one of its balloons just completed “a lap around the world in 22 days and has just clocked the project’s 500,000th kilometer as it begins its second lap.”

Project Loon, unveiled nearly a year ago, is an attempt to use solar-powered balloons to create networks that can send wireless Internet signals to areas that would be hard to reach with wired Internet. The balloons are supposed to form a mesh network 20 kilometers above the ground, with each balloon communicating with its neighbors and ultimately to ground stations connected to Internet providers. Internet signals would be sent to antennas installed on buildings.

It’s just in the prototype phases, but Google’s testers have been busy. The balloon that circled the world “enjoyed a few loop-de-loops over the Pacific ocean before heading east on the winds toward Chile and Argentina, and then made its way back around near Australia and New Zealand,” Google’s Project Loon team said in a Google+ update Thursday. “Along the way, it caught a ride on the Roaring Forties—strong west-to-east winds in the southern hemisphere that act like an autobahn in the sky, where our balloons can quickly zoom over oceans to get to where people actually need them.”

Google has said it uses complex algorithms to manage the balloons’ flight patterns, and these tests help the company improve the system:

Traversing the stratosphere is particularly challenging this time of year because the winds actually change direction as the southern hemisphere moves from warmer to colder weather, resulting in divergent wind paths that are hard to predict. Since last June, we’ve been using the wind data we’ve collected during flights to refine our prediction models and are now able to forecast balloon trajectories twice as far in advance. In addition, the pump that moves air in or out of the balloon has become three times more efficient, making it possible to change altitudes more rapidly to quickly catch winds going in different directions. There were times, for example, when this balloon could have been pulled into the polar vortex—large, powerful wind currents that whip around in a circle near the stratosphere in the polar region—but these improvements enabled us to maneuver around it and stay on course. We can spend hours and hours running computer simulations, but nothing teaches us as much as actually sending the balloons up into the stratosphere during all four seasons of the year.

Google has changed the balloon designs as well. "Earlier balloon designs used just one solar panel pointed up toward the sky, but we learned that two facing diagonally actually allows us to capture more sunlight at latitudes close to the poles," the company said. "Capturing sunlight more efficiently allows us to collect more power with less weight and charge our batteries for a longer period of time."

Facebook is also getting into the flying Internet business, with plans to use solar-powered planes to deliver wireless Internet access.