The US military is testing stratospheric balloons that ride the wind so they never have to come down

The idea of a balloon that floats high up above Earth indefinitely is a tantalizing one. Solar power would allow such stratospheric balloons to operate like low-cost satellites at the edge of space, where they could provide communication in remote or disaster-hit area, follow hurricanes, or monitor pollution at sea. One day, they could even take tourists on near-space trips to see the curvature of the planet.
Read more: https://www.technologyreview.com/s/612417/darpa-is-testing-stratospheric-balloons-that-ride-the-wind-so-they-never-have-to-come-down/?source=Snapzu