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.
It’s not a new idea. Indeed, the original stratospheric balloons were flown by NASA in the 1950s, and the agency still uses them for science missions. And Project Loon, owned by Google’s parent company Alphabet, successfully deployed such balloons to provide mobile communications in the aftermath of Hurricane Maria in Puerto Rico.
There’s a major snag, though: current balloons shift with the wind and can only stay in one area for a few days at a time. At the height of the stratosphere, some 60,000 feet (18,300 meters) up, winds blow in different directions at different altitudes. In theory it should be possible to find a wind blowing in any desired direction simply by changing altitude. But while machine learning and better data are improving navigation, the progress is gradual.
Read more at MIT Technology Review
Image: Strat-OAWL. CREDIT: Ball Aerospace