Neutral mention · rule
A lot of people don't realize that a relatively simple balloon can be designed to take off from anywhere in the world, reach any other point in the world, and hover for multiple days sending back data with very little deviation. All the balloon needs is a way to change its altitude, that's it, it doesn't need any actuators to move in horizontal direction. Google's project Loon (https://x.company/projects/loon/) did this and I thought it was pretty darn cool. The way it works is this: different layers of stratosphere have different wind directions. If you can accurately predict the wind directions in different layers, you can in theory move in horizontal direction just by…
Read the full comment
changing your altitude. Loon had pretty good models and simulated the wind directions well. Their balloon used to take off from Nevada and reach Kenya (I believe) and hover there for multiple days to provide comms. They use a cool reinforcement learning based controller in their loop: https://www.nature.com/articles/s41586-020-2939-8 I remember some Chinese researchers writing papers on this topic back then and them saying they'd have good results if they had access to data from Loon: https://www.nature.com/articles/srep45976 I don't think Loon ever shared any data publicly but Loon did get shut down (like a lot of other Alphabet's moonshots) and I remember some of their tech and patents were sold to SoftBank and others. I was surprised US did not try to stop this in the interest of national security.