Drone aircraft are a much better option than balloons which can't be directed. You can keep a drone over an urban area, deploy, bring it down and keep it separa

Drone aircraft are a much better option than balloons which can't be directed. You can keep a drone over an urban area, deploy, bring it down and keep it separated from other drones in a much more controlled way. Mesh networking them is also a possibility. You can also move a drone in case of particularly large storm cells. 20km is above most weather, but a large cumulonimbus can occasionally get up there. Good to see Vern Raburn's name there too - he did some innovative work at Eclipse before the GFC wiped them out.