From Daily Mail:
A fleet of tiny satellites could one day be used to detonate plasma bombs in Earth’s upper atmosphere to improve the range of radio communications.
The US Air Force has granted contracts to three research teams to develop the technology needed to do this, with hopes that CubeSats could carry massive amounts of ionized gas to the ionosphere to create radio-reflecting plasma.
The ionosphere begins roughly 40 miles above the surface and becomes denser with charged particles at night, allowing signals to travel much farther.
Ground-based radio signals are limited by the curvature of Earth’s surface, and those travelling more than about 44 miles are typically stopped if they aren’t given a boost, according to New Scientist.
These communications can be improved by bouncing the radio signals between the ionosphere and the ground, allowing them to zigzag over greater distances.
In one of the USAF-backed projects, researchers with General Science and Drexel University in Pennsylvania are working to develop a way to vaporize metal by heating it beyond its boiling point.
This would allow it to react with atmospheric oxygen to produce radio-reflecting plasma.