Ex-DECie (31337) Andreas Spiess demonstrates bridging 36,000km using an ESP32 SoC with (only) 15mW of power. He doesn't mention (the obvious) here, but another way of accomplishing this is to enhance the other side of the link INSTEAD OF the ESP32 side. It is slightly more complex to do that (still 1960s technology), but something that a nation state with its own space fleet (and "weather balloons") would easily be able to accomplish. Seems like the firmware source and the build system capable of producing a bit-perfect mirror of what ships on every version of these devices should be at least escrowed and audited somewhere. Seems like it... ;)
Isn't it only 20000 km to the other side of the world?
This is to a satellite, so the distance is correct and has line of sight. The main enabler is a hack to the ESP firmware (done elsewhere) which changes the frequency from the WiFi frequency.
[And it's morse code, which simplifies things a lot]