I like this kind of story, seems like something Popular Communications, Omni mags, or the WWCR program Signals would have covered.
Have you heard about the ham and experimenter high altitude balloons that run on micro solar power and send telemetry as they float around the world?
Atomic power source, that would be what the Voyager is using, I've heard that called an atomic battery. I wonder how it converts the heat to power, and how much current and voltage it puts out?
Boomer