Probably releasing the next generation of Covid.
The balloon monitors kitchen stove emissions.
That was my first thought, too.
Too low for an EMP.
“Probably releasing the next generation of Covid.”
Guns, germs, and steel... except this germ warfare is contemplated unlike the unleashing of the small pox epidemic in the new world.
Your post brought to mind a book I read back in the early 80’. It was one of those pulp sci-fi/military/espionage novels named “Famine”.
The story (and I’ll try to be brief) is that a blight of some sort has started spreading all over the country, destroying crops of all kinds. At the same time, people are starting to get sick after eating canned goods.
The protagonist, a military investigator, discovers that cans have a microscopic hole in them, and the contents were poisoned. Then cattle and other livestock start to get sick all over the country.
After a lot of investigating, he finds a plot where people have infiltrated canning facilities all over the country, and they installed nearly undetectable machinery that poked the tiny holes in every can.
He also found out that another company, called “Your Spread From The Sky”, used small aircraft to overfly large swaths of farmland and livestock areas, taking pictures of the land and offering the photos to ranchers and farmers as a souvenir...for a small fee, of course. What the guy found out was that it was a shell company, which was ultimately owned...by the KGB. The aircraft were also equipped with hidden sprayers that released an agent that poisoned both crops and livestock.
Basically, the entire food supply chain for the US was destroyed. Riots and soon starvation ran rampant., Even the military was running out of food and soldiers were too weak from hunger and constant fighting hungry mobs to defend the country. The government collapsed ...and the Soviets come in, offering an antidote to all their problems (which they created)...IF they will surrender to them. Unable to come up with a solution, they capitulated.
The last paragraph tells about the investigator and his girlfriend, starving and wandering along the California coast, laying down in exhaustion on the beach. After a while, he hears a droning. He looks up to see formations of TU-95 Soviet bombers heading east.
This balloon...something similar?