“Back over a year ago when the Chinese Balloon was flying over the USA, we had a lengthy discussion on FR about this very topic and it was determined then that no FAA flight plan is required and quite frequently these hobbyist balloon due circle the globe multiple times.”
Yes I remember that discussion. It was a learning exercise for me.
I said this in another post, I hold a General Ham Radio License, if I lived out in the country, I would love to give this a try, launch a relatively sophisticated ballon not only for tracking purposes, I’ve seen a couple on YouTube that can take pictures from 50,000 ft, just to see if I could do it and to learn something.