USA seems to be one of the least regulated countries when it comes to amateur ballooning. Under FAA rule 101 exceptions, a tiny balloon can be launched without notice, probably due to the vast geography and airspace that USA possesses. I have been doing it myself and in most of the Europe, normally, a NOTAM is required at least few days in advance and aircraft are to coordinate their actions based on the location of the balloon launch/flight path. It is nevertheless a fun, inspiring and niche hobby, when something takes off of the palm of your and and flies around the planet few days later.
USA seems to be one of the least regulated countries when it comes to amateur ballooning. Under FAA rule 101 exceptions, a tiny balloon can be launched without notice, probably due to the vast geography and airspace that USA possesses. I have been doing it myself and in most of the Europe, normally, a NOTAM is required at least few days in advance and aircraft are to coordinate their actions based on the location of the balloon launch/flight path. It is nevertheless a fun, inspiring and niche hobby, when something takes off of the palm of your and and flies around the planet few days later.