I'm trying to determine exactly when we first knew about this high-altitude PRC balloon.
The Washington Post on Tuesday and The Globe and Mail on Wednesday said that the U.S. tracked the PRC spy balloon from its liftoff in Hainan Island. They observed it making a course change away from the Pacific military bases of the United States towards the mainland.
How is it that NORAD did not know about the high-altitude balloon until it was over mainland North America, or did they know?