Comment Comment by lettergram They also could have had ground penetrating radar. Note the path of the balloon was over the US missile siloshttps://geo-matching.com/content/new-approach-to-use-ground-...Outside the atmosphere you would not be able to do it parent lettergram 3 years ago
https://geo-matching.com/content/new-approach-to-use-ground-...
Outside the atmosphere you would not be able to do it