(CNN) Exclusive: US developed method to track China’s spy balloon fleet within last year, sources say. Quoting,
But the new method is important because the balloons are extremely difficult to track without it – they are slow-moving and can fly extremely high, in some cases as high as much as 60 miles up,
This error appears to be propagation of a typo in a government report.
For theoretical and practical reasons, the limit is close to 170,000 feet, 32 miles.
The world record is held by NASA “Big 60”.