>Such balloons typically fly at 80,000 feet or more – NASA’s version cruises at 120,000 feet.. The U.S. Air Force’s F-15 Eagle and F-22 Raptor both have a stated operating altitude of around 65,000 feet. While they might be able to get close enough to fire a missile, the balloon may be too high for them to shoot.
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Pentagon said it was at about 60,000 ft