So, it took two sidewinder missiles at about $472,000 each to pop that balloon over Lake Huron. Why don't they use their 20mm canon?
https://www.foxnews.com/us/us-military-first-shot-unknown-octagonal-object-lake-huron-missed
US fighter jets fired five heat-seeking AIM-9X Sidewinder missile to take down four aerial objects floating high over U.S. and Canadian airspace between Feb. 4 and Feb. 12, U.S. officials said. The unidentified floating octagon shot down over Lake Huron in upper Michigan required two Sidewinders, because the first one failed to detect the object, "did not fuse," and crashed "harmlessly" into Lake Huron, U.S. officials said Tuesday.
The military and Biden administration got some blowback for using $400,000 Sidewinders to take down four balloons, three of which likely turned out to be "benign" objects. But "the military's ability to respond to balloons and similar craft is constrained by physics and the capabilities of current weapons," The Washington Post reports, and you can't really pop a giant balloon with gunfire at 40,000 feet.
https://www.msn.com/en-us/news/world/why-the-u-s-used-missiles-not-cheap-bullets-to-shoot-down-chinese-balloon-3-unidentified-objects/ar-AA17w5rP?ocid=entnewsntp&cvid=c68ed2f67e69486d9dd07a7dfc1cbdf2
"You can fill a balloon full of bullet holes, and it's going to stay at altitude," David Deptula, a retired Air Force lieutenant general and fighter pilot, tells the Post. The air pressure that high up doesn't allow helium to freely escape through small holes, even if fighter jets flying by at hundreds of miles per hour can riddle the near-stationary balloon with bullets.
Canada figured that out the hard way in 1998, when it tried to bring down a giant runaway weather balloon launched from Saskatchewan to measure ozone levels, CBC News recalled right after the Chinese spy balloon incident. "Canadian CF-18 fighter jet pilots caught up with the balloon off the coast of Newfoundland and took aim, firing more than 1,000 rounds of ammunition at it. But the balloon survived the assault, soldiering on over the North Atlantic," floating above British, Norwegian, and Russian airspace before finally crashing in Finland.
The British press roasted Canada's Air Force pilots for failing to pop the rogue balloon, but then British and U.S. pilots also tried to shoot it down and failed
