After the sightings of a Chinese balloon in 2023 (later shot down off the coast of South Carolina), the U.S. began more closely scrutinizing its airspace at high altitudes, including by radar enhancements that allowed the U.S. to better categorize and track slower-moving objects.
[1][2] General Glen VanHerck, the commander of NORAD, said that in 2021, up to 98% of raw radar data was not routinely analyzed, because the military aimed to filter out radio signal emanating from flocks of birds or weather balloons (as opposed to potential threats).
[4] On February 14, after unidentified high-altitude objects had been detected and shot down over northern Alaska, Yukon, and Lake Huron, White House spokesman John Kirby said that the U.S. Intelligence Community "will not dismiss as a possibility that these could be balloons that were simply tied to commercial or research entities and therefore benign.
[8] Since several of the objects were downed in relatively inaccessible locations, ranging from sea ice off the Arctic Ocean coast of Alaska to remote alpine terrain in Yukon and deep US-Canada boundary waters in the middle of Lake Huron, recovery efforts have required considerable amounts of coordination and care.
[9][10][11] On February 16, 2023, the Royal Canadian Mounted Police announced that the search for the Lake Huron object had been suspended due to deteriorating weather and low chance of recovery.