The balloon was first sighted in American airspace on Wednesday, Feb. 1, over Billings, Montana. The Department of Defense called the aircraft a "high-altitude surveillance balloon."
Its path carried it "over a number of sensitive sites," potentially including a nuclear missile silo field at Malmstrom Air Force Base, which is around 170 miles to the northwest of Billings. This has fueled speculation that the craft was gathering intelligence on nuclear missile sites in Montana. (Related: China has been spying on American computer systems through compromised chips.)
F-22 fighter jets were scrambled to shadow the surveillance craft in case a decision was taken to shoot it down. But the White House vetoed this proposal, claiming that the risk of debris injuring civilians on the ground was too great.
The surveillance balloon is a large helium balloon estimated to be about 120 feet long and 120 feet tall. It is powered by two solar panels and includes cameras, sensors and radars.
When the balloon was spotted, it was hovering at an altitude of around 60,000 feet, but officials believe it can climb to a maximum height of 120,000 feet – triple the ceiling of commercial airliners and nearly double the ceiling of American fighter jets.
Officials believe the balloon was launched from mainland China, passing by Japan as it reached the Pacific. It crossed Alaska and Canada before reaching Montana from the north.
China claimed that the aircraft is a civilian balloon used for meteorological and weather research that had "deviated far from its planned course" due to inclement weather.
"The Chinese side regrets the unintended entry of the airship into U.S. airspace due to force majeure," said the Chinese foreign ministry in a statement
China's claim was immediately refuted by U.S. officials. The State Department acknowledged China's statement of regret, but remained "confident in our assessment of the situation."
"We know it's a surveillance balloon," said Brig. Gen. Patrick Ryder.
Worse, defense analysts are suggesting that the balloon could be used as a delivery platform for nuclear weapons.
A 2015 report by the American Leadership and Policy Foundation, written by Air Force Maj. David Stuckenberg, one of the nation's leading experts on electromagnetic pulse (EMP) weapons, noted that specially designed balloons could carry nuclear payloads over the United States. These nuclear-armed balloons could be used to launch strikes or interfere with the electrical grid.
"Using a balloon as a [weapon of mass destruction] platform could provide adversaries with a pallet of altitudes and payload options with which to maximize offensive effects against the U.S.," wrote Stuckenberg. "A high-altitude balloon could be designed, created and launched in a matter of months. There is nothing to prevent several hundred pounds of weapons material from being delivered to altitude."
Stuckenberg said flying over American airspace is "clearly a provocative and aggressive act."
"It was most likely a type of dry run meant to send a strategic message to the U.S.A.," he said. "We must not take this for granted."
Learn the latest activities of the Chinese state at CommunistChina.news.
Watch this clip from Fox News discussing how people are baffled by how the massive Chinese spy balloon made it into the United States.