The suspected spy balloon that the U.S. military shot down Saturday was part of a worldwide espionage effort that the Chinese carried out over several years, according to the U.S. Department of Defense.
Pentagon spokesperson Brigadier General Pat Ryder said Wednesday that the high-altitude balloons had been spotted over Latin America, South America, Southeast Asia, East Asia and Europe in recent years.
New information about the program has come to light in recent days following U.S. military efforts to study the massive airship as it traversed the continental U.S. last week. High-flying U-2 spy planes flew into the stratosphere to capture detailed imagery of the balloon floating at around 60,000 ft., while sensors on the planes collected electronic data that emanated from the payload slung underneath the balloon, U.S. officials said.
In essence, the Pentagon says it was able to turn the tables against the Chinese, gathering massive amounts of information on the 200-ft. balloon and its alleged spying apparatus, which was roughly the size of a jetliner. “Last week provided the United States with a unique opportunity to learn a lot more about the Chinese surveillance balloon program—all information that will help us to continue to strengthen our ability to track these kinds of objects,” Ryder said.
Read more: Chinese Balloon Wreckage Could Offer Clues Into Years-Long Spy Operation
The result was a more comprehensive picture of the balloon fleet’s mission and flight signatures, U.S. officials said. Armed with new information obtained in observing the balloon’s four-day trip over the country, the U.S. was able to forensically piece together a picture of past flights. The Pentagon now assesses that China sent balloons over the continental U.S. at least four times over the past six years that went undetected until one entered American airspace last week. Three of those overflights took place during the Trump Administration, along with two under Biden. “We do know there’s variation in the various sizes, and capabilities of the balloon,” Ryder said. “Whereas some of these balloons previously had not been identified, subsequent intelligence analysis did enable us to indicate that these were Chinese balloons.”
Previous flights were shorter in duration, U.S. officials said, but the fact that an immense foreign aircraft was able to penetrate U.S. defense systems multiple times without detection is alarming. The U.S. has shared what it’s learned with foreign allies and partners so they’re able to detect and monitor for the Chinese airships in the future. “I would not be surprised if the (People’s Republic of China) starts to reevaluate its dirigible collection program,” Ryder said.
The Chinese balloon traveled above the Aleutian Islands near Alaska on Jan. 28, then through Canada two days later, and ultimately into the continental U.S. over Idaho on Jan. 31, U.S. officials said. It became national news Feb. 2 after the Pentagon admitted the alleged spy balloon was inside the country.
The Chinese government confirmed that the balloon was theirs as the aircraft drifted through the Midwest, but insisted it was merely a “civilian airship” used for weather research that accidentally entered U.S. airspace. The U.S. has dismissed this benign depiction, saying the balloon deliberatively lingered over “sensitive” military sites, including Montana’s Malmstrom Air Force Base, one of three in the U.S. that hosts nuclear-tipped intercontinental ballistic missile fields.
Read more: How an Alleged Spy Balloon Derailed an Important U.S.-China Meeting
The U.S. government says the balloon didn’t have any additional surveillance capabilities beyond what’s aboard China’s constellations of spy satellites that have circled the globe for decades. But the balloon’s ability to maneuver over and zero in on specific sites does distinguish it from spacecraft.
The Pentagon hopes that new information about China’s surveillance practices will be collected from the operation to salvage remnants of the balloon that U.S. fighter jets shot down Saturday off the South Carolina coast. The Navy has sent in underwater drones carrying side-scan sonar arrays, as well as an oceanographic survey ship to map out the sea-bottom and identify every piece possible.
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Write to W.J. Hennigan at william.hennigan@time.com