From January 28 to February 4, 2023, a high-altitude balloon originating from China drifted across North American airspace, including Alaska, western Canada, and the contiguous United States. On February 4, the U.S. Air Force shot down the balloon over U.S. territorial waters off the coast of South Carolina near the city of Myrtle Beach. Debris from the wreckage was recovered and sent to the FBI Laboratory in Quantico, Virginia, for analysis. U.S. officials stated that the balloon carried intelligence-gathering equipment but does not appear to have sent information back to China. They believed that while the balloon carried a motor, it could not overcome high altitude winds and the Chinese leadership was not aware of the balloon going off course.
When the object was first spotted, the Pentagon characterized it as a surveillance balloon. The Chinese government maintained it was a civilian (mainly meteorological) airship that had been blown off course. According to U.S. officials, the balloon carried antennas and other equipment capable of geolocating communications signals, and similar balloons from China have flown over more than 40 nations. Analysts said that its flight path and structural characteristics were unlike those of a typical weather balloon. American officials later disclosed that they had been tracking the balloon since it was launched from Hainan and its original destinations were likely Guam and Hawaii, but prevailing winds blew it off course and across North America.
The incident increased U.S.–China tensions. The United States called the balloon's presence a violation of its sovereignty, and its secretary of state Antony Blinken postponed a long-awaited diplomatic visit to Beijing. Canada summoned the Chinese ambassador in response to the incident.
Forensics of the wreckage have confirmed that the balloon's sensors had never been activated while it was flying over the continental US, and so it did not transmit any intelligence back to China. In December 2023, NBC news reported that according to US intelligence officials, the balloon had made use of a commercially available American internet service provider to communicate, and that it was "primarily for navigation".
Three other high-altitude objects, over Northern Alaska (February 10), Yukon (February 11), and Lake Huron (February 11–12) respectively, were detected and subsequently shot down; a later assessment said they had no relation to China.
Background
History and development of reconnaissance balloons
Balloons have been valued for their ability to observe the battlefield and direct artillery. Their usage peaked during World War I, after which they were increasingly replaced by airplanes. During the Cold War, the United States sent hundreds of high-altitude balloons, ostensibly for "meteorological survey" under Project Genetrix, over China and other Eastern Bloc countries to gain intelligence on their nuclear capabilities, drawing their protests.
Although mostly supplanted by surveillance satellites and unmanned aerial vehicles, balloons have retained some advantages, such as a lower cost of production and deployment. By 2019, the Pentagon had invested millions in COLD STAR (Covert Long Dwell Stratospheric Architecture), a project for stealthy balloons that are now being transitioned from narcotics surveillance into military service. China recognizes the importance of catching up to foreign countries in this domain. Its military publications have highlighted the use of balloons to assess the early warning and response capabilities of enemy air defenses and to enhance China's own defense capabilities.
Past Chinese balloons and unidentified objects
Suspected Chinese surveillance balloons have been detected in U.S. airspace in the past, namely over Guam, Hawaii, and Florida. One incursion occurred earlier during Joe Biden's presidency (2021–2025) and three occurred during Donald Trump's first presidency (2017–2021). These incursions did not persist as long as the one in 2023, and China was able to recover those balloons.
Other pre-2023 incursions have remained unexplained and are classified by U.S. authorities as unidentified aerial phenomena. In 2022, the Office of the Director for National Intelligence said that there had been at least 171 reports of unexplained aerial phenomena in the United States, and the intelligence community has been unable to determine their precise nature. The commander of United States Northern Command (USNORTHCOM), General Glen VanHerck, said that U.S. failure to detect and identify all such incursions is "a domain awareness gap that we have to figure out". In response, the U.S. changed the sensitivity of its radar detection systems, which enabled it to detect additional UFOs.
The U.S. Department of State said that many Chinese balloons have flown over more than forty countries and said that they have carried out surveillance linked to the Chinese military. In 2020 and 2021, similar balloons were sighted in Sendai and Hachinohe, Japan, respectively, but they were not identified as of Chinese origin at the time. A similar aircraft was sighted in January 2022 over India's strategically important Andaman and Nicobar Islands. In February 2022, Taiwan's Ministry of National Defense said that several balloons detected off the coast of the country were likely used for meteorological observations for China's Eastern Theater Command. Another crashed near Taiwan in February 2023, carrying an antenna, a transmitter, and temperature and humidity sensors and was likely from China as well.
U.S.–China tensions
The 2023 balloon incident occurred while U.S.–China relations were at their worst in decades, following suspected incidents of Chinese espionage and amid increasing strategic competition in military and economic sectors. In 2022, the United States, along with some of its allies, imposed stringent export controls on "foundational technologies", such as semiconductor microprocessors, to China in order to hamper the latter's development of advanced technology and military tools. The US has also sought to maintain critical supply chains independent from China.
Incident
Balloon
Size, propulsion, and payload
The balloon carried an underslung payload described as a "technology bay" estimated to be the size of "two or three school buses" and was powered by sixteen solar arrays mounted on the payload. The balloon was 200 feet (61 m) tall according to U.S. General Glen D. VanHerck. AI startup Synthetaic, using image data from Planet Labs spacecraft, reported the balloon's diameter as 148 feet (45 m). USNORTHCOM and NORAD Commander, General Glen VanHerck, estimated the payload weighed more than 2,000 pounds (910 kg).
The Chinese balloon was a superpressure balloon similar to earlier NASA designs, where the volume of the balloon is kept relatively constant in the face of changes in ambient pressure outside the balloon, and the temperature of the contained lifting gas. This allows better altitude control and much longer endurance compared to the more common variable-volume balloon design.
National Security Council spokesman Admiral John Kirby said the craft had a propeller and could be maneuvered. U.S. officials told foreign diplomats in Beijing that the craft had rudders and propellers. A Chinese Foreign Ministry spokesperson said it had "limited self-steering capability".
The U.S. Department of Defense said the balloon did not present a military or physical threat to people on the ground while it remained in the air, and that shooting it down over water would be safer and increased the opportunity to study the wreckage for intelligence purposes.
Citing a PLA procurement portal, a U.S. official said that the balloon was manufactured by a civilian Chinese defense contractor.
Further analysis revealed a number of foreign origin parts including an Iridium Communications 9602 satellite communication unit and parts from Texas Instruments, Omega Engineering, Amphenol, onsemi, and STMicroelectronics.
Signals intelligence capabilities
Experts noted that weather balloons typically are about 20 feet (6 m) wide, less than a quarter of the balloon's diameter. Those interviewed by BBC News said it was unusual for weather balloons to last as long as the one involved in the incident and that the balloon "might have been more sophisticated than China claims".
Images from U-2 flybys and forensic analysis of the payload showed antennas that likely were used for collecting and transmitting signals intelligence. A publicly released U.S. State Department document, after the balloon was downed and debris collected, said that the balloon's solar arrays produced sufficient power to operate "multiple active intelligence collection sensors" and that the antennas on the balloon could collect and geolocate communications, including radio and mobile phone signals, but it was unknown if any specific devices were targets. Former U.S. Air Force Lt. General Charles "Tuna" Moore said that the surveillance technology aboard was inconsistent with meteorological missions and hypothesized that the Chinese would be interested in finding vulnerabilities and "building a picture of our radar, weapon system and communication capabilities".
U.S. authorities did not name the manufacturer of the balloon but said with high confidence that the entity has "direct commercial ties" to the People's Liberation Army. They cited this as an example of military-civil fusion, where China encourages competition from and technology exchange with its private sector.
Detection
High-altitude balloons are extremely difficult to detect. A 2005 study by the U.S. Air Force's Air University states surveillance balloons often present very small radar cross-sections, "on the order of hundredths of a square meter, about the same as a small bird", and essentially no infrared signature, which complicates the use of anti-aircraft weapons. A 2009 research paper by a USAF officer stated that balloons "are inherently stealthy" due to a tiny infrared signature at high altitude (as the balloon possesses no engines) and because of the difficulty of radar detection (as the balloons lack sharp edges and metal structures).
The balloon's first reported sighting was on February 1, 2023, when civilians on a commercial airliner spotted it. On the same day, former Billings Gazette editor Chase Doak spotted the object above Billings, Montana, after seeing reports that the airspace around Billings was closed. He had initially assumed it was a star or a UFO. Doak contacted his friend and Billings Gazette photographer Larry Mayer, and the two photographed the balloon using telephoto lenses. Mayer also sent the images to various government agencies. After the photographs were published in the Billings Gazette and received widespread media coverage, the U.S. Department of Defense and the Canadian Department of National Defence announced on February 2 that NORAD was aware of a high-altitude surveillance balloon believed to belong to China and had been tracking it for "several" days. The balloon was flying at an altitude of 60,000 feet (18,000 m) over Billings at the time.
American defense officials considered shooting the balloon down but initially decided not to due to the risk of debris injuring civilians on the ground. A meeting was convened between Secretary of Defense Austin, Chairman of the Joint Chiefs of Staff General Mark Milley, NORTHCOM/NORAD Commander General VanHerck, and other military commanders. Biden was advised by officials not to shoot it down because debris could threaten civilians or cause property damage.
Flight path
According to U.S. intelligence and retrospective analysis of satellite images, the balloon was tracked near Hainan island of China as early as January 15. It was able to change its altitude before entering the Pacific Ocean, where officials believe it was blown off-course. Retired NASA engineer Rodger Farley told the New York Times that winter winds may vary too little in direction to allow for course corrections.
The balloon entered U.S. airspace above the Aleutian Islands on January 28, 2023, then moved across Alaska, and entered Canadian airspace over the Yukon and Northwest Territories on January 30, 2023. After flying southeast over British Columbia, the balloon re-entered the U.S. in northern Idaho on January 31 and Montana on February 1, where it was spotted over Billings. Montana is the location of multiple intercontinental ballistic missile installations, such as Malmstrom Air Force Base, causing suspicion that the balloon had been launched to surveil said nuclear installations. The U.S. ground-based intercontinental nuclear arsenal is composed of about 400 LGM-30 Minuteman III missiles deployed around Malmstrom AFB in Montana, Minot AFB in North Dakota, and Francis E. Warren AFB in Wyoming. Meteorologist Dan Satterfield calculated a possible trajectory along this path using the HYSPLIT atmospheric model, consistent with data on prevailing westerlies from China to Montana. The balloon was spotted above northwest Missouri, near Kansas City, on February 3, and subsequently passed near Whiteman Air Force Base, which houses nuclear-capable Northrop Grumman B-2 Spirits.
According to some U.S. officials, China attempted to speed up the balloon, after its presence became known to the public, in order for it to exit U.S. airspace more quickly. Other officials reported that the balloon loitered near sensitive military sites and made multiple passes under control. Experts interviewed by Time said that the balloon traveled much farther than a typical weather balloon would and Chinese officials should not be surprised that it would eventually reach the contiguous United States or be detected. The balloon flew at an altitude of 60,000 feet (18,000 m). In comparison, business jets can reach 51,000 feet (16,000 m), commercial airliners can reach 45,000 feet (14,000 m), and the SR-71 (a now-retired American surveillance plane) has reached 90,000 feet (27,000 m).