Spy balloons have been surveilling humans since 1794

The US employed an F-22 to shoot down the balloon on February 4. But these intelligence-gathering devices have a long history.

The spy ballon on Feb. 4, 2023. Photo by Peter Zay/Anadolu Agency via Getty Images

On February 4, a pilot in an F-22 Raptor stealth fighter jet scored the plane’s first air-to-air kill, firing a missile at the Chinese surveillance balloon drifting off the coast of South Carolina. The shot, an AIM-9X Sidewinder fired from 58,000 feet above the ground, hit the balloon at an altitude of up to 65,000 feet, and ended a week-long incident in which the military, the public, and Congress all followed the course of the balloon with great interest.

“The balloon, which was being used by the PRC [People’s Republic of China] in an attempt to surveil strategic sites in the continental United States, was brought down above US territorial waters,” Secretary of Defense Lloyd J. Austin III said in a written statement

The balloon entered the sky above Montana on February 1, where it caused a halt to flights in and out of Billings International Airport. For four days, from Wednesday to Saturday, the balloon followed the wind across the US, until ultimately meeting its missile-induced end over the ocean. 

At a press conference February 2, a senior defense official noted that the US had tracked the balloon and “had custody” of it ever since it entered the country’s airspace. This includes previous fly-bys of the balloon with F-22s over Montana, although the decision was made not shoot it down then out of a concern for risk to those below.

The defense official repeatedly identified the balloon as created and operated by China, acknowledging when a reporter highlighted that Montana houses siloed nuclear ICBMs. The location of the silos is by design not secret—part of Cold War nuclear strategy that dictated the placement of the silos set them far away from dense urban centers, in part to ensure some incoming nuclear missiles would aim for the silos instead of cities. The day-to-day operation of missile silos can still contain some fresh information, so it is possible that is what was targeted by the balloon’s sensors.

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“Our best assessment at the moment is that whatever the surveillance payload is on this balloon, it does not create significant value added over and above what the [People’s Republic of China] is likely able to collect through things like satellites in low-Earth orbit,” said the official. “But out of an abundance of caution, we have taken additional mitigation steps.  I’m not going to go into what those are.  But we know exactly where this balloon is, exactly what it is passing over. And we are taking steps to be extra vigilant so that we can mitigate any foreign intelligence risk.”

At the same briefing, the official noted that this was not the first time “that you had a balloon of this nature cross over the continental United States.  It has happened a handful of other times over the past few years, to include before this administration.”

While this event garnered widespread national fascination—it was even fodder for a skit on Saturday Night Live—the use of balloons for gathering intelligence dates back centuries. Here’s what to know about their history. 

f-22 raptor fighter jet
An F-22 in Virginia, on Jan. 6, 2023. US Air Force / Mikaela Smith

Trial balloons

Balloons have been used in military surveillance since 1794, when revolutionary France employed them to watch movements of people and cannons from above. In the US Civil War, the Union and Confederate forces used balloons, flying as high as 1,000 feet, to document activity below. Communication with balloons then was tricky, with balloonists using either signal flags or telegraph wires to report what they observed. These balloons were tethered, allowing crews on the ground to draw the balloons back into place. In this sense, the balloons were more like deployable observation towers, rather than true scouting vehicles.

Later, World War I saw balloons used to photograph battlefields below. While film took time to develop, the long static fronts of the Great War ensured that such information was useful, or at least useful if the balloonists collecting it were not shot down by early fighter planes. In World War One, Frank Luke Jr was a US Army pilot who earned the nickname “Arizona Balloon Buster” for shooting down 18 German observation balloons. 

World War I also saw the use of dirigibles, or rigid airships, which flew as bombers as well as spotters. Airships could move under their own power and without tethers, allowing them deadly access to the skies above enemy lines. 

In World War II, Japan built high-altitude balloons that were lofted into the newly discovered jet stream, and then carried by the high-altitude wind across the pacific. More than 9,000 FuGo balloons were launched into the jet stream, complete with incendiary bombs designed to burn down cities and forests. The FuGo attacks were limited in effectiveness because they relied on winds that were strongest in November through March, when the Pacific Northwest was wet and cold, limiting the ability of fires to spread. Indeed, apart from fires, the only deaths directly attributed to FuGo attacks were that of a picnicking family, investigating a mysterious device.

Eyes floating in the sky

Long-range balloon surveillance is limited by how the balloon can be directed and what information it can communicate. Weather balloons, launched hourly, record atmospheric conditions. The famous 1947 balloon crash at Roswell, New Mexico, was of an instrument carrying acoustic sensors, designed to listen for the sounds of Soviet nuclear detonations.

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One reason to use balloons is that they can carry large payloads, as a lighter-than-air body of sufficient size floats in the sky, instead of needing to generate lift. The US general responsible for North America described the balloon as “up to 200 feet tall, with a payload the size of a jetliner.”

As for what the balloon was actually recording, that remains to be seen. It is possible that its high-altitude flight allowed for greater surveillance of radio and other wireless transmissions than can a satellite, though that is more speculative than proven.

Recovery of the downed balloon, and especially its sensor package, could prove revelatory, though it should be assumed that any sensitive information and technology taken into military possession will be classified, only parts of which may be selectively released. Given the widespread interest of other militaries in developing surveillance balloons, as well as the revelation that these overflights have happened before, it is likely that the modern balloon race is only just beginning.