The balloon identified above the airspace of the United States, which according to the Department of Defense would have been launched by China to spy on sensitive targets, is a rare means but still with significant and interesting uses, and above all with a long history.
The US government announced Thursday evening that it had identified a “spy balloon”, which from the photos released looks like a kind of balloon with some equipment attached to it: it was also spotted by civilians over Montana, a sparsely populated state in the northwest of the United States. According to a Defense Ministry spokesman, the balloon entered American airspace “a couple of days ago” (the press conference took place on Thursday, so we’re talking about the beginning of the week), but it was being watched by the American defense since some time.
Hot air balloons like the one found over the United States are not a danger to civil or military aviation, because they fly much higher: basically between 24 and 37,000 meters above sea level. Airliners usually fly at an altitude of around 12,000 metres, while fighter jets rarely exceed 20,000 metres.
The Defense Department said it was sure the balloon came from China, although it did not provide specific proof. He also said confidently that it would be a “spy balloon”, that is, used for the surveillance of sensitive targets. The Chinese government has instead said that the balloon would be a “civil aircraft” used for weather surveys, which went off course.
However, the US Secretary of State, Antony Blinken, has decided to postpone an important visit to Beijing that was scheduled for the weekend.
Surveillance balloons have a very long history but for some decades they have been considered obsolete, superseded by satellites and other apparently more sophisticated means. The last major balloon surveillance programs date back to the early stages of the Cold War, in the 1950s and 1960s. However, as the spy balloon spotted over the United States shows, some experts believe that things could change, and that balloons could once again play a role in some countries’ surveillance programs, thanks to small but important technological advances.
The idea of using hot air balloons for military surveillance dates back to shortly after the invention of the hot air balloon by the French Montgolfier brothers in 1782–1783.
The first to use balloons in battle was the French army, which used them for the first time at the Battle of Fleurus in 1794, one of the first of revolutionary France against the other European powers. For the occasion, the French army also created a balloon battalion. At the time, balloons were mainly used as means of observation: they were filled with hydrogen or helium and remained anchored to the ground by metal cables. They were used to observe the battlefield from above, manage troop placement and artillery strikes.
This use of aerostatic balloons fixed to the ground continued for over a century, but systems were soon added which provided that the balloon moved, either directly piloted or towed from the ground. Reconnaissance balloons played a notable role in the American Civil War (1861–1865), although probably the zenith of their military utility was during World War I, when both armies flew balloons over the battlefield with a few observers on board who guided artillery fire on enemy targets.
On the fronts of the First World War, balloons rose at the start of an attack and remained anchored to the ground, as fixed aerial positions, at an altitude of 1,000-1,500 metres. They were considered to be of great strategic importance, and were protected by the artillery and flak of their own armies. Also for this reason the so-called “Balloon busters” became famous, i.e. the pilots of war planes who had the task of shooting down enemy aerostatic balloons.
It was by no means an easy task, both because the balloons were well defended by flak and because normal shells punched too small holes in the balloons to cause sufficient casualties to bring them down. For this, special, larger bullets were invented. Scores of pilots on both sides died attempting to shoot down the balloons, while some remained quite famous in military history for their successes.
During World War II military aviation had made sufficient improvements to make the use of balloons unnecessary in battle. At that time the enthusiasm for balloons had also been deflated by the terrible accident of the Hindenburg, the German airship which caught fire in 1936.
The Japanese military, however, rather ingeniously began to build “incendiary balloons,” which were flown at very high altitudes and used high-altitude currents to reach the United States, where they plummeted, releasing an incendiary load. About 300 of these balloons from Japan reached the United States: they caused rather limited damage, but greatly worried the American government, which feared that the Japanese could use them to spread biological weapons.
During the Cold War, some countries attempted to use balloons for espionage and surveillance operations, with mixed success. The United States, in the late 1940s and early 1960s, initiated some espionage programs with balloons, mainly directed against the Soviet Union. The most famous is probably Project Moby Dick, which was active in the second half of the 1950s and involved the use of very long and slender Skyhook-type balloons, to the base of which was attached a box containing a camera. The box was disguised as a weather survey device, and the American idea was to launch many of these balloons, hoping that at least some would then fall back on Allied territory.
In 1956, the United States fired over 500 balloons at the Soviet Union from their bases in West Germany and Turkey. The Soviets noticed this very quickly and started shooting them down with fighter jets. 90 percent of the Project Moby Dick balloons were lost, but the 44 balloons that returned to American hands carried valuable information, such as photos of a large Soviet nuclear complex that the rest of the world knew nothing about at the time.
After the 1960s, however, the development of satellites made surveillance balloons increasingly obsolete. They were never completely abandoned (the United States also used some reconnaissance balloons in the recent wars in Afghanistan and Iraq in the 2000s), but there were no more specific military programs.
As some analysts have noted, there are some innovations that could herald renewed use of balloons in the future. Obviously, aerostatic balloons are already used in some circumstances, for example for weather surveys or for scientific purposes. But for some years now there has been talk of their use also in the military, intelligence or surveillance fields.
Favoring the return of balloons could be the fact that cameras and other surveillance systems have now reached such a level of miniaturization that even very sophisticated devices can be mounted on a balloon, and provide excellent quality data and images. An aerostatic balloon today can mount cameras and video cameras, radars, sensors of various types, communication tools and solar panels to give energy to everything.
Satellites are and will remain for a long time to come the best tool for surveillance and espionage, but balloons could provide a viable alternative in some circumstances.
First of all they are much cheaper: satellites must be sent into space with extremely expensive rockets, which balloons do not need. Satellites follow predefined orbits and are difficult to detect, while hot air balloons, even those launched at very high altitudes, can be maneuvered within certain limits. This is a relatively recent discovery: using small fans powered by solar panels, it is possible to change the altitude of balloons, allowing them to be swept along by the various currents found at high altitudes. With a little study and a certain degree of approximation, it is possible to use the currents to make the balloon go where you want it.
Since they don’t need an engine, balloons can stay in the air for months, and they can stay fixed on the same target for a very long time.
The most modern aerostatic balloons escape radar, and above all they are very difficult to shoot down: they fly at altitudes that cannot be reached by fighter jets, and even if they are hit, they do not explode like balloons, but lose air slowly and gradually. We must also consider that modern aerostatic balloons are enormous: they can measure more than a million cubic meters and be as tall as a 20-storey building: deflating such an object can be extremely difficult.
In 1998 a Canadian weather balloon went off course and headed into Russian airspace. The air forces of three countries (Canada, the United States and the United Kingdom) attempted to shoot it down while it was still over the sea, but it was an almost impossible undertaking.
First of all it was difficult to find, precisely because balloons are not detected by radar. When it was found, fighter jets were sent to shoot it down: two Canadian F-18s hit the balloon with over 1,000 large-caliber shells, but although they managed to puncture it, they failed to deflate it significantly. They also launched missiles at him, but they passed through the balloon without exploding. Finally, it took six days for it to crash to the ground.