For the Americans, the diplomatic arm wrestling with China has turned into a ball-trap: a balloon qualified as a spy and three flying machines not very well identified were shot down in less than ten days in the stratosphere while this type of balloons, until then, was in no way a threat. A first ended up in the Atlantic on February 4 after flying over a good part of American territory; a second fell over Alaska on Friday even as White House National Security Council spokesman John Kirby admitted, “We don’t know who owns it, if it’s a State or a company or an individual, we do not know. […] And we do not yet understand its use.” A third “cylindrical in shape”, this time with the help of Canadian planes, was brought down over the Canadian territory of the Yukon (Saturday) and a last one (Sunday) above Lake Huron between Canada and the United States, octagonal in shape “with ropes hanging down” and “without a visible nacelle”, said a senior Canadian administration official.
For many specialists, it is above all a question, on the American side, of marking the occasion to show that they have control of their airspace governed according to the Chicago Convention of 1944 at an altitude of twenty kilometers. “Which does not mean that what is above, the exoatmospheric zone, is a space of lawlessness”, specifies Philippe Steininger, the military adviser to the president of the National Center for Space Studies (Cnes). In this sense, each state could therefore assert its sovereignty at an altitude where “the laws of Newton no longer apply, but that of Kepler”, continues the specialist, a former general in the Air Force. Namely the boundary between the atmosphere and space. However, there is no official value. The physicist Theodore von Karman fixed it at 83.6 kilometers, others estimate it at 100 kilometers.
4,000 balloons sent by France
Still, the episode of clay pigeon shooting between Americans and Chinese highlights how very high altitude is becoming a strategic issue for the great powers, in particular the stratosphere (especially between 10 and 50 kilometers above sea level). “For sixty years, France has sent nearly 4,000 balloons there, estimates Vincent Dubourg, head of balloon activity at Cnes. But all for scientific purposes: meteorology, testing of devices that will go into space, etc. ” None of them were shot. What is new is that some States, China but also the United States which also regularly take off, do not warn the authorities of the countries overflown, in fact stirring up suspicions about the probably unscientific objectives of these secret missions. . Experts are far from agreeing on the interest of so-called “spy” stratospheric balloons. In principle, these aerostats evolve with the winds, so they are difficult to control to observe a territory. Moreover, it was a little quickly forgotten in the Sino-American affair, but another balloon similar to the one shot down on February 4 was spotted above Latin America in an area of little interest to spy on, this which can accredit the thesis of uncontrollable craft that have drifted.
On the other hand, the huge solar panels they sported suggest not only that they were made to fly long distances but that they needed solar energy to power several instruments. Aerial imagery specialists are not certain, however, that a drifting balloon is the best tool for scrutinizing a site like that of the famous nuclear silos in the state of Montana, as the Americans have claimed. “But some of these aircraft are said to be “manoeuvring” so that a priori they could hover longer above a point and drift less”, specifies one of them. However, satellite imagery seems more relevant since it now allows images at the scale of a few tens of centimeters. More likely, and as a senior US State Department official revealed after recovering the remains of the balloon shot down on February 4 in the open sea, it was equipped with large antennae, which gave it a real capacity listening: “It is possible that the Chinese were trying to intercept certain communications around or in these sensitive sites”, thinks an expert.
More discreet and lower than satellites
The objective of the military who are more and more interested in the stratosphere is therefore to develop devices capable of evolving there because they are higher than an airplane while being more discreet and lower than satellites (therefore less expensive to deploy and less easy to locate). “We can’t be absent from this slice of altitude. That’s for sure”, assured the Major General of the Air and Space Force during a recent conference organized by the French army. ‘air. France, in particular via the Cnes and its experience of stratospheric balloons, has a number of assets, even if it is likely that a project will only succeed at European level.
On the balloon side, the French space agency is working with engineers from Hemeria on a maneuvering balloon project. “We work with them because they specialize in balloon envelopes and to make them more maneuverable you need two: one classic inflated with helium to provide lift, and a second with air to play on the trajectory”, explains Vincent Dubourg. This technology for maneuvering balloons has already been mastered by the Americans, including the company Raven Aerostar, which has recovered Google’s giant “bi-balloons” (Loon project). The French, via a European defense fund, hope to develop an aircraft of the same type, with a large payload, by 2026.
In terms of airships, Thales Alenia Space is working on the Stratobus equipped with four electric motors that allow it to fight against the winds and ensure permanence above a specific location. With 140 meters long, it could carry a payload of 250 kilos. “The Stratobus would be the ultimate weapon in the stratosphere for observational applications,” said an expert. The project launched in 2016 remained on the drawing board for a long time. But before the episode of the Chinese balloons, the European Union had saved it during 2022 by allocating to Thales teams an additional budget whose objective would be to produce a small demonstrator.
Finally, still in the stratosphere, Airbus is working on a very high altitude drone called Zephyr which has the wingspan of Concorde (25 meters) and capable of flying at an altitude of 21 kilometers. It is clearly a surveillance drone that can cover an area of 400 square kilometers. According to Airbus, the program is in its final design and has proven its reliability by flying sixty-four consecutive days in 2022. The European has even just created a spin-off, Aalto, in order to ensure its marketing and industrialization. with a market launch expected from… 2024. Long uncrowded, the stratosphere has already become a space to be conquered. The Chinese balloons are only a first demonstration.