the eyes, ears and mouthpiece of the French defense in the room

From the beginning of the strategic dimension of the space domain, the French political authorities from the late 1950s made a significant and continuous effort to benefit it.

This course of action has borne fruit, so much so that our armed forces are now equipped with high-performance space capabilities covering a very broad spectrum of missions (space telecommunications, surveillance and electronic listening), which few countries can do before. A new generation of satellites to support joint operations is currently being created.

By the end of this move, the armed forces will have their own three CSO optical observation satellites, a constellation of three CERES electronic listening satellites and two Syracuse 4 military telecommunications satellites; in a way the eyes, ears and mouthpiece of the French defense in the room.

OSC: eyes

In 1995, the first European military optical observation satellite was put into orbit. It is French and is called Hélios 1. With it, the French armies have access to high-resolution space images. The two Helios 1s were replaced in the mid-2000s by two Helios 2s with increased performance.



Read more: Bonnes Feuilles: “Conquering the cosmos, 60 years of French space adventure”


The Helios family sequence in orbit has been ensured since December 2018 by the CSO program (for space optical component), which provides for three identical satellites evolving in a heliosynchronous polar orbit; two of 800 kilometers for the reconnaissance mission and one of 480 kilometers for the identification mission, providing access to more precise information. The first two CSOs are operational, the third will be in 2023.

Model of an optical space component (OSC) satellite.
Wikimedia, CC BY-SA

CSO opens up access to visible and infrared image quality unparalleled in Europe. Technological innovations applied to its large-diameter mirror and its focal planes thus make it possible to acquire extremely high-resolution color images, in other words, images that not only allow elements of interest to be detected, but also to understand their nature and identify them . With CSO, it thus becomes possible to distinguish whether a person is armed or the details of a weapon system.

Thanks to its infrared capability, which captures the thermal signature of the observed scenes, the CSO instrument also allows night images at a level of performance that cannot be matched by that achieved with Helios 2.

But for a soldier, seeing, characterizing and identifying is not enough in itself. It is also a matter of geolocating, with the best possible precision, the observed objects, and from this point of view, the performance achieved by the CSO enables it to meet the highest military requirements. With CSO, the collection of information from space not only takes a significant qualitative leap forward, thanks to the very high performance of the satellites, but it is also enhanced in terms of the amount of information obtained and its reactivity. Compared to the previous generation, we thus have many more images delivered much faster.

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In this program, the state and the French space industry have been able to combine their talents to create a system at the highest level in the world. The Directorate General of Armaments (DGA) provided the management, assisted by the National Center for Space Studies (CNES), to which it delegated project management for the production of the satellites and the ground segment of the mission, while the national industry has also been able to meet the program’s technological challenges.

CERES: the ears

For some, Ceres is the Roman goddess of harvest and fertility; for the French military, this name evokes above all a space intelligence system.

Since November 2021, the three CERES (for Spatial Electromagnetic Intelligence Capability) satellites have been in orbit. The CERES constellation makes it possible to detect, characterize and precisely locate electromagnetic signals emitted by radars or communication systems. The system covers a wide range of frequencies and makes it possible to revisit the detected transmitters every day.

The constellation of CERES satellites, a unique system in Europe, Ministry of the Armed Forces, 16 November 2021.

With CERES, the French military can thus monitor the electromagnetic spectrum with the aim of developing an enemy order of battle or preparing electronic warfare measures; they can also accurately monitor potential targets. The first of its kind in Europe, the CERES system is the heir to 25 years of national efforts in the field of electromagnetic listening from space and takes advantage of the results of a number of demonstrators which have made it possible to validate the technologies initiated by CERES.

In the 1990s, the Cerise and Clémentine demonstrators first made it possible to validate the possibility of detecting an electromagnetic signal from space, then the Essaim demonstrators in the 2000s and Elisa in the 2010s made it possible to validate the principle of placing a transmitting on the ground through formation flight.

It is precisely with this technique that the three CERES satellites determine the position of a transmitter on the surface of the globe. This will be all the more precise as the positioning of the satellites is strict. This is where the know-how of the CNES teams, which keep CERES in orbit, is called upon. With the Essaim and Elisa demonstrators, the forerunners of CERES, these teams developed and then refined a technique to form a formation of satellites and maintain it over time with precision and efficiency.

Syracuse: the megaphone

Over the past forty years, several generations of telecommunications satellites have provided the French armies with a very long range communications capability. The Syracuse 1 to 3 systems have replaced each other, and Syracuse 4 is currently in place. With this system of increased performance, the ambition is to meet the increased throughput requirements of the armies linked to the increasing digitization of the battlefield, and to provide a service to new users such as aircraft or vehicles in motion.

To this end, Syracuse 4, in addition to its very strong jamming resistance and X-band communication capabilities, provides new military Ka-band capabilities. This new system takes full advantage of the dynamism of the civil commercial sector, where our manufacturers are particularly well placed, relying on the most promising innovations in digital technology. The first Syracuse 4 satellite is in place in geostationary orbit and will be connected to another platform in 2023.

Towards a new era

“Know to anticipate to be able”; the formula is from Auguste Comte and conveniently connects in a logical sequence three verbs essential to the military art. In this area, more than in any other, these cannot be combined today without the contribution of space capacity.

The French defense has understood this and for several years has been obliged to replace its space intelligence and telecommunications systems. With CSO, CERES and Syracuse 4, it now has top-level capabilities. However, it is already preparing the next generation with CNES and the industry, which is expected at the beginning of the next decade. Iris, Céleste and Syracuse 4C will then open a new era.

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