Exo-Atmospheric Apace: The Sea Seen From Above

“The French Navy often has its gaze and sensors turned towards the sky and space. Satellites allow it to conduct its surveillance and anti-trafficking operations, to communicate with all parts of the globe and to collect scientific data”, recalled on twitter, on September 7, 2021, Admiral Pierre Vandier, chief of Navy General Staff.


The Navy is historically a user of space, and in particular of the celestial bodies that evolve there, for astronomical navigation. The conquest of space in the 1950s and the putting into orbit of the first artificial satellites gave it new navigation, communication and intelligence tools. The satellite era marks a paradigm shift: with satellites, the high seas threaten to no longer be a space of dilution for surface vessels.

With the advent of the nuclear age and the development of intercontinental missiles, in particular sea-to-ground strategic ballistic missiles launched from ballistic missile nuclear submarines, exo-atmospheric space has become a space of operations for the Navy. Between the initial propulsion phase and the final phase of re-entry into the atmosphere, ballistic missiles operate above the atmospheric layer; their trajectory then only depends on their initial speed and the Earth’s attraction.

To maintain this capability at its best, the Navy regularly conducts acceptance firings. Carried out without a nuclear charge, they make it possible to validate the technological developments of ballistic missiles and to continuously improve their performance.

Today, the Navy is one of the first users of artificial satellites. Apart from the well-known functions of positioning, navigation and time reference (positioning, navigation and timing, PNT) provided in part by these objects, State action at sea, operational deployments, surveillance of protected marine areas also require satellite services. The use of space is today essential to the preparation and conduct of Navy missions. In a context of crisis or high-intensity military engagement, being equipped with efficient, sovereign and secure space observation and communication capabilities is essential.


The legal foundations for the exploration and use of exo-atmospheric space by States were laid down by the international treaty of 1967, when Russians and Americans were engaged in the conquest of the Moon. Still in force, it lays down the main principles of space law. While it provides for the free use of space for peaceful purposes, it prohibits the placement of nuclear weapons or any other form of weapon of mass destruction in orbit around the Earth, as well as their installation on the Moon or another celestial body. It leaves, on the other hand, the possibility of transiting these weapons through space.

With the proliferation of space objects, the risks of saturation of certain orbits, collisions and fallout have since increased; space waste is increasing. The democratization of access to space, often poorly controlled, further increases the risks of space pollution and collision.

The use of space has become militarized. The military means (lethal or not) making it possible to operate in the space domain have developed, whether from space to Earth (intelligence, which poses a threat to our forces); from space to space (use of malicious vehicles: satellite-killing satellites or information “gatherers”) or from Earth to the ground segment of space systems (Syracuse and Galileo stations, for example). Satellites are also vulnerable to jamming and can be blinded by directed energy weapons (laser, for example) implemented from the ground or from space.


For its communications, intelligence gathering and navigation, the Navy uses military and civilian satellites. In particular, it is a client of joint military observation satellites (Helios and now CSO, which provides very high resolution images day and night), communications (Syracuse III, soon to be completed and then replaced by Syracuse IV) and electromagnetic intelligence ( Ceres).

The Navy participates in the protection of French space capabilities with the test and measurement building (BEM) Monge. Its main mission is to collect and exploit the parameters of missile firings in flight. But its space observation and satellite tracking capabilities are also used to prevent potential damage to French space systems.

To ensure the surveillance and security of some 10 million km² of French maritime space, the Navy has acquired, with the Trimaran III service, the capacity to use data from 300 satellites. These will provide almost real-time coverage of the entire French exclusive economic zone. The monitoring system deployed as part of Trimaran III will be based on data provided by the nanosatellites of the startup Unseenlabs, which observe the Earth in the non-visible electromagnetic spectrum. In particular, it will make it possible to locate and track ships to fight against illegal activities at sea: illegal fishing, pollution, piracy, etc.

Syracuse IV

Constellation of geostationary satellites coupled with a new generation of ground stations, compact and mobile, the Syracuse IV system will provide armies with the very high speed secure links necessary for the conduct of their operations. Designed to deal with jamming and cyber attacks, it will replace the current Syracuse III secure radio communication system. The first satellite was launched on October 24, 2021; a second will be in 2022. By 2030, a final satellite will complete the system.

At the same time, the 400 associated stations (theater hubs, deployable tactical stations, individual stations, naval stations, etc.) will gradually be delivered to the forces to equip infantrymen, vehicles, aircraft, surface ships and submarines. In the Navy, the deployment of these antennas has already started on high seas patrol boats (PHM) and La Fayette type frigates (FLF) in 2021. Multi-mission frigates (FREMM), defense and (FDI), Suffren -type submarines and amphibious helicopter carriers (PHA) will be equipped with them by 2023.

Related posts