Essaim (''swarm'', in French) was a French military reconnaissance microsatellite constellation. Its main purpose was to collect and map signals intelligence around the world. The

Direction générale de l'armement The Direction générale de l’armement (DGA; English: Directorate General of Armaments), is the French Government Defence procurement and technology agency responsible for project management, development and purchase of weapon systems for the Fr ...

(DGA) described it as a "vacuum cleaner for adiowaves".

Description

Essaim was a constellation of four 120 kg microsatellites (one of which was a spare) in

low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never mor ...

(LEO). They were demonstration models which were supposed to last three years. They flew separated by a few hundreds of kilometers. Missions were designed by the ''Celar'' (Centre d'électronique de l'armement) in

Bruz Bruz ( or ) is a commune in the Ille-et-Vilaine department in Brittany in northwestern France. Geography Bruz is located near the center of the Ille-et-Vilaine department, 14 km from Rennes. It is near the confluence of the rivers Vil ...

, near Rennes and were uploaded from

CNES The (CNES; French: ''Centre national d'études spatiales'') is the French government space agency (administratively, a "public administration with industrial and commercial purpose"). Its headquarters are located in central Paris and it is und ...

Toulouse Toulouse ( , ; oc, Tolosa ) is the prefecture of the French department of Haute-Garonne and of the larger region of Occitania. The city is on the banks of the River Garonne, from the Mediterranean Sea, from the Atlantic Ocean and from Pa ...

to the constellation. Collected data followed the same path in reverse order.

Launch

The constellation was launched from

Kourou Kourou () is a commune in French Guiana, an overseas region and department of France in South America. Kourou is famous for being the location of the Guiana Space Centre, the main spaceport of France and the European Space Agency (ESA). It i ...

, in

French Guiana French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas department/region and single territorial collectivity of France on the northern Atlantic coast of South America in the Guianas. ...

, by an Ariane 5 G+

launch vehicle A launch vehicle or carrier rocket is a rocket designed to carry a payload ( spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and ...

on 18 December 2004. The flight was shared with Helios 2A and two other auxiliary payloads:

Parasol An umbrella or parasol is a folding canopy (building), canopy supported by wooden or metal ribs that is usually mounted on a wooden, metal, or plastic pole. It is designed to protect a person against rain or sunburn, sunlight. The term ''umbr ...

and

Nanosat A small satellite, miniaturized satellite, or smallsat is a satellite of low mass and size, usually under . While all such satellites can be referred to as "small", different classifications are used to categorize them based on mass. Satellites ca ...

. Individual members of the constellation were Essaim 1 (

COSPAR ID The International Designator, also known as COSPAR ID, is an international identifier assigned to artificial objects in space. It consists of the launch year, a three-digit incrementing launch number of that year and up to a three-letter code repr ...

: 2004-049C), Essaim 2 (COSPAR ID: 2004-049D), Essaim 3 (COSPAR ID: 2004-049E) and Essaim 4 (COSPAR ID: 2004-049F).

Decommissioning

ESSAIM disposal and passivation operations took place in October 2010. The satellites are expected to reenter within 15 to 19 years (2025-2029).

References

External links

Microsatellites Essaim: aspirateur d'ondes

ESSAIM cluster disposal: orbit management
Reconnaissance satellites of France Signals intelligence satellites Spacecraft launched in 2004 Spacecraft launched by Ariane rockets Derelict satellites orbiting Earth Satellite constellations Satellites in low Earth orbit Military equipment introduced in the 2000s {{france-mil-stub

Description

Launch

Decommissioning

See also

References

External links