Essaim (satellites)

Essaim ("swarm", in French) is a French military reconnaissance microsatellite constellation. Its main purpose is to collect and map signals intelligence accross the world. The DGA describes it as a "vacuum cleaner for [radio] waves".

Description

Essaim is a constellation of four 120 kg microsatellites (including one spare) in low earth orbit. They are demonstration models wich were supposed to last three years. They fly separated by a few hundreds of kilometers. Missions are designed by the "Celar" (Centre d'électronique de l'armement) in Bruz, near Rennes and are uploaded from CNES in Toulouse to the constellation . Collected data follows the same path in reverse order.

Launch

The constellation was lauched from Kourou, in French Guyana, by an Ariane 5 G+ rocket on December 18, 2004. The flight was shared with Helios 2A and two other auxiliary payloads: Parasol and Nanosat.Individial members of the constellation are Essaim 1, Essaim 2, Essaim 3 and Essaim 4.

External links

* [http://www.defense.gouv.fr/dga/votre_espace/presse/articles/microsatellites_essaim_aspirateur_d_ondes A presentation of Essaim, with photographs]
* [http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=2004-049C NSSDC Master Catalog - Essaim 1]
* [http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=2004-049D NSSDC Master Catalog - Essaim 2]
* [http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=2004-049E NSSDC Master Catalog - Essaim 3]
* [http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=2004-049F NSSDC Master Catalog - Essaim 4]