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Satellite de Télécommunications pour Expérimenter de Nouvelles Technologies en ORbite


Designation n/a
Launch date 11 Dec 2002
Country of origin France
Mission Technology
Geostationary orbit 11°W or 47°E
Launch vehicle Ariane V157

End of life

Out of service 11 Dec 2002
Cause Launch failure

The satellite was a collaborative program between CNES, France Telecom, Alcatel Space and Astrium (was Matra Marconi Space). 85% of the equipement on board was new. It costed approx EUR 450 million. Operated by CNES.

External resources


Lookup sat-index archive

Technical data


Prime contractor Alcatel Space
Platform Spacebus-3000B
Mass at launch 2210 kg
Mass in orbit  
Dry mass 1186 kg
Dimension 4.5 x 3.2 x 2.6 m (15.6 m span in orbit)
Solar array gallium arsenide solar cells on germanium (GaAs/Ge)
Stabilization 3-axis
DC power EOL: 2100 W
Design lifetime 9 years

MMS provided Power supply, On-board data management, attitude control, experiments concerning radiation effects and EMC in the plasmic propulsion.

Had lithium-ion batteries provided by SAFT. Had Fakel SPT-100 (plasma) and Snecma PPS-1350 motors. Also had a GPS receiver for autonomous navigation.

3 antennas: 1 multibeam reconfiguration antenna with 48 radiant subpanels, a 2.4m reflector and a very narrow adjustable spot (1.8°).


Main transponders
Backup transponders  
Bandwidth 36 MHz
72 MHz
EIRP max  
G/T max  

The Ku-band payload had three transponders: (1) a very wide band transponder based on MMIC technology. The transponder enables data communication over a wide band, i.e., at high transmission rates, (2) a transponder using intermediate frequency conversion (IF < 1.5 GHz) and surface acoustic wave filters. It includes three channels with selectable bandwidth (36 or 72 MHz), (3) a digital television transponder which can multiplex onboard up to twelve TV programs to DVB-S standard and MPEG-2 format. This enables local broadcasters to access the satellite using small terminals.


Main transponders
Backup transponders  
Power 1 TWTA
Bandwidth 2 x 40 MHz channels separeted by 1 GHz
Coverage Europe (center = Bourges, FR) and Guyana (center = Kourou, FR)
EIRP max  
G/T max  
Frequencies uplink: between 44 and 45 GHz
downlink: between 20.2 and 21.2 GHz

EHF-band payload: funded by DGA (French MoD), devoted to propagation and transmission experiments. The transmission mission concerns a 44/20 GHz transparent repeater and is aimed to test new signal processing methods in the context of future military satellite telecommunications systems. The propagation mission will consist of two high frequency beacons, the first one at 20.7 GHz and the second one at 41.4 GHz.
The payload is called EXPRESS (EXperimentation of PRopagation in the EHF-band with the Satellite Stentor)
The main efforts will concern the most severe climates, and this is the reason for having a spot beam for both beacons on French Guyana and around.

2 antennas (one for receive and transmit (44/41.4 GHz) and one transmit antennate at 20 GHz)
2 beacons at 20.7 GHz (EIRP > 15 dBW) and 41.4 GHz (EIRP > 22 dBW) RHCP.
The 41.4 GHz beacon cannot be switched on the same beam as the transponder at the same time.

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