Stentor
Satellite de Télécommunications pour Expérimenter
de Nouvelles Technologies en ORbite
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.
http://nss.cnes.fr/english/satellite/satellite.html
http://www.estec.esa.nl/xewww/cost255/ws/98c08/c255a17.html
Lookup sat-index archive
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
|
3 |
Backup
transponders
|
|
Power
|
|
Bandwidth
|
36
MHz
72 MHz
|
Coverage
|
|
EIRP
max
|
|
G/T
max
|
|
Polarization
|
|
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
|
1 |
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
|
|
Polarization
|
|
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.