Thales Alenia Space
To Deliver Very-High-Resolution Optical Imaging Instrument To
Astrium
(9 July 2008) Thales Alenia Space is
ready to deliver the high-resolution (HR) optical imaging instrument for
integration in the first Pleiades earth observation
satellite.
The Pleiades project is part of ORFEO*, a joint
Franco-Italian initiative by the countries' national space agencies CNES and
ASI, marking a major technological advance in optical earth observation
systems. The dual-technology program addresses both military and civil needs
for European users, including mapping, volcano monitoring, geophysical and
hydrology studies, urban planning, etc. As prime contractor for the Pleiades
system-in particular the ground segment-CNES selected Astrium as satellite
prime contractor and Thales Alenia Space for the imaging
instruments.
The Pleiades optical high-resolution imaging instruments
offers enhanced resolution of 70 cm over a wide swath (20 km) in both the
visible and near infrared bands. This very high resolution instrument also
introduces significant innovations such as the highly-integrated detection
sub-assemblies (SEDHI), while also reducing volume three-fold compared to
previous generations. The instrument provides very high dimensional stability
thanks to a concept combining a carbon/carbon structure (material insensitive
to moisture and with a very low coefficient of thermal expansion) and Zerodur
mirrors. To optimise in-flight performance, the instrument has an innovative
thermal refocusing system, eliminating the need for a complex
mechanism.
The absence of this mechanism plus the satellite's own
enhanced performance (satellite pointing/tilting capabilities, downlink
transmission rate of 450 Mbit/s) means a significant increase in mission
performances.
The first flight-model instrument is now ready for
delivery, after successfully passing its environmental tests. The performances
of optical and radiometric tests, as measured in a Class 100 clean room in
Cannes-the level required for this class of instrument-are excellent. The
instrument will be integrated on the first satellite flight model, which will
then undergo checks at Astrium's facility in Toulouse.
The two Pleiades
observation satellites have a design life of five years and offer a high degree
of in-orbit agility thanks to their manoeuvring capability. They will be able
to acquire a series of images both along the swath or across the swath to
create a veritable mosaic of ground scenes. They are scheduled for launch in
2010 and 2011 respectively.
The Pleiades contract confirms Thales Alenia
Space's position as the European leader in very-high performance, very-high
resolution imaging instruments. The new instrument leverages the broad array of
competencies that Thales Alenia Space has developed during major programs,
including payloads for Helios I & II for very high geometric resolution,
the Vegetation instrument (on board Spot 4 and 5) and the MERIS instrument (on
board Envisat) for high-resolution geometric and radiometric imaging of land
and ocean surfaces. Thales Alenia Space also built the IASI Infrared
Atmospheric Sounding Instrument on board METOP, enabling French national
weather service Méteo France to significantly improve weather
forecasting accuracy.
* (Optical and Radar Federated Earth
Observation)
About Thales Alenia Space
The European leader in
satellite systems and a major supplier of orbital infrastructures, Thales
Alenia Space is a joint venture between Thales (67%) and Finmeccanica (33%).
Thales Alenia Space and Telespazio form the "Space Alliance". Thales Alenia
Space sets the global standard for space-based telecommunications, radar and
optical Earth observation, defence and security, navigation and science. Thales
Alenia Space has 7,200 employees and 11 production plants, with operations in
France, Italy, Spain and Belgium.
(source: Thales Alenia
Space)
