SPACE SEGMENT

The Space Segment comprises one operational satellite in geo-synchronous orbit, located 36,000 kms above the equator with one spare satellite ready for deployment. The first operational satellite was successfully launched on the 21st October 2000 and full commercial service have begun in a gradual roll out starting from April 2001 in many countries in Thuraya's coverage area.

The Thuraya Geo satellite, which constitutes the Space Segment, is operated and managed by a sophisticated and integrated ground network known as the Ground Segment. The Ground Segment includes the Satellite Operation Centre, which monitors and controls satellite movement, ensuring the overall and ongoing maintenance of satellites in geo-synchronous orbit.

Satellite Overall Design

Number of satellites: 2.
Type of orbit: Geo-synchronous orbit with 6° inclination.
Orbital locations: 44° E and 28.5° E.
Service life of 12 years.
Compatible with Sea Launch and Ariane 5 launch vehicles and others
Supplier: Hughes Space & Communications International, Inc.

Payload Subsystem

12.25 meter aperture deployable satellite antenna.
On-board digital signal processing (DSP) to facilitate interconnectivity between the common feeder link coverage and the spot beams to make effective use of the feeder link band and to facilitate mobile to mobile links between any spot beams.
Digital beam-forming capability which will allow Thuraya to reconfigure beams in the coverage area, to enlarge beams and to activate new beams. It also allows the system to maximise coverage of "hot spots", or those areas where excess capacity is required.
The flexibility to allocate 20% of the total power to any spot beam.
The flexibility to reuse the spectrum up to 30 times and therefore use the spectrum efficiently.
The signal characteristics of 8 time-multiplexed voice circuits:
Modulation pi/4 QPSK
FDMA carrier channel BW 27.7 kHz
Channel bit rate is 46.8kbps.

Bus SubSystem

Power
     (1) Solar
     (2) Beginning of life 13KW
     (3) End of life 11KW
     (4) Panels are 2 wings of 4 panels each w/dual-junction gallium arsenide cells.
Batteries
(1) 2.250 A-hr cells
Dimension
     (1) In Orbit
     (2) L, solar arrays 34.5 m (113ft)
     (3) W,antenna 17m (55.7 ft)Service life of 12 years.
Stowed
(1) H:7.6m (25 ft)
(2) W:3.75m * 3.75m (12.3 ft)
Weights
(1)5250 Kg (11,576 lb) Launch
(2) 3200 kg (7,056) In orbit (beginning of life)

Space Segment THURAYA’s Uplink Beacon Station (UBS)

THURAYA's satellite coverage area consists of over 250 high-gain-spot-beams that are created by a combination of its 40-foot by 50-foot ellipse antenna and state of-the-art onboard Digital Beam Forming processor. Each spot beam is about 450 Km in diameter (if measured at coverage center).

Due to the fact that THURAYA satellite is orbiting in an inclined orbit of about ±6° at the beginning of its life, all spot beams are maintained in their designated location by adopting:

Satellite orbit-normal operation
Continuous Primary-Gateway-upload of beam coefficients and utilizing the On-Board Digital Beam Forming to compensate for beams’ deformation.
Satellite body pointing correction toward THURAYA coverage center, and hence the large L-Band Antenna pointing correction, by using a combination of ground Up link Beacon Station (UBS) and Sun sensors on-board the satellite.

THURAYA system utilizes two UBSs for hot back up in order to provide continuous pointing accuracy of the L-Band antenna and hence un-interrupted, high availability and high quality service to our valued customers.

THURAYA has set up its second Uplink Beacon Station in Egypt in an agreement with Telecom Egypt (TE), a prominent telecommunications company in Egypt. The Almaadi installation is one of the leading earth stations in the Middle East providing satellite communications. THURAYA’s first UBS is located in the Primary Gateway (PGW) in Sharjah, UAE.