Thaicom 8 Satellite

Photo: Orbital ATK
Photo: Orbital ATK

Thaicom 8 is a commercial communications satellite built by Orbital ATK and operated by Thaicom PLC to deliver broadcasting services to a wide coverage area over South and Southeast Asia and Africa.

Thaicom selected satellite builder Orbital ATK and launch provider SpaceX for the construction and launch of Thaicom 8 in April 2014 after the successful collaboration with the two companies in the Thaicom 6 mission launching in January 2014. The Thaicom 8 project is valued at $178.5 million.

The Thaicom 8 satellite has a launch mass of around 3,100 Kilograms and is based on Orbital ATK’s GEOStar 2.3 satellite platform, a flight proven satellite bus suitable for all types of commercial communications payloads. The 2.3 version of the GEOStar bus is suitable for smaller satellite missions with a payload power of up to 5.0 Kilowatts. The first StarBus-based satellite was launched in 1997.

GEOStar2.3 features a rectangular satellite body with a central structural tube housing the apogee motor of the spacecraft. The platform provides payload mounting structures on the north and south side panels and the nadir-facing deck offering excellent Earth-pointed fields of view.

Image: Orbital ATK
Image: Orbital ATK

The satellite has two four-panel Solar Arrays covered with Ultra-Triple-Junction Gallium-Arsenide Solar Cells feeding Li-Ion batteries and all satellite subsystems. Thaicom 8 features a liquid-fueled propulsion system centered around the IHI BT-4 engine. BT-4 was developed by IHI Aerospace, Japan and has a dry mass of 4 kilograms and a length of 0.65 meters. The engine provides 450 Newtons of Thrust and uses Hydrazine and Mixed Oxides of Nitrogen as propellants. Attitude control and stationkeeping in Geostationary Orbit is accomplished using a Hydrazine monopropellant thruster system.

The spacecraft uses state of the art navigation sensors and attitude actuation is provided by reaction wheels as part of a zero-momentum system.

Thaicom 8 hosts an all-Ku-Band communications payload comprised of 24 active transponders, feeding three deployable single offset reflectors. The reflectors measure 2.4, 2.6 and 2.5 by 2.7 meters in diameter and are deployed once the satellite reaches Geostationary Orbit.

The Thaicom 8 satellite will operate from 78.5° East in Geostationary Orbit delivering three coverage zones – East Africa, India and surrounding areas, and Thailand and neighboring countries. Thaicom 8 will be co-located with the Thaicom 5 and 6 satellites in operation since 2006 and 2014.

Thaicom 8 Coverage Zones - Image: Orbital ATK
Thaicom 8 Coverage Zones – Image: Orbital ATK