THEOS (satellite)
THEOS (Thailand Earth Observation System) is the first national Earth observation satellite, the Thai Space Agency GISTDA ( Geoinformatics and Space Technology Development Agency). He should take pictures for cartographic, agricultural and forestry as well as coastal protection and flood monitoring tasks.
History
Since the 1970s, Thailand is involved in Earth observation programs of other countries. After working with vendors such as Landsat, Radarsat and SPOT Thailand has decided to launch its own Earth observation satellites. The contract with EADS Astrium SAS for the development of the satellite was signed on 19 July 2004. In February 2007, the construction of the satellite was completed. It should be started with the help of a Russian Dnepr rocket in December 2007 by the rocket base in Jasny. After several start delay the launch took place on 1 October 2008 at 6:37 UTC. Is controlled by the satellite is THEOS Control Center in Si Racha in Chonburi province.
Technology
The satellite is equipped with a panchromatic telescope and a multispectral camera and is based on the AstroSat -500 satellite bus of EADS. He has a three -axis control and therefore can take pictures in a 1000 km wide corridor along its flight path (50 ° off the perpendicular ). For single shots shots are possible in a 1900 km wide corridor or stereo recording of a given area.
Specifications
- Mass: 750 kg
- Size: 2,1 m x 2,1 m x 2,4 m
- Solar power: 980 W ( EOL)
- Orbit: Sun synchronous in 822 km height with 101.4 minutes round trip time
- Inclination: 98.7 °
- Again overflight period: 26 days
- Memory Capacity: 51 Gb
- Data transmission: Mission Data in the X-band with 120 Mbit / s transmission capacity, & CTT TT & C at S-band
- Control: 3-axis stabilization with star trackers, gyro, GPS, magnetometer and sun sensor
- Control thrusters: Hydrazintriebwerke with 80 kg of propellant supply
- Planned life time: at least five years