ISRO's latest satellite, INSAT-4B was successfully launched in the geosynchronous transfer orbit from French Guyana on 12th March, '07 by the European Ariane-5 ECA launch vehicle of Arianespace. The lift-off was scheduled for the early hours of 11th March but due to a technical problem, the launch was postponed just seven minutes before the blast-off.
The 3,025 kg Insat-4B is the second largest in the Insat-4 series with 12 high power Ku-band transponders and 12 C-band transponders. The master control facility (MCF) at Hassan in Karnataka acquired the first signals from Insat-4B at 4.02 am IST, 30 minutes after it was lifted off. MCF is responsible for initial phase and in-orbit operation of all geostationary satellite of ISRO. The initial checks on the satellite indicated normal health of the satellite. MCF subsequently issued commands to the satellite to make the earth viewing face to orient towards earth. The 31st flight in Ariane-5 series, carrying ISRO's Insat-4B and its co-passenger, Skynet-5A of EADS Astrium, was lifted off at 3.33 am IST from Korou, French Guyana.
Established in 1983, the Indian National Satellite (INSAT) is the largest domestic communication satellite systems in the Asia Pacific Region with nine satellites in operation. It provides services in telecommunication, television broadcasting, meteorology including disaster warning, tele-education and tele-medicine. The system has 175 transponders at present for communication services besides meteorological instruments (Very high Resolution Radiometer and Charged Coupled Device i.e CCD cameras). With the addition of Insat-4B, the communication capacity will be further increased to 199 transponders. INSAT-4B will augment the INSAT capacity for Direct-to-Home (DTH) television services and other communication and television services.
Sun TV's DTH will have seven Ku-band transponders on Insat-4B while Prasar Bharati's free-to-air (FTA) package DD Direct Plus will have five on the same satellite. With this Sun TV will become the third private player in the rapidly expanding DTH market in India presently dominated by Zee network’s Dish TV and, Tata Group and Star TV’s joint venture, TataSky. The payloads will be checked out before the commissioning of the satellite.
Insat-4B carries the following payloads :
• 12 Ku-band 36 MHz and 27 MHz usable bandwidth transponders (9 and 3 respectively) employing 140 W TWT as to provide an EIRP of 52 dBW over the footprint covering Indian mainland.
• 12 C-band 36 MHz bandwidth transponders employing 63 W TWT to provide an EIRP 39 dBW with expanded coverage encompassing Indian geographical boundary, area beyond India in southeast and northwest regions.
Insat-4B will be manoeuvred to its final geostationary orbit, which is about 36,000 km above the equator, by firing its 440 Newton Liquid Apogee Motor (LAM). When the satellite reaches near geosynchronous orbit, deployment of its solar panels and two antennas will be carried out and the satellite put in its final 3-axis stabilized mode. This will be followed by trim manoeuvres to take the satellite to its designated orbital slot at 93.5 degree East longitude where it will be co-located with Insat-3A.
ISRO to earn 1250 crore from Insat-4B
With the paucity of transponders, the DTH companies had much before booked their space on Insat-4B. News reports prior to the launch point said that ISRO will earn a revenue of Rs 1250 crore with the launch of Insat-4B as transponders are fully booked on the back of booming demand for DTH services. ISRO chairman, Madhavan Nair said, “Before the launch itself, most of the capacity has been allotted to various users”. ISRO officials said each transponder is sold for a close to a $ 1 million every year. The satellite has a lifespan of 12 years. The development cost of Insat-4B, primarily intended for DTH applications is Rs 210 crore, while the launch cost charged by European space consortium Arianespace is Rs 225 crore. Nair has suggested the new DTH transponder users to adopt new techniques that would cut down their bandwidth requirement by up to two-third. “There's a lot of demand for DTH programmmes. I have been advising them that they should try and integrate their requirements and may go in for modern techniques so that the number of transponders can be effectively utilized”.