4th Indian generation satellite 'INSAT-4B' launched successfully

Bangalore, Mar 12 (UNI) India's latest fourth generation satellite 'INSAT-4B' aimed to give a fillip to the Direct-to-Home TV transmission began its space odyssey today as it successfully hurtled into a geosynchronous transfer orbit by a heavy Ariane-5 launcher at the Spaceport of Kourou in French Guyana.

The Ariane-5 blasted off at around 0433 hrs with a twin passengers of the British Military satellite Skynet 5A and INSAT-4B. In a precise operation, the launch separated INSAT-4B for around 31 minutes after the launch.

The Indian Space Research Organisation, in a release here, said the satellite launched in 3-axis stabilised mode ''is now orbiting the earth once in 10 hrs and 34 minutes''. Its perigee (nearest point to earth) was 243 km while an apogee (farthest point to earth) of 35,876 km and an inclination of 4.52 degree with respect to the equator.

The 3025-kg satellite would be over the next few days manoeuvred to its space home of 93.5 degree east longitude where it would be co-located with INSAT-3A.

With 12 high-powered Ku-band transponders and 12 C-band transponders, INSAT-4B will further augment the INSAT capacity for the DTH television services and other communication and TV services.

Once INSAT-4B is commissioned, India would have a total transponder capacity of 199 in the INSAT constellation of communication satellites.

The over Rs 200 crore satellite would also be a commercial success as each of the 24 transponders was expected to bring in a revenue of little over one million US dollars per year during its 12-year mission life.

ISRO Chairman G Madhavan Nair termed the launch an important one to the country and complimented Arianespace for a precise launch.

The satellite is the 13th to be launched from Kourou.

Space controllers at the Master Control Facility (MCF) at Hassan in Karnataka acquired the first signals from INSAT-4B at 0402 hrs.

The initial checks on the satellite have indicated its normal health.

The MCF subsequently issued commands to the satellite to make the earth viewing face to orient towards earth. The calibration of the gyros on board the satellite was also carried out.

The satellite's orbit is being precisely determinedby continuous ranging from the participating ground stations across the globe.

In the coming days, 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 the two antennas would be carried out and the satellite put in its final 3-axis stabilised mode.

This would be followed by trim manoeuvres to take the satellite to its designated orbital slot. The payloads would be checked before the commissioning of the satellite.

Eds: pick up suitably from earlier series.

UNI