India's GSAT-18 communication satellite launched successfully

India today successfully launched its latest and heaviest communication satellite GSAT-18 from European Space Centre Arianespace's spaceport in Kourou in French Guiana.

The launch was carried out by a heavy duty Ariane 5 VA-231 launch vehicle in the early morning hours today (6 October 2016). After a smooth countdown, the Ariane 5 launch vehicle lifted off right on schedule at 0200 hrs (2:00 am) IST today.

After a flight of 32 minutes and 28 seconds, GSAT-18 separated from the Ariane 5 upper stage in an elliptical Geosynchronous Transfer Orbit (GTO) with a perigee (nearest point to Earth) of 251.7 km and an apogee (farthest point to Earth) of 35,888 km, inclined at an angle of 6 degree to the equator.

The 3,404 kg GSAT-18 carries 48 communication transponders in C-band, upper extended C-band and Ku-band for providing various services to the country.

Isro's Master Control Facility (MCF) at Hassan in Karnataka took over the command and control of GSAT-18 immediately after its separation from the launch vehicle. Preliminary health checks of the satellite revealed its normal health.

In the coming days, Isro will perform orbit raising manoeuvres to place GSAT-18 satellite in the Geostationary Orbit (36,000 km above the equator) by using the satellite's propulsion system in steps.

After the completion of orbit raising operations, the two solar arrays and both the antenna reflectors of GSAT-18 will be deployed. 

Following this, the satellite will be put in its final orbital configuration. GSAT-18 will be positioned at 74 deg East longitude in the geostationary orbit and will be co-located with the Indian operational geostationary satellites.

Later, it is planned to experimentally turn on the communication payloads of GSAT-18. After the successful completion of all the in-orbit tests, GSAT-18 will be ready for operational use.

GSAT-18 is the 20th satellite from the ISRO to be launched by the European space agency and the mission is the 280th for Arianespace launcher family.

The ISRO, which has been dependent on Ariane-5 rocket for carrying its heavier satellites, is developing GSLV Mk III for this purpose.

ISRO chairman AS Kiran Kumar said, the next step after the successful launch of GSAT-18 was to carry out a series of manoeuvres before positioning it in its orbital location.

''The necessary preparations have been made and our team back in India is working on mission operations at Master Control Facility, Hassan,'' he said.

''GSAT 18 is an important satellite for us that will enable the continuity of the vital communication services in our country by replacing the currently ageing satellites,'' the ISRO chief said.

Television, telecommunication, VSAT and digital satellite news gathering were a few of the services that GSAT 18 will support in coming days, he added.

Pointing out that two more satellites GSAT 17 and GSAT 11 were getting ready for the launch by Arianespace during early next year, Kumar said ''realisation of both these satellites is in advanced stage''.

''While GSAT 17 is an important satellite for replacing our satellites, GSAT 11 will be the first generation of high- throughput satellite of ISRO. Both of these upcoming launches are crucial for the Indian space programme,'' he added.