Article Posted on : - Aug 27, 2015

ISRO's communication satellite GSAT-6 on board GSLV-D6 which will be launched from the spaceport of Sriharikota on Thursday. Photo: PTI/ ISRO

CHENNAI (PTI): The 29-hour countdown for the launch of India's latest communication satellite GSAT-6 has begun, ISRO said.

"The 29-hour countdown activity of GSLV-D6/GSAT-6 Mission commenced on Wednesday at 11:52 hr IST," ISRO sources said.

The Mission Readiness Review (MRR) committee and Launch Authorisation Board (LAB) cleared the starting of the 29-hour countdown at 1152 hrs, ISRO said.

The launch of Geo-synchronous Satellite Launch Vehicle (GSLV) D6 carrying GSAT-6 is scheduled at 1652 hours on Thursday from Satish Dhawan Space Centre at the spaceport of Sriharikota in Andhra Pradesh.

GSAT-6 is the 25th geostationary communication satellite of India built by ISRO and 12th in the GSAT series.

GSAT-6 provides communication through five spot beams in S-band and a national beam in C-band for strategic users, ISRO said.

The mission life of the satellite is nine years.

The cuboid shaped GSAT-6 has a lift-off mass of 2117 kg.

Of this, propellants weigh 1132 kg and the dry mass of the satellite is 985 kg, it added.

One of the advanced features of GSAT-6 satellite is its S-Band Unfurlable Antenna of 6 m diameter. This is the largest satellite antenna realised by ISRO.

The antenna is utilised for five spot beams over the Indian mainland. The spot beams exploit the frequency reuse scheme to increase frequency spectrum utilisation efficiency

ISRO said after satellite's injection into GTO (Geosynchronous Transfer Orbit) by GSLV-D6, ISRO's Master Control Facility (MCF) at Hassan takes control of GSAT-6 and performs the initial orbit raising manoeuvres by repeatedly firing the Liquid Apogee Motor (LAM) on board the satellite, finally placing it in the circular Geostationary Orbit.

After this, deployment of the antenna and three axis stabilisation of the satellite will be performed. GSAT-6 will be positioned at 83 deg East longitude.