Indian National Satellite-4A, India's fourth generation communication satellite, is all set for the December 22 blast off onboard a generic Ariane five launch vehicle from the European spaceport of Kourou in French Guyana. 

Preparations were in the final stages for the launch onboard the 169th flight of Ariane. Its co-passenger was MSG-2 of the European EUMETSAT, a meteorological satellite, as Indian Space Research Organisation release said adding, the launch window had been fixed between 0403 and 0431 hrs. 

INSAT-4A, the first satellite to be launched in the INSAT-4 series, carries 12 high power Ku-band transponders to meet the requirement of Direct-To-Home television services, apart from 12 C-band transponders to augment INSAT capacity for communication and DTH services.

The Ku band transponders had been booked by the Tata Sky joint venture, launching a DTH service in the country, and are capable of accommodating 150 TV channels. 

Weighing 3,080 kg at lift-off, INSAT-4A is the heaviest satellite of ISRO. The Master Control Facility at Hassan in Karnataka was fully prepared to take control of INSAT-4A soon after Ariane five placed it in the Geosynchronous Transfer Orbit of about 620 km x 36,000 km.  

In the following days after launch, MCF will conduct operations like orbit raising manoeuvres to take the satellite into the final 36,000 km circular geosynchronous orbit.

Deployment of solar arrays and antennae would be carried out before positioning the satellite in its designated orbital slot of 83 degree east longitude along with INSAT-2E and INSAT-3B.

MCF will also carry out the satellite's regular operations and control during its service life. Doordarshan will telecast live the launch of INSAT-4A from 0345 hrs on DD-National.