New Delhi: The countdown for the launch of Indian Space Agency ISRO's heaviest ever rocket GSLV Mark III D-1 began at 3.58 on Sunday evening. The most powerful launch vehicle ever developed by the ISRO, it is set to carry the communication satellite GSAT-19 into a geosynchronous transfer orbit, about 17 minutes after its lift off at 5.28 pm on Monday. It is set to blast off from the second launch pad of the SatishDhawan Space Centre, Sriharikota.

ISRO has said, the countdown process is progressing smoothly as per the elaborate plan devised for the first ever developmental flight of the launch vehicle. Currently, the filling of liquid fuel in the second stage of the rocket is going on, as part of the countdown process.

The GSLV Mark-III D-1 mission assumes greater importance than the previous GSLV flights because the indigenously made heavy thrust cryogenic engine is going to be flight-tested on Monday. The thrust of the complex engine is 20 tonnes, capable of lifting payloads of upto 4-tons to a geosynchronous transfer orbit. The design and development of the rocket is a result of the rich experience of the ISRO in handling solid, liquid and cryogenic propulsion technologies. Its predecessor GSLV Mark II has already become flight-proven with four consecutive successes since January 2014, said a media report from Chennai.