Chennai, March 29 (IANS): The 27-hour count down for the flight of the Indian rocket with its communication satellite GSAT-6A is progressing smoothly, said an official of the Indian space agency.

The countdown for the rocket launch began at 1.56 p.m. on Wednesday and is progressing well.

During the countdown, the rocket will be fueled up and its systems would also be checked.

The 415.6 ton GSLV rocket measuring 49.1 metre tall is scheduled to blast off at 4.56 p.m. from the second launch pad from at Indian rocket port in Sriharikota, 105 km from here on Thursday.

The GSAT-6A satellite will be put into orbit around 17 minutes after the rocket's lift off.

According to ISRO, two improvements-induction of high thrust Vikas engine and electromechanical actuation system - have been made in the rocket's second stage this time around.

The ISRO said that the GSAT-6A was similar to the GSAT-6.

The satellite will provide a platform for developing technologies such as demonstration of 6m S-Band Unfurlable Antenna, handheld ground terminals and network management techniques. These are useful in satellite-based mobile communication applications.

ISRO Chairman K.Sivan had earlier told IANS that the GSAT-6A would be followed by the launch of navigation satellite, which will be in the next fiscal.

In the Union budget for 2018-19, the Department of Space has been tasked with three earth observation space crafts ready for launch; four Polar Satellite Launch Vehicle (PSLV) flights; one each of Geosynchronous Satellite Launch Vehicle MkII and Mk III.