Isro's GSLV D-6 heavy-lift rocket places GSAT-6 satellite in orbit

The Indian Space Research Organisation (Isro) today successfully launched the heavy-lift Geo-synchronous Satellite Launch Vehicle (GSLV) D6 to place India's latest communication satellite GSAT-6 in orbit.

The three-stage heavy-lift rocket GSLV D-6 with indigenous cryogenic upper stage successfully placed the 2,117 kg GSAT-6 communication satellite in orbit.

The GSLV D-6 is the second successful consecutive launch of the GSLV series with indigenous cryogenic upper stage. Isro had, on 5 January 2014, launched GSLV D-5, after a similar attempt failed in 2010.

Thursday's launch is the ninth time Isro was using a GSLV rocket.

The 49.1-metre-high spacecraft lifted off normally from the second launch pad of Satish Dhawan Space Centre with a lift-off weight of 416 tonne at 4.52 pm, and placed GSAT-6 in the intended orbit about 17 minutes after lift-off.

The 2,117 kg-weighing GSAT-6 communication satellite is primarily intended for use by the country's strategic users and other specific authorised users. The cuboid-shaped satellite with a mission life of nine years also includes a first-of-its-kind S-Band unfurlable antenna with a diameter of six metres - the largest antenna Isro has ever made for a satellite.

The satellite will transfer itself eventually to the final geostationary orbit at 83 degree East longitude.

"The performance of GSLV D-6 has been normal and the intricacies of the rocket have been understood," Isro chairman AS Kiran Kumar said soon after the launch, from the Mission Control Room.

The cryogenic stage was "technically a very complex system" compared to solid or earth-storable liquid propellant stages due to its use of propellants at extremely low temperatures and the associated thermal and structural challenges, ISRO stated.

Today's launch had made the national space agency more confident of launching heavy rockets with indigenous cryogenic upper stage, which can lift payloads weighing about 2.2 tonnes.

Mission director Umamaheswaran said that the launch was a "Onam" gift of Isro to the country.

The 29-hour countdown for this launch began at 11.52 am on Wednesday after the Mission Readiness Review (MRR) committee and Launch Authorisation Board (LAB) cleared the starting of the countdown. The launch itself took place at 4.52 pm on Thursday from Satish Dhawan Space Centre at the spaceport of Sriharikota in Andhra Pradesh.