Isro’s GSLV-D6 with indigenous cryo engine successfully places GSAT-6 in orbit

Sriharikota: Indian Space Research Organization (Isro) on Thursday cleared all doubts on its cryogenic capabilities, successfully launching the Geostationary Satellite Launch Vehicle (GSLV-D6), placing GSAT-6, a 2,117kg communication satellite in orbit.

This marks the second successful GSLV launch using an indigenous cryogenic engine. The first launch, on April 15, 2010 was a failure, followed by the second one on January 5, 2014 which was a success.

GSLV-D6 carrying GSAT-6 lifted off from Sriharikota spaceport at 4.52pm as scheduled. This was the ninth flight of the Geostationary Satellite Launch Vehicle.

Around 17 minutes after liftoff, the rocket injected GSAT-6 into a Geosynchronous Transfer Orbit (GTO), making the mission a success.

“We have understood the intricacies of a cryogenic engine. The rocket performed normally. This shows that our January, 2014 success with the cryogenic engine was not a fluke. Only numbers will demonstrate the reliability of the launches. It is up to us to ensure that we do not make any errors. ” said Isro chairman A S Kiran Kumar.

“GSLV will command its own market but for that we need more successful launches. As of now we have sent a two tonne satellite and it has been successful, there is a good market for this. If we keep showing a good success rate, GSLV will be a good candidate for commercial launches. Progressively more and more people are coming to us for commercial launches. It is up to us to improve capacity building,” he said

He said satellite that was launched on Thursday would be used for various government purposes.

Speaking about future plans, the Isro chairman said, “We are targeting a four-tonne payload with the Mark III. As part of cooperation with the US space agency NASA, we will be launching a satellite using GSLV – Mk II in 2021. Isro will also launch four nano satellites from the US as a piggy back luggage for its Astrosat that is to be launched next month using a PSLV.”

Satellite director Prakash Rao said, “GSAT- 6 features an unfurlable antenna. When deployed, it will be the largest on board any satellite. The advantage is that the footprint on the ground is larger and the devices can be more compact.”

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

GSLV-D6 vehicle was configured with all its three stages including the cryogenic upper stage (CUS) similar to the ones successfully flown during the previous GSLV-D5 mission in January 2014.

The metallic payload fairing of GSLV-D6 had a diameter of 3.4 m. The overall length of GSLV-D6 was 49.1 mass with a lift-off mass of 416 tonne.

The cryogenic upper stage on GSLV-D6 was designated as CUS-06. A cryogenic rocket stage is more efficient and provides more thrust for every kilogram of propellant it burns compared to solid and earth-storable liquid propellant rocket stages.