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May 2018

GSLV SUCCESS BUT GSAT-6A FAILS

Despite A Flawless Launch By The Indegenous GSLV Rocket, The GSAT-6A Failed In Space.

Manufacturing Satellites and launch rockets is an extremely lucrative business. Only a handful of countries have the capability and they charge a huge premium. ISRO plans to enter this elite group and not only save the country foreign exchange but also earn handsomely by manufacturing satellites and launching them for other countries.


POWERFUL SATELLITES

Modern day satellites provide high power signals for TV channels, communications and broadband making it possible to receive their signals directly by consumers. These high power satellites necessarily require large and heavy solar rays to generate power and large dish antenna to downlink their signals with high signal strength. Both these add substantially to the satellites weight.





POWERFUL ROCKETS

Communication satellites need to be located in geo-sync orbit 36,000 Kms above the Equator. Extremely powerful rockets are required to loft satellites weighing more than 4 tons into geo-sync orbit.

ISRO's solid fuel PSLV rocket can only loft satellites weighing less than 1 ton into high orbit.

The liquid fuel GSLV rocket is being developed by ISRO for lofting heavy satellites into geo orbit. The GSLV development has been difficult and time consuming with many failures.


GSAT - 6A & GSLV

On Thursday, 29 March 2018, ISRO's GSLV rocket lifted off from Sriharikota, with the GSAT-6A defence communications satellite.

It was a text book perfect launch, providing much cheer to the GSLV rocket team.

The GSAT-6A satellite was placed perfectly in its geo-transfer orbit.


ORBIT RAISING FAILS

"After the successful launch of Gsat-6A from Sriharikota's Satish Dhawan Space Centre. on Thursday, ISRO was supposed to perform 3 orbit-raising manoeuvres to take the satellite from the launch orbit to the designated geo stationary orbit (at 36,000 km). The first manoeuvre was performed successfully on Thursday. The second orbitraising exercise was performed on Saturday. As the ISRO ground station was gearing up for the third manoeuvre, the communication link with the satellite snapped," ISRO chief K Sivan explained to the press. 'There has been an unfortunate power system anomaly... the satellite should have gone into safe mode but that did not happen. All contact was lost," he added.

Orbit-raising is the raising of a satellite's orbit using small compressed gas cylinders on the satellite.


GSAT-6A

The ₹ 260 Crore, 2,140 Kg GSAT-6A satellite is predominantly a S-band satellite with a huge - 6 meter diameter dish, capable of sending & receiving signals from hand-held devices, for the armed forces.

The hand-held communications devices are being developed by the Defence Research and Development Organisation (DRDO).

The GSAT-6A was to have shared its orbital location at 83 degrees with the GSAT-6 & enhanced the communications capabilities of the older satellite.


PUSHING AHEAD

IRSO is pushing ahead with its future launches as scheduled, despite this setback. The previous ISRO failure was on 31 August 2017, when the PSLV failed to launch the IRNSS-1H satellite. n