ISRO GSAT-11 successfully launched: Ariane-5 rocket lifts India's heaviest communication satellite into orbit

India’s biggest and most powerful communication satellite GSAT-11 has been successfully launched into orbit a few minutes past 2 am IST on Wednesday. Arianespace confirmed a successful launch this evening after an on-target separation of the GSAT 11 and GEO-Kompsat 2A satellites for India and South Korea.

In 2012, the Department of Space gave Indian Space Research Organisation’s plans a green light to build India’s heaviest-ever communications satellite — the GSAT-11. In the six years since, GSAT-11 grew from being a 4.5-ton sketch to a 5.8-ton marvel with solar panels 4-metres long (almost the size of a small room).

Initially slated for a launch on 25 May, GSAT-11 was recalled by ISRO for further tests in India just days before its planned launch. After shipping the heavy hunk of metal and solar panels all the way to France, ISRO engineers decided to err on the side of caution and postponed the launch. This was to make time for some tests on GSAT-11 after a previously-launched communications satellite GSAT-6A went missing after what seemed a perfect launch to ISRO. ISRO engineers soon confirmed that  **there are no problems or glitches with GSAT-11** , after which a new date for the satellite’s third and possibly final launch on 5 December was set.Arianespace released GSAT-11 into the Earth’s geo-transfer orbit (GTO) in a 33-minute flight on 5 December. The satellite will soon be manoeuvred into its final place in the geostationary orbit using onboard thrusters operated by ISRO engineers to point towards India.

Why isn’t GSAT-11 being launched in India?

What with GSAT-11 being ISRO’s heaviest satellite weighing close to 5.8 tons, the agency doesn’t currently have a rocket capable of lifting the satellite to orbit in one piece. The GSLV Mk-III can carry a maximum of 4 tons in satellites as of today. Instead, the French Arianespace’s Ariane-5 rocket — a world reference for reliable, heavy-weight launchers — with a carrying capacity of 9.1 tons, was chosen as ISRO’s hired hand to launch GSAT-11.

What will ISRO’s GSAT-11 do?

The Rs 1,174-crore GSAT-11 satellite is designed to boost the reach, speeds and capacity in India’s commercial telecom sector. The satellite will help meet the country’s growing mobile and internet usage in households, businesses and public organisations, ISRO **said** . Once launched, GSAT-11 will be India’s most capable and top-of-the-line satellite in orbit (and ISRO’s portfolio). GSAT-11 is expected to bring far greater speeds (16 Gbps of it, no less) to meet the growing data demands of Indian telecom subscribers. It is also expected to bridge the communication gap between the country’s urban and rural population. Large parts of rural areas still remain untouched by the scope of commercial telecom today — something GSAT-11 is designed to address. Under Digital India’s  BharatNet project , GSAT-11 will boost access to voice and video streaming in most, if not all, of rural India, ISRO said. “With India moving fast towards implementing ‘Smart Villages and Cities’, they can be efficiently linked through a large communication satellite,” K Sivan, chairman of ISRO,  said in a curtain raiser. GSAT-11 has a mission lifetime of 15 years.

How will GSAT-11 work?

In a first for an ISRO satellite, GSAT-11 will carry a next-generation I-6K bus (communication satellite hub) to provide services in two widely-used wavelengths for telecommunications: the Ku- and Ka-bands. Ku- and Ka-bands are different frequencies of microwaves in the electromagnetic spectrum. GSAT-11 has 32 Ku-band transponders and 8 Ka-band hubs on board, making GSAT-11 three to six times more powerful than any of ISRO’s (and India’s) satellite roster today. [caption id=“attachment_5668991” align=“alignnone” width=“1280”] GSAT-11’s ‘multi-spot’ beam coverage area. Image courtesy: ISRO[/caption] GSAT-11 is reportedly bringing bandwidths of 14 Gigabit/s in voice and video broadband services anywhere in the Indian mainland or islands over its 15-year lifespan. It will use ‘spot beams’ to cover the expansive area (see image above). Four terrestrial gateways or ‘hubs’ located in Delhi, Ahmedabad, Bengaluru and Ranchi, will connect the satellite to users. Each of these hubs is also connected to each other through an optical fibre network to ensure the connectivity is seamless.