What is ISRO’s ‘fat boy’ GSLV Mk III? Everything you need to knowhttps://indianexpress.com/article/what-is/what-is-isros-fat-boy-gslv-mk-iii-satellite-everything-you-need-to-know-4678650/

What is ISRO’s ‘fat boy’ GSLV Mk III? Everything you need to know

ISRO's 'fat boy' GSLV Mk III satellite will use an indigenous Cryogenic rocket stage. Here's more about it.

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The GSLV Mk III, launching in June 5, 2017. (ISRO)

The Indian Space Research Organisation will be launching GSLV Mk III, a heavy launch capability launcher, on June 5. Called the ‘Fat Boy’, the GSLV Mk III will enable India to send manned missions to space. Additionally, the rocket will also aid in making India self-reliant for launching satellites as the GSLV would be capable of placing 4-tonne class Geosynchronous satellites into orbit.

The rocket will use an indigenous Cryogenic rocket stage. The first time the LVM 3 made a test flight was on December 18, 2014 as the LVM3-X/CARE mission, lifted off from Sriharikota.

The Fat Boy is 43.43 metres in height and 4 metre round. It has a lift off mass of 640 tonnes, equal to the weight of 200 elephants. As opposed to the GSLV Mk II which can only place 2 tonne class of satellites in space, the GSLV Mk III will be able to place 4-tonne class satellites into Geosynchronous Transfer Orbits.

The indigenous cryogenic stage LVM 3 placed in the satellite also makes it capable of placing heavy payloads into Low Earth Orbits of 600 km altitude. The C25, powered by CE-20, is India’s largest cryogenic engine which has been designed and developed by the Liquid Propulsion Systems Centre of ISRO. A cryogenic engine provides more thrust for every kilogram of cryogenic propellant – liquid hydrogen or liquid oxygen – that it burns. It can store 27 tonnes of such propellant, with a thrust of 186 kiloNewton.


The LVM 3 also has two Solid Rocket Boosters, S200, that provide a huge thrust that is required for it to lift off. They require a burntime of 130 seconds, and have a thrust of 9316 kiloNewton.

Talking to the Times of India, Kiran Kumar, ISRO chairman, said, “Till now, GSLV Mk II can put a 2.2-tonne satellite into the geostationary orbit. But GSLV Mk III can put a 4-tonne satellite into the geo orbit and even an 8-tonne satellite into the low earth orbit (LEO).”

Even though the rocket enables a manned mission, the ISRO chairman said that won’t be possible until prior government approval. “Until we get the final approval from the government, Isro won’t work on the manned mission. Our key priority is to meet the national demand of providing more number of satellites into orbits in the field of communication, remote sensing and navigation. Therefore, we are focusing on increasing our launch capacities both in lower and geostationary orbits and to make our launches cost-effective,” he said.

Tapan Misra of Ahmedabad-based Space Application Centre, told Times of India, “GSLV Mk III will have one of the world’s heaviest sold motor engines and will have two strap-ons. This rocket is much more manoeuvrable than other rockets launched earlier and this feature will help us change its position in space.”