GSLV-Mk III: Isro to launch India's most powerful rocket today

The 25 and a half-hour countdown for GSAT-19 communication satellite began at 3.58 pm on Sunday

The Indian Space Research Organisation (Isro) is set to launch its most powerful rocket carrying high-tech communication satellite on Monday. 

The Geosynchronous Satellite Launch Vehicle (GSLV-Mk III), nicked named ‘fat boy’, has a capacity to hurl four-tonne communication satellites into a higher orbit. It also has the potential to carry a 10-tonne capsule for a manned mission to space.

The 25 and a half-hour countdown for GSLV-Mk III carrying GSAT-19 communication satellite began at 3.58 pm on Sunday.

If it succeeds, a single GSAT-19 satellite will be equivalent of having a constellation of six to seven older varieties of communication satellites in the space. Of a constellation of 41 in-orbit Indian satellites, 13 are communication satellites, according to reports.

The design and development of GSLV-Mk III are based on Isro’s rich experience in handling solid, liquid and cryogenic rocket propulsion technologies. The engine is also less complex than the ones influenced by Russian designs.

“This (GSLV-Mk III) will increase our capability to launch satellites many fold,” said A S Kiran Kumar, chairman of Isro. “It is completely indigenous.”

The GSLV-MK III, development of which had been delayed by nearly a decade, will help Isro reduce the use of foreign launchers for its heavier satellites. Till now, Isro has contracted Arianespace, the French space agency, to launch its four- to six-tonne satellites used for communication and direct-to-home TV telecast.

It is a preferred vendor to hurl small and mini satellites into low-earth orbit with its polar satellite launch vehicle (PSLV).

On Monday, GSLV-MK III will be carrying a 3,136 kg GSAT-19 satellite with communication transponders. The satellite will also test technologies such as miniaturised heat pipe, fibre optic gyro, micro electro-mechanical systems accelerometer, Ku-band TTC transponder and indigenous Lithium-ion battery.

The GSLV programme has had a chequered history. India had initially signed a deal with Russia to source cryogenic technology, which was scuttled by the US, citing the missile technology control regime (MTCR) in the early 1990’s. Later, Russia relented and lent around six cryogenic engines without technology transfer. India entered MTCR last year.

Isro assembled its first GSLV rocket with a Russian engine and launched it in 2001. But the thrust was not enough to place the satellite in its orbit. Since then, it has been working on its own cryogenic stage influenced by the Russian technology and launched several GSLV-Mk II rockets, before making it operational last year. So far, Isro has launched 10 GSLV rockets, including three with cryogenic stage built on its own.

In December 2014, Isro tested a miniature version of the GSLV-Mk III without a cryogenic engine to demonstrate the design. In a sub-orbital flight, the rocket carried a 3,775-kg crew module atmospheric re-entry experiment to prove a technology that would be used during manned missions in the future.

Space test

• Name: GSLV-Mk III
• Height: 43.43 metre
• Vehicle diameter: 4.0 metre
• Heat shield (payload fairing) diameter: 5.0 metre
• Number of stages: 3
• Lift off mass: 640 tonnes
• Estimated cost: Around Rs 400 crore
• Description: GSLV-Mk III has 2 solid strap-ons, a core liquid booster and a cryogenic upper stage. Designed to carry 4-tonne class of satellites into higher orbit or 10 tonnes to low earth orbit, twice the capability of GSLV Mk II
• Capablity: GSLV Mk-III capable of launching satellites weighing close to 5,000 kg
• Future ready: Paves way for manned missions into space. Currently, the US, Russia and China only have capability of launching manned missions

Compiled by T E Narasimhan