In the month of December 2014, the Geosynchronous Satellite Launch Vehicle (GSLV) Mark III is expected to lift off for the first time from Sriharikota on an experimental flight that will assess the rocket’s performance. It will be the ISRO’s most powerful rocket, capable of putting four-tonne communication satellites into orbit. The forthcoming launch will also provide an early test of a crew module being developed for human space flight.
During the 1990s, it became clear that a new launcher was needed to meet the country’s requirements for heavier communication satellites with large numbers of transponders. Rs. 2,498 crore project for developing the GSLV Mark III was approved by the Government in May 2002
TECHNOLOGY & EXPERIMENTAL FLIGHT
The GSLV Mark III is a three stage launch vehicle. It has two huge solid propellants boosters as first stage, flanking a big liquid propellant core as second stage and a cryogenic upper stage. The GSLV Mark III has just four propulsion modules while its predecessor, the GSLV, has seven, which is crucial for increasing the rocket’s reliability and reducing launch costs.
While the solid booster and the liquid propellant core stage completed ground tests and were qualified for flight about three years back, development of the cryogenic engine for the Mark III’s upper stage is still in progress. For the experimental launch, the Mark III will be equipped with a dummy cryogenic engine and stage that will simulate the weight and other characteristics of the flight version.
The rocket will give the crew module a velocity of 5.3. km/second before it separates at a height of about 125 km. The capsule will then descend and splashdown in the Bay of Bengal, about 600 km from Port Blair in the Andaman Islands.
The GSLV Mark III is more sensitive than the Polar Satellite Launch Vehicle (PSLV) and the current GSLV to disturbances that might occur as it accelerates through the dense atmosphere. The ability of the rocket’s control systems to effectively handle such perturbations without violating the vehicle’s structural capabilities will be tested during the experimental flight.
According to ISRO, the first developmental flight of the GSLV Mark-III, with a functional cryogenic engine and stage, could take place in two years’ time.