ISRO getting ready for the crucial GSLV test flight

ISRO is getting ready for the crucial testing of the Geosynchronous Launch Vehicle Mark III (LVM3-X mission) which is expected to lift off from Sriharikota (SHAR) on December 18^th between the launch window of 9am to 12 am. India’s aspirations for deep space and putting bigger satellites into the Geo Transfer Orbit (GTO) had been contained by the absence of reliable launch vehicles. To give a major fillip for launching communication satellites and further manned crews into the space, ISRO is working relentlessly to develop the GSLVs.

The 155 Crore experimental mission with upgraded GSLV is the heaviest and most powerful launch vehicle capable of placing communication satellites of INSAT-4 class kind of satellites weighing 4-4.5 tonnes into GTOs. The earlier GSLV Mark II vehicles could carry INSAT-II class of satellites weighing 2-2.5 tonnes. Mark III 42.4 meters tall and weighing 630 tonnes at launch is double the weight of the existing GSLVs. This experimental mission carrying the crew module into the suborbital space 125 km from the surface of Earth will attain speed of 5.3 kilometres per second, is aimed to test the atmospheric stability of the rocket. The improved GSLV has reduced number of propulsion modules which increase the reliability of the launch vehicle and reduce the launch costs. It has four propulsion modules against the seven of its GSLV predecessors.

GSLV Mark III has three different stages. The first stage contains two S-200, Large Solid Boosters (LSB), with 200 tonnes of Solid propellant is the largest in the world, flanking the large liquid propellant stage. LSBs burn for 130 seconds and generate about 5,150 kilo newton thrust. They are equipped with flex seal which helps in correcting the orientation of rocket. Only the American space shuttle, Titan IV-B and Europe’s Ariane 5 has more solid propellant than GSLV Mark III. Of these only Ariane 5 is operational. During rocket launch, since the solid propellant generates high thrust, the sheer volume of the sound can damage the rocket. Hence a sound suppression system has been installed in the launch pad which will spray about 20 tonnes of water per second to dampen the effect of the sound during lift-off.

The second stage is a 4 meter, Liquid motor; L-110 containing 118 tonnes of liquid propellant with two improved Vikas engines generating 700 kilonewtons thrust each. These will burn for 200 seconds. During the flight as the thrust from the solid motor begins to tail off around 113 seconds, sensors on board will detect the decline in acceleration and subsequently ignite the L-110 and the two Vikas engines.  Before the two S-200 boosters separate and fall off, solid boosters and liquid Vikas engines work together for some time.  The core third stage is cryogenic stage containing LOX (Liquid Oxygen) and LH2 (Liquid Hydrogen) provide half the velocity required to put satellite into the orbit. While the solid motors and liquid stage completed ground tests and were ready for flight three years back, development of cryogenic engine is still in progress and will be ready by 2015.

Meanwhile for the experimental launch, the third stage is replaced by a passive cryo engine  will carry 3735 kg CARE (Crew- module Atmospheric Re Entry Experiment) Module, bed room sized, cup cake shaped, aluminium module intended to accommodate three crew members. The endeavour of the mission is to test the atmospheric phase of the flight and measure the thermal pressure. GSLV Mark III is more sensitive than the PSLV and the ability of rocket control systems to handle perturbations as it meanders through the dense environment without violating the vehicle’s structural capabilities will be monitored during the experimental flight.

This mission touted to be precursor for India’ manned space flight programme planned for 2020. After 325 seconds after liftoff, the crew module will separate from the rocket at an altitude of 126 km. It would make a re-entry into the earth’s atmosphere experiencing   gruelling 1600 degrees C temperature. It descent will be facilitated by three parachutes tested at Chandigarh and Sriharikota facilities. About 1280 seconds after launch, the crew will make a splash down in Bay of Bengal 600 km from Port Blair and will be recovered by Indian Coast guards. Though the crew will not carry any humans, recovered module will be tested for all the safety parameters.

GSLV can enhance the satellite launch capabilities of ISRO for GTO, LEO (Low Earth Orbits), polar and intermediate circular orbits. A sturdier GSLV would make India self reliant thereby it can emerge as the most lucrative competitor in the multibillion dollar satellite launch vehicle global market.

 

 

 

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