Largest home- built rocket set for lift- off.
This will be the GSLV's sixth flight in the past decade, and the first one using an indigenously developed cryogenic engine. All the previous flights used cryogenic engines built with help from Russia. The GSLV- D3, which will be launched on Thursday, deploys Cryogenic Upper Stage that will use super cooled propellants. It is a complex technology possessed by only a select band of space faring countries.
The 29- hour countdown for the lift- off from the spaceport on the east coast began at 11.27 am on Wednesday and will continue till the launch which is slated at 4.27 pm on Thursday. Officials of the Indian Space Research Organisation ( ISRO) said the countdown was progressing satisfactorily.
Countdown for a launch is not merely the counting of hours preceding the launch, space agency officials explained.
It is an exercise during which mandatory checks are carried out on hundreds of parameters, and most importantly, fuel is loaded onto different stages of the rocket.
The 50- metre tall GSLV is a three- stage rocket. At liftoff, its mass will be 416 tonnes.
The rocket's first stage is powered by solid propellants.
Around this stage are four strap- on motors that are powered by liquid propel- lants. The second stage again uses liquid propellants, while the third stage is propelled by the cryogenic engine.
" All operations to fill the propellants are progressing as planned and will continue through the night," ISRO spokesperson S. Satish said from Sriharikota. " The filling of cryogenic stage will take place on Thursday morning." The solid core motor of the first stage is said to be one of the largest rocket motors in the world and will use 138 tonnes of a propellant called Hydroxyl Terminated Poly- Butadiene ( HTPB).
The second stage carries 38.5 tonnes of liquid propellant as well as four strap- on motors of the first stage, each carrying 42 tonnes of propellant.
The third stage carries 12.5 tonnes of super cooled liquid hydrogen as fuel and liquid oxygen as oxidiser.
Besides the locally developed cryogenic stage, the GSLV- D3 will test two more new technologies -- advanced telemetry and mission computers, and a larger composite payload shield.
The rocket will put into orbit the GSAT- 4 satellite, which also deploys several new technologies for the first time. The satellite, weighing two tonnes, will have several transponders, including for Wide Area Differential Global Positioning System.
The ISRO is ready for testing several new technologies in its most crucial test after the Chandrayaan flight in October 2008.
Copyright 2009 India Today Group. All Rights Reserved.
Provided by Syndigate.info an Albawaba.com company