Launch will be the first mission of the GSLV after two such rockets failed
"The 29-hour countdown for the GSLV launch is expected to commence around 11.20 a.m. Saturday and the rocket is expected to blast off at 4.18 p.m. Sunday from (India's rocket port) Sriharikota (in Andhra Pradesh)," an Indian Space Research Organisation (ISRO) official told IANS over phone from Bangalore Thursday.
He did not want to be named in the report.
The space agency's Mission Readiness Review (MRR) team and the Launch Authorisation Board (LAB) has cleared the rocket launch for Jan 5. The rocket was moved to the launch pad Dec 28, 2013.
In the wake of ISRO's successful Mars mission last year, all eyes are on the space agency to see whether the GSLV, powered by its own crucial cryogenic engine, would successfully deliver its baby -communication satellite, the 1,982 kg GSAT-14 - into outer space.
ISRO was to launch this rocket last August but aborted it just hours before the deadline as the fuel started leaking from its second stage or engine.
According to the ISRO official, the second stage was replaced with a new one built with a different metal.
"We also replaced some critical components in the four strap-on motors of the first stage as a matter of precaution," said the official.
The Sunday launch will be the first mission of the GSLV after two such rockets failed in 2010.
One of the GSLV rockets was fitted with the Indian cryogenic engine and the other with a Russian engine.
The GSLV is a three-stage/engine rocket. The first stage is fired with solid fuel, the second is the liquid fuel and the third is the cryogenic engine.
The successful launch of this rocket is crucial for India as it will be the first step towards building rockets that can carry heavier payloads, up to four tonnes.
According to ISRO, several design changes have been incorporated into the rocket for a safe blast-off.
Design changes were made in the lower shroud/cover that protects the cryogenic engine during the atmospheric flight; wire tunnel of the cryogenic stage to withstand larger forces during the flight; and the revised aerodynamic characterisation of the entire rocket.
Others included video imaging of lower shroud movement during various flight phases; fuel booster in cryogenic engine; and ignition sequence of the cryogenic engine.
ISRO said indigenisation of many critical systems, including liquid hydrogen propellant acquisition system (to prevent possibility of outside contamination), was achieved.
It is going to be a tense 17.8 minutes wait for the ISRO scientists Sunday after the 49.13-metre tall rocket, weighing 414.75 tonnes blasts off till the GSLV safely delivers GSAT-14 to augment the Indian transponder - receivers and transmitters of signals - capacity.
When that happens, India will join a select club of spacefaring nations having the crucial cryogenic engine technology necessary to carry heavy satellites up into space.