GSLV-D5 rocket launch postponed, countdown clock stopped due to leak

India's 200 crore space mission has run into trouble with the lift-off of India's heavy rocket geosynchronous satellite launch vehicle-D5 (GSLV-D5), carrying communication satellite GSAT-14, delayed due to a leak. The countdown began on Sunday at 11.50 am at Sriharikota rocket port in Andhra Pradesh, for the launch scheduled at 4.50 pm today. It was halted one hour and 14 minutes ahead of lift-off, after some 'leakage' was detected. Officials say they are not sure when the countdown can be resumed. The mission was called off at a fairly advanced stage of the 29-hour countdown, and with only a little over an hour left for the lift-off that was scheduled for 4.50 p.m., at the second launch pad of the Sriharikota spaceport near here.

This was the eighth flight of the GSLV, the fourth developmental flight and only the second time in three years that the indigenously-developed cryogenic upper stage was flight-tested. The Rs. 205-crore expendable rocket’s mission was to inject the cuboid-shaped and 1982-kg weighing GSAT-14 in orbit to signal India’s entry into an ivy league of nations with frontier capabilities of launching 2,000-2,500 kg class of advanced communication satellites in outer space. The GSAT-14, the 23rd geostationary communication satellite built by ISRO, would have joined a line-up of nine Indian satellites to help provide a host of satellite-based communication services, including tele-education and tele-medicine. The satellite’s mission was also to augment the in-orbit capacity of the extended C and Ku-band transponders in the INSAT-GSAT ecosystem to set the stage for new and exciting experiments driven by satellite-based communication. The rocket port is located about 80 km from Chennai. "The rocket cost is around Rs. 160 crore and the cost of the satellite is around Rs. 45 crore," an official of the Indian Space Research Organisation (ISRO) told IANS, preferring anonymity. The key significance of this Rs. 205 crore launch is that the rocket's cryogenic engine is indigenously developed by ISRO.

This was the first mission of GSLV in the last three years, after two such rockets failed in 2010. One of the GSLV rockets flew with an Indian cryogenic engine, and the other one with a Russian engine. The GSLV is a three stage/engine rocket. The first stage is fired with solid fuel, the second with liquid fuel and the third is the cryogenic engine. The successful flight of this rocket is crucial for India as it will be the first step towards building rockets that can carry heavier payloads of up to four tonnes. An ISRO official, preferring anonymity, told IANS that several design changes had been incorporated in Monday's rocket after studying the past GSLV rockets and the issues faced in them. 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.

"We have reverted to 3.4 metre heat shield to protect the satellite. The last GSLV rocket that failed had a four-metre heat shThe leak was reportedly observed in the second stage of the 49-metre tall GSLV-D5. The rocket adopts a three-stage fuel cycle — the core solid stage, liquid and a cryogenic upper stage. At about 4 p.m., ISRO Chairman K. Radhakrishnan, accompanied by a team of glum-looking scientists, met the media to formally declare that the GSLV-D5 mission had been called off. “The countdown was progressing well. However, a few minutes ago, we observed a leak in the fuel systems of the second stage. Because of this, we are calling off the launch,” Dr. Radhakrishnan said. The immediate task for ISRO teams in the fuel leak situation was to quickly drain out the liquid propellants that had been loaded into the second stage, the four L40 strap-ons and the cryogenic stage, the ISRO chief said.

“We need to make an assessment of the cause of the leak and the actions that need to be taken before further preparations for the next launch,” Dr. Radhakrishnan said. The GSLV-D5 is also being hauled back to the Vehicle Assembly building, he said.ield. One of the earlier GSLV rockets had problems in its aerodynamics," the official said. Other changes included video imaging of lower shroud movement during various flight phases, fuel booster in cryogenic engine, and ignition sequence of the cryogenic engine, he said. ISRO said indigenisation of many critical systems including liquid hydrogen propellant acquisition system (to prevent possibility of outside contamination) was achieved. ISRO officials told IANS that though the rocket's rated carrying capacity is around 2.2 tonnes, it was decided to carry a sub-two tonne satellite with minimum number of transponders (receivers and transmitters of communication signals), to be on the safe side. ISRO's earlier attempts to fly a GSLV rocket carrying slightly over two tonne satellites have ended in partial/total failures. Meanwhile, it is going to be tense 17 minutes for the ISRO scientists on Monday after the 49.13 metre tall rocket weighing 414.75 tonnes blasts off at 4.50 pm, till the GSLV rocket safely delivers GSAT-14 to augment the Indian transponder capacity.

ISRO is planning to launch an upgraded version of GSLV Mark III rocket next year with a dummy payload. The design payload capacity of GSLV Mark III is four tonnes. During the countdown to the rocket launch, fuelling of the three stage/engine GSLV rocket's four strap-on motors and the second stage with liquid fuel will be completed by August 19 morning, while the first-stage core engine is powered by solid fuel. The process of fuelling the cryogenic engine will begin around 10 hours prior to the launch.