Thursday, April 15, 2010

India's GSLV-D3 Rocket Launch Fails

India's Geosynchronous Satellite Launch Vehicle (GSLV-D3 -- built with Rs. 330 crore ($74.4 million) mission (rocket Rs. 180 crore, GSAT-4 satellite Rs.150 crore) -- failed on 15 April because two small cryogenic engines apparently failed to ignite within minutes of its launch, leading it to deviate from its path. The GSLV-D3 was launched using an Indian-designed and built cryogenic engine for the first time.

The rocket lifted from the Indian Space Research Organization's (ISRO) Satish Dhawan Space Centre (SDSC) launch pad in Sriharikota at 1057 GMT. However, the launch was not perfect with the GSLV-D3 failing to send any data after 500 seconds of taking off. The rocket deviated from its path and the scientists monitoring the launch said that they did not receive any speed and altitude data from the vehicle.

Cause of Failure
ISRO Chairman K. Radhakrishnan said: 'The vehicle was tumbling. The control was lost as two small cryo engines did not ignite.'

The GSLV-D3 was to put the 2.2-tonne communication satellite GSAT-4 into the Geo Transfer Orbit (GTO) on 15 April evening. Until now ISRO had been using Russian cryogenic engines in its GSLV missions as the United States had forced Moscow not to sell the cryogenic technology to India in 1992.

Previous GSLV Flights
The previous five GSLV flights from Sriharikota from 2001 to 2007 used the Russian cryogenic engines. The GSLV-D3 vehicle is 49 meters tall and weighs 419 tones. It is a three-stage rocket. The core first stage is powered by solid propellants. Around this core stage are four strap-on motors powered by liquid propellants. The second stage again uses liquid propellants. The third upper stage is propelled by the indigenously made cryogenic engine. Filling of the second stage and the four strap-on booster motors with liquid propellants will be completed during the countdown.

In addition, the filling of the cryogenic engine with liquid hydrogen and liquid oxygen will continue till almost the end of the countdown. This is to prevent loss of cryogenic fluids due to evaporation. Certain mandatory checks of the vehicle and charging of the batteries in both the rocket and the satellite would be done during the countdown.

The GSAT-4 weighs 2,220 kg. It carries a communication payload called Ka-band transponder for wide-band multimedia services, e-commerce and high bandwidth Internet. The navigation payload named the GPS-aided Geo-Augmented Navigation (GAGAN) system will help commercial aircraft to land accurately in runways during inclement weather.

Salient Features
The cryogenic stage was built at the Liquid Propulsion Systems Centre (LPSC), Mahendragiri, Tamil Nadu. Cryogenic engines are crucial for putting communication satellites weighing more than two tones into a GTO. Cryogenic technology involves the use of liquid oxygen at minus 183 degrees Celsius and liquid hydrogen at minus 253 degrees Celsius.

Mohammed Muslim, Project Director, Cryogenic Upper Stage Project (CUSP), said the cryogenic technology was the most complex one to be developed by the ISRO. It has taken us 15 years to achieve this. It is normal time for any country and we are the sixth country to acquire this technology (after the United States Russia, Europe, Japan, and China). This is a highly guarded technology. The ISRO had not taken chances with this mission and "the vehicle has been reviewed and checked point by point any number of times.

The ISRO built the cryogenic engine from scratch after the U.S. pressured Russia in April 1992 and July 1993 into agreeing not to sell cryogenic technology to India. In January 1991, India and the erstwhile Soviet Union had reached an agreement, under which the Soviet space agency, Glavkosmos, would sell cryogenic stages and transfer the cryogenic technology to India.

US Pressure Pays
Under the US pressure, Russia in July 1993 went back on its agreement to transfer the cryogenic technology. In lieu of the technology, it agreed to sell two additional cryogenic stages to India. The last five flights of the GSLV from Sriharikota were powered by the Russian cryogenic stages. A cryogenic stage includes the engine, propellant tanks, motor casing and wiring.

In fact, it took the ISRO all these years to develop the cryogenic technology because it had to develop special materials. At very low temperatures of liquid hydrogen and liquid oxygen, metals become brittle. The ISRO, therefore, had to develop new alloys, new welding techniques and new types of lubricants.

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