India set to join elite club with GSLV launch.
Fixed onto a giant ' umbilical tower', connected to a network of cables and hoses, the 50m tall, 416- tonne Geosynchronous Space Launch Vehicle ( GSLV-- D3) is now undergoing its final checks.
The GSLV- D3 has an advanced telemetry system and advanced mission computers, besides a larger payload fairing made of composites.
The launcher has been assembled and tested at the Satish Dhavan Space Centre ( SDSC). ISRO brought the crucial cryogenic phase from Mahendragiri in Tamil Nadu and the 2.2- tonne experimental satellite GSAT-- 4 from Bangalore.
After the assembly, the GSLV has been slid along a rail to the launch pad. Scientists are getting ready on the ground for the countdown that will start on Wednesday at 11.27am.
" It will be a landmark launch," M. C. Dattan, director of India's space port, said.
Dattan's colleagues at the ISRO are particularly concerned about the upper stage of the rocket that runs on the first cryogenic engine India has built. When it fires in space for 720 seconds to launch the satellite GSAT- 4, after the first two conventional stages take it to a certain altitude, India will join an elite club. Only five nations -- the US, Russia, Japan, China and France -- can propel launch vehicles on super- cool liquid hydrogen and oxygen.
Cryogenic denotes a rocket stage that is much more efficient, providing more thrust for every kg of propellant compared to stages that run on solid and liquid propellants.
So far, India depended on the Russian cryogenic technology.
The cryogenic stage is complex because of the use of propellants at low temperatures.
Oxygen becomes liquid at - 183 degree Celsius and hydrogen at - 253 degree Celsius. So the propellants have to be pumped using very fast ( 40,000 revolutions per minute) turbo pumps with complex ground support systems.
At the launch pad, a couple of ' cryo arms', each supporting 1,700 kg of hoses will be feeding 12.5 tonne of liquid hydrogen and oxygen to the launcher a few hours before the launch. " The filling will continue till 30 seconds prior to the launch," Srivastav V. K., a senior SDSC scientist, said.
" It is to ensure there is no operational loss. If there is any loss it will be refilled." ISRO spokesperson S. Satish said scientists have taken pains to make every system foolproof, and that explains why the engine that was first tested in 2000, took 10 years of testing and development to the rocket phase.
" About 2,000 ISRO scientists will be at work," V. Seshagiri Rao, deputy director of the SDSC, said. Once the countdown starts, operations will be remotely controlled from ' Zero Point' -- 7 km away from the launch pad. " The temperature of the flame at lift- off will be about 3,000 degree Celsius and the ground temperature will be about 1,000 degree Celsius," a scientist said.
" This is not the rainy season.
We are worried about lightning, though," an official said.
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