ISRO is hoping to end 2009 in style with the take-off of its fully indigenous geosynchronous satellite launch vehicle (GSLV) carrying an experimental satellite GSAT 4 in mid-December.

The GSLV-D3 will have an indigenously built cryogenic engine that will be used for the first time in the rocket's upper stage. The GSLV-D3 is slated to be launched from ISRO's spaceport Sriharikota, about 80 km northeast of Chennai, to carry the GSAT-4 communication satellite into a geo-stationary orbit, about 36,000 km above the earth. The 49-metre-tall rocket will have a lift-off weight of 414 tonnes.

Only a few countries like the US, Russia, France, Japan and China have developed their own cryogenic engines and India is expected to join this club.

For all the five earlier GSLV missions, ISRO had used Russian cryogenic engines.

"The cryogenic engine reached Sriharikota early this month from ISRO's facility in Mahendragiri in Tamil Nadu. The GSAT 4 communication satellite is expected to reach here by the middle of next month. Final tests are being done at Bangalore where it was built," M.Y.S. Prasad, associate director, Satish Dhawan Space Centre, told IANS on phone from ISRO's launch centre at Sriharikota.

He said the physical inspection of the cryogenic stage is on and the engine's sensors are to be calibrated. It will be fuelled by liquid oxygen and liquid nitrogen.

While GSLVs with Russian cryogenic engines have been designated as operational rockets after two developmental flights, the one that will go up in December is called 'developmental flight 3' (GSLV D3) as it will be fired by the ISRO-developed cryogenic engine.

The last GSLV went up on Sep 2, 2007, carrying the 2,130 kg INSAT-4CR satellite.

Speaking about how far the three-stage rocket had been assembled, Prasad said: "The first stage - solid fuel booster and four strap-on motors - has been assembled. The assembly of the second stage liquid engine is under progress and will be over in one and a half weeks. The last stage is the cryogenic stage."

Last December, the indigenously developed cryogenic upper stage engine passed the flight acceptance test with the engine tested for 200 seconds.

The development of cryogenic engines involves mastering materials technology, operating rotary pumps and turbines which run at 42,000 revolutions per minute (RPM).

The development of a cryogenic engine is crucial for ISRO to build more powerful GSLV rockets that can carry four-tonne satellites.

Further, ISRO is lagging behind in launching its GSAT series for want of a cryogenic engine. GSAT 4 was supposed to have gone up two years back.

Weighing around two tonnes, GSAT 4 will carry a multi-beam Ka-band bent pipe and regenerative transponder and navigation payload in C, L1 and L5 bands. The satellite can guide civil and military aircraft.

GSAT 4 will also carry a scientific payload, TAUVEX, comprising three ultra violet band telescopes developed by Tel Aviv University and Israel space agency (ELOP) for surveying a large part of the sky in the 1,400-3,200 Angstrom wavelengths.

The GSLV rocket will place GSAT 4 in the geo transfer orbit (GTO) from where the satellite will be taken up to an altitude of 36,000 km and then positioned.

According to Prasad, ISRO is gearing up to launch six rockets per year and has created a huge liquid fuel storing facility for that purpose at Sriharikota.

Share This Article With Planet Earth

del.icio.us	Digg	Reddit
YahooMyWeb	Google	Facebook

Related Links
Indian Space Research Organisation (ISRO)
Rocket Science News at Space-Travel.Com