India gets ready to fire its own cryogenic rocket engine

BANGALORE - India Wednesday readied itself to join the elite space club by firing for the first time its own cryogenic rocket engine to launch an advanced communication satellite.

“The 29-hour countdown began 11.27 a.m. at Sriharikota for launching the geo-synchronous satellite launch vehicle (GSLV-D3) Thursday at 16:27 IST with a geo-stationary satellite (GSAT-4) as its main payload,” Indian Space Research Organisation (ISRO) Director S. Satish told IANS.

The Sriharikota spaceport is located on a small island in Andhra Pradesh in the Bay of Bengal, about 80 km northeast of Chennai.

The preparations during the countdown include filling up the second stage and four strap-ons of the 416-tonne rocket with about 200 tonnes of liquid propellants.

“In the run up to lift-off, the cryogenic upper stage will also be filled with propellants. Certain mandatory checks and charging of batteries on the 50-meter tall rocket and the 2.2-tonne satellite on board will be carried during the countdown,” Satish said.

The cryogenic engine provides the Rs.175-crore rocket more thrust for every kg of propellant (fuel) it burns compared to solid and earth-storable liquid propellant stages. In the cooling cryo upper stage, oxygen liquefies at minus 183 degrees centigrade and hydrogen at minus 253 degrees centigrade.

“The Indian cryo engine will be flight tested in the upper (third) stage of the rocket within 8-10 minutes after lift-off. It will burn for 720 seconds (12 minutes) to separate the satellite from the launcher and inject it into the geosynchronous transfer orbit,” Satish said.

All going well and weather permitting, the crucial launch exercise will be about 19-20 minutes, with the first stage taking 150 seconds (2.5 minutes) to lift-off and soar into the sky. The second stage will be fired for 290 seconds (4.8 minutes) to zoom further and shut off to fire the cryo stage to enter the higher earth orbit in the next 12 minutes.

Readiness of the ground stations at Sriharikota, Biak in Indonesia and the master control facility (MCF) at Hasan in Karnataka, about 180 km from here, are also being tested simultaneously.

Only five countries - United States, Russia, France, Japan and China - have the cryogenic engine upper stage technology to launch heavier satellites in geostationary orbit.

India is the sixth country to design and develop the cryogenic technology.

When the U.S. prevented Russia from transferring its cryogenic technology to India in 1992, the state-run ISRO embarked on a mission in 1994 to design and develop the cryo engine for achieving self-reliance in such complex technology at a cost of Rs.335-crore (Rs.3.35 billion) in 16 years.

“The technology denial regime has spurred us to develop our own cryogenic upper stage to launching heavier satellites in the higher orbits, about 36,000 km from the earth,” ISRO chairman K. Radhakrishnan told reporters here recently.

India, however, had imported seven cryo engines from Russia but used five to launch heavy satellites (above two-tonne class) in GSLV-Mark I and Mark-II rockets during the last decade.

The Rs.150-crore GSAT-4 has one Ka-band regenerative transponder and a navigation payload that will operate in C-band and L1 and L5 bands for global positioning system (GPS) aided geo augmented navigation (Gagan).

Being an experimental mission and wholly funded by the Indian government, there is no insurance cover for the launch as well as the satellite.

As a technology demonstrator, GSAT-4 will enable testing of many future communication satellite technologies. After reaching GTO, the satellite will use its own propulsion system to reach its geostationary orbital home and will be stationed at 82 degrees east longitude there, Radhakrishnan noted.

Besides the cryogenic engine, the GSAT-4 has advanced telemetry system and advanced mission computers and larger composite payload faring.

The advanced version of the GSLV is a three-stage rocket with solid, liquid and cryogenic stages. The solid core motor of the first stage is one of the largest rocket motors in the world and uses 138 tonnes of propellant (fuel-oxidiser).