Thiruvananthapuram: The test flight of a Geo-synchronous Satellite Launch Vehicle (GSLV-D3) powered by an Indian cryogenic engine with super-cooled fuel has been put on hold as it is undergoing final evaluation, a top space official said today.

"We are undertaking a thorough review of the indigenously built cryogenic engine before finalising the launch date of GSLV-D3," Indian Space Research Organisation (ISRO) chairman K. Radhakrishnan told the sources here.

Clarifying that there was no delay as such in the rocket's launch from the Sriharikota spaceport, about 80 km northeast of Chennai, Radhakrishnan said the launch schedule would be decided at a review meeting later this month in Bangalore.

"We will decide the launch schedule at a review meeting in the next two weeks. As we want to make sure the cryogenic engine performs successfully after the launch, a final check-up is underway," Radhakrishnan said on the margins of a space summit at the 97th Indian Science Congress (ISC2010) that began here on Sunday.

The successful test-firing of an indigenous cryogenic engine will take India into the elite space club of the US, Russia, China, France and Japan that have the capability to make such engines.

A cryogenic engine uses liquid hydrogen as fuel at minus 265 degrees Celsius and liquid oxygen at minus 240 degrees Celsius as oxidiser in the upper stage of a rocket like the GSLV to deploy satellites in geo-synchronous orbit.

If the fuel mix is not in the exact proportion, the rocket can explode in the geo-synchronous orbit.

"We are planning to first launch Cartosat-2B in March using the Polar Satellite Launch Vehicle (PSLV) and follow it up with the launch of GSLV-D3 later this year," Radhakrishnan noted.

The GSLV-D3 is set to carry GSAT-4 communication satellite into the geo-stationary orbit, around 36,000 km above the earth.

The state run Indian space agency tested the cryogenic engine for the full flight duration of 720 seconds (12 minutes) at its liquid propulsion systems centre in December 2007 at Mahendragiri in southern Tamil Nadu.

"The ground test validated the design and performance of the cryogenic engine for use in the GSLV test flight," a space official said.

ISRO took up the development of cryogenic stage in 1996 to achieve self-reliance in cryogenic propulsion technology.

ISRO so far used Russian made cryogenic engines for the launch of GSLVs.

Besides Cartosat-2B, the polar rocket will carry on board Alsat, a small Algerian satellite, two Canadian nano-satellites and Studsat, another nano-satellite built by students of Indian universities.

As a remote sensing earth observation satellite in a sun-synchronous polar orbit, the 680 kg Cartosat-2B will carry a sophisticated panchromatic camera to take images for cartographic applications such as mapping, land information and geographical information system.

Cartosat-2A was launched in April 2008. IANS