Dr Kasturirangan, in an interview said the launch was likely to take place next year. The launch was most crucial and critical for the country and all efforts were being made to ensure its success, he added.

With the upper cyrogenic stage obtained from Russia, the much delayed GSLV, that would put a 2500 kg satellite in the geostationary orbit over 36,000 km above the earth, was scheduled for launch this year, according to the ISRO's calender.

Russia, which had earlier agreed for joint development programme of the crucial cryogenic upper stage with India, had however, backed out following the United States' sanctions. However, it had agreed to provideseven cryogenic engines to the country before the indigenous development could fructify. The first of these engines had already arrived and development of the first two stages of the GSLV launch that was likely to be similar to the polar satellite launch vehicle was awaited.

Dr Kasturirangan said work on the GSLV would commence immediately after the launch of the polar satellite launch vehicle PSLV-C2 scheduled to take off from Sriharikota during the last quarter of May. Besides the first Indian Ocean study satellite -- Oceansat-I, the PSLV-C2 would also launch a German and a Korean satellite that would ride piggyback on Oceansat.

Being developed at a sanctioned cost of Rs 1105.30 crore, the first developmental flight of the three stage GSLV will carry the experimental GSAT-1, that aimed to demonstrate advanced communication technologies such as digital audio, data and video broadcasting. The payload included two S-band transponders, a high power C-band transponder and two indigenously developed C-bandtransponders.

The three stage GSLV that will put Insat class satellites in geosynchronous transfer orbit has a three-stage configuration with the first two stages adopting the PSLV modules and four liquid strapons that were derived from the second stage of PSLV employing the same Vikas engine.

The GSLV-D1 will lift off from Sriharikota which is acquiring a second launch pad to provide redundancy to the existing launch pad for current versions of PSLVs and GSLVs, besides enabling the launch of advanced launch vehicles to geostationary transfer orbit with capability to launch four tonne class satellites. The second launch pad was being built at a cost of Rs 289 crore.

Meanwhile, preparations are on in full swing for the launch of the second operational flight of PSLV series (PSLV-C2) that will put into sun synchronous orbit, the IRS-P4 (Oceansat-1) along with two other small satellites.

Dr Kasturirangan said the IRS-P4 was now in the thermovac test and would shortly be ready for transhipment toSriharikota. The launch vehicle stages were all in preparedness for integration of the launch vehicle and the micro-German satellite, 50 kg Tubsat had already reached Sriharikota. The other payload 100 kg Kitsat of Korea was awaited.

He said the PSLV-C2 would lift off during the last week of May.

He said corrective actions had been taken for the PSLV-C2 flight after a detailed post-flight analysis of the first operational flight, whose fourth stage, had recorded under-performance due to malfunctioning of the pressure regulation system.

Asked about the indigenous development of the cryogenic engines, Dr Kasturirangan said the project, taken up at a sanctioned cost of Rs 335.89 crore, was making a `most satisfactory progress'. The cryogenic stage, that would have a thrust of 7.5 tonnes, would undergo few first two in the preliminary stages later this year. Such projects would definitely take some time in view of the complex technologies involved, he added.