The second developmental flight of India's prestigious Geosynchronous Satellite Launch Vehicle (GSLV-D2) is all set for launch at 1658 IST on Thursday with the final countdown progressing 'perfectly as per schedule', the Indian Space Research Organisation said.

"The final countdown which started at 0158 IST (T minus 39 hrs) on Wednesday is progressing smoothly and the launch is expected to take place as scheduled if everything goes well during the remaining duration of the countdown," an ISRO spokesman told PTI at the Satish Dhawan Space Centre (SDSC) at Sriharikota, about 100km from Chennai.

The vehicle in its full configuration is ready at the launch pad in the SDSC and fuelling of the various stages, including the crucial cryogenic upper stage, will take place between T minus 6 and T minus 4 hours of the countdown, the spokesman said.

"We hope to launch the vehicle at the first opportunity (1658 IST) itself provided there are no hold-ups," the spokesman said.