India's maiden unmanned moon mission's launch rehearsals at Sriharikota progressed satisfactorily and scientists geared up for the 52-hour countdown for Chandrayaan-1's historic space voyage on Wednesday.

"All the preparatory work is going on as usual and the formal countdown would begin tomorrow morning about 0400 hrs," Satish Dhawan Space Centre (SDSC) Associate Director Dr M Y S Prasad told PTI at Chennai. Sriharikota is about 100 km from Chennai.

"All the work including the checking of payloads went satisfactorily. The spacecraft launch would take place as per the schedule," he said.

The integrated launch vehicle has already been moved into the second launch pad (umbilical tower) at the spaceport of Sriharikota and launch rehearsals are underway, sources in India Space Research Organisation at Bangalore said.

SDSC officials said if the weather does not play truant, the Polar Satellite Launch Vehicle(PSLV-C11) would take off from the second launch pad on October 22 at 0620 hrs.

"After the rehearsals, we will make sure that everything is in place before the countdown," they said.

Chandrayaan-1 is the first spacecraft mission of ISRO beyond Earth orbit. It would be followed by Chandrayaan-2 which features a lander and a rover. India and Russia would jointly participate in this project. However, there might be a provision to accommodate payloads from other space agencies like in Chandrayaan-1.

"This apart, studies are being conducted by ISRO on sending unmanned spacecraft to planet Mars as well as to asteroids and comets. Through such programmes, ISRO intends to undertake the exploration of space besides its primary mission of developing and utilising space technology for the overall development of the country", ISRO officials said.