"As a result of the manoeuvres, the farthest point of Chandrayaan-1 orbit (aposelene) from the moon's surface was first reduced from 7,502 km to 255 km and finally to 100 km while the nearest point (periselene) was reduced from 200 km to 182 km and finally to 100 km", ISRO said.

During these operations, Chandrayaan-1's liquid engine built by Liquid Propulsion Systems Centre, Thiruvananthapuram, has been fired a total of ten times successfully.

In its present operational orbit, the Chandrayaan-1 spacecraft takes about two hours to go round the moon once.

From this operational circular orbit of about 100 km height passing over the polar regions of the moon, it is intended to conduct chemical, minerological and photo geological mapping of the moon with Chandrayaan-1's 11 scientific instruments (payloads).

Two of those 11 payloads -- Terrain Mapping Camera (TMC) and Radiation Dose Monitor (RADOM) - have already been switched on. TMC has successfully taken the pictures of the Earth and the Moon.

After its successful launch by PSLV-C11 on October 22 into an initial Earth orbit, the Chandrayaan-1 spacecraft proceeded towards the Moon and successfully entered into an elliptical orbit around that celestial body on November 8.

Since its launch, the spacecraft's health and orbit have been continuously monitored from the Spacecraft Control Centre of ISRO Telemetry, Tracking and Command Network with critical support from antennas of Indian Deep Space Network (IDSN) at Byalalu on the outskirts of Bangalore.