Chandrayaan-I: On the Moon approximately in 15 days

Sriharikota, Oct 22 (UNI) Approximately 15 days after the lift off from the SHAR Range on PSLV-C11, Chandrayaan-I, India's first unmanned space mission will make its landing on the Moon and plant the Indian tricolour.

A jubilant ISRO chief Madhavan Nair, addressing the ISRO community said ''the first leg of our journey to moon is a success. The remaining journey will take place in another 15 days and the ISRO team is capable of achieving it.'' The voyage to the Moon will commence from earth onboard the PSLV-C11 and first reach a highly elliptical Initial Orbit with the perigee (nearest point to Earth) being about 250 km and apogee (farthest point from the Earth) about 23,000 km, before reaching its intended 100 km height from the Lunar surface on November eight.

After circling the Earth in its Initial Orbit for a while, Chandrayaan-1 would be taken to two more elliptical orbits whose apogees lay still higher at 37,000 km and 73,000 km respectively.

This will be done at opportune moments by firing the Liquid Apogee Motor (LAM) when the spacecraft is near perigee.

Subsequently, the LAM will be fired again to take Chandrayaan-1 to an extremely high elliptical orbit whose apogee lies at about 3,87,000 km.

In this orbit, the spacecraft will make one complete revolution around the Earth in about 11 days. During its second revolution around the Earth in this orbit, the spacecraft would approach the Moon's North pole at a safe distance of about a few hundred kms since the Moon would have arrived there from its journey round the Earth.

Once the Chandrayaan-1 reaches the vicinity of the Moon, the spacecraft would be oriented in a particular way and its LAM again fired.

This will slow down the spacecraft sufficiently to enable the gravity of the Moon to capture it into an elliptical orbit and the spacecraft's orbit around the Moon will be reduced in steps.

After a careful and detailed observation of perturbations in its intermediate orbits around the Moon, the height of Chandrayaan-1's orbit would be finally lowered to its intended 100 km height from the lunar surface.

Later, the Moon Impact Probe, with the Indian Tricolour painted on it, will be ejected from Chandrayaan-1 spacecraft at the earliest opportunity to hit the lunar surface in a chosen area.

Following this, cameras and other scientific instruments (11 payloads, including five from India, three from European Space Agency, two from the US and one from Bulgaria) will be turned on and thoroughly tested, leading to the operational phase of the Mission that would last for two years exploring the Lunar Surface.

UNI GV GM VV AK RAI0752