In what may well be the first step towards establishing the first "human colony" on the moon, the Indian Space Research Organisation is examining the possibility of establishing a robotic set-up or unmanned mission on the moon.

Called Chandrayaan I and II, the basic objective of the project is to examine whether a robotic set-up can function as a stopover to refuel reusable spacecraft for various planetary missions and, eventually, create a self-sustaining environment to support a human colony on the moon.

Chandrayaan I, which is scheduled for launch in April 9, 2009, will examine the possibility of processing Helium-3 to produce energy, said M Annadurai, Project Director, Chandrayaan, ISRO.

Chandrayaan II is being planned sometimes between 2013 and 2014.

Helium-3 is considered a very good source of energy unlike thorium, plutonium or uranium that have radiation effects.

"The robotic set-up can also find the existence of water, from which we can get hydrogen and oxygen to use as propellants," Annadurai added.

The concept of having an outpost is driven by the fact that any spacecraft being launched from the moon will require one-sixth the amount of propellant it would need on earth.

"Basically we can escape the earth's gravity," explained Annadurai.

ISRO has added a new 32-metre indigenous antenna in the Indian Deep Space Network at Byalalu, Bangalore, to track Chandrayaan-I.

Chandrayaan II is scheduled for December 2010. This will be in partnership with Russia [Images], an agreement for which was signed during the last visit of the Indian Prime Minister to Russia.

The estimated cost of the Chandrayaan missions is approximately Rs 386 crore each.

During Chandrayaan II, Isro is also planning to land robots near the polar region of the moon to drill the polar ice cap and study the availability of water.

"If water is available, we will be able to collect helium and with hydrogen as the base, it is possible to feed the whole robotic base there," said Annadurai, adding that a human colony can eventually be established in the long run if the system becomes self-sustainable.