Oct 23, 2008

Tech - An international mission with India as Captain

T.S. Subramanian

CHENNAI: Although 60 spacecraft have been sent since 1959 to study the moon, this is the first time that as many as 11 scientific instruments are being carried on a spacecraft, Chandrayaan-1 — five from the Indian Space Research Organisation, two from the National Aeronautics and Space Administration, three from the European Space Agency and one from Bulgaria.

M. Annadurai, Project Director, called the spacecraft “an international mission with India as the captain.” “We are carrying a spectrum of instruments that people have not sent to study the moon earlier.”

Addressing a press conference at Sriharikota on Wednesday after the PSLV-C11 successfully put Chandrayaan-1 into its initial orbit, ISRO Chairman G. Madhavan Nair said the scientific instruments on board were “unique for the spectrum of their coverage.” These were “the most comprehensive set of instruments to fly on board a spacecraft to the moon in recent history.” The instruments would provide a map of the entire surface of the moon — its hills, valleys and craters, and look for minerals such as thorium, uranium, silicon and magnesium.

“We will also try to see whether there is any trace of water ice on the moon,” Mr. Nair said.

The data sent by these instruments would also reveal whether helium-3, which would be the fuel of the future, was available in abundance on the moon.

“A search for the presence of water ice will be made in multiple ways by Chandrayaan-1,” said Mr. Annadurai. Imaging instruments on board the spacecraft could detect the presence of water ice. The signals observed by the X-ray payloads would be useful in identifying the presence of water ice in the permanently shadowed regions of the moon.

The Lunar Laser Ranging Instrument would send high-energy lasers to the lunar surface and these would bounce back to the spacecraft. The lasers would help in measuring the depth of the moon’s craters and the height of its mountains.

An important instrument was the Moon Impact Probe (MIP), on which was painted the Indian national flag. The MIP would be ejected from Chandrayaan-1 soon after the spacecraft reached its final orbit of 100 km around the moon on November 15, Mr. Annadurai said. After a 20-minute descent, it would crash-land on the moon.

The MIP has three instruments — a video camera that will take pictures of the lunar surface as the MIP descends towards the moon; a mass spectrometer that will “sniff” and analyse the constituents of the thin atmosphere present above the moon; and an altimeter that will measure every second the altitude of the MIP from the moon during its fall. When the MIP crashes on the moon, it will kick up dust. The video camera will take pictures of this dust. The video images of the lunar surface and the dust will help in determining where the lander/rover in the Chandrayaan-2 mission can land on the moon.

T.K. Alex, Director, ISRO Satellite Centre, Bangalore, which built Chandrayaan-1, said: “The spacecraft is in right orbit. It is in good health. The outlook is excellent.”

George Koshy was the mission director and C. Venugopal, the vehicle director.

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