India - Chandrayaan mission on target

CHENNAI: Nine out of 11 scientific instruments on board Chandrayaan-1 have been switched on, and the data that have been radioed in by them are being analysed.

According to M. Annadurai, Project Director, Chandrayaan-1, the data include three-dimensional pictures of the Moon’s surface taken by the Terrain Mapping Camera, an instrument built by ISRO’s Space Applications Centre, Ahmedabad.

The TMC has fore, nadir and aft cameras. Of the nine instruments that have been activated, the Moon Impact Probe, painted in the colours of the Indian flag, landed on the Moon on November 14.

Two more to go


The instruments that remain to be activated are the High Energy X-ray Spectrometer (HEX) and the Sub keV Atom Reflecting Analyser (SARA). HEX, built by the Physical Research Laboratory, Bangalore and the ISRO Satellite Centre, Bangalore, will study the Moon’s polar regions for deposits of water ice and prospect areas for high uranium and thorium concentration.

SARA will investigate the surface composition, how its surface reacts to the solar wind and how materials are altered in space. SARA has been jointly built by the Swedish Institute of Space Physics and the Space Physics Laboratory of the Vikram Sarabhai Space Centre, Thiruvananthapuram.

HEX and SARA, both high voltage instruments, will be switched on in the first week of December. “These are high voltage systems. You have to wait for some time in orbit before they are switched on,” Mr. Annadurai said.

When the ISRO performed a series of manoeuvres by firing Chandrayaan-1’s onboard engine to take the spacecraft to the Moon and then lower it into the final lunar orbit at an altitude of 100 km above it, the two systems could have been exposed to gases.

These gases should be “evacuated’ before the two instruments were activated, he said. The calibration of instruments was under way. Teams dealing with the instruments were studying the data received. “The science data needs to be fully reviewed and analysed,” said Mr. Annadurai.