CHENNAI: The Lunar Laser Ranging Instrument (LLRI), one of the 11 scientific instruments on board Chandrayaan-1, was activated on Sunday, when the spacecraft was passing over the western part of the Moon’s visible atmosphere.
A press release from the Indian Space Research Organisation said the LLRI was a radar that would generate information on the height of hills, mountains, and depth of craters and valleys of the Moon.
It sent high-energy lasers towards a strip of the moon’s surface and they would be reflected to the spacecraft. With this, the instrument can measure the height or depth of the Moon’s hills or craters.
An ISRO official said if the laser returned late, it signified the presence of a crater or a valley. If it came back early, it meant there was a mountain or a hill.
Analysis of the data from the LLRI would help in understanding the internal structure of the Moon and the mystery behind its origin. The LLRI was built by the ISRO’s Laboratory for Electro-Optics Systems (LEOS) in Bangalore.
On November 15, the TMC took pictures of the polar region, which showed many large and small craters including the rim of the 117 km-wide Moretus crater. On November 13, it took pictures of the equatorial region, showing craters and also part of the Torricelli crater.
Chandrayaan-1’s Moon Impact Probe (MIP), which crash-landed on the Shackleton crater on November 14, has also beamed several pictures of the lunar surface. The Radiation Dose Monitor (RADOM), an instrument from Bulgaria to investigate the moon’s radiation environment, has been switched on.
The pictures and scientific data sent by Chandrayaan-1 from its orbit 100 km above the moon are being received by the antennas with 32 metre and 18 metre diameter at the Indian Deep Space Network at Byalalu village, near Bangalore.
The spacecraft operations are being done from the Spacecraft Control Centre of the ISRO Telemetry, Tracking and Command Network at Bangalore.