ISRO is running against time to establish communication with Vikram Lander. On Thursday, scientists from NASA also joined ISRO in its quest to re-establish contact with Vikram.
Lander Vikram has so far not responded to communications from ISRO. The Indian Space agency is in race against time to make the contact with Vikram before September 21.
Scientists at ISRO are worried because of the changing climate on moon's South pole. It is known that the temperatures on moon's south pole will dip drastically after September 21.
After September 21, darkness will fall on moon's South pole. The dark period equates to 14 nights on earth. This will make contacting Vikram even difficult. You can also call it near-impossible.
What makes contacting Vikram Lander more challenging post September 21:
The temperature on moon's surface will fall to as low as minus 200 degrees celsius. Scientists have also said that Vikram lander is not equipped to bear such extreme cold. It was precisely the reason ISRO had targetted a 15-day window for Vikram lander, during which it was supposed to carry out data collecting work on moon's surface. The extreme cold weather on moon would also damage electronic equipment like antenna and other external features of Vikram lander.
How ISRO is trying to establish contact with Vikram lander
ISRO is sending electromagnetic waves to communicate with Vikram Lander. Frequencies in the S-Band (microwave) and the L-Band (radio waves) of the electromagnetic spectrum are generally used for communication across the Space.