After coming across the '20 minutes of terror' followed by 3 minutes of vertical descent, Chandrayaan-3 finally touched upon the south pole of moon yesterday. Now the lunar module comprising the Vikram lander and Pragyan rover - carrying six scientific payloads between them- has one lunar day or 14 earth days to gather information enough to satisfy the quest of the legion of the inquisitive ISRO scientists.
About the 14-day deadline
It is widely known that the lander and the rover are working under a dedaline pressure of next 14 earth days. This deadline is critical as the rover Pragyan will significantly slow down after this time span as the moon's 'sunlight cycle' will come to an end and the night phase will initiate, which will continue to prevail for the next 14 days.
Considering the scarcity of sunlight during the night phase, it is quite certain that the modus operandi of the rover will face hindrances. Moreover, it has been reported that at night, the mercury level plummets to a destructive -208 degrees Fahrenheit or - 133 degrees Celsius, which apparently won't be convenient for the smooth functiong of the rover, lander and the payloads.
It has been reported that during this time, the rover will be touch with the lander and that will relay data back to ISRO's mission command centre. ISRO will have no direct link with the rover for this period.
The scientists picked August 23 as the landing date as it was the start of one lunar day cycle. If Vikram failed to touch down on that day, ISRO had a back-up plan - land on August 24.
If there was still no touch down (and the lander was undamaged), ISRO reportedly planned to try again 29 days later - after a full day/night cycle on the moon.
The lunar module has alredy started sending images of the lunar surface and here's how the moon surface was looking like right before the touch down.
Fate of lunar modules after mission
Upon completion of the lunar mission, neither the lunar module containing Vikram and Pragyan, nor the propulsion module will find their way back to Earth. They will continue to reside in the moon only. Altjough, they will lose their functionality eventually and ISRO is yet to designany plan to revive them.