Explained: why Vikram lander and Pragyan rover's mission life is 14 days

After the successful deployment of Chandrayaan-3's lander and rover on the moon, ISRO is hoping that their mission life will not be limited to one lunar day or 14 earth days and that they will come back to life when the sun again rises on the Moon, to carry on with the experiments and studies there.

Following the deployment of the lander and rover, the systems on them are now ready to perform experiments one after the other so as to complete them within 14 earth days, before the pitch darkness and extreme cold weather engulfs the Moon.

The lander (Vikram) touched down near the south pole of the Moon at 6.04 pm on Wednesday, successfully completing one of the Chandrayaan-3 mission's stated objectives of soft landing on the lunar surface.

Earlier today ISRO announced that the rover (Pragyan) rolled down from the lander, stating, "India took a walk on the Moon." ISRO had earlier said the 26 kg six-wheeled rover was scheduled to descend from the lander's belly onto the Moon's surface, using one of its side panels which acts as a ramp.

The lander and rover -- with a total mass of 1,752 kg -- are designed to operate for one lunar daylight period (about 14 Earth days) to study the surroundings there.

However, ISRO officials do not rule out the possibility of them coming back to life for another lunar day.

Explaining what would happen after the lander's soft landing and deployment of the rover, ISRO Chairman S Somnath had earlier said, "After this, all the experiments (by payloads on lander and rover) will take place one after the other -- all of which have to be completed in just one day on the Moon, which is 14 (Earth) days." Noting that as long as the sun shines, all the systems will have its power, he said, "The moment the sun sets, everything will be in pitch darkness, temperature will go as down as low as minus 180 degree celsius. So it is not possible for the systems to survive, and if it survives further, then we should be happy that once again it has come to life and we will be able to work on the system once again." He said, "We hope it would happen that way." The rover will carry out in-situ chemical analysis of the lunar surface during the course of its mobility.

It would study the surface of the Moon through its payloads APXS (Alpha Particle X-Ray Spectrometer) to determine the elemental composition of lunar soil and rocks around the lunar landing site.

Another payload on the rover, the Laser-Induced Breakdown Spectroscope (LIBS), will derive the chemical composition and infer mineralogical composition to further enhance understanding of the lunar surface.

The Moon's south pole region is also being explored because there is a possibility of water being present in permanently shadowed areas around it, according to ISRO officials.

The rover will send the data to the lander which will then send it to Earth.