Shortly after the touchdown, one side panel of the Vikram lander will unfold, creating a ramp for the Pragyan rover. The six-wheeled Pragyan with a national tricolour and an Isro logo embossed on its wheels will descend from the lander’s belly on the lunar surface after 4 hours, moving at a speed of 1cm per second and using navigation cameras to scan its lunar surroundings. As it will roll, the rover will leave imprints of the tricolour and Isro logo on the lunar regolith (soil), making a mark of India on the Moon. The rover has instruments configured with payloads to provide data related to the Moon’s surface. It will gather data on the elemental composition of the Moon’s atmosphere and send data to the lander. With three payloads, the Vikram lander will measure the near surface plasma (ions and electrons) density, carry out measurements of thermal properties of the lunar surface, measure seismicity around the landing site and delineate the structure of the lunar crust and mantle.The solar-powered lander and rover will have about two weeks to study the lunar surroundings. The rover can only communicate with the lander, which communicates directly with the Earth. Isro says the Chandrayaan-2 orbiter can also be used as a contingency communications relay. On Monday, the Chandrayaan-2 orbiter established communication with the lander module.
Speaking to TOI, Isro chairman S Somanath said the “actual distance travelled by the rover during the 14 Earth days can’t be estimated now. Because that will be done based on various things (calculations)”.
For the rover and lander to survive for the second lunar day, they have to first withstand the freezing temperatures of minus 238 degrees Celsius of a lunar night in the south pole. The Isro chairman told TOI that there is a possibility that both the lander and rover will live for another lunar day.
On Monday, the Isro chairman briefed Space Minister Jitendra Singh in Delhi on the health status of Chandrayaan-3 and said all systems are working perfectly and no contingencies are anticipated on Wednesday. In the next two days, the health of Chandrayaan-3 will be continuously monitored. The final sequence of landing will be loaded two days ahead and tested out, he said.
The space minister said the primary objectives of Chandrayaan-3 mission are threefold: demonstrate safe and soft-landing on the lunar surfac’; demonstrate rover roving on the Moon; and to conduct in-situ scientific experiments. India will be the fourth country in the world to achieve the landing feat after the US, Russia, and China, but it will be the only country in the world to land on the lunar South Pole, he said.
Singh told TOI, “The reason why we are going to the South Pole is we want to explore the unexplored. We have received images of dark (permanently shadowed) craters on the Moon which hint that it could possess water. If Chandrayaan-3 finds more evidence of water, which consists of hydrogen and oxygen, then it opens up a lot of scientific opportunities. If hydrogen could be tapped from water, it could be a rich source of clean energy.”