Chandrayaan-3, India's third lunar mission, will launch on July 14 aboard the GSLV-Mk3 or LVM3, and if all goes according to plan and Vikram (lander) would touch down on moon on August 23 or 24. Isro chairman S Somanath said in Bengaluru: “If the launch takes place on that day [July 14], we'll reach the moon by the end of August.
Landing will be on August 23 or 24 as we want the landing to happen when the sun rises on the moon so we get 14-15 [earth] days to work. If landing cannot happen on these two dates, we'll wait for another month and land in September.” Chandrayaan-3 is a follow-on mission to Chandrayaan-2.
Chandrayaan-3 is made up of three modules: propulsion, lander, and rover, unlike its predecessor, which also carried an orbiter in addition to Vikram and Pragyan (the rover). The total weight of the spacecraft will be 3,900 kg, of which 1,752 kg will be the rover and 1,148 kg will be the propulsion module. On the proposed landing site, he said: “We cannot go to the South Pole as the sun won’t be visible and the lander and rover will have no power. We will go 70 degrees south.”
He said the life of the lander and rover will be for 14 earth days but the same could get extended. Fourteen earth days would be one lunar day, which is measured in terms of time between sunrise and sunset on moon, or the time taken for sun to return to the same position in the lunar sky.
“Once the sun sets, there will be no power for the lander and rover to function and all the equipment will stop working. However, our tests show that there are possibilities of the batter getting recharged upon the next sun rise. If that happens, we could get another 14 days or maybe even more,” Somanath said.
Pragyan will slide down from Vikram after a successful touchdown, which will be caught on camera by the lander, and start to travel on the lunar surface using its wheels. Additionally, Pragyan has cameras for avoiding obstacles.