Bengaluru/New Delhi | Ahead of its planned landing on the moon's untouched south pole on August 23, Chandrayaan-3's lander module has established a two-way communication with Chandrayaan-2's orbiter and the ISRO said on Monday all systems are working perfectly and no contingencies are anticipated.
The two-way contact potentially offers ground controllers more channels for communication with Chandrayaan-3.
"Welcome, buddy!' Ch-2 orbiter formally welcomed Ch-3 LM(Lander Module). Two-way communication between the two is established. MOX has now more routes to reach the LM," the national space agency said in a post on 'X'. The MOX (Mission Operations Complex) is located at ISRO Telemetry, Tracking and Command Network (ISTRAC) in Bengaluru.
According to the Indian Space Research Organisation(ISRO), the LM Vikram with rover Pragyan in its belly is expected to touch down on the surface of the Moon around 6.04 pm on August 23. It also said the live telecast of the historic landing event will begin at 5.20 pm on that day.
The Chandrayaan-2 spacecraft comprising orbiter, lander and rover was launched in 2019. The lander with a rover inside crashed into the moon's
surface, failing in its mission to achieve a soft-landing. The ISRO had said that due to the precise launch and orbital manoeuvres, the mission life of the Ch-2 orbiter is increased to seven years.
The ISRO also released images of the lunar far side area captured by the Lander Hazard Detection and Avoidance Camera (LHDAC). The camera assists in locating a safe landing area -- without boulders or deep trenches -- during the lander's descent.
The photos come a day after Russia's Luna-25 spacecraft crashed into the moon after spinning out of control, in a setback to Russia's space ambitions.
A success for Chandrayaan-3 would make India only the fourth country to successfully land on the moon, after the former USSR, the United States and China and the first to land on the treacherous lunar south pole. India's third lunar mission was launched on July 14 embarking on a more complicated 41-day voyage to the moon.
ISRO Chairman S Somanath called on the Union Minister of State (Independent Charge) Science and Technology Dr Jitendra Singh in New Delhi and apprised him of the health status and readiness of Chandrayaan-3 for the moon landing.
Somanath informed the minister that all systems are working perfectly and no contingencies are anticipated on Wednesday, according to an official release.
In the next two days, the health of Chandrayaan-3 will be continuously monitored, he said, adding the final sequence of landing will be loaded two days ahead and tested out. The mission life of the lander and rover is one lunar day or 14 earth days.
Referring to the expected touchdown, former ISRO chairman G Madhavan Nair said it's a very complex manoeuvre and one has to be cautious as all systems have to work in unison for its success.
Nair, who headed the space agency when Chandrayaan-1 mission was launched in 2008, said a successful landing would herald a big beginning for ISRO's next phase of planetary exploration.
"It's a very complex manoeuvre. We narrowly missed it (soft-landing on the Moon in Chandrayaan-2 mission) in the last two kilometres (above the lunar surface)," he told PTI.
"So, there are a host of things that have to work in unison...thrusters, sensors, altimeters, computer software and all those things. Any glitch happening anywhere...we can be in trouble," Nair said.
"We have to be really cautious and watch. Of course, I understand that ISRO has done enough simulations and also redundancies have been built in so that chances of such failure are remote. Still, we have to keep our fingers crossed."
Another former ISRO chief K Sivan said the failure of Russia's Luna-25 moon mission will have no impact on the Chandrayaan-3 venture.
"It will not have any impact," Sivan, who was heading the ISRO when the Chandrayaan-2 mission was launched in 2019, told PTI when asked if the Indian space agency would be under more pressure ahead of the soft landing, following the Russian setback.
Days ahead of Chandrayaan-3's launch, Somanath had said it is loaded with more fuel, a slew of safety measures and a bigger landing site, adding ISRO has opted for a "failure-based design" to ensure that the rover successfully lands on the moon even if some things go wrong.
Somanath said instead of a success-based design in Chandrayaan-2, the space agency opted for a failure-based design in Chandrayaan-3, focused on what all can fail and how to protect it and ensure a successful landing.
"We looked at very many failures sensor failure, engine failure, algorithm failure, calculation failure. So, whatever the failure we want it to land at the required speed and rate. So, there are different failure scenarios calculated and programmed inside."
The primary objectives of Chandrayaan-3 mission are threefold, (a) to demonstrate safe and soft Landing on lunar surface; (b) to demonstrate Rover roving on the moon, and (c) to conduct in-situ scientific experiments.
Scientists from several space agencies have detected frozen water in the south pole craters.
This ice could potentially serve as a reservoir for fuel, oxygen, and drinking water, thereby bolstering future lunar habitation endeavours.