Chandrayaan-3: What will happen when Vikram lander touches down on Moon?

Chandrayaan-3 landing date: If everything goes by the book, India will land on the South Pole of the Moon, a feat no nation has ever achieved

Chandrayaan-3, India's lunar mission, has kept the country on its toes since its launch on July 14. After a 41-day voyage, its lander, Vikram, will attempt to land on the Moon on August 23 at 6:04 pm (IST). If everything goes by the book, India will land on the South Pole of the Moon, a feat no nation has ever achieved.

Chandrayaan-3: The mission so far

The Chandrayaan-3 mission was launched from Satish Dhawan Space Centre, Sriharikota, on July 14 at 2:35 pm.

On July 15, 17, 18 and 25, the spacecraft performed an orbit-raising manoeuvre, escaping the Earth's surface.

On August 1, it performed the slingshot move, pulling away from Earth's orbit to the Moon's orbit. On August 5, it entered lunar orbit.

It performed several lunar bound manoeuvres on August 6, 9, 14 and 16. Then, on August 17, the lunar lander, Vikram, separated from the propulsion module. On August 20, Vikram underwent successful deboosting.

Chandrayaan-3: What is the landing date?

The Vikram lander will attempt the soft landing, the most difficult part of the mission, on August 23, 6:04 pm. The live telecast of the historic landing event will begin at 5.20 pm on that day.

The landing has also returned the memories of India's 2019 lunar mission, Chandrayaan-2. During its landing, the lander, with a rover inside, crashed into the Moon's surface, failing in its mission to achieve a soft landing.

The orbiter, however, is still in space.

Chandrayaan-2 meets Chandrayaan-3

Chandrayaan-3's lander module on Monday established two-way communication with Chandrayaan-2's orbiter.

"Welcome, buddy!' Chandrayaan-2 orbiter formally welcomed the Chandrayaan-3 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 (formerly Twitter). The mission operations complex (MOX) is located at Isro Telemetry, Tracking and Command Network (ISTRAC) in Bengaluru.

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.

What happens after Vikram lander's touchdown on the Moon?

After the lander lands on the surface of the Moon, one side panel of Vikram will unfold, creating a ramp for the Pragyaan rover to come out. Pragyaan's wheels have been embossed with the Tricolour and Isro's logo.

Pragyaan will descend from the lander's belly after four hours of Vikram's landing. It will then scan the lunar surface with navigation cameras. Also, as it rolls, it will leave imprints of the Tricolour and Isro logo on the lunar surface, making India's mark.

The rover will then provide data on the composition of the Moon's atmosphere and send data to the lander. The lander will communicate with Isro.

Vikram also has other payloads that will measure lunar seismicity and thermal properties of the lunar surface near the South Pole and check the properties of near-surface plasma density.

What if anything goes wrong?

According to a report by the Times of India (TOI), if factors turn unfavourable for Vikram's landing on August 23, it will be postponed to August 27.

Isro chief S Somanath has, however, said that Chandrayaan-3 had undergone several tests and will most likely land on the Moon. He said Isro has 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," Somanath said, as quoted by the news agency PTI.