Chandrayaan 3: Why it's key to NASA's astronaut mission to Moon in 2025 | South Pole Landing

One of the biggest hurdles before India's third Moon mission is the area of the Moon where ISRO has planned a landing.

The landing site is near the Moon's South Pole and is similar to the Chandrayaan 2 mission.

All previous spacecraft sent by other countries have landed near the Moon's equator which is smoother and gets more sunlight for solar-powered instruments.

However, the Moon's poles don't get much sunlight, and the temperature can fall as low as minus 230°C.

The poles also have large craters, and the region remains unexplored from the surface.

NASA wants to send astronauts to the South Pole to look for frozen water.

And so, data from Chandrayaan 3 can play an important role in NASA's future mission.

Chandrayaan-3 is a follow-on mission to Chandrayaan-2 and its objectives are to demonstrate safe and soft-landing on the lunar surface, roving on the Moon, and to conduct in-situ scientific experiments.

Chandrayaan-2 had failed in its lunar phase when its lander 'Vikram' crashed into the surface of the Moon following anomalies in the braking system in the lander while attempting a touchdown on September 7, 2019. Chandrayaan's maiden mission was in 2008.

The Rs 600 crore Chandrayaan-3 mission was launched on July 14 onboard Launch Vehicle Mark-III (LVM-3) rocket, for a 41-day voyage to reach near the lunar south pole.

The soft-landing is being attempted days after Russia's Luna-25 spacecraft crashed into the Moon after spinning out of control.

After the second and final deboosting operation on August 20, the LM is placed in a 25 km x 134 km orbit around the Moon.

The module would undergo internal checks and await the sun-rise at the designated landing site, ISRO has said, adding that the powered descent -- to achieve soft-landing on the Moon's surface -- is expected to be initiated at around 5:45 pm on Wednesday.

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The critical process of soft-landing has been dubbed by many including ISRO officials as "17 minutes of terror", with the entire process being autonomous when the lander has to fire its engines at the right times and altitudes, use the right amount of fuel, and scan of the lunar surface for any obstacles or hills or craters before finally touching down.

(with PTI inputs)