Why in Broadcast?

• India has become the first country to successfully land on the near side of southern lunar pole as Chandrayaan-3 successfully made a soft landing, on 23 August, 2023.

Important Announcements

• The point where the moon lander of Chandrayaan-3 landed will now be known as ‘Shiv Shakti’.
• The point where Chandrayaan 2 left its footprints will now be called ‘Tiranga’.
• 23rd August will be celebrated as the National Space Day.

Significance of Landing on Lunar South Pole

• Most of the moon landings were at the equatorial regions of the moon, since the terrain and the atmosphere here is benevolent due to adequate sunlight and smooth terrain
• China’s Chang-4, though landed on the far side of the moon, i.e. the side of the moon that is not facing earth, still was near the equatorial region of the moon
• Lunar poles are considered difficult to explore due to their rugged terrain, presence of large craters and extreme temperatures.
• There have been evidences, (Chandrayaan-1 indicated) that these regions may have presence of ice in its deep craters.
• Since frozen in time, they could provide major insights for early solar system.

Four Stages of Soft Landing

• Rough Breaking Phase: It includes reducing the lander’s horizontal velocity from a range of 1.68 km/sec, at a height of 30 km from the lunar surface, to almost zero.
• Attitude Hold Phase: It starts at height of 7.42 km from the surface, lasting around 10 seconds. The lander should tilt from a horizontal to a vertical position while covering a distance of 3.48 km.
• Fine Braking Phase: It lasts around 175 seconds. The lander has move fully into a vertical position, traversing final 28.52 km to the landing site. The altitude will come down to 800-1,000 m, and it would reach a nominal speed of 0 m/sec.
• Terminal descent is the final stage, when the spacecraft is supposed to descend totally vertically onto the surface
• It was between Attitude Hold Phase and Fine Breaking Phase, where Chandrayaan-2 failed.

Challenges

• Due to thin atmosphere of moon there is less friction and a propulsion system is required to slow down the spacecraft.
• This in turn requires lot of fuel, making the spacecraft even heavier.
• There is no precision in terms of landing location and spacecraft has to rely on the computer calculations and decisions to navigate through the terrains of moon.

Way Forward

• If Chandrayaan-3 can lead the way in this challenging region, future astronauts, based on ISRO’s pioneering work, will be able to collect core samples and volatiles from these regions.
• This could have a profound impact on the future of deep space exploration and eventual commercial activities.