Reaching Lunar South Pole: The Triumph of Chandrayaan-3

On August 23, 2023, at 18:04 IST, India wrote history by becoming the first nation to soft-land a spacecraft near the uncharted southern polar region of the Moon.

1. Why the Lunar South Pole?

The South Pole of the Moon is of extreme strategic, scientific, and structural interest. It is dotted with permanently shadowed craters (PSRs) which are believed to act as cold traps, containing vast reservoirs of water ice. This ice could provide vital resources for future human habitats:

• Drinking water for astronauts.
• Oxygen for breathing.
• Hydrogen and oxygen for liquid rocket fuel propellant.

2. Engineering Overhauls: Moving from Failure to Success

ISRO implemented a "failure-based design" philosophy for Chandrayaan-3, adding redundant safeties over its predecessor:

• Sturdier Legs: Reinforced Vikram's legs to withstand higher landing velocities.
• Larger Solar Panels: Wrapped Vikram in more solar cells to secure power generation under any orientation.
• Laser Doppler Velocimeter (LDV): Added a brand-new instrument to calculate precise three-dimensional velocities in real-time.

3. The Scientific Revelations of Rover Pragyan

The 26-kilogram Pragyan rover performed chemical and physical experiments on-site:

1. Laser-Induced Breakdown Spectroscopy (LIBS): Directly detected Sulfur (S), Titanium, Silicon, and other metallic elements.

2. ChaSTE Experiment: Inserted a thermal probe 10 centimeters into the lunar soil, measuring a sharp temperature difference of over 60°C within just a few centimeters of depth. This proved lunar soil is an outstanding thermal insulator!