Chandrayaan-3

Context: Indian Space Research Organisation (ISRO) plans to launch the Chandrayaan-3 mission, India’s third lunar mission, to the moon on July 14. 

Chandrayaan-3: 

• Chandrayaan-3 is a follow-on mission to Chandrayaan-2 to demonstrate end-to-end capability in safe landing and roving on the lunar surface. 
• It will be launched onboard a Launch Vehicle Mark 3 from Sriharikota, Andhra Pradesh. 
• Cost of the mission: Rs 615 crore
• Duration: The mission is only meant to last for a half lunar day, which is roughly equal to 14 Earth days. 

Objectives: 

• To demonstrate a Safe and Soft Landing on Lunar Surface (near the lunar South Pole).
• To demonstrate Rover roving on the moon (which will carry out in-situ chemical analysis of the lunar surface during the course of its mobility)
• To conduct in-situ scientific experiments.

Soft-landing on Moon:

• This will be India’s second attempt to soft-land a lander and rover on the lunar surface.
  • Chandrayaan-2 was launched in July 2019 in the form of an orbiter and a lander (‘Vikram’) bearing a rover (‘Pragyan’).
  • While the orbiter entered into orbit around the moon, the surface mission failed in September 2019 when the lander crashed instead of executing a slow descent.
• Chandrayaan-3 consists of a Lander and a Rover similar to Chandrayaan-2, but would not have an orbiter.
  • The rocket (LVM-3) will place the payload in an elliptical orbit around the earth, where a propulsion module will take over and pilot the lander to a circular orbit around the moon.
  • Finally, the lander will detach and begin a series of manoeuvres culminating in a gradual landing (on August 23-24, 2023) over the surface of the moon.
• To improve the chances of success at this stage, ISRO made changes to the software and hardware of the Chandrayaan-3 mission, especially for the lander thrusters. Additionally, ISRO has developed improved soft-landing sequences and the lander has four thruster engines instead of five, sturdier legs and larger solar panels, and will carry more fuel.

Several advanced technologies in Chandrayaan-3:

• Propulsion module has a Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload to gather data on the polarisation of light reflected by Earth so that researchers can look for other planets with similar signatures. Hence, it will assist with exoplanet searches. 
• Lander payloads:
  • Chandra’s Surface Thermophysical Experiment (ChaSTE) to measure thermal conductivity and temperature on the surface;
  • Instrument for Lunar Seismic Activity (ILSA) to detect moonquakes;
  • Langmuir Probe to estimate the density and variation of plasma, or superheated gas, in the moon’s environment; 
  • A Laser Retroreflector Array (from NASA) to measure distances using laser ranging to understand the dynamics of the Moon system. 
• Rover payloads:
  • Alpha Particle X-ray Spectrometer (APXS) to look for elements in the lunar soil and rocks;
  • Laser Induced Breakdown Spectroscope (LIBS) to examine the chemical and elemental composition of the lunar surface.

Significance of Chandrayaan-3:

• Chandrayaan-3 offers opportunities for India to lead the world’s response to the moon’s growing importance in the scientific and political milieus.
  • Chandrayaan-3 is India’s second attempt to achieve a soft landing on the Moon’s surface. Only three countries – the United States, Russia and China – have successfully landed spacecraft on the airless lunar surface.
  • Chandrayaan-3 will be the first to land on the South Pole of the Moon. All other spacecraft which have landed on the moon have landed in the equatorial region, a few degree latitude north or south of the lunar equator. 

Why moon’s South Pole? 

• Experts note that there is a possibility of the presence of water at the South Pole. Water ice has been detected at both poles of the Moon, but the South Pole has more area in permanent shadow and colder temperatures, so it is thought to have more water ice.
• Moreover, the South Pole witnesses extremely cold temperatures; this means that anything trapped here would remain frozen in time, without undergoing much change. The rocks and soil in this region could therefore provide clues to the early solar system.

Further, South Pole is located in the South Pole-Aitken basin, which is a huge crater. There may be material from the deep crust and upper mantle of the Moon on or near the surface.