Chandrayaan-3

Background
• ISRO, on July 14, 2023, launched Chandrayaan 3, its 3rd lunar mission.
• India expects to become the fourth country after the erst while the USSR, USA, and China will do soft-landing on the Moon.
• The cost of the mission is approximately around Rs 615 cr, considered the ISRO’s most difficult mission till date.
• Chandrayaan 3 was launched on Launch Vehicle Mark-3, which previously launched the Chandrayaan 2.
• Chandrayaan 3 is also a technological demonstrator to test landing and roving capabilities.
• The Vikram Lander and Pragyaan rover has the same name as the lander and Rover of Chandrayaan 2 and has a similar design.

Soft landing
• A soft landing means a safe landing. This implies that the space craft should be safe after its landing.
• Soft landing is essential as the ISRO can take up crucial international space projects once it can prove its soft-landing capabilities to the world.

Previous Lunar missions of India

1. Chandrayaan- 1

• Chandrayaan-1, India’s first mission to the Moon, was launched successfully on October 22, 2008, from SDSC SHAR, Srihari Kota.
  • The spacecraft was orbiting around the Moon at a height of 100 km from the lunar surface for chemical, mineralogical, and photo-geologic mapping of the Moon.
  • The spacecraft carried 11 scientific instruments built in India, the USA, the UK, Germany, Sweden, and Bulgaria.
  • After completing all the primary mission objectives, the orbit was raised to 200 km in May 2009. Chandrayaan-1 played a crucial role in the discovery of water molecules on the Moon.
  • The satellite made more than 3400 orbits around the Moon, and the mission was concluded when communication with the spacecraft was lost on August 29, 2009.

2. Chandrayaan – 2

• A highly complex mission, representing a significant technological leap compared to the previous missions of ISRO, which brought together an orbiter, Lander, and Rover to explore the Moon’s South Pole.
  • This unique mission aims at studying not just one area of the Moon but all the areas combining the exosphere, the surface, and the sub-surface of the Moon in a single mission.
• The launch of Chandrayaan 2 was successful. It completed a distance of 3,84,000 Km from Earth to Mars.
  • However, upon landing, despite being only half a km away from the surface of the Moon, it could not soft land due to a software glitch.
  • The plan was to study the Moon’s surface for 14 days and send the information using the Vikram Rover.
  • However, the mission was left uncompleted due to the failure of communication devices.

Mission objectives of Chandrayaan-3 are:
1. To demonstrate Safe and Soft Landing on Lunar Surface
2. To demonstrate Rover roving on the moon and
3. To conduct in-situ scientific experiments.

Significance of Chandrayaan 3
• The primary objective of Chandrayaan 3 is to demonstrate the engineering and capability behind landing a spacecraft on the surface of the Moon.
• The mission will make ISRO ready to prepare for a lander for Mars.
• Also, the mission is significant for the upcoming Indo-Japanese mission to the Lunar south pole.

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Importance of its landing location
• Earth is tidally locked to the Moon. This implies that only one side of the Moon is always visible to the Earth. 41% of the Moon remains hidden from the Earth.
• Similarly, there are large craters on the South pole of the Moon where sunlight has not reached for billions of years.
• By studying these craters, we can get important information about the origins of our solar system.
• It is often believed that water may be hidden in these craters.
• Also, there is a presence of hydrogen, methane, ammonia, sodium, silver, and mercury; This location becomes an important center for upcoming solar missions.

Improvements from chandrayaan 2 to chandrayaan 3

1. Payload
   • The payload of Chandrayaan 2 was a complex one. It had three components – A lander, a Rover, and an orbiter. Also, the orbiter had completed its mission.
   • The payload of Chandrayaan 3 is much more simplified. It only has a rover and a lander.
2. Powerful lander

• The legs of the lander have been made much more robust compared to the previous version. Thus, it can better resist the impact of landing and survive it.

3. Engine capacity
   • The engine of Chandrayaan 2 was not powerful enough to slow down in time for landing, causing it to fall about 750 km off the intended spot.
   • Now the engine capacity of its lander has increased. At the same time, a hazardous detection system has also been added to it.
   4. Instruments
   • Chandrayaan 3 has a Propulsion Module, which will work from Earth orbit to Moon orbit. It carries one payload known as SHAPE, which stands for Spectro Polarimeter of Habitable Planet Earth.
   • It will read the Earth’s data and use it to find habitable exoplanets outside our solar system.
4. Launch Vehicle
   • Launch Vehicle Mark 3 can carry 30% more weight than our 1st GSLV Mark 2 Launch Vehicle.
   • The success of this launch vehicle is essential for India as this will prepare ISRO to send heavier payloads into space and demonstrate our capabilities to the world.

6. Cost
   • Chandraayan 2 was launched for approximately ₹ 870 cr. At the same time, the total budget of Chandrayaan 3 will be approximately around ₹615 cr.
7. Payloads of Chandrayaan 3
8. Lander payloads
   • Chandra’s Surface Thermophysical Experiment (ChaSTE) – To measure the thermal conductivity and temperature
   • Instrument for Lunar Seismic Activity (ILSA) – For measuring the seismicity around the landing site
   • Langmuir Probe (LP) – To estimate the plasma density and its variations. A passive Laser Retroreflector Array from NASA is accommodated for lunar laser ranging studies.
   • RAMBHA – Vikram lander Consists of RAMBHA, which will study the ionosphere and wispy atmosphere above the Moon.
9. Rover payloads
   • Alpha Particle X-ray Spectrometer (APXS) and Laser Induced Breakdown Spectroscope (LIBS) – for deriving the elemental composition in the vicinity of landing site.

Challenges –

Absence of solar power when Lunar night begins
• Lander and Rover require solar power to function.
• After the landing, the expected lifetime of the mission will be around 14 days.
• After 14 days, when the lunar night begins, there is no atmosphere on the Moon to redistribute heat on the surface. Therefore, the temperature range drops from 120 degrees Celsius to -120 degrees Celsius once the sun sets.
• Lander and Rover cannot withstand this cold without solar power to keep them warm.

Conclusion
• The ability to make a soft landing on a planetary body is a crucial technology which can impact ISRO’s ability to carry out, or participate in, other scientific missions to the moon.
• The US Artemis programme significantly expands the scale of future exploration.
• In the future, there is a likelihood of discontinuing the International Space Station, leading several nations, including the US, to explore the construction of more permanent structures on the lunar surface.
• India aspires to become a significant partner in these endeavors.

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