Chandrayaan 3: Mission Overview, Objectives, Mission profile, Previous Chandrayaan Missions

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 consists of Lander and Rover configuration. It has been launched by Launch Vehicle Mark 3 (LVM3) from Satish Dhawan Space Centre, Sriharikota (SDSC SHAR). This article aims to provide a comprehensive overview of the Chandrayaan 3 and its mission objectives, mission profile, previous Chandrayaan missions & conclusion.

Mission Overview

The propulsion module carried the lander and rover configuration till 100 km lunar orbit. The propulsion module has Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload to study the spectral and Polari metric measurements of Earth from the lunar orbit.

• 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(LRA) from NASA is accommodated for lunar laser ranging studies.
• 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.

Chandrayaan-3 consists of an indigenous Lander module(LM), Propulsion module(PM) and a Rover with an objective of developing and demonstrating new technologies required for Inter planetary missions. The Lander is equipped with the capability to soft land at a specified lunar site and deploy the Rover which will carry out in-situ chemical analysis of the lunar surface during the course of its mobility. The Lander and the Rover have scientific payloads to carry out experiments on the lunar surface.

The main function of the Propulsion module(PM) is to carry the Lander module(LM) from launch vehicle injection till the final lunar 100 km circular polar orbit and separate the LM from PM. Apart from this, the Propulsion Module also had one scientific payload as a value addition which operated post separation of the Lander Module.

Mission Objectives of Chandrayaan 3

The following are the objectives behind Chandrayaan 3 mission:

• To demonstrate Safe and Soft Landing on Lunar Surface
• To demonstrate Rover roving on the moon 
• To conduct in-situ scientific experiments.

To achieve the mission objectives, several advanced technologies are present in Lander which are as follows:

• Altimeters: Laser & RF based Altimeters
• Velocimeters: Laser Doppler Velocimeter & Lander Horizontal Velocity Camera
• Inertial Measurement: Laser Gyro based Inertial referencing and Accelerometer package
• Propulsion System: 800N Throttleable Liquid Engines, 58N attitude thrusters & Throttleable Engine Control Electronics
• Navigation, Guidance & Control (NGC): Powered Descent Trajectory design and associate software elements
• Hazard Detection and Avoidance: Lander Hazard Detection & Avoidance Camera and Processing Algorithm
• Landing Leg Mechanism.

Objectives of Payloads: Chandrayaan 3

The objectives of scientific payloads planned on Chandrayaan-3 Lander Module and Rover are provided below:

Lander Payloads	Objectives
Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere (RAMBHA)	To measure the near surface plasma (ions and electrons) density and its changes with time
Chandra’s Surface Thermo physical Experiment (ChaSTE)	To carry out the measurements of thermal properties of lunar surface near polar region.
Instrument for Lunar Seismic Activity (ILSA)	To measure seismicity around the landing site and delineating the structure of the lunar crust and mantle.
LASER Retroreflector Array (LRA)	It is a passive experiment to understand the dynamics of Moon system.

Elements of Chandrayaan 3

Mission Profile of Chandrayaan 3

Chandrayaan Missions of India

Chandrayaan missions are specifically designed for lunar exploration. Below are the information about Chandrayaan 1 and chandrayaan 2 missions:

• Chandrayaan-1: It was launched in 2008. The mission aimed to create a detailed three-dimensional atlas of the Moon’s near and far sides while conducting chemical and mineralogical mapping with high resolution. It made significant discoveries, such as detection of water and hydroxyl on the lunar surface and confirming the presence of ice in the North Polar region.
• Chandrayaan-2: The mission was launched in 2019. It consisted of an Orbiter, Lander and Rover. Although the lander and rover experienced partial success due to the crash on the lunar surface, the Orbiter successfully collected valuable data, including the discovery of water signatures across all latitudes.
• Chandrayaan-3: The main objective of Chandrayaan 3 is to demonstrate India’s technical capabilities and achieve a successful soft landing on the moon. This landing requires precise control to bring the spacecraft from high speeds to a gentle touchdown without human intervention. The scientific payloads carried by the lander and rover are similar to those of the previous mission, focusing on studying lunar quakes, thermal properties, plasma changes near the surface and accurately measuring the Earth-moon distance. 

Conclusion

Chandrayaan 3 mission showcased both technological and strategic achievement in terms of lunar exploration. Its successful soft-landing in the south polar region provided crucial information on the composition and thermophysical properties of the lunar side of the moon. This achievement demonstrated both India’s robotic exploration capabilities and also established a foundational base for understanding sustained lunar scientific inquiry for the betterment of mankind.

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