Chandrayaan 3: Mission, Objectives, And More You Would Like To Know

Chandrayaan-3 is a follow-up mission to Chandrayaan-2, with the goal of demonstrating the entire process of safely landing on and moving across the lunar surface. This mission includes a Lander and Rover setup, launched using the LVM3 vehicle from SDSC SHAR in Sriharikota. 

The propulsion module will carry the Lander and Rover to a lunar orbit positioned 100 km above the surface. Notably, the propulsion module is equipped with the Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload, designed to analyze Earth's spectral and polarimetric characteristics from the moon's perspective.

The Lander carries a set of scientific instruments: ChaSTE (Chandra’s Surface Thermophysical Experiment) for assessing thermal conductivity and temperature, ILSA (Instrument for Lunar Seismic Activity) to measure seismic activity around the landing area, and LP (Langmuir Probe) for determining plasma density and its fluctuations. Additionally, a passive Laser Retroreflector Array provided by NASA is included to support lunar laser ranging investigations.

The Rover is equipped with an Alpha Particle X-ray Spectrometer (APXS) and a Laser-Induced Breakdown Spectroscope (LIBS) to determine the elemental composition around the landing zone.

Chandrayaan-3 is an upcoming lunar mission composed of a Lander module (LM), Propulsion module (PM), and Rover. Its main purpose is to demonstrate advanced technologies for interplanetary missions. The Lander can make a soft landing on the moon and release the Rover, which will perform chemical analyses of the lunar surface while moving. Both the Lander and Rover have scientific instruments for experiments. The Propulsion Module transports the Lander to a lunar polar orbit 100 km above the surface, separating afterwards. This module also has an extra-scientific instrument for post-separation operations. The mission will be launched using the LVM3 M4 vehicle and placed in an Elliptic Parking Orbit (EPO) measuring about 170 x 36500 km.

Chandrayaan 3: Mission Objectives

The goals of the Chandrayaan-3 mission encompass:

• Showcasing a secure and gentle landing on the lunar surface

• Illustrating the movement of the Rover on the moon

• Performing scientific experiments directly on the lunar surface.

Chandrayaan 3: Mission Objectives: How to Achieve?

To accomplish the mission objectives, the Lander incorporates a range of sophisticated technologies, including:

• Altimeters: Laser-based and RF-based altimeters for measuring altitude

• Velocimeters: Laser Doppler Velocimeter and a camera for capturing horizontal velocity

• Inertial Measurement: Laser Gyro-based inertial referencing and a package containing accelerometers

• Propulsion System: Throttleable liquid engines with a thrust of 800N, 58N attitude thrusters, and electronic controls for engine modulation

• Navigation, Guidance & Control (NGC): Design of the powered descent trajectory and associated software components

• Hazard Detection and Avoidance: Camera and algorithms for detecting and avoiding hazards during landing

• Landing Leg Mechanism.

To demonstrate these advanced technologies under terrestrial conditions, several specialized tests for the Lander have been planned and successfully executed, including:

• Integrated Cold Test - Utilizing a helicopter as a test platform to assess integrated sensors and navigation performance

• Integrated Hot Test – Employing a tower crane as a test platform to evaluate closed-loop performance with sensors, actuators, and NGC

• Lander Leg Mechanism Performance Test - Conducted on a lunar simulant test bed to simulate various touchdown scenarios.