Q.What is the main task of India’s third moon mission which could not be achieved in its earlier mission? List the countries that have achieved this task. Introduce the subsystems in the spacecraft launched and explain the role of the Virtual Launch Control Centre’ at the Vikram Sarabhai Space Centre which contributed to the successful launch from Sriharikota.

Body Analysis

Countries That Have Achieved a Soft Moon Landing

Prior to Chandrayaan-3, only three nations had successfully executed a soft landing on the Moon:

1. United States (NASA)
2. Soviet Union (now Russia)
3. China (CNSA)

With the success of Chandrayaan-3, India became the fourth country globally to achieve this milestone and the first to land near the lunar south pole.

Subsystems of the Chandrayaan-3 Spacecraft

Chandrayaan-3 comprised three primary modules and several critical subsystems:

• Lander Module (Vikram): Engineered for the soft-landing phase. It was equipped with hazard detection cameras, laser altimeters, and throttleable liquid-propellant thrusters to ensure a controlled descent.
• Rover Module (Pragyan): A six-wheeled robotic vehicle housed inside the lander. It carried scientific payloads, including the Alpha Particle X-ray Spectrometer (APXS), to analyze the chemical and elemental composition of the lunar soil.
• Propulsion Module: Responsible for carrying the lander-rover configuration from the launch vehicle injection orbit to a 100 km circular lunar orbit. It also carried a payload called SHAPE to study Earth's spectro-polarimetric signatures from lunar orbit.
• Navigation, Guidance, and Control (NGC) System: Utilized advanced gyroscopes, star sensors, and accelerometer arrays to continuously calculate the spacecraft's trajectory and make real-time course corrections.
• Communication Subsystem: Facilitated data transmission between the Lander, the Rover, the Propulsion Module, and Earth-based stations (IDSN).
• Thermal Control Subsystem: Maintained optimal internal temperatures for sensitive electronics amidst the extreme thermal variations of the lunar environment.

Role of the Virtual Launch Control Centre (VLCC) at VSSC

The Virtual Launch Control Centre (VLCC) at the Vikram Sarabhai Space Centre (VSSC) in Thiruvananthapuram played a pivotal role in the successful launch of Chandrayaan-3 from the Satish Dhawan Space Centre (SDSC) in Sriharikota:

• Remote Monitoring and Diagnostics: The VLCC enabled real-time monitoring of the LVM3-M4 launch vehicle's health parameters, system pressures, and electrical systems during the countdown and launch phases.
• Decision Support Systems: It provided critical data analytics and simulated predictive models to help scientists quickly identify and mitigate any pre-launch anomalies.
• Resource Optimization: By enabling remote operations, the VLCC reduced the requirement for physical personnel at the launch site, enhancing safety and operational efficiency.
• Inter-centre Coordination: It acted as a seamless communication hub, bridging VSSC, SDSC, and the Mission Operations Complex (MOX) at ISTRAC to ensure synchronized decision-making.