India Chandrayaan-3 (Lunar Mission) Successful Moon Landing

On July 14, 2023, India successfully launched Chandrayaan-3, marking a significant achievement in lunar exploration. The mission culminated in the successful landing of a lander and rover at the lunar south pole region on August 23, 2023, at 18:02 IST. This accomplishment not only made India the first country to softly land a spacecraft near the lunar south pole but also established it as the fourth nation to achieve a successful Moon landing.

A previous attempt, Chandrayaan-2, was launched by the Indian Space Research Organisation (ISRO) on July 22, 2019. However, this mission faced challenges as the lander deviated from its intended trajectory and crashed during its attempted landing in September 2019. Following the Chandrayaan-2 setback, Chandrayaan-3 and other lunar missions were proposed to continue India's lunar exploration endeavours.

The European Space Tracking network (ESTRACK), operated by the European Space Agency (ESA), provided crucial support to Chandrayaan-3. This collaboration was part of a cross-support arrangement, wherein ESA offered tracking assistance for upcoming ISRO missions, including the Gaganyaan human spaceflight program and the Aditya-L1 solar research mission. In return, ISRO pledged similar tracking support for future ESA missions using its own tracking stations.

The Chandrayaan-3 spacecraft was composed of three main components:

1. Propulsion Module: This module facilitated the journey of the lander and rover configuration to a lunar orbit of 100 kilometers. It featured a box-like structure with a prominent solar panel on one side and a cylindrical mounting structure (Intermodular Adapter Cone) for the lander on top.
2. Lander (Vikram): The Vikram lander was responsible for executing the soft landing on the lunar surface. It possessed a box-shaped design, equipped with four landing legs and four landing thrusters capable of generating 800 newtons of thrust each. The lander carried the rover and a range of scientific instruments for on-site analysis. Unlike its predecessor from Chandrayaan-2, the Chandrayaan-3 lander featured four variable-thrust engines with improved attitude control capabilities. This modification addressed one of the main causes of Chandrayaan-2's landing failure, ensuring better control during descent. The lander was also enhanced with a Laser Doppler Velocimeter (LDV) for measuring attitude in three directions. Structural improvements, increased instrumentation redundancy, and multiple contingency systems were integrated to enhance the lander's survivability during descent and landing. The landing region was more precisely targeted at 4 km by 4 km based on high-resolution images provided by Chandrayaan-2's orbiter.
3. Rover (Pragyan): The Pragyan rover, weighing 26 kilograms, was a six-wheeled vehicle with dimensions of 917 mm x 750 mm x 397 mm. Its purpose was to conduct various measurements supporting research on lunar surface composition, the presence of water ice in lunar soil, lunar impact history, and lunar atmosphere evolution.

The launch of Chandrayaan-3 took place on July 14, 2023, using an LVM3-M4 rocket from the Satish Dhawan Space Centre Second Launch Pad in Sriharikota, Andhra Pradesh, India. After various maneuvers, the spacecraft was successfully inserted into lunar orbit on August 5, 2023, through a lunar-orbit insertion (LOI) operation performed from the ISRO Telemetry, Tracking, and Command Network (ISTRAC) in Bengaluru. On August 17, the Vikram lander separated from the propulsion module to initiate the final phase of the mission.

The lander's descent on August 23, 2023, was a crucial moment. As it neared the Moon's surface, its engines fired for a braking maneuver at an altitude of 30 kilometers. After approximately 11.5 minutes, the lander reached an altitude of 7.2 kilometers, maintained that altitude for about 10 seconds, stabilized itself using eight smaller thrusters, and transitioned from a horizontal to a vertical orientation while continuing its descent. It then employed two of its four engines to slow down its descent to around 150 meters above the surface. After hovering at this altitude for roughly 30 seconds, the lander continued its descent and successfully touched down at 12:32 UTC.

To fund the project, ISRO initially requested 75 crore (approximately US$9.4 million) in December 2019. This funding would cover machinery, equipment, capital expenditure, and operational expenses. The former chairman of ISRO, K. Sivan, confirmed the project's existence and estimated its cost to be around 615 crore (equivalent to 721 crore or US$90 million in 2023).

In conclusion, Chandrayaan-3's successful launch, landing, and exploration marked a significant achievement for India's space program. The mission's innovative design and improvements based on lessons learned from Chandrayaan-2 contributed to its success, solidifying India's position in lunar exploration and paving the way for future ambitious space endeavours.