India's Lunar Milestones Celebration On August 23: How Chandrayaan-3 Outshines Previous Moon Missions

Chandrayaan-3 is poised for a significant milestone as it approaches its scheduled landing on the Moon's south polar region on Wednesday at 6:04 pm, following a 40-day journey. The Indian Space Research Organisation (ISRO) has confirmed that the Chandrayaan-3 mission is proceeding on schedule.

Should the Chandrayaan-3 mission successfully achieve a lunar touchdown and deploy a robotic lunar rover, India will join the ranks of the United States, China, and the erstwhile Soviet Union as the fourth country to master soft-landing technology on the Moon.

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Historical Context of Chandrayaan Missions

The Chandrayaan mission series, initiated by ISRO, includes a sequence of lunar exploration missions. The first mission, Chandrayaan-1, was launched in 2008 and successfully entered lunar orbit.

Chandrayaan-2 experienced a setback during its lunar phase when its lander, Vikram, crashed into the Moon's surface on September 7, 2019, due to anomalies in the braking system.

Chandrayaan-3, a continuation of the Chandrayaan-2 mission, aims to demonstrate safe and soft-landing capabilities on the lunar surface, roving on the Moon, and conducting in-situ scientific experiments. The mission, costing approximately Rs 600 crore, was launched on July 14, 2023, aboard the Launch Vehicle Mark-III (LVM-3) rocket for a 41-day voyage to the lunar south pole.

Mission Details and Progress

The spacecraft underwent a series of orbit-raising manoeuvres to gradually increase its orbit before transitioning directly towards the Moon. These earth-bound manoeuvres continued until July 31, after which the spacecraft entered translunar orbit.

The Trans Lunar Injection (TLI) manoeuvre on August 1 slingshotted the spacecraft towards the Moon. Chandrayaan-3 entered lunar orbit on August 5, with subsequent orbit reduction maneuvers performed on August 6, 9, 14, and 16. On August 16, the fifth and final orbit reduction manoeuvre was successfully executed.

On August 17, the Lander Module (LM), consisting of the Vikram lander and the Pragyan rover, separated from the Propulsion Module. A "deboost" process was carried out to position the lander in an orbit with a Perilune of 30 kilometres and an Apolune of 100 kilometres.

Following a second and final deboosting operation on August 20, the Lander Module was placed in a 25 km x 134 km orbit around the Moon. The landing attempt is scheduled for August 23 at 6:04 pm.

Chandrayaan-3 Components and Objectives

Chandrayaan-3 comprises three main components: the Lander Module (LM), the Propulsion Module (PM), and the Rover. The Lander Module is designed to soft-land at a specified lunar site and deploy the Rover, which will conduct research on the lunar surface. Both the Lander and the Rover are equipped with scientific payloads for surface experiments, while the Propulsion Module's role is to transport the Lander Module from launch vehicle injection to the final lunar orbit.

The Propulsion Module also carries the SHAPE payload -Spectro-polarimetry of Habitable Planet Earth- to study Earth from lunar orbit. The mission's success will further bolster India's space exploration capabilities and promote investment in private space launches and satellite-based businesses.

Landing and Post-Landing Operations

Upon landing, the Chandrayaan-3 mission is expected to remain operational for approximately two weeks, during which it will conduct a series of experiments, including a spectrometer analysis of the lunar surface's mineral composition. Shortly after touchdown, a side panel of the Vikram lander will unfold to create a ramp for the Pragyan rover. The rover will then descend onto the lunar surface and commence its activities, moving at a speed of 1 cm per second, while transmitting data about the lunar surface and its processes.