Comparing Chandrayaan 3 and Chandrayaan 2 Missions: Key Differences

The Chandrayaan missions launched by the Indian Space Research Organisation (ISRO) are among the most ambitious and innovative in lunar exploration. While both Chandrayaan 2 and Chandrayaan 3 share a common goal of exploring the moon, they have distinct differences in their mission designs, objectives, and equipment. This article highlights the key differences between these two missions.

Main Components and Approaches

Chandrayaan 2 and Chandrayaan 3 both comprised a lander and a rover, but the designs and approaches differed significantly. Chandrayaan 2, launched in 2019, consisted of an orbiter, the Vikram lander, and the Pragyan rover. Its primary mission was to study the lunar topography, mineralogy, elemental abundance, and lunar exosphere, with a particular focus on finding water ice in the polar regions. The Vikram lander aimed to achieve a soft landing within a 500mx500m area.

In contrast, Chandrayaan 3, launched in 2023, aimed to land with a more stringent accuracy. The lander, also named Vikram, was paired with the Pragyan rover. The absence of an orbiter in Chandrayaan 3 was a deliberate choice, based on a failure-based approach to ensure mission success. The lander aimed for a soft landing within a 4kmx2.4km area, showcasing a significant improvement in landing accuracy.

Primary Objectives

The primary objectives of the two missions also differed. Chandrayaan 2's main aim was to explore the lunar topography, mineralogy, elemental abundance, and the exosphere. It also sought to detect water ice in the polar regions. With Chandrayaan 3, the objectives shifted. The mission aimed to conduct a soft landing on the lunar south pole, deploy the rover, investigate the composition and distribution of water on the lunar surface, and study the mineralogy and geology. The mission also focused on understanding the lunar environment and its impact on the moon.

Design and Equipment

The designs and equipment of Chandrayaan 2 and Chandrayaan 3 were also different, reflecting the lessons learned from the previous mission. The Chandrayaan 2 lander had a central thrust and five legs, while Chandrayaan 3 improved the design by removing the central thrust, strengthening the legs for high-velocity landings, and adding more solar panels for extra power and sustainability. These modifications were observed in the previous mission and were implemented to mitigate potential failures and ensure mission success.

The apparatus carried by the two missions also differed. Chandrayaan 2's orbiter carried nine scientific instruments, while Chandrayaan 3's orbiter carried only one instrument: The Spectro-Polarimetry of Planet Earth (SPE). Both missions used the same launch rocket, although some minor modifications were made to enhance performance. Additionally, Chandrayaan 2 had a single main computer, while Chandrayaan 3 was equipped with two onboard computers to enhance reliability and operational flexibility.

Payloads and Scientific Instruments

The payloads and scientific instruments on Chandrayaan 2 and Chandrayaan 3 were also distinct. Chandrayaan 2's lander payload included RAMBHA, ChaSTE, ILSA, and LP, while the Pragyan Rover carried an Alpha-particle X-ray spectrometer and a Laser-induced Breakdown Spectroscope. Chandrayaan 3's payloads include RAMBHA from NASA, ChaSTE, LP, and ILSA. The Pragyan rover's payloads remain consistent with those of Chandrayaan 2.

Both missions have contributed immensely to our understanding of the lunar environment and are milestones in the annals of space exploration. Chandrayaan 3, with its refined design and objectives, is set to build on the achievements of Chandrayaan 2 and further our knowledge of the moon.