Launched on July 14, Chandrayaan-3 successfully entered the moon’s orbit just 11 days ago. Unlike its predecessor, the mission’s goal is to accomplish what was previously unattained: a gentle landing on the lunar surface in proximity to the South Pole, followed by surface exploration.
Chandrayaan-3, the latest lunar mission by the Indian Space Research Organisation (ISRO), successfully attained its final lunar orbit of 153×163 km on Wednesday.
This accomplishment comes after a series of meticulously executed maneuvers that gradually reduced the spacecraft’s orbit and velocity around the moon.
ISRO confirmed the upcoming separation of the lander-rover module from the propulsion module on Thursday. ISRO conveyed, “The time has come for the Propulsion Module and the Lander Module to embark on their independent journeys.” Following the separation, the lander-rover module will initiate preparations for a powered descent to the lunar surface, scheduled for August 23.
Conversely, the propulsion module will remain in its current orbit for approximately three to six months. During this time, it will undertake a scientific mission named Spectro-polarimetry of Habitable Planet Earth (SHAPE), focused on studying Earth’s spectro-polarimetric signatures from its lunar vantage point.
The experiment’s purpose is to investigate the spectral characteristics of a habitable planet, in this case, Earth, which could contribute to the exploration of exoplanets and the search for signs of extraterrestrial life. Chandrayaan-3 was launched on July 14 and successfully entered the moon’s orbit 11 days ago.
The mission’s primary objective is to achieve what its predecessor, Chandrayaan-2, could not—a soft landing near the moon’s South Pole, followed by surface exploration. To ensure the success of Chandrayaan-3, alterations were made to the lander’s design and mission specifications. ISRO Chairman S. Somanath elaborated on the approach, stating, “Unlike Chandrayaan-2, where we designed for success, Chandrayaan-3 follows a failure-based design approach.
We are anticipating potential issues and designing to mitigate them.” Enhancements to the lander’s capabilities include improved maneuverability during descent, an expanded landing area of 4 km x 2.4 km, increased sensor integration, removal of one thruster, and reinforced landing legs to accommodate slightly higher velocities during landing.
Additional solar panels were integrated to ensure mission continuity even if the lander encounters periods without direct sunlight.
Extensive testing was conducted to bolster Chandrayaan-3’s resilience in diverse scenarios. It’s noteworthy that Chandrayaan-2 marked India’s initial attempt at developing a lander and rover for a lunar mission.
The initial plan involved collaboration with Russia for the lander-rover module; however, Russia withdrew due to technological concerns arising from the failure of its Fobos-Grunt mission to Mars’s moon.
The failure of Chandrayaan-2 during its final phase was attributed to a combination of factors. Somanath cited issues with the lander’s engines, which generated slightly more thrust than anticipated. Programming constraints prevented maneuvering during a critical camera-coasting phase, leading to cumulative errors.
Subsequent course corrections were hindered by the spacecraft’s limited software-controlled turning capability. Additionally, conflicting requirements emerged between reducing descent velocity and accelerating towards the desired landing site.
As a result, the lander experienced a higher-velocity impact upon landing. Chandrayaan-3’s mission objectives, design enhancements, and meticulous preparations underscore India’s commitment to lunar exploration and technological advancement in space exploration endeavors
