Chandrayaan-3 lander's journey to the moon has successfully returned to Earth orbit, showcasing key technologies for India's prospective lunar sample return mission.

The propulsion module that facilitated the Chandrayaan-3 lander's journey to the moon has successfully returned to Earth orbit, showcasing key technologies for India's prospective lunar sample return mission.

Image Credit :India's space agency, ISRO Chandrayaan-3 lander's

India's space agency, ISRO, disclosed on December 4 that the 2,145-kilogram propulsion module, previously engaged in transporting the Chandrayaan-3 lander from an initial elliptical Earth orbit to low lunar orbit, had completed a series of maneuvers since October. These maneuvers effectively brought the spacecraft back from a low lunar orbit to a high Earth orbit. This unexpected development was not previously communicated by ISRO.

Initially launched on July 14, the propulsion module, a modified version of ISRO's I-3K satellite bus, underwent various maneuvers, including raising the apogee of its orbit, translunar injection burn, and lunar orbit insertion burn. Subsequently, it transitioned into a nearly circular orbit about 150 kilometers above the moon, ultimately separating from the lander on August 17.

While the lander successfully touched down on the moon on August 23, the propulsion module continued its orbital trajectory, equipped with an instrument named Spectro-polarimetry of Habitable Planet Earth (SHAPE), dedicated to observing the Earth. Post-lander separation, ISRO provided minimal information about the propulsion module's activities.

ISRO's decision to return the propulsion module to Earth orbit stemmed from the realization that the precision of the launch and previous maneuvers had left more than 100 kilograms of propellant on board. The maneuvering plan, initiated on October 9, involved raising the apolune, or high point in its lunar orbit, from 150 to 5,112 kilometers.

A transearth injection maneuver on October 13 set the module on a trajectory for four close approaches to the moon before departing its sphere of influence on November 10. Subsequently, the spacecraft entered a high Earth orbit, achieving its first perigee on November 22 at an altitude of 154,000 kilometers.

ISRO emphasized that these maneuvers not only enabled SHAPE to continue observations closer to Earth but were also designed to glean additional information for future lunar missions and demonstrate operational strategies for a sample return mission.

While ISRO has not formally announced plans for a lunar sample return mission, discussions about such a mission have taken place. Officials have acknowledged a tight timetable for space exploration goals set by the Indian government, potentially including a lunar sample return within four years. This aligns with a broader vision mentioned in a meeting chaired by Indian Prime Minister Narendra Modi on October 17, which outlined ambitious objectives such as an Indian space station by 2035 and a crewed lunar landing by 2040.

The propulsion module's return to Earth orbit represents a noteworthy technological demonstration for lunar sample return, adding to the anticipation surrounding India's lunar exploration endeavors. As ISRO continues to advance its capabilities, the successful completion of such missions will contribute significantly to the nation's standing in space exploration.