Chandrayaan-3 Propulsion Module Successfully Transferred from Lunar to Earth Orbit

In an unprecedented feat, the Propulsion Module (PM) of Chandrayaan-3 has achieved a remarkable transition, moving from its initial lunar orbit to now gracefully orbiting the Earth. Originally tasked with facilitating the soft landing near the lunar south pole and conducting experiments with the Vikram Lander and Pragyaan rover, Chandrayaan-3 achieved its mission goals with Vikram's historic touchdown on the Moon's surface on August 23. Following this, Pragyaan rover operations were conducted for the designated mission duration of one lunar day. The primary purpose of the PM was to transport the Lander module from GTO to its final lunar polar circular orbit before separating from the Lander. Subsequently, the SHAPE payload in the PM was activated for spectro-polarimetry of Earth. With meticulous orbital maneuvers and efficient fuel usage, the PM retained over 100 kg of fuel post-lunar operations, surpassing its initial fuel estimates. Seizing the opportunity to gather additional insights for future lunar missions and demonstrate mission strategies for sample return missions, a decision was made to repurpose the available fuel. Consequently, the PM was maneuvered to an Earth orbit in a meticulously planned trajectory to ensure safety protocols, preventing collisions with the Moon's surface or Earth's GEO belt. Several precise maneuvers were executed, notably elevating the apolune altitude and performing a Trans-Earth injection maneuver in October 2023. Subsequently, the PM embarked on a trajectory involving four Moon fly-bys before departing the Moon's Sphere of Influence (SOI) on November 10, eventually entering Earth's orbit. Presently, the PM orbits Earth with a period of nearly 13 days and an inclination of 27 degrees, ensuring no imminent threats to operational Earth-orbiting satellites. The SHAPE payload continues its Earth observation operations whenever within its field of view, even conducting a special operation during a Solar Eclipse on October 28, 2023. The maneuver planning, execution, and analysis carried out by ISRO's UR Rao Satellite Centre flight dynamics team during this operation have yielded significant outcomes for future missions. These include trajectory planning from Moon to Earth, software module development for such maneuvers, executing gravity-assisted flybys, and ensuring controlled end-of-life measures to prevent debris creation upon the PM's re-entry. This monumental achievement marks a pivotal stride in space exploration, showcasing India's prowess in precision maneuvering and strategic mission planning for future interplanetary endeavors.