The primary goal of the Chandrayaan-3 mission was to showcase a soft landing near the lunar south polar region and conduct experiments using instruments on the Vikram and Pragyaan modules. The Indian Space Research Organization (ISRO) reported a unique experiment where the Propulsion Module (PM) of Chandrayaan-3 was maneuvered from an orbit around the Moon to an orbit around Earth.
ISRO shared the update on Chandrayaan-3’s Propulsion Module: “Ch-3’s Propulsion Module (PM) takes a successful detour! In another unique experiment, the PM is brought from Lunar orbit to Earth’s orbit. An orbit-raising manoeuvre and a Trans-Earth injection manoeuvre placed PM in an Earth-bound orbit.”
The Vikram Lander successfully touched down on the Moon on August 23, deploying the Pragyan rover. The scientific instruments operated for one lunar day, meeting the mission objectives of Chandrayaan-3. The Propulsion Module’s primary objective was to transport the Lander module from Geostationary transfer orbit (GTO) to the final lunar polar circular orbit, separating the Lander afterward.
Following the successful separation, the SHAPE payload in the PM was operated to continue Earth observations. The plan involved re-orbiting the PM to a suitable Earth orbit, considering collision avoidance and safety measures. The mission executed maneuvers to raise apolune altitude, target an Earth orbit of 1.8 lakhs x 3.8 lakhs km, and perform a Trans-Earth injection maneuver.
The PM completed four Moon fly-bys and departed the Moon’s Sphere of Influence (SOI) on November 10. Currently, it is orbiting Earth, and the SHAPE payload is operational when Earth is in its field of view. The operations include a special activity during a Solar Eclipse on October 28, 2023.
The return maneuvers of Chandrayaan-3’s PM provided valuable insights for future missions, such as planning and executing trajectories and maneuvers for Moon-to-Earth return, software module development for maneuver planning, gravity-assisted flyby across celestial bodies, and ensuring controlled end-of-life measures to prevent debris creation on the Moon’s surface.
