05 December 2023- In a landmark achievement that underscores its growing capabilities in space exploration, the Indian Space Research Organisation (ISRO) has successfully repositioned the Propulsion Module (PM) of its Chandrayaan-3 mission from orbiting the Moon to orbiting Earth. This maneuver, reminiscent of the hop experiment on the Vikram Lander, is not just a technical triumph but a symbol of human ingenuity and the potential for future interplanetary missions.
Chandrayaan-3, launched on July 14, 2023, from Satish Dhawan Space Centre, set off on a voyage to demonstrate a soft landing near the lunar south polar region and conduct experiments using the instruments on the Vikram lander and Pragyaan rover. Making global headlines, the mission achieved a historic milestone on August 23rd with Vikram Lander’s successful lunar touchdown, followed by the deployment of the Pragyaan rover.
The mission, having met its primary objectives, took an innovative turn with the Propulsion Module, initially tasked with transporting the Vikram lander to the Moon. Thanks to precise orbit injection by LVM3 and optimal Earth/lunar burn maneuvers, over 100 kg of fuel remained in the PM. This surplus fuel spurred ISRO to extend the mission’s scope, aiming to gather additional data for future lunar missions and demonstrate strategies for a potential sample return mission.
The re-orbiting of the PM to Earth was meticulously planned, considering collision avoidance strategies to prevent any potential impact on the Moon’s surface or interference with the Earth’s Geostationary Orbit (GEO) belt. The first maneuver on October 9, 2023, raised the apolune altitude to 5112 km. The subsequent Trans-Earth injection maneuver on October 13th positioned the propulsion module in an Earth orbit with a period of nearly 13 days and a 27-degree inclination.
Since departing from the Moon’s Sphere of Influence (SOI) on November 10th, the propulsion module has successfully completed multiple Moon fly-bys and crossed its first perigee on November 22nd at an altitude of 1.54 lakh km. The UR Rao Satellite Centre, along with ISRO’s flight dynamics team, developed an analysis tool for this operation, validated through the return maneuvers.
The mission’s novel approach extends to the operation of the Spectro-polarimetry of HAbitable Planet Earth (SHAPE) payload aboard the PM, providing valuable Earth observation data. This includes a special observation during the solar eclipse on October 28, 2023, offering unique insights into our own planet.
ISRO’s Chandrayaan-3 mission marks a significant milestone in India’s space exploration history. It not only demonstrates the ability to navigate complex orbital maneuvers but also contributes valuable insights and techniques for future interplanetary missions. This achievement is a clear indicator of India’s growing role in the global space community and a beacon of inspiration for future missions that may one day venture beyond the Moon and back.