Chandrayaan-3 spacecraft achieves ‘near-circular orbit’ around Moon after performing another maneuver


Pubnews: Chandrayaan-3 spacecraft achieves ‘near-circular orbit’ around Moon after performing another maneuver. India’s ambitious third lunar mission, Chandrayaan-3, reached another milestone on Monday, as it conducted yet another maneuver to bring it even closer to the lunar surface, according to the Indian Space Research Organisation (ISRO).

The national space agency, headquartered in India, announced that the spacecraft has successfully achieved a “near-circular orbit” around the moon following its launch on July 14. Chandrayaan-3 entered lunar orbit on August 5, and subsequent orbit reduction maneuvers were executed on August 6 and 9.

ISRO conveyed in a tweet, “The circular orbit phase has commenced. Today’s precise maneuver has established a near-circular orbit of 150 km x 177 km.”

The next maneuver is scheduled for August 16, around 8:30 am.

As Chandrayaan-3’s mission advances, ISRO is progressively performing maneuvers to gradually lower its orbit and position it over the lunar poles. According to ISRO sources, another operation is planned for August 16, with the objective of transitioning the spacecraft to a 100 km orbit. Subsequently, the landing module, comprising the lander and rover, will detach from the propulsion module.

Following this, the lander is projected to undergo a “deboost” maneuver, culminating in a soft landing on the Moon’s south polar region on August 23.

Chandrayaan-3 spacecraft achieves 'near-circular orbit'

In a statement last week, ISRO chairman S Somnath highlighted the critical aspects of the landing process, particularly the need to alter the lander’s velocity from a horizontal orientation at an altitude of 30 km to the final vertical landing approach. He noted that this shift from horizontal to vertical is a pivotal challenge in the process.

Somnath elucidated, “At the outset of the landing process, the velocity is approximately 1.68 km per second, but this velocity is horizontal in relation to the Moon’s surface. Chandrayaan-3, however, must attain a vertical orientation, of nearly 90 degrees. This necessitates a shift from horizontal to vertical—a fascinating mathematical calculation. We’ve conducted extensive simulations, as this is where we encountered issues in the previous Chandrayaan-2 mission.”

Moreover, ensuring minimal fuel consumption, accurate distance calculations, and proper algorithm functionality are integral elements of the mission.

He added, “We’ve incorporated extensive simulations, adjusted the guidance design, and integrated numerous algorithms to ensure a successful landing and to control the necessary dispersion at all stages.”

Over the course of three weeks since its launch on July 14, ISRO has executed more than five maneuvers, progressively positioning the Chandrayaan-3 spacecraft into orbits of varying proximity to Earth. On August 1, a pivotal catapult maneuver propelled the spacecraft from Earth’s orbit toward the Moon. Following this trans-lunar injection, Chandrayaan-3 transitioned away from Earth’s orbit to embark on its lunar trajectory.

Chandrayaan-3 is a sequel to Chandrayaan-2, which showcased successful safe landing and orbiting capabilities on the lunar surface. The mission encompasses an indigenous propulsion module, a lander module, and a rover, aimed at advancing and demonstrating technologies requisite for inter-planetary missions.

The propulsion module will propel the lander and rover configuration to a lunar orbit of 100 km. The propulsion module carries a Spectropolarimetry of the Habitable Planet Earth (SHAPE) payload designed to analyze Earth’s spectral and polar measurements from lunar orbit.

Chandrayaan-3’s mission objectives encompass achieving a secure and gentle lunar landing, demonstrating rover mobility on the Moon, and conducting on-site scientific experiments.

The lander will possess the ability to effect a gentle landing at a predetermined lunar site and deploy the rover, which will perform in-situ chemical analyses of the lunar surface during its mobility.

Both the lander and rover carry scientific instruments to execute experiments on the lunar terrain.