India joins the exclusive club of nations that have reached the Moon. Chandrayaan-3 probe landed on the surface on the Moon August 23, marking a significant milestone for the entire nation. The historic touchdown occurred at 12:33 GMT, according to the Indian Space Research Organization (ISRO). “We have achieved a soft landing on the Moon! India is on the Moon!” announced Sreedhara Somanath, the president of ISRO, after the landing.
“This success belongs to all of humanity and will assist future lunar missions of other countries” said Indian Prime Minister Narendra Modi after the landing. ‘I am confident that all countries, including those in the global south, can achieve such feats. We can all aspire to reach the Moon and beyond.’
Two hours after the landing, ISRO released images showing the Moon ‘s surface as seen from the Chandrayaan-3 probe during descent. The agency successfully established a communication link between the spacecraft and mission control.
Soon, a solar-powered rover named Pragyan is expected to emerge from the Chandrayaan-3’s lander, Vikram. Robotic duo will spend one lunar day (approximately 14 Earth days) exploring the area. The goal is to gather scientific data about the Moon’s composition before the batteries run out after sunset.
“The entire country is excited about this mission” said Anil Bhardwaj, director of the Physical Research Laboratory (PRL) in India, which built some of the instruments onboard Chandrayaan-3, before the landing. “We all hope to derive new science from this mission”.
Lunar south pole
Chandrayaan-3 probe is India’s second attempt to land near the Moon ‘s south pole, a largely unexplored region of immense interest to both scientists and exploration advocates. It is believed that the lunar south pole harbors significant quantities of ice water, which could be extracted to produce rocket fuel and provide vital support for future crewed missions. The first attempt to land on the Moon, in September 2019, failed when the Chandrayaan-2 lander crashed on the Moon due to a technical issue.
After four years and many design and software updates, the Chandrayaan-3 spacecraft was launched aboard an LVM3 rocket on July 14 from a spaceport in Sriharikota, on India’s eastern coast. The spacecraft entered an elliptical orbit around the Moon earlier this month. It then performed several maneuvers to transition to an almost circular path, bringing it to about 150 kilometers above the lunar surface.
On Thursday, August 17, the Vikram-Pragyan duo separated from the mission’s propulsion module, which will study Earth from its orbit around the Moon. The lander and rover, which had entered lunar orbit after separation, successfully performed braking maneuvers on Friday, August 18, and Sunday, August 20, to approach the lunar surface.
Lesson from Chandrayaan-2
While still in lunar orbit, the duo established contact with Chandrayaan-2’s orbiter. This orbiter has been orbiting the Moon since 2019, serving as a communication bridge with Earth. When the sun rose at the targeted landing site, mission control ordered its descent to the Moon, activating its fully automatic landing system.
The historic landing was broadcast live by ISRO and aired on the Indian public broadcaster Doordarshan. At 12:33 GMT, the Vikram lander touched down in its target area, at about 70 degrees south latitude. This location is close to where Russia had hoped its Luna-25 mission would land on Monday, August 21. Russia failed, and the probe crashed miserably on the Moon.
India’s success today can be attributed to “significant modifications” to its landing strategy after the Chandrayaan-2 crash in 2019, said Bhardwaj. The onboard algorithms that calculate the spacecraft’s real-time velocity during descent were reworked to allow “greater freedom to deviate” from the protocol. A larger target landing zone, stronger legs for Vikram, and dynamic engines that adjusted speed contributed to the mission’s success.
Now that Vikram has settled on the Moon, Pragyan is expected to move on the lunar surface and begin analyzing the soil and lunar rocks. Similar to the ill-fated rover on Chandrayaan-2, Pragyan’s wheels are engraved with the Ashoka Chakra, a religious symbol representing a wheel with 24 spokes depicted on the Indian flag.
So, when Pragyan approaches the Moon, ISRO hopes both symbols will be imprinted on the surface. The Vikram lander is also equipped to detect lunar earthquakes near the landing site using an onboard seismometer and to probe the lunar soil to record its temperature.