On a fateful Wednesday evening, the nation will collectively hold its breath for twenty agonizing minutes. The Vikram lander of India’s Chandrayaan-3 mission will venture to achieve a gentle touchdown on the moon’s surface, carrying the Pragyaan rover within its belly. This historic attempt near the moon’s south pole is poised to etch its place in history books, as it mirrors the tension of a tightly contested T-20 cricket match.
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— ISRO (@isro) August 22, 2023
The moon as captured by the
Lander Imager Camera 4
on August 20, 2023.#Chandrayaan_3 #Ch3 pic.twitter.com/yPejjLdOSS
Chandrayaan-3’s Remarkable Journey and Lunar Landing Process
Commencing its journey with a majestic lift-off, ISRO’s Bahubali rocket, or the Mark-3 launch vehicle, propelled Chandrayaan-3 into orbit. Embarking on elliptical orbits around Earth, Chandrayaan-3 gradually gained the required velocity.
The voyage took a decisive turn on August 1, as Chandrayaan-3 embarked on its 3.84 lakh km journey towards the moon. By August 5, the spacecraft gracefully settled into the moon’s orbit, where it remained stable for several days.
A pivotal maneuver unfolded on August 17 when the propulsion module separated from the Vikram lander and Pragyaan rover. At this juncture, the satellite orbited at a distance of 153 km by 163 km around the moon. The propulsion module continued its independent lunar odyssey.
Bringing the Vikram lander closer to the lunar surface, it entered a 134 km by 25 km elliptical orbit, primed for the powered descent phase. This delicate process had been previously executed with success in Chandrayaan-2.
The Daring Descent
The climax arrived on the anticipated landing day, marked by the heart-pounding “twenty minutes of terror.” With commands relayed from Bengaluru, the Vikram lander commenced its descent from an altitude of 25 km above the moon’s surface.
Initiating a powered descent, the Vikram lander hurtled toward the moon at a velocity of 1.68 km per second, equivalent to an astonishing 6048 km per hour — nearly ten times the speed of an airplane.
As the lander slowed down, its engines fired to execute the rough braking phase, a process lasting around 11 minutes. Following strategic maneuvers, the lander transitioned to a vertical orientation in the “fine braking phase.”
Critical Moments and Success
Notably, it was during the fine braking phase of Chandrayaan-2 that the Vikram lander faltered, leading to an unfortunate crash. This time, at 800 meters above the lunar surface, both horizontal and vertical velocities reached zero. The Vikram lander hovered above, meticulously surveying the landing site.
Progressing downward, the lander halted at 150 meters, capturing images to detect hazards and identify the optimal landing spot. With precision, it touched down, employing just two engines and equipped with legs designed to withstand an impact of up to 3m/second or about 10.8 km per hour.
Nail-Biting Saga
Upon detecting the lunar surface, the lander’s sensors signaled the engines to shut down, conclusively ending the nerve-wracking twenty minutes. Lunar dust, or regolith, stirred by the landing, settled as the ramp opened. Subsequently, the Pragyaan Rover descended cautiously.
With the rover safely on the lunar terrain, a momentous occasion unfolded: the Vikram lander captured images of the rover, while the Pragyaan rover reciprocated, transmitting captivating selfies from the lunar surface to India.
A New Chapter of Lunar Exploration
Now, the stage is set for scientific exploration. Both the Vikram lander and the rover, powered by solar energy, are engineered to endure a lunar day, equivalent to 14 Earth days. Barring any unforeseen obstacles, India is poised to join an elite group as the fourth nation to execute a soft moon landing.
The impending Chandrayaan-3 mission epitomizes the prowess of human endeavor and technological innovation. As the Vikram lander and Pragyaan rover embark on their lunar sojourn, they carry the aspirations of a nation and the promise of groundbreaking discoveries that await on the moon’s enigmatic surface.
