1 / 11For any Moon mission, the vast expanse between Earth and the Moon is a formidable challenge in itself. However, the real test is a soft-landing on the lunar surface. Chandrayaan-3, India’s third lunar mission, is expected to make a soft-landing near the South Pole of the moon on August 23. It is India's second attempt at achieving a soft-landing on the moon's surface. (Image: Narendra Modi Twitter)
2 / 11Luna-25, Russia's first Moon mission in 47 years, which was expected to make a soft-landing August 21-22, has crashed into the surface of the Moon after spinning into an uncontrolled orbit. (Image: Reuters)
3 / 11Achieving a soft landing on the Moon embodies an intricate ballet of engineering marvels – overcoming blazing speeds, lunar dust disturbances, and achieving a controlled descent are its cornerstones. (Image: ISRO Twitter)
4 / 11Soft-landing vs hard-landing | Soft-landing: This entails a controlled descent, ensuring the craft’s safe and gradual touchdown. Soft-landings become indispensable in crewed missions and scenarios where scientific measurements and tests follow the landing.
5 / 11Soft-landing vs hard-landing | Hard-landing: Often termed crash landings, hard-landings transpire at a higher descent speed. While they possess a lower level of complexity, these landings typically end in the spacecraft’s destruction. Hard-landings serve a purpose when the craft’s mission is already fulfilled, as seen in instances like aerial surveys. (Image: PTI)
6 / 11What a soft-landing entails | This critical phase demands a precise orchestration of engine firings, altitude adjustments, fuel consumption, and meticulous scans of the lunar terrain. The whole process unfolds autonomously. (Image: ISRO)
7 / 11Altitude – 100 km | The lander separates from the propulsion module and enters a 100 km x 30 km orbit. In this orbit, the closest proximity to the lunar surface is merely 30 km. (Image: ISRO)
8 / 11Altitude – 30 km | The lander engages its thrusters, commencing the powered braking phase to gradually guide it toward the lunar surface. During this phase, the lander also reorients itself to a 90-degree angle, ensuring a stable and secure landing posture. (Image: ISRO)
9 / 11Altitude – 100 m | The lander will carefully analyse potential obstacles; if none are detected, the lander initiates a methodical descent, employing its thrusters judiciously until it gently makes contact with the lunar ground. Chandrayaan-2 failed between these two stages. It came within 2.1 km of the Moon but crashed after that. (Image: ISRO)
10 / 11What is lunar dust | Lunar dust, composed of minute abrasive particles from the lunar surface, emerges as a pivotal adversary during soft landings. The lander’s thrusters, which regulate its descent speed, create an exhaust plume that stirs up lunar dust around the craft. This disturbance can lead to compromised visibility, as exemplified by NASA's video of the Apollo 15 lander’s touchdown, where the plume engulfed the surroundings. (Image: Shutterstock)
11 / 11Chandrayaan-3 comprises three modules – an orbiter, Vikram lander, and Pragyan rover. The propulsion module’s role is to transport the lander and rover to the moon. It does not make a lunar landing. On August 17, the Vikram lander module successfully separated from the propulsion module. Accompanied by the Pragyan rover, the lander is now set to independently navigate the remaining path to the Moon's surface for a soft landing targeted for August 23. Following a successful landing, the lander will stay stationary at the touchdown site, and the rover will commence its lunar exploration activities. (Image: ISRO)
