It is a big day for the Indian Space Research Organisation (ISRO) as it gears up to launch Chandrayaan-3, while eyeing a successful soft landing on the moon—a dream that was shattered when the Vikram lander of Chandrayaan-2 crash-landed on the lunar surface in 2019. India's ambitious third lunar exploration mission will lift off from Sriharikota in Andhra Pradesh at 2:35pm on Friday.
1. The Chandrayaan-3 will be launched into space by the Launch Vehicle Mark -III. ISRO's most powerful rocket, the LVM3 is often referred to as the 'Baahubali' of rockets and is equipped with two solid fuel boosters that will provide the initial thrust for takeoff. After the solid boosters separate from the launch vehicle, it will be powered by the liquid stage. Friday's mission is the fourth operational flight of LVM3 vehicle has proved its versatility to undertake complex missions including injecting multi-satellites, interplanetary missions among others.
2. The spacecraft will carry three modules—lander module, propulsion module and rover module which is housed inside the lander. One of the most ambitious goals of the Chandrayaan-3 mission is a soft landing on the south pole of the moon using the lander. The propulsion module will carry the lander and rover to the moon, and the lander payload will be responsible for the safe landing. The rover will then be deployed to explore the lunar surface, and scientific experiments will be conducted to learn more about the moon. If successful, India will become only the fourth country—after the United States, China and Russia—to land on the surface of the moon. Landing on the moon's south pole is a challenging task owing to the uneven lunar terrain. The ISRO, equipped with learning from the previous setback, is hoping for a successful outcome this time.
3. The propulsion module of the Chandrayaan-3 mission also carries the Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload, which will study the spectral and polarimetric measurements of earth from the lunar orbit. This will also help scientists learn more about the earth's atmosphere and climate.
4. If Friday's launch is successful, Chandrayaan-3 will take a month to reach the lunar surface. The spacecraft is expected to reach the moon by August 23-24. As ISRO aims to strike a balance between efficiency and affordability, the scientists have devised a sling-shot method, which takes advantage of the earth's gravity, to assist the launch. Instead of following a direct trajectory, Chandrayaan-3 will use an elliptical orbit using the earth's gravitational forces to gain momentum.
5. ISRO Chairman S Somanath said instead of a success-based design in Chandrayaan-2, the space agency opted for a failure-based design in Chandrayaan-3, focused on what all can fail and how to protect it and ensure a successful landing. Somnath said that Chandryaan-2 was equipped with five engines, which developed a higher thrust during the landing. The other reason for failure was the small 500m x 500m site identified for landing the spacecraft. This time, scientists have expanded the area of landing to 4km x 2.5km. It can land anywhere, so it doesn't limit you to target a specific point, Somnath said.