Chandrayaan-3 lunar touchdown at 18:04 hours on August 23, lander orbit reduced

Bengaluru: ISRO on Sunday said it has successfully reduced the orbit of Chandrayaan-3 mission's lander module, and it is now expected to touch down on the surface of the Moon at 1804 hours on August 23. The space agency said the lander module would undergo internal checks ahead of the planned soft landing. The lander module (LM), comprising the lander Vikram' and rover Pragyan', is expected to touch down on the lunar surface on Wednesday, August 23 at 18.04 hours, ISRO said.

Earlier ISRO had said that the touchdown would take place at at 5.47 pm on August 23. Now, it has been moved by 17 minutes. The second and final deboosting (slowing down) operation has successfully reduced the LM orbit to 25 km x 134 km. The module would undergo internal checks and await the sunrise at the designated landing site. The powered descent is expected to commence on August 23, 2023, around 1745 hrs IST, ISRO said in a post on 'X' (formerly Twitter) in the early hours of Sunday.

According to ISRO, India's pursuit of space exploration will reach a remarkable milestone with the Chandrayaan-3 mission poised to achieve a soft landing on the surface of the Moon. This achievement marks a significant step forward for Indian Science, Engineering, Technology, and Industry, symbolising our nation's progress in space exploration, it said. This eagerly anticipated event will be broadcast live on August 23, starting from 17:27 Hrs IST on multiple platforms, including the ISRO Website, its YouTube channel, ISRO's Facebook page, and DD National TV channel. "The soft landing of Chandrayaan-3 is a monumental moment that not only fuels curiosity but also sparks a passion for exploration within the minds of our youth," ISRO said.

"It generates a profound sense of pride and unity as we collectively celebrate the prowess of Indian science and technology. It will contribute to fostering an environment of scientific inquiry and innovation," it said. In light of this, all schools and educational institutions across the nation are invited to actively publicise this event among students and faculty, and organise a live streaming of the Chandrayaan-3 soft landing on campuses, ISRO said. On Thursday, 35 days after the mission was launched on July 14, the lander module of Chandrayaan-3 had successfully separated from the propulsion module.

ISRO sources earlier said that after the separation, the lander would undergo "deboost" (the process of slowing down) operations to place it in an orbit where when it's at a point closest to the Moon (Perilune) it would be at a distance of 30 kilometres and at its farthest point from the Moon (Apolune) it would be 100 km away. At this point, the soft landing on the south polar region of the Moon will be attempted. At around 30 km altitude, the lander enters the powered braking phase and begins to use its thrusters to reach the surface of the Moon, they said. At an altitude of about 100 m, the lander would scan the surface to check whether there are any obstacles and then start descending to make a soft landing. Post its launch on July 14, Chandrayaan-3 entered into lunar orbit on August 5, following which orbit reduction manoeuvres were carried out on the spacecraft on August 6, 9, 14 and 16, ahead of the separation of both its modules on August 17, in the runup to the landing on August 23.

Earlier, over five moves in the three weeks since the July 14 launch, ISRO had lifted the Chandrayaan-3 spacecraft into orbits farther and farther away from Earth. Then, on August 1 in a key manoeuvre - a slingshot move - the spacecraft was sent successfully towards the Moon from Earth's orbit. Following this trans-lunar injection, the Chandrayaan-3 spacecraft escaped from orbiting the Earth and began following a path that would take it to the vicinity of the Moon. Chandrayaan-3 is a follow-on mission to Chandrayaan-2 and seeks to demonstrate end-to-end capability in safe landing and roving on the lunar surface.

The mission objectives of Chandrayaan-3 are to achieve safe and soft landing on the lunar surface, to demonstrate the rover's mobility on the Moon, and to conduct in-situ scientific experiments. The lander has the capability to soft land at a specified lunar site and deploy the rover that will carry out in-situ chemical analysis of the Moon's surface during the course of its movements. The lander and the rover are carrying scientific payloads to carry out experiments on the lunar surface.