India, Sept. 1 — Scientists from the Indian Space Research Organisation will conduct Chandrayaan 2’s final orbit lowering manoeuvre on Sunday evening.
This will be the final orbit in which the orbiter module of the spacecraft will stay for a year and conduct experiments to study the lunar terrain, the thin atmosphere around the moon, lunar ionosphere, and minerals on the moon.
The manoeuvre, which is planned to happen between 06:00 and 07:00 pm, will bring the spacecraft close to a circular orbit of 100x 100km. This is the stage till where India’s first mission to moon had come, after which a scientific probe was crashed on the lunar surface to collect data.
For Chandrayaan 2, the most challenging part of the journey will begin tomorrow when the lander-rover will separate from the orbiter. After the separation, the propulsion system on-board the indigenously developed lander will be operated for the first time. So far, all the “burns” in the Earth and Moon orbit happened with the propulsion system of the orbiter.
For the lander-rover, two more orbit lowering manoeuvre, including one to test the lander propulsion system, will be performed to bring the lander-rover into a 100x30km orbit. This intermediate orbit was suggested by the group of eminent scientists that had suggested some corrections to the lander design and the orbit in 2018, resulting in the mission being pushed.
The powered descent to the surface of the moon will begin at 01:40 am on September 7. And, after “15 minutes of terror” the lander-rover will reach the surface of the moon.
The site of final landing will be autonomously selected by the lander-rover by comparing photographs taken by its cameras to those stored on-board. The landing site has to be such that it is at a high plain between two craters allowing it access to the shadowed areas for experiments and the sunlit area for its solar panels.
The inclination of the landing site also has to be less than 12 degrees to prevent the lander from toppling over.
Source from HT media