Chandrayaan-2's journey to Moon, after leaving Earth's orbit, to start today

India's Chandrayaan-2 satellite is set to move towards the Moon after leaving the Earth's orbit, with the Indian Space Research Organisation (ISRO) planning to carry out a crucial manoeuvre early on Wednesday. The Bengaluru-headquartered space agency has said it will carry out the manoeuvre called Trans Lunar Insertion (TLI) between 03:00 and 04:00 hours (IST).

The Chandrayaan-2 spacecraft is expected to reach the moon's orbit on August 20 and land on the lunar surface on September 7, according to the ISRO.

"At around 3.30 am on August 14, we are going to have a manoeuvre called trans-lunar injection. By this manoeuvre, the Chandrayaan-2 will leave the earth and move towards the moon. On August 20, we will be reaching the moon," ISRO Chairman K Sivan said on Monday.

Stating that Chandrayaan-2 will be around the moon on August 20, he said, "Subsequently, we have planned to have a series of manoeuvres around the moon and finally, on September 7, we will be landing on the moon near its south pole."

The ISRO has so far performed five earth-bound orbit raising manoeuvres.

The fifth earth-bound orbit raising manoeuvre for Chandryaan-2 was performed successfully on August 6 using the onboard propulsion system for a firing duration of 1,041 seconds, following which the ISRO had said all the spacecraft parameters were normal.

India's Geosynchronous Satellite Launch Vehicle, GSLV MkIII-M1, successfully launched the 3,840-kg Chandrayaan-2 spacecraft into the Earth's orbit on July 22.

A series of orbit manoeuvres was carried out using Chandrayaan-2's onboard propulsion system to raise the spacecraft orbit in steps and then place it in the Lunar Transfer Trajectory to enable the spacecraft to travel to the vicinity of the moon.

After leaving the Earth's orbit and on entering the Moon's sphere of influence, the onboard propulsion system of Chandrayaan-2 will be fired to slow down the spacecraft, which will enable it to be captured into a preliminary orbit around the moon, the ISRO said.

Later, through a set of manoeuvres, the orbit of Chandrayaan-2 around the Moon will be circularised at a height of 100 km from the lunar surface. Subsequently, the lander will separate from the orbiter and enter into a 100kmx30km orbit around the Moon, and then, it will perform a series of "complex braking" manoeuvres to soft land in the south polar region of the Moon on September 7.

Chandrayaan-2 is the country's second mission to the Moon. It comprises a fully indigenous orbiter, a lander (Vikram) and a rover (Pragyan). The rover (Pragyan) is housed inside the lander (Vikram).

Following the landing, the rover will roll out from the lander and carry out experiments on the lunar surface for a period of one lunar day, which is equal to 14 earth days.

The mission life of the lander is also one lunar day. The orbiter will continue its mission for a year.

According to the ISRO, the mission objective of Chandrayaan-2 is to develop and demonstrate the key technologies for end-to-end lunar mission capability, including soft-landing and roving on the lunar surface.

On the science front, this mission aims to further expand the knowledge about the moon through a detailed study of its topography, mineralogy, surface chemical composition, thermo-physical characteristics and atmosphere, leading to a better understanding of the origin and evolution of the Moon, the space agency had said.