On Wednesday, the Chandrayaan-2 spacecraft left Earth’s orbit and moved towards the Moon, which it will orbit over a series of manoeuvres before the ultimate soft landing, scheduled on September 7.
SO FAR, since its launch on July 22, Chandrayaan-2 had been orbiting the Earth, moving into higher and orbits. This is achieved by a series of “Earth-bound orbit-raising manoeuvres”. There were five such manoeuvres before the mission left Earth orbit on Wednesday. These raised the orbits around Earth successively to 230 × 45,163 km (July 24), 251 × 54,829 km (July 26), 276 × 71,792 km (July 29), 277 × 89,472 km (August 2) and 276 × 1,42,975 km (August 6). The two figures with each orbit refer to the distance at the nearest and farthest points.
ON WEDNESDAY, the final orbit-raising manoeuvre was carried out. Chandrayaan 2 has now entered the Lunar Transfer Trajectory, and is now heading for its next orbit, which will be around the Moon.
ON AUGUST 20, Chandrayaan-2 will approach Moon and the spacecraft’s liquid engine will be fired again to insert the spacecraft into a lunar orbit. Following this, there will be further four orbit manoeuvres to take the spacecraft into its final orbit, passing over the lunar poles at a distance of about 100 km from the Moon’s surface (see table).
After that, the soft landing. The Vikram lander will separate from the orbiter on September 2. Two orbit manoeuvres will be performed on the lander before the initiation of powered descent on September 7.
Chandrayaan 2 will land on the Moon’s south polar region, unexplored by science so far. ISRO said in a statement that the south pole is especially interesting because of the lunar surface area here that remains in shadow is much larger than that at the north pole. There is a possibility of the presence of water in permanently shadowed areas around it.