India’s moonshot Chandrayaan 2 has been successfully manoeuvred into lunar orbit today, after nearly 30 days of space travel. This was one of the trickiest operations in the mission.
A higher-than-expected approach velocity would have bounced off the spacecraft into deep space, while a slow approach would have led to the moon’s gravity to pull Chandrayaan 2 and crash it on the lunar surface.
The approach velocity had to be just right and the altitude over the moon rather precise. Even a small error would have killed the mission.
“Following this, a series of orbit manoeuvres will be performed on Chandrayaan 2 spacecraft to enable it to enter its final orbit passing over the lunar poles at a distance of about 100 km from the moon’s surface,” the Indian Space Research Organisation said in a post on its website today.
“Subsequently, the lander will separate from the orbiter and enter into a 100 km x 30 km orbit around the moon. Then, it will perform a series of complex braking manoeuvres to soft land in the south polar region of the moon on September 7, 2019,” ISRO said.
The process of landing Chandrayaan 2 on the moon is very complex since it blasted off at a velocity of 39,240 kilometres per hour, which is almost 30 times the speed at which sound travels through air.
The former director of the ISRO satellite centre M Annadurai, who was the head of India’s first moon mission Chandrayaan 1, described the complexity of the operation: “It is like a gentleman with a rose in hand proposing to a lady who is dancing at a stunning speed of 3,600 kilometres per hour (almost five times the speed of an airplane), and not next door, but at a distance of 3.84 lakh kilometres away. If the couple have to meet, then the precision and accuracy is of utmost importance.”