India's moonshot will mark an epoch

Chandrayaan 3 will help understand our closest neighbour better, and act as a landmark for Indian science and technology

- Anil Bhardwaj

At 2.35pm on July 14, India's space programme will mark an epoch, as the Chandrayaan 3 blasts off from the Satish Dhawan A Space Centre, Sriharikota. On board the country's third mission to the moon will be a lander (Vikram), a rover (Pragyan) and a propulsion module- the major differentiator from the earlier iteration of the Moon mission that carried an orbiter instead. The integrated craft will reach a 100km circular polar orbit sometime in the third week of August, and then the lander will slowly descend on the surface of the Moon, becoming in the process the first country to land in the unexplored high-latitude regions of the Moon. Somewhere around August 23, we hope to touch down on the lunar surface. At stake are critical questions of science - how are seismic waves produced on the Moon? Exactly how does the lunar surface act as a thermal insulator? What is the elemental and chemical composition of the Moon? And, what is its plasma distribution profile? These seemingly abstract queries hold the key to understanding our closest interplanetary neighbour better.

The mission builds on the excellent work done by Chandrayaan 2, which launched an orbiter on the lunar orbit that continues to transmit critical data. This orbiter has helped us save in terms of mass for carrying payload this time and store more propellant (since the device continues to work, there is no need to launch a new one). In 2019, the Chandrayaan 2 lander worked very well for more than 90% of its trajectory but veered off course in the final kilometre of the descent, suffering a crash landing. Since then, the landing technology that was developed and used for the first time four years ago, has been honed and sharpened.