Chandrayaan-3 is just 6 days away from moon, critical slingshot manoeuvre tonight

Chandrayaan-3, the nation's third lunar mission, is rapidly approaching the lunar orbit, with a pivotal slingshot manoeuvre scheduled between 12 am and 1 am on August 1. This midnight trans-lunar injection (TLI) manoeuvre, lasting approximately 28 to 31 minutes, will see the spacecraft's thrusters fired at the closest point to Earth (perigee) rather than at the farthest point (apogee).

The reason for attempting the slingshot from perigee lies in the spacecraft's elliptical orbit around Earth, with its velocity ranging from 1 km/second to 10.3 km/second. The highest velocity is achieved at perigee (10.3 km/second), making it the ideal point for the slingshot manoeuvre as the spacecraft needs to attain a high velocity to head towards the Moon. Additionally, changing the angle for travel towards the Moon becomes feasible when the operation is conducted at perigee.

To execute the TLI manoeuvre, the pre-written and preloaded commands will be enabled approximately five to six hours ahead of the expected thruster firing time.


Apart from altering the spacecraft's orientation for the journey towards the Moon, the thrusters' firing will contribute to increasing its velocity. Following TLI, Chandrayaan-3's velocity is projected to be approximately 0.5 km/second higher than at perigee.

Typically, it takes around 51 hours to traverse 1.2-lakh km. Although the average distance between Earth and Moon stands at 3.8-lakh km, the actual distance varies daily based on their positions, ranging from 3.6-lakh km to 4-lakh km. Reaching the Moon's orbit is just the initial step, considering India's previous achievements of placing satellites around the Moon in 2008 (Chandrayaan-1) and 2019 (Chandrayaan-2). The true significance of Chandrayaan-3 lies in the critical phase after the spacecraft arrives at the Moon.

Once Chandrayaan-3 captures a lunar orbit, a series of manoeuvres become necessary to lower the spacecraft's altitude and position it into a 100 km circular orbit. At this point, the propulsion module will be separated from the landing module, which is scheduled for August 17. The landing attempt itself is planned for August 23, marking a crucial milestone for the ambitious lunar mission.