Live streaming on ISRO website, YouTube channel, Facebook page, DD National from 5.27 pm

Bengaluru: India’s Chandrayaan-3 is poised to make history by attempting a soft landing of the Vikram Lander, carrying the Pragyaan rover, near the moon’s south pole on Wednesday, Aug. 23, at 6.04 pm. The final intense twenty minutes of its journey are likened to ‘twenty minutes of terror’.

Following a majestic liftoff, the Indian Space Research Organisation’s (ISRO) Mark-3 rocket, also known as the Bahubali launch vehicle, successfully placed Chandrayaan-3 into orbit.

Chandrayaan-3 followed a series of elliptical orbits around Earth, gaining velocity.

On Aug. 1, Chandrayaan-3 was directed toward the moon for its 3,84,000-kilometre journey. By Aug. 5, the Chandrayaan-3 satellite elegantly entered the moon’s orbit and achieved stability. During its time in lunar orbit, Chandrayaan-3 underwent a period of stabilisation.

In a critical and complex manoeuvre on Aug. 17, the propulsion module separated from the Vikram lander, with the Pragyaan rover, while the satellite was in a 153 km by 163 km orbit.

The propulsion module continued its orbit around the moon in a 153 km by 163 km trajectory.

Meanwhile, the Vikram lander gradually approached the lunar surface in a 134 km by 25 km elliptical orbit, setting the stage for the powered descent. Up to this point, this process had been executed successfully during Chandrayaan-2.

ISRO announced that space enthusiasts worldwide can witness the Chandrayaan-3 landing live at 6.04 pm on the official ISRO website, official YouTube channel, ISRO’s Facebook page, and DD National, starting from 5.27 pm.

Tomorrow, following commands from Bengaluru, the Vikram lander will initiate its descent towards the lunar surface from an altitude of 25 km. During the powered descent, the Vikram lander will accelerate toward the moon’s surface at a speed of 1.68 km per second, roughly equivalent to 6,048 km per hour, nearly ten times the velocity of an aeroplane.

The Vikram lander will then decelerate as all its engines fire, although the lander will remain almost horizontal to the lunar surface. This phase, known as the rough braking phase, lasts for approximately 11 minutes. Through a series of manoeuvres, the Vikram lander will become vertical to the moon’s surface, marking the start of the ‘fine braking phase.’

It was during the fine braking phase of Chandrayaan-2 that the Vikram lander lost control and crashed. At an altitude of 800 metres above the moon’s surface, both horizontal and vertical velocities approach zero, causing the Vikram lander to hover above the lunar terrain, surveying the landing area.

The Vikram lander descends further to hover again at 150 metres, capturing images for hazard detection and searching for the optimal landing spot. It eventually touches down on the lunar surface with only two engines firing and its legs are designed to absorb an impact of up to 3 metres per second, roughly 10.8 km per hour.

Upon sensing contact with the lunar surface, the engines will shut down, ending the suspenseful twenty-minute sequence. The lunar dust, or regolith, disturbed during landing, will settle. Subsequently, the ramp opens, and the Pragyaan Rover is released slowly.

Once the Pragyaan Rover touches the lunar surface, it gains freedom to navigate the terrain. A significant moment arrives when the Vikram lander captures images of the rover and the Pragyaan rover takes images of the lander, marking India’s first lunar surface selfies.

Both the Vikram lander and rover are solar-powered and designed to operate for one lunar day, equivalent to 14 Earth days.