A significant accomplishment for the expedition was made when the Chandrayaan-3 landing module, which included the lander Vikram and the rover Pragyan, successfully detached from the propulsion module.
“The landing module and propulsion module have been successfully separated. Following a de-boost scheduled for tomorrow (August 18) at 4pm, the landing module is expected to move to a slightly lower orbit, according to Isro.
A day after guiding the spacecraft, which is an integrated module with the propulsion module resting on top of the landing module, into “an orbit of 153km x 163km, as intended,” Isro performed the separation maneuver.
Isro Chairman S. Somanath stated in his post-launch remarks on July 14 that the spacecraft’s altitude would be decreased to a 100 km circular orbit and that the landing module will separate on August 17. This was a “nominal” estimate.
The spacecraft was placed into a 119km x 127km orbit during Chandrayaan-2, which with its final lunar-bound maneuver was aiming for a 100km circular orbit. Based on estimates made closer to the last lunar movement, that was only slightly different from the original plans but still in the anticipated direction.
According to a top scientist who spoke with TOI on July 15, the goal for Chandrayaan-3 was to attain a circular orbit at a height of either 100 km or 150 km. Another scientist had stated, “That will be decided closer to the day of the manoeuvre. Isro added that the orbit obtained on Wednesday “was as intended”.
The objective of Chandrayaan-3, according to a leading scientist who spoke with TOI on July 15, was to achieve a circular orbit at a height of either 100 km or 150 km. That would be decided closer to the day of the maneuver, another scientist had said. The orbit obtained on Wednesday “was as intended,” Isro noted.
As Isro chairman S. Somanath had earlier stated, the process of reducing the lander’s velocity from 30km height to the final touchdown will start once the 30km x 100km orbit, the landing’s most crucial step, has been accomplished.
Before Vikram makes the final drop on August 23, Isro will also have to get over the stage where the spacecraft’s horizontal orientation must change to a vertical one.
Chandrayaan-3 was put into orbit on July 14th, 34 days ago. After achieving its initial orbit immediately after launch, Chandrayaan-3 underwent five Earth-bound maneuvers between July 15 and July 25, increasing its height to more than 1.2 lakh kilometers at its closest approach to the planet.
Then, on August 1, Isro performed the trans-lunar injection (TLI), which set the spacecraft on a course toward the moon at a height of around 3.6 lakh kilometers. On August 5, the lunar orbit insertion (LOI) put the spacecraft in an elliptical orbit around the moon. Five lunar-bound maneuvers and the separation of the landing module came next.