Chandrayaan-3: Vikram 2nd de-boost at 2am Sunday will set stage for August 23 landing | India News – Times of India

BENGALURU: Vikram, the Chandrayaan-3 lander, which became independent for the first time since July 14 on Thursday (August 17), will perform the crucial second de-boost manoeuvre at 2am Sunday.
“Sunday’s de-boost would be the last operation unless there is a need for some corrections after the manoeuvre. If the de-boost goes as planned, next action would be on August 23, when we attempt landing,” Isro chairman S Somanath told TOI.
The lander, which has the rover (Pragyan) in its belly, performed its first solo operation Friday, getting even closer — 113km x 157km orbit — to the lunar surface.The second de-boosting manoeuvre will take Vikram further close to the lunar surface and into the intended orbit from where the soft-landing is planned for. Going by the mission profile so far, Sunday’s manoeuvre, while very critical, will be for a short duration.
The objective of Sunday’s manoeuvre will be to reduce Vikram’s Perilune to around 30km, while the Apolune will be around 100km. During Chandrayaan-2, the second deboost had put the landing module in an orbit of 35km x 101km, which Isro had said was the desired orbit.
With Chandrayaan-3, given that the orbit achieved ahead of the separation was not as close to the 100km x 100km circular orbit, and the orbit achieved after the first deboost is also higher compared to 2019, the lander will have to do a bit more work to reached the intended orbit from where the power descent for landing will be planned.

The health of the propulsion module, which continues to orbit around Moon carrying one payload, was also normal as of Saturday.
Friday’s manoeuvre, which has brought the Perilune (closest point to Moon) closer to 100km and the Apolune (farthest point from Moon) to nearly 150km assumes importance for two reasons. The first, it reduced the landing module’s — Vikram with Pragyan (the rover) in its belly — orbit, setting the stage for the second deboost early on Sunday.

The second, was the first time that Vikram, which is designed to perform the soft-landing, had to perform a task in Chandrayaan-3’s journey. Since July 14, Vikram sat on top of the propulsion module as a passenger until Friday.
As per the current plan, Isro will attempt soft-landing of Vikram on August 23 and Sunday’s manoeuvre will be critical in reaching the final descent stage.