BENGALURU: Isro on Wednesday guided Chandrayaan-3 even nearer to the lunar floor with the completion of its third lunar-bound manoeuvre, together with the lunar orbit insertion (LOI) carried out on Sunday.

“Even closer to Moon’s surface… Chandrayaan-3’s orbit is reduced to 174km x 1,437km following a manoeuvre performed today (Wednesday). The next operation is scheduled between 11.30am and 12.30pm on August 14,” Isro stated.
On Monday, Isro diminished the altitude of Chandrayaan-3 by round 14,000km to convey it to 4,313km near Moon, the subsequent lunar-bound manoeuvres will likely be on August 14, when Isro will additional scale back the space between the spacecraft and Moon, on August 16, when Chandrayaan-3 enters the 100km round orbit, and August 17, when the touchdown module, comprising the lander (Vikram) and the rover (Pragyan) break free from the propulsion module.

Once the touchdown module separates, Isro will de-boost the touchdown module to an orbit the place the Perilune (closest level to Moon) is 30km and the Apolune is 100km. The last touchdown will likely be tried from this orbit.
And late on Tuesday, Isro chairman S Somnath, in a lecture at an occasion organised by Disha Bharat, an NGO in Bengaluru, reiterated the varied redundancies launched in Chandrayaan-3 to make sure a secure touchdown on August 23.
Reducing Velocity Key
“The most critical part of the landing is the process of reducing the velocity of the lander from 30km height to the final landing. At 30km, the spacecraft is horizontal. Transferring the spacecraft from a horizontal orientation to vertical is very challenging, we had problems here with Chandrayaan-2. We have to ensure that not too much fuel is consumed, the distance is calculated correctly, all algorithms work… For this, we’ve changed the guidance design, introduced newer algorithms and extensive simulations have been done.” Somanath stated.
As reported earlier by TOI, he pointed to varied redundancies launched within the touchdown module for a secure touchdown. Reiterating them, Somanath stated: “We’ve designed it in such a way that if all the sensors fail, we will still be able to land provided that the propulsion system works. Even if two engines fail, we will be able to land.” Isro might want to use solely two of the 4 engines on Vikram lander for the ultimate descent.
“…The whole design is such that it should be able to handle many failures, provided that the algorithms work properly,” he added.