Chandrayaan-3: ISRO All Set To Initiate Automatic Landing Sequence To Activate Throttleable Engines For Descent

Chandrayaan-3 Landing: After receiving the command for Automatic Landing Sequence, the Lander Module will activate the throttleable engines for powered descent. 

Chandrayaan-3's lander module is expected to arrive at the designated point at around 5:44 pm IST. Chandrayaan-3 is set to land on the lunar south pole at 6:04 pm IST on August 23, 2023.

Source : Twitter/@ISRO

Chandrayaan-3 Landing: The Indian Space Research Organisation (ISRO) is all set to initiate the Automatic Landing Sequence (ALS) to activate the throttleable engines of Chandrayaan-3 for powered descent towards the lunar surface. Chandrayaan-3's lander module is expected to arrive at the designated point at around 5:44 pm IST. Chandrayaan-3 is set to land on the lunar south pole at 6:04 pm IST on August 23, 2023.

After receiving the command for Automatic Landing Sequence, the lander module will activate the throttleable engines for powered descent. 

Chandrayaan-3 Mission:
All set to initiate the Automatic Landing Sequence (ALS).
Awaiting the arrival of Lander Module (LM) at the designated point, around 17:44 Hrs. IST.

Upon receiving the ALS command, the LM activates the throttleable engines for powered descent.
The… pic.twitter.com/x59DskcKUV

— ISRO (@isro) August 23, 2023

ISRO will start streaming the landing event online at 5:20 pm IST. The operations will be performed at the Mission Operations Complex (MOX) of ISRO Telemetry, Tracking and Command Network (ISTRAC), Bengaluru. 

Chandrayaan-3's descent towards the lunar surface will involve several complex manoeuvres. The last 15 minutes of the mission are known as the '15 minutes of terror'. During this period, Chandrayaan-3 will undergo different phases of descent. These include initial preparation, velocity reduction, orientation change, attitude hold phase, fine braking, final descent and touchdown. 

The first phase will last for 1,139 seconds, the second phase will last for 690 seconds, the third step will be performed simultaneously with the second one, the fourth phase will be a sensitive one, and last for 10 seconds, the fifth phase will vertically align the Vikram lander, and the final descent phase will take Vikram to a height of 150 metres above the lunar surface.

After Vikram successfully lands on the lunar south pole, the sensors will signal the computer onboard the spacecraft in order to power the lander completely, and allow the rover ramp to be unfurled.