What is the “15 Minutes of Terror”?
The critical technical manoeuvre that the Chandrayaan-3 lander will have to perform on August 23 when it enters the final 15 minutes of its attempt to make a soft landing on the Moon will be to transfer its high-speed horizontal position to a vertical one in order to facilitate a gentle descent on to the surface. The “15 Minutes of Terror” portion of the mission will be the most critical, but ISRO is sure that the Vikram lander will be able to execute these manoeuvres and land safely on the Moon’s south pole.
Daily Current Affairs Quiz: August 2023
The initial preparation phase
The initial preparation phase comprises the final 1,139 seconds of the Chandrayaan-3 mission, and it is during this stage that the most critical operations will be performed.
The velocity reduction phase
The velocity reduction phase will take 690 seconds, during which thrusters will be fired to reduce Vikram’s velocity to one-fourth of its initial speed.
The fine braking phase
The delicate braking phase is the final essential manoeuvre. During this phase, the lander will be vertically oriented and hover 800 to 1,300 metres above the landing spot. The lander will then use its thrusters to make small adjustments to its position in order to land safely.
The landing
Once the Vikram lander successfully lands on the lunar south pole, the sensors will signal the computer onboard the spacecraft. After that, the lander will be fully powered up, and Vikram will unfold the rover ramp, allowing the Pragyan rover to begin its lunar mission.
Learning from the failures
“Before the Chandrayaan-2 probe could approach its final “terminal descent phase,” it lost control and collided with the Moon’s surface during the “attitude hold phase” and the “fine braking phase”. The failure studies were used to boost the likelihood of a touchdown for Chandrayaan-3. The initial rough braking phase of Chandrayaan-2 used a first-order automated guidance system; whereas Chandrayaan-3 is using a second-order guidance system. In Chandrayaan-3, the rough braking phase also uses an immediate thrust regulation.”
