india

Updated: Sep 08, 2019 00:53 IST

A teary-eyed K. Sivan, chairman of the Indian Space Research Organisation (ISRO), being consoled by Prime Minister Narendra Modi six hours after the ISRO control centre lost communication with the Vikram Lander will remain one of the most enduring images of the mission.

Modi had reached the ISRO Mission Control Centre complex in Bengaluru at 1.25am on Saturday ti view the landing. Apart from all the scientists, engineers, and technicians working on the mission, 84 children from India and Bhutan were also present in the control room along with the Prime Minister. The excitement had been rising since the arrival of the Prime Minister and reached a fever pitch just 30 seconds before the manoeuvre to decelerate and bring down the altitude of the Vikram lander began.

There was clapping and cheering in the room.

For the anxious ISRO scientists, the “fifteen minutes of terror” began at 1.38am on Saturday. This was the most crucial part of the Chandrayaan 2 mission, which India had hoped would make it one of the four countries that have successfully soft-landed on the moon.

A successful first and second absolute navigational phase had the scientists in the mission control room smiling and cheering. Their expression changed to one of concern as there was a deviation from the planned path about 12 minutes after the powered descent started.

During the third fine braking phase, the last reported d horizontal velocity was 48mps and vertical velocity 60 metres per second. This was to be further reduced for the vertical descent phase where the horizontal velocity had to be zero and vertical velocity very low in preparation for a soft-landing.

The concerned scientists, including Sivan, former ISRO chairperson AS Kiran Kumar, and mission director Ritu Karidhal, started discussing what the loss of communication could mean.

The chairperson then went over to the Prime Minister to brief him. Even as the faces of scientist in front of the consoles seemed downcast, the others appeared confused as to what happened.

A few minutes later, an emotional Sivan announced, “Vikram lander descent was as planned and normal performance was observed up to an altitude of 2.1 km. Subsequently, communications from the lander to the ground stations were lost. The data is being analysed.”

The Prime Minister left him with words of encouragement, “This is not a small achievement what you have done. Your effort is commendable and we hope for the best. We have learnt something today. You have served the country, science, and the mankind very well.”