Chandrayaan-2: Agonising, heart-breaking final moments

Agonising, traumatic, absolutely devastating! It couldn’t have been more heart-breaking for the scientists tracking every nano-second of Chandrayaan-2 Lander’s powered descent onto the lunar surface. The mission flawlessly covered 3,84,398 kms, but the final 2.1 km last-mile link loss abruptly ended a dream.

At the ISRO Telemetry, Tracking and Command Network (ISTRAC) Mission Control Room here early Saturday morning, applause greeted Vikram’s every drop in altitude. But as the Lander’s path, projected on a giant screen, inched closer to the surface, the tension was palpable, unbearably real.

The Lander’s powered descent was a study in clockwork precision. Kicking off exactly at 1.38 am, the process began with a Rough Breaking Phase. Splashing across the giant screen was a velocity figure that read 1,680 metres per second (mps).

Loud cheers escaped the hall as the altitude fell from 30.430 km to 30.429 km. In just three minutes, that initial velocity was down to 360 mps. That was when the laymen realised what the ‘Rough Breaking’ meant. At stake was an unprecedented soft-landing and the Lander had to be very, very slow on impact.

Euphoric one moment, tense the next, emotions ran deep. Scientists sat glued to their consoles, former ISRO heads occupied the front rows. Watching them all from an elevated podium was Prime Minister Narendra Modi. The shifting numbers had everyone’s attention.

The half-way mark had been reached. “Orbital velocity now down by 50%. Lander descending at 760 mps,” the announcement was clear, confident, articulated to impress. “The trajectory has a close match with the pre-flight predictions,” said the voice. The dynamic graphic on the screen proved it right.

The crowd’s response was electrifying, loud. The mood turned upbeat, as Vikram’s descent steadily progressed from 1.45 am to 1.47 am. A minute later, it was time for another round of applause. The Rough Breaking Phase was now complete, and the Lander was just 7.4 km away from touchdown.

At five kms from the surface, the mission kicked off its second maneouvre: The Fine Breaking Phase. The velocity was now down to 96 mps. The time: 1.51 am, the destination: 400-700m altitude. The end was near, and Vikram’s gaze on the landing site was spot on.

Two minutes ticked by, as if in slow motion. The touchdown time, 1.53 am passed by. Perhaps for the first time in the entire 47-day mission, a deadline had crossed. Three more minutes went by, but silence prevailed.

At precisely 1.57 am, Isro Chairman K Sivan got up from his seat. Few realised the gravity of that moment, as he walked up to brief Modi as the world watched in despair. The communication link with the Lander was lost. It was Sivan’s toughest message to deliver.