Bengaluru: As originally planned, the lander commenced the descent at 1: 38 am from its orbit 100 km away from the lunar surface. The on board computer was programmed to control the glide through a four-phase operation: rough breaking phase, fine breaking phase, hovering phase, and parabolic descent, gradually decreasing the speed of ‘Vikram’ from 1.6 km a second to almost zero meters ahead of landing at 1.55 am.
The lander moved flawlessly as four onboard engines functioned like brakes, and brought it down, 60 meters a second at the end of the first and second phase of operations.
Just as it entered the hovering and landing phases, however, tension mounted in the Mission Operations Complex with Dr Sivan and his team frantically checking their consoles for some positive signals.
As the seconds ticked away, Dr Sivan conferred with senior colleagues, and slowly made his way to the VIP viewing gallery to break the bad news to Mr Modi.
Soon Mr Modi left the gallery and the wait for a word on the lander got longer.
A few minutes later, an announcement was made that the lander has established communication with the orbiter, but the excitement was short-lived as a crest-fallen Dr Sivan made the announcement: "Lander 'Vikram's' descent was as planned and normal performance was observed up to an altitude of 2.1 km. Subsequently communication from the lander to the ground stations was lost. Data is being analyzed."
With the setback, the six-wheeled rover 'Pragyan', programmed to leave footprints of Isro and Ashoka Chakra on lunar soil after rolling out of 'Vikram' between 5:30 am and 6: 30 am, was lost.
