Chandrayaan-3 successfully soft-landed on the Moon’s surface at 6.04 pm Wednesday evening – a feat matched only by Russia (then the Soviet Republic), the United States and China – guaranteeing India pride of place in the global space race. Chandrayaan-3’s nearly 400,000 km journey to the Moon culminated in a nerve-wracking final 20 minutes – the ‘power descent’ phase, which is an automated landing sequence carried out by the lander.
As the minutes ticked by – and the altitude counter on the live feed from the Indian Space Research Organisation’s (ISRO) Mission Control near Bengaluru dropped slowly and steadily – a billion Indians’ continued praying in unison, guarding the Vikram lander on its safe descent.
Shortly after the Chandrayaan-3 landed, a jubilant ISRO Chairman S Somnath addressed the media, prefacing his remarks with a victorious shout – ‘India is on the Moon’ – and Mr Somnath was asked what, in his opinion, were the most critical elements in Chandrayaan-3’s journey.
“The most difficult part of the mission is the launch itself… you should not forget that the GSLV Mark 3 (the rocket that launched the Chandrayaan-3 module that contains the Vikram lander and the Pragyan rover) did the job of putting the spacecraft into the right orbit.”
“It went to 36,500 km and up to trans-lunar injection (which is a propulsive move used to set a spacecraft on a trajectory to the Moon) phase it went very well,” Mr Somnath said.
The Chandrayaan-3 module separated from the rocket 16 minutes after launch and orbited the Earth six times, reaching a maximum distance of 36,500 km before the first orbit-raising move on July 15, taking it to a distance of 41,672 km.
“The second critical event is called ‘landing and capturing on the Moon’. If you miss it then it (the possibility of landing on the lunar surface) is gone. You cannot retrieve it and there is no mission,” the top scientist explained.
‘Capturing the Moon’ refers to the critical moments when Chandrayaan-3 must identify a landing site – in which it is aided by a slew of high-powered cameras developed inhouse by ISRO – while it deboosts from lunar orbit and prepares for descent.
Miscalculations at this stage will be disastrous since it means the Vikram lander could crash as it attempts to touch down.
“Third critical moment is separation of lander and orbiter, which happened at the appropriate time. Again, you must remember that this was after spending many days in space, in orbit, and the mechanism had to work without problems, which it did.”
The Vikram lander, which contains the Pragyan rover, separated from the propulsion module on Thursday, August 17.
A smiling ISRO chief then said, “The last critical moment, of course, you watched along with us”, referring to the tense moments leading up to Chandrayaan-3’s Moon soft landing.