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Monday, September 9, 2019

Chandrayaan 2: All is not lost!

It was Friday night and Saturday’s morning. Time: 1.38 am. The terrifying 15 minutes began. Vikram commenced its descent to the moon from a height of 35 km from the lunar surface. Its throttleable engines were doing a fine job. Its velocity was being gradually reduced from the present 6,048 mt per second. As planned for, everything was going on smoothly. Women and men in front of the monitors clapped gleefully.  

Then began the ‘fine-breaking’ stage. And the central engine was on. Speed had fallen to 86 mt per second. Time: 1.51 am. Vikram was gliding in a parabolic path. It was just 2.1 km away from its destination. It was slowing down to about 50 mt per second. About to start its vertical descent. Three more minutes to land—yeah, three long minutes. Silent prayers from the control room. Suddenly the green line on the screen started deviating from its path. Bated breaths. Green line stopped moving.  All around tension.  Smiles vanished. Heavy-sighs. Vikram fell silent. And soon it became clear: Vikram failed to land softly on moon. Deadly-silence. Swelled-up eyes. Silent sobs. Control room landed in a state of gloom. Cheerful Indians sitting in front of TVs at once turned dumb, throats choked.  Ha! It was all a bit of an anti-climax.

Of course, as the day dawned, it slowly became clear that all is not lost. As Madhavan Nair, former ISRO Chairman said, “We need not worry too much … 95% of mission objectives have been achieved … already.” For the orbiter is healthy and continues to circle around the moon at a relatively low altitude. Fortunately, 90% of experiments on board Chandrayaan 2 are in the orbiter and it is reported to be doing a fine job. The brighter side is: it will watch over the world’s sole natural satellite beyond its planned period of an year for almost seven years owing to the savings effected in energy consumption while flawlessly inserting it into a stable lunar orbit.  

Further, “the data from CHACE-2 (Chandra’s Altitudinal Composition Explorer) reveals that it is functioning perfectly alright and “the data from it are excellent”. Similarly, RAMBHA-Dual Frequency Radio Science Experiment too is in orbiter and thus ISRO is sure to get a wealth of data from it. Which means ISRO will be able to carry on its planned cutting-edge lunar research regardless of failure of Vikram’s soft landing: One, its terrain mapping camera, TMC2 will transmit a detailed cartography of the lunar surface helping ISRO create 3D maps of the hitherto elusive-topography of lunar surface with locked up supplies of water ice; two, it enables ISRO scientists to look at the regions of moon that are perpetually in shadow and by using the bounced off signals from inside the surface level formations and the perturbations thereof, they shall be able to calculate the thicknesses of said formations;  and three, all this cumulatively improves our understanding of the moon’s geology and particularly enables us to understand how moon’s south polar region differs from the rest. Over it, its X-ray monitor shall through light on how much solar radiation makes to the moon and how it changes along its way.  

That said, we must also note that our scientists have attempted to do something very, very difficult: land Vikram on the Moon’s South Pole, which is covered by craters, the rims of which are exposed to near constant solar illumination while their interiors are permanently shaded from sunlight. These cold traps contain fossil hydrogen, water ice and other volatiles. Secondly, gravity is stronger in some regions than others, creating a ‘lumpy’ gravitational field. This is noticed in certain basins such as Aitkin basin of the south-pole that were impacted by asteroids. These regions of excess distribution of mass below the lunar surface, also called as ‘mascons’ are known to exhibit unexpectedly strong gravitational pull.   Such unexpected variations in the gravitational pull might have affected the lander’s speed – turning ISRO’s initial calculations topsy-turvy –resulting in its crash-landing.  Or, the lunar dust from the surface might have damaged the solar panels/communication gadgets of the lander as it is landing resulting in loss of communication. 

Or, as the last 15 minutes of dissent being autonomous—a feat of total autonomy with no scope for interruption from the ground station that ISRO attempted for the first time, might have gone awry. Even otherwise, landers are always slippery. Hitherto 38 attempts of soft landing on moon were made by various space agencies of the world and only 20 have been successful. After all, failure is a part of every experiment. As the days rolled on, it became clear that lander is not totally lost, for the orbiter had spotted it in one piece but tipped onto its side. Of course, as result of it all attempts to communicate with it turned unsuccessful. So, the need of the hour is: courage—courage to face the failure squarely and use it as a stepping stone for the next success.

And ISRO has overcome many such failures of the past with great successes. That’s what ISRO’s history says. And our PM has aptly captured this tradition when he said: “You are those people who live for India’s victory, for her success and strive to keep India’s head high.” So right now, ISRO needs to find out what went wrong in the lander’s final moments by making use of every available bit of data and telemetry just before the green line frozen on the screens. It has to stimulate various scenarios with the engineering data collected from the failed landing and check where and how the lander didn’t behave they way they planned for. After all didn’t ISRO set right the glitch in launch vehicle—GSLV Mark 3—developed during the first scheduled lift-off  on July 15th  within no time?

It is worth recalling here what Chandra once said: in scientific pursuits, “what is essential, however, is to have the ideal of gaining knowledge and to work steadfastly towards the ideal. One should not care to worry about what happens.” So, ISRO as he said, has to pursue its project with “enough enthusiasm and passion. That is enough.” And for that matter, isn’t science, as Dr Vijaya Raghavan, the principal scientific adviser said, nothing but a “feeling of adventure, of the unknown, of setbacks, [and] of moving forward.”  The goal of Chandrayaan 2 is “to inspire”. On that score, he is right when he dubbed “Chandrayaan 2 as a 100% success.”   

So, cheer up ISRO! For, you have already covered a distance of 3,83,007.9 km. Success is not far off… it’s after all 2.1 km away. Look into your past and get emboldened to march ahead with a greater resolve …Start thinking positively about your chances for success. Believing that you will succeed is sure to make you more likely to succeed, at least that's what psychology studies reveal. Adversities have always aided ISRO in mastering technology and particularly, affordability. It’s not a cliché, that’s what your history tells. You are sure to cross the rest too, soon. And the nation is by your side. Be brave, get up, dust off and start afresh with renewed knowledge ... you did it in the past ... and there is no reason why you won't succeed this time round. Good luck!


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