NASA has announced it has discovered the remains of the Vikram lander, part of the Chandrayaan 2 mission’s vaunted lunar surface component, on the Moon. It has credited a tipoff from an Indian programmer and mechanical engineer named Shanmuga Subramanian for the discovery.
Subramanian, whose Twitter account lists his location as Chennai, told the New York Times that he pored through images of the lunar surface obtained by NASA’s Lunar Reconnaissance Orbiter “in his spare time” and spotted the debris from the lander.
The Indian Space Research Organisation launched its ambitious Chandrayaan 2 to the Moon in July, with an orbiter to orbit the satellite and a lander-rover combo to descend onto the lunar soil and conduct surface studies. However, in the early hours of September 7, 2019, ISRO ground control lost its signal connection with the Vikram lander a short distance from the Moon’s surface and it was presumed a failure.
In typical fashion, ISRO clammed up about the details – partly in an effort to ascertain the cause of the failure, which has cost India Rs 970 crore to build and launch – fanning the flames of misinformation. There were soon reports citing unknown sources that the lander had landed on the Moon’s surface but was simply tilted on its side, some going so far as to claim ISRO had obtained images of this as well.
But at the same time, based on telemetry data obtained from the occasional photograph of screens inside ground control, observers found that the lander would have slammed onto the Moon instead of gently touching down and should have been shattered into pieces.
Subramanian’s detection, later follow-up by the LRO team after he tipped them off in early October, confirms the latter inference. The LRO camera has a resolution of 1.3 m/pixel, and “the three largest pieces of debris were about two pixels by two pixels in size and cast a one-pixel shadow,” the newspaper wrote quoting NASA. In effect, Vikram met the same end that Beresheet, the private Israeli lander, had in April this year.
Earlier, Reddit user @Ohsin had superimposed images obtained from the LRO and from the Orbiter High Resolution Camera onboard the Chandrayaan 2 orbiter to find that the Vikram lander had not landed where it was supposed to. In a comment posted earlier on December 3, Subramanian credits users @Ohsin and @Astro_Neel for his discovery. He also received an email from John Keller, the deputy project scientist of the LRO mission at NASA, a picture of which he posted on Twitter, congratulating him “for what I am sure was a lot of time and effort on your part”.
— Shan (@Ramanean) December 2, 2019
ISRO has already embarked on another mission with similar objectives – to autonomously soft-land a lander and rover on the Moon – called Chandrayaan 3, with the exacting deadline of November 2020. According to a grant demand document submitted to Parliament, the organisation has asked for Rs 60 crore to make the arrangements and is likely to ask for more in future (the launch of a GSLV Mk III rocket alone costs upwards of Rs 300 crore).
Subramanian’s discovery is also a shot in the arm for citizen astronomy, whereby scientists place data obtained from instruments like the LRO in the public domain, allowing non-scientists to play around with it. Such initiatives enable research institutions to work with a larger number of people, especially to perform simple repetitive tasks like looking for certain patterns in images, towards obtaining a result.
However, citizen science in general is predicated on the free availability of data, and on this count ISRO has been criticised on numerous occasions, not least after the events of September 7 itself. In fact, an official admission of the reason the Vikram lander crashed – a thruster malfunction – emerged only a week ago during a Q&A session in the Lok Sabha.
ISRO is expected to make a statement of its own this week with reference to the NASA LRO announcement.