On Tuesday, NASA confirmed the findings of Chennai based engineer Shanmuga Subramanian who located the debris of Chandrayaan-2’s Vikram lander on the lunar surface by comparing two images released earlier by the US space agency. The Indian Space Research Organisation (ISRO) meanwhile is saying that Chandrayaan-2’s orbiter had already found Vikram, implying that Shanmuga’s discovery is nothing new.
ISRO Chairperson K Sivan said that ISRO’s orbiter had located Vikram, and that it was declared on ISRO’s website as well. A statement from the space agency from September 10 says, “Vikram lander has been located by the orbiter of Chandrayaan-2, but no communication with it yet. All possible efforts are being made to establish communication with lander.”
Further, senior advisor to ISRO, Tapan Mishra, took to Facebook on Tuesday, with some observations on NASA’s images which showed the debris of Vikram lander.
He essentially said that due to the speed and weight of Vikram, combined with the lesser gravity on the moon as compared to the Earth, the impact should have been much more prominent.
“The lander with partially burnt fuel must have had a mass of 700-800 kg, similar to that of a sedan car or a small aircraft. And as per ISRO data, it was travelling at a speed of 534 km per hour, speed of a jet aircraft. With this impact like jet crash on lunar regolith, a very fine dust of 0.5 m to 5-6 m thick covering of lunar surface, I expected a great upheaval in the first impact site, spreading around 10m or more across. Almost like a small crater or dent. In fact the dust or debris could jump up much more than on earth, as lunar gravity is one sixth of that of earth. But surprisingly not a single change in dent one can see, except local brightness variation,” he said.
He also argued that the ‘dark patch’ that should have been visible due to the spillage of leftover fuel from Vikram after the crash, was not there.
Tapan ended the post by saying that common sense engineering can be different from reality, and called NASA’s images “very educative”. Read his full post here:
Chandrayaan-2, India’s second lunar mission, aimed for its lander Vikram to make a soft landing on the moon’s south pole. However, it was unsuccessful as ISRO lost contact with the lander minutes before the scheduled landing, and just 2.1 kilometres from the lunar surface, on September 7.
Following this, NASA had released images captured by its Lunar Reconnaissance Orbiter (LRO) Camera, asking the public to compare them. Shanmuga spent hours in front of the computer comparing the two photos – one from December 2017 and the other from after ISRO lost contact with Vikram -- and noticed some differences in the lunar surface. On October 3, he tweeted to NASA, “Is this Vikram lander? (1 km from the landing spot) Lander might have been buried in Lunar sand?” He also wrote to both ISRO and NASA on October 18 about the same.
On December 2, NASA confirmed that it was indeed Vikram lander’s debris.