Chandrayaan-2 rover, lander may have partially survived landing, says engineer who discovered Vikram lander debris

A mechanical engineer from Chennai, Shanmuga Subramanian, who spotted debris of the Chandrayaan 2 lander in images from NASA in 2019, has now sent a round of emails to the Indian Space Research Organisation, NASA and the media, claiming that the rover likely survived the hard landing. His claims were based on images from NASA's Lunar Reconnaissance Orbiter in May 2020.Subramanian claims that the Pragyan rover left tracks, suggesting that it moved at least a few meters away from the Vikram lander after the landing, as per his email and a Twitter thread sharing his theory. In images from the NASA Lunar Reconnaissance Orbiter's (LRO) overhead pass of the Chandrayaan 2 lander's suspected crash site, Subramanian had spotted the debris of the Vikram lander."Previous images before impact show nothing in the area...whereas after impact the images (do) show some objects..." he said. "Debris we found might be of the other payloads...engines & skeleton lander containing (the) rover would have jumped off the impact & landed...(the) rover was designed to automatically come out after 3 hours," he added.However, more recent images from the crash site show that the rover may have survived, Subramanian claims.“Going by 4 January images [made public in May], I think Pragyan may be intact and that it has rolled out a few metres from the lander," he told The Times of India. "We need to know how the rover may have moved and I hope ISRO is able to confirm this."Responding to Subramanian's findings, the Chairman of ISRO said that they had not heard from NASA about the images, and are looking into the data Subramanian has sent them."We’ve heard nothing from NASA so far on the matter. But yes, the person who had identified Vikram debris earlier has sent us an email about this. Our specialists are looking into the matter, and we cannot say anything at this juncture," Dr K Sivan told TOI."We will have to analyse and see what may have happened. There is nothing concrete now,” Sivan added.[caption id="attachment_7730531" align="alignnone" width="1280"] Vikram lander's ejecta as seen be LRO's camera. Image: NASA[/caption]Based on his own investigation, Subramanian proposed that the rover’s movement in the images could be explained by a one-way lapse in communication between the lander and ground stations. While ISRO was unable to communicate with the lander even before its planned soft-landing, the lander may have relayed some of the many commands that ISRO was pinging to test communications and prompt a response from the lander-rover duo after its crash.If this was how events unfolded, ISRO may not have known that the communication was successful, Subramanian suggests.NASA has also shared that except for some regions, the South Pole is not bathed in sunlight throughout the year. This is because of the Moon’s tilt, and similar to the pattern of sunlight in the Earth's south pole, which leaves the poles either lit well or poorly for months at a time.This, along with the long shadows cast by structures in the lunar South Pole, are likely why NASA wasn't able to spot the lander debris in the LRO's 17 September and 18 November images, the space agency had said. Subramanian, however, claims the debris is clearly visible in LRO images from 4 January and 14 March 2020.Also read: How NASA's LRO found ISRO's Vikram lander with assistance from Chennai engineer[caption id="attachment_7306991" align="alignnone" width="1280"] An illustration of Chandrayaan 2's lander Vikram. Image: ISRO[/caption]