On September 7th 2019, ISRO attempted to land a lunar lander ,Vikram, with rover , Pragyan, on the moon. It was very exciting to watch until the lander lost communication with ground station during its final descent, just 2.1 kms above the lunar surface!
I have screenshot the profile of the landing trajectory from the live stream and it is clear that it went off its profile at the very end.
I wanted to know what went wrong for such a failure to occur, and if it's not known for sure, what the most likely scenario is.
My rough guess is that something went wrong with the attitude control system of the lander. Maybe the lander had some level of autonomy in choosing a landing ground; as it landed, the sensors identified the landing area not suitable for landing and it decided to change its route leading to high momentum build up that was hard to recover from. Or it was just a matter of some external disturbance that was not accounted for.
The latest news that has come out 2 days ago about the investigation of what happened but nothing solid has been stated. Link: https://www.hindustantimes.com/india-news/keep-it-simple-former-isro-scientist-explains-what-lead-to-chandrayaan-2-s-vikram-crash/story-M6DDnfOFJl3OkZ12F2fJIM.html
I think this would be a great case study to learn lessons from.