ISRO (Indian Space Research Organization) will simulate various scenarios to find out why Vikram Lander failed to land smoothly on the moon's surface, said a retired senior ISRO official. According to him, ISRO has to see whether any simulation prior to the launch was overlooked. The simulation will include what it had not done and what it had assumed to arrive at the probable cause of its moon lander Vikram hitting the lunar surface after veering away from its plotted path and losing communication. On September 7, the Vikram Lander made a crash landing on the Moon's south polar region and lost all communication.
According to space experts, normally any data loss from a satellite suggests that the spacecraft has suddenly changed its attitude. The loss of communication link means that the target/satellite experienced a large angular rotation. Further, the loss of communication link could also be due to wrong input being loaded on to the lander. According to an official, Chandrayaan-2 mission was done into four parts: putting the Chandrayaan-2 spacecraft into earth orbit; taking it into the moon orbit; soft landing of the lander Vikram; and rover Pragyan rolling down to carry out scientific experiments. Out of these, the first two proved to be successful.
On July 22, Chandrayaan-2 was launched into the space India’s heavy lift rocket Geosynchronous Satellite Launch Vehicle-Mark III (GSLV Mk III). The Chandrayaan-2 spacecraft comprised of three segments - the Orbiter, Vikram and Pragyan. The spacecraft had successfully completed revolving around five orbits. On September 2, the Vikram Lander was separated from the orbiter and had started its journey towards the lunar surface. It was aimed for a soft-landing on the moon's south polar region, making India the fourth country to do so.
On September 7 morning at 1:50 AM when Vikram was scheduled to land, ISRO's Deep Space Antenna lost communication with Chandrayaan-2's lander - Vikram as it descended towards the lunar surface. The lander had descended from 30 km to 2 km smoothly. During the final smooth braking stage, it had lost communication with Mission Control.