On July 22, 2019, India successfully launched Chandrayaan-2, the second mission to the moon. Twenty-two days later (August 14), after a series of orbit raising manoeuvres, the spacecraft finally escaped the earth’s gravity and followed a path towards the moon. Six days later, Chandrayaan-2 was successfully inserted into lunar orbit. Finally, on September 2, the Vikram lander separated from the Orbiter, performed two de-orbit manoeuvres and on September 6, began its descent to the moon’s surface. The descent went as planned up to an altitude of 2.1 km from the Moon’s surface before communication from the lander to the ground stations was lost. The Vikram lander had apparently crash-landed on the Moon.
Soon a national-level failure analysis committee headed by Dr. V. Narayanan, Director of the Liquid Propulsion Systems Centre (LPSC), was formed with experts drawn from national institutes and ISRO to study the cause of failure and to propose necessary corrections. The committee pinpointed three crucial mistakes that had happened in succession resulting in the crash.
There are four important phases before the touchdown on the moon — the rough braking phase, the attitude-hold (orientation) phase, the fine braking phase, and the landing phase.
