- Awareness in space.
Context: The status of Chandrayaan 2 mission is unknown hours after Chandrayaan 2’s lander Vikram began final descent towards the moon and lost contact with ground control around 2.1 km from the lunar surface.
What is soft landing? How was it supposed to take place? Challenges therein?
- A soft-landing protects the object from impact while a hard landing doesn’t.
- Soft-landing ensures that the object is able to carry out further experimentation on the target planet or satellite, mostly with the help of a rover vehicle.
- Soft-landing on any planetary surface is complicated. Vikram was to use five thrusters — four at the corners and one at the centre to make its final descent.
- Maintaining the required velocity with such thrusters is difficult as a fine balance among them needs to be maintained.
- Then there is the issue of moon dust which could wreck the engines of the thrusters.
On the day of landing on September 7, the Vikram lander had to perform a series of complex manoeuvres, including imaging the landing site.
Vikram was supposed to begin its descent form a height of 35 km above the lunar surface and a velocity of around 6,000 kmph. In just over 10 minutes, the Vikram lander had to drop to a height of 7.4 km above the Moon altitude and lower its speed to around 526 kmph.
Further, the lander had to reduce its speed to 331.2 kmph and reach a height of 5 km above the lunar surface.
At 100 metres above the lunar surface, the Vikram lander had to hover for about 25 seconds during which it was supposed to choose between two pre-determined landing sites.
Four hours after landing, the Pragyan rover would be unloaded from the Vikram lander.
WHY THE SOUTH POLE?
The south polar region of the Moon has not received sunlight for billions of years and is among the coldest spots in the Solar System. This, Isro says, makes lunar south pole region ripe to contain tonnes of water and “an undisturbed record” of the Solar System’s origins.
Sources: the Hindu.