By Express News Service
Chandrayaan-3, ISRO’s third lunar exploration mission, is all set to create history by landing on the uncharted south pole of the moon. The LM comprising the lander (Vikram) and the rover (Pragyan), is scheduled to make a touchdown near the south polar region of the Moon at 6:04 pm today.
Fourteen-day Moon mission
The lander and rover have a mission life of one lunar day, which is about 14 Earth days. Temperatures dip to as much as -1800C during lunar nights. However, there is an outside possibility of the lander and the rover coming back to life for another lunar day, claim scientists.
The powered braking of Vikram lander will begin at 5.45 pm with the retro firing of four thruster engines to reduce speed. Scientists call it 17 minutes of terror as the whole process will be automated. Complete instructions will be fed to Vikram by 3.45 pm.
The challenge is to reduce Vikram’s horizontal velocity from 1.68 km/sec at a height of 30 km to almost zero for a soft landing.
At an altitude of 6.8 km, two engines will shut down. The other two will give reverse thrust to further slow down Vikram as it descends.
Landing is scheduled at 6.04 pm. If all goes well, after Vikram settles on the lunar surface, it will release a rover on board to take pictures of the surface and conduct experiments with two onboard instruments.
At an altitude of 150-100 metres, Vikram’s sensors will scan the surface to check for obstacles before final descent. If the sensors spot a hill or a boulder at the landing spot it can move laterally up to 150 m to a better landing spot.
Quick-fire experiments
“After powered descent onto the landing site, there will be deployment of ramp and rover coming out. After this, all the experiments will take place one after the other — all of which have to be completed in just one day on the Moon, which is 14 (Earth) days,” ISRO chief Somnath said.
“This whole process of turning from horizontal to vertical is a very interesting calculation mathematically. We have done a lot of simulations. It is here where we had the problem last time (Chandrayaan-2),” the ISRO chief added.
Chandrayaan-3 is a follow-on mission to Chandrayaan-2 and its objectives are to demonstrate safe and soft-landing on the lunar surface, roving on the Moon, and to conduct in-situ scientific experiments.
Chandrayaan-2 had failed in its lunar phase when its lander ‘Vikram’ crashed into the surface of the Moon following anomalies in the braking system in the lander while attempting a touchdown on September 7, 2019.
The LM of Chandrayaan-3 had successfully separated from the Propulsion Module on August 17, which was 35 days after the satellite was launched on July 14.
Meanwhile, the Propulsion Module, whose main function was to carry the Lander Module from launch vehicle injection till lander separation orbit, will continue its journey in the current orbit for months/years, the space agency said.
Post its launch on July 14, Chandrayaan-3 entered into the lunar orbit on August 5, following which orbit reduction manoeuvres were carried out on the satellite on August 6, 9, 14 and 16, ahead of the separation of both its modules on August 17.
Earlier, over five moves in the three weeks since the July 14 launch, ISRO had lifted the Chandrayaan-3 spacecraft into orbits farther and farther away from the Earth.
Then, on August 1 in a key manoeuvre — a slingshot move — the spacecraft was sent successfully towards the Moon from Earth’s orbit.
(With additional inputs from PTI)
Chandrayaan-3, ISRO’s third lunar exploration mission, is all set to create history by landing on the uncharted south pole of the moon. The LM comprising the lander (Vikram) and the rover (Pragyan), is scheduled to make a touchdown near the south polar region of the Moon at 6:04 pm today.
Fourteen-day Moon mission
The lander and rover have a mission life of one lunar day, which is about 14 Earth days. Temperatures dip to as much as -1800C during lunar nights. However, there is an outside possibility of the lander and the rover coming back to life for another lunar day, claim scientists.googletag.cmd.push(function() {googletag.display(‘div-gpt-ad-8052921-2’); });
The powered braking of Vikram lander will begin at 5.45 pm with the retro firing of four thruster engines to reduce speed. Scientists call it 17 minutes of terror as the whole process will be automated. Complete instructions will be fed to Vikram by 3.45 pm.
The challenge is to reduce Vikram’s horizontal velocity from 1.68 km/sec at a height of 30 km to almost zero for a soft landing.
At an altitude of 6.8 km, two engines will shut down. The other two will give reverse thrust to further slow down Vikram as it descends.
Landing is scheduled at 6.04 pm. If all goes well, after Vikram settles on the lunar surface, it will release a rover on board to take pictures of the surface and conduct experiments with two onboard instruments.
At an altitude of 150-100 metres, Vikram’s sensors will scan the surface to check for obstacles before final descent. If the sensors spot a hill or a boulder at the landing spot it can move laterally up to 150 m to a better landing spot.
Quick-fire experiments
“After powered descent onto the landing site, there will be deployment of ramp and rover coming out. After this, all the experiments will take place one after the other — all of which have to be completed in just one day on the Moon, which is 14 (Earth) days,” ISRO chief Somnath said.
“This whole process of turning from horizontal to vertical is a very interesting calculation mathematically. We have done a lot of simulations. It is here where we had the problem last time (Chandrayaan-2),” the ISRO chief added.
Chandrayaan-3 is a follow-on mission to Chandrayaan-2 and its objectives are to demonstrate safe and soft-landing on the lunar surface, roving on the Moon, and to conduct in-situ scientific experiments.
Chandrayaan-2 had failed in its lunar phase when its lander ‘Vikram’ crashed into the surface of the Moon following anomalies in the braking system in the lander while attempting a touchdown on September 7, 2019.
The LM of Chandrayaan-3 had successfully separated from the Propulsion Module on August 17, which was 35 days after the satellite was launched on July 14.
Meanwhile, the Propulsion Module, whose main function was to carry the Lander Module from launch vehicle injection till lander separation orbit, will continue its journey in the current orbit for months/years, the space agency said.
Post its launch on July 14, Chandrayaan-3 entered into the lunar orbit on August 5, following which orbit reduction manoeuvres were carried out on the satellite on August 6, 9, 14 and 16, ahead of the separation of both its modules on August 17.
Earlier, over five moves in the three weeks since the July 14 launch, ISRO had lifted the Chandrayaan-3 spacecraft into orbits farther and farther away from the Earth.
Then, on August 1 in a key manoeuvre — a slingshot move — the spacecraft was sent successfully towards the Moon from Earth’s orbit.
(With additional inputs from PTI)
