NEW DELHI: After travelling a long journey of 3.8 lakh km from Earth to Moon , Chandrayaan-2 on Sunday evening reached another milestone when it entered the circular lunar orbit, which is the final destination for the orbiter and lander to complete their 42-day journey together. The integrated module’s entry to the almost circular orbit of 119 x 127km happened after the last lunar-orbit manoeuvre was conducted at 6.21pm on for 52 seconds.

Isro chairman K Sivan told TOI, “After the Chandrayaan-2 launch (on July 22), we have been working on the composite module and using its propulsion system to manoeuvre it. Around 1pm tomorrow (Monday), Vikram lander will get separated from the orbiter to continue its downward journey to land on Moon. Vikram’s separation will be just like the “parting of a bride from her parent’s house. From tomorrow onwards, our entire focus will be on Vikram. However, a separate team will also monitor the orbiter.”

The orbiter will spend the rest of its lifespan of over a year in this circular orbit. With eight payloads and power of 1000W, the 2,379kg orbiter will conduct remote-sensing observations of Moon. Besides taking scores of Moon images from the 100km altitude, the orbiter with the help of its payloads will conduct elemental composition of Moon, mineral mapping, look for water ice, polar-region mapping to find sub-surface water ice and topography mapping.

“On Vikram, Isro will conduct two deorbit manoeuvres on September 3 and 4 using the lander’s propulsion system to lower its altitude. “The final powered descent will start at 1.40am on September 7 to make the lander soft-land near the south pole at 1.55am,” Sivan said.

During the last 15 minutes of the descent, the lander will go down at a velocity of 2 metre per second and touchdown between two craters Manzinus C and Simpelius N at a latitude of about 70.9 degrees South 22.7 degrees East. If it fails to land on the desired spot, Isro also has an alternative site which is 67.7 degrees South and 18.4 degrees West. A successful landing will make India the fourth country after the US, Russia and China to attain the capability to softland on Moon.

After landing of Vikram, the six-wheeled Pragyan rover, housed within the lander, will roll out of it and touch Moon’s ground after four hours. The 27-kg rover, which is loaded with two payloads and has images of Tricolour and Isro logo embossed on it, will move on the lunar surface at a speed of 1cm per second. During its lifespan of one lunar day (14 Earth days), Pragyan, which can generate 50W power using solar energy, will move up to 500 metre and take images and analyse content on the lunar surface. It will send back data via Vikram to Earth within 15 minutes.



In Video: Chandrayaan-2 successfully enters Moon’s circular orbit