BENGALURU: The first of the two de-orbiting manoeuvre on lander Vikram was conducted on Tuesday morning to lower its orbit to 104 Km X 128 Km. To complete the de-orbit process, the lander’s propulsion system was fired for a direction of just four seconds.
De-orbiting is conducted to lower the spacecraft’s orbital altitude to bring it closer to the surface. Lander Vikram will make a precision landing in the wee hours of Saturday at about 2 am. It is scheduled to touch down near the south pole, the first country ever to land a craft in this unexplored region of the moon.
Once the landing is completed, the rover Pragyan, carried within lander Vikram, will roll out on to the lunar surface to conduct exploratory experiments. This will happen between 5.30 am and 6.30 am on Saturday.
On Monday afternoon, at 1.15 pm, the lander Vikram separated from the Chandrayaan-2 orbiter, which will continue in its orbit for a period of over a year, mapping the lunar surface as it does so.
The second and final de-orbiting manoeuvre is scheduled between 3.30 am and 4.30 am on Wednesday to bring the lander’s orbital altitude down to 36 Km X 110 Km. From this orbital altitude, the lander Vikram will begin its powered descent when it approaches the lunar south pole at 1.40 am on Saturday. It will take about 15 minutes for the lander to touch down on the lunar surface, to record a historic first.
ISRO scientists said as the lander approaches the lunar surface, it will begin imaging the landing site to find a safe and hazard-free zone to touch down. This will be crucial as an uneven landing site could tilt the lander and make the rolling out of the rover difficult, which in turn could jeopardise the mission.
After a successful landing, the rover will roll out to carry out experiments on the lunar surface for a period of 1 Lunar day, equal to 14 earth days, while the Orbiter will continue its mission for a duration of one year. The lander will remain static at the landing location, and will relay data of the rover and its own to the orbiter, which in turn will relay it to the Indian Deep Space Network (IDSN) located at Byalalu, near Bengaluru.