Business Standard

Chandrayaan-2 schedule tweaked for soft-landing on previously fixed date

Isro would be adjusting the travel time by tweaking the earth-bound and the lunar-bound phases, according to officials

T E Narasimhan  |  Sriharikota 

India’s second Moon mission Chandrayaan-2 lifts off onboard GSLV Mk III-M1 launch vehicle from Satish Dhawan Space Center at Sriharikota in Andhra Pradesh. ISRO had called off the launch on July 15 after a technical snag was detected ahead of the lif
India’s second Moon mission Chandrayaan-2 lifts off onboard GSLV Mk III-M1 launch vehicle from Satish Dhawan Space Center at Sriharikota in Andhra Pradesh. ISRO had called off the launch on July 15 after a technical snag was detected ahead of the lift

Notwithstanding the one-week delay in lift-off, the Chandrayaan-2 mission would likely see the lander and rover modules of the spacecraft making a soft-landing on the lunar surface on the previously fixed date of September 7.

Scientists at the Indian Space Research Organisation (Isro) have reworked the Chandrayaan-2 schedule so that it could land on the moon’s south pole as scheduled earlier.

For this, Isro would be adjusting the travel time by tweaking the earth-bound and the lunar-bound phases, according to officials.

According to the new timeline, the earth-bound phase has increased by six days to 23 days; earlier it was 17 days. The time for Lunar Orbit Insertion (LOI) would now be only 13 days (it was previously 28 days). Thus, the space agency has reduced the journey time by nine days; it had lost seven days due to postponing of the launch, which was earlier scheduled on July 15, said experts.

K Sivan, chairman of Isro, told Business Standard that the space agency has 45 days for the mission and it can always adjust the journey. “To go to the moon, it will take only five days. During the rest of the period, the satellite would be orbiting either earth or the moon. So we can adjust during the period,” he said.

According to the new schedule, Chandrayaan-2 would be orbiting the earth for 23 days, and on August 13, Isro would conduct the Trans Lunar Injection.

The satellite would be in the Lunar Transfer Trajectory from Day 23 to Day 30. On August 20, it would be inserted into the lunar orbit and be there till September 1.

On September 2, the lander and orbiter would be separated from the orbiter, and on September 3, Isro would conduct a deboosting. On September 7 (the 48th day from the launch), according to the earlier plan, the lander would touch the moon surface.

According to the experts, the mission’s earth orbital distance has increased by 6,000 km from the previously planned trajectory due to the delay. Isro has increased the efficiency of the GSLV Mk 3, the launch vehicle, by 15 per cent, thus making up for the delay.

Experts have earlier said that for the moon mission, the launch window depends on the location from where the rocket is being launched and what is the location where the space agency wants to it to land.

It depends on the exact geometry of the particular location on the moon, which has to come close to the earth, and at the same time, the launch site and the lander should also have a close distance.

First Published: Tue, July 23 2019. 03:06 IST
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