Chandrayaan 2 flight schedule tweaked for new launch

The launch is scheduled for 2.43 pm on Monday

GSLV Mk 3 PTI The GSLV Mk 3 is seen at the second launch pad ahead of the launch of Chandrayaan-2, in Sriharikota | PTI

Preparations for the launch of India's second lunar mission, Chandrayaan 2, are picking up tempo once again. The launch is scheduled for 2.43 pm on Monday, a week after the initial, high media optic launch was called off at the eleventh hour due to a technical snag. 

Although there is no VVIP guest this time, President Ram Nath Kovind not making a second trip to Chennai, there is no dearth of non-VVIP guests who are willingly doing a repeat. Indian Space Research Organisation (ISRO) is expecting the spectator galleries to be even more packed, if that is possible, this time. The ISRO has a viewing space of around 7,000 and people have to register in advance to view a live launch from this gallery. It opened registration at 6 pm on July 22, and in less than an hour, it had to close registrations because around 7,500 people had already registered. This time, the launch being during the day, many more people have shown enthusiasm, said an ISRO spokesperson. Last time, the launch was scheduled for 2.51 am, and yet, the galleries were full of enthusiasts from across the country. Jyotsna Dhawan, daughter of ISRO's third chairperson Satish Dhawan after whom the space port at Sriharikota is named, too, has indicated that she will witness the launch. She had come for the earlier launch date of July 15, too. 

Meanwhile, ISRO says that there will be no change in the scope of the mission. 

But with the changed dates of the launch, there are changes in the travel schedule. After the lift off of July 22, Chandrayaan will remain in the earth bound phase (under the influence of the earth's gravity) for 23 days, as against the previous schedule of 17 days. The trans lunar injection (leaving earth's influence and heading towards the moon's) will now happen on Day 23. The lunar transfer trajectory will be from Day 23 to Day 30, and the probe will enter the moon's orbit (Lunar Orbit Insertion) on Day 30, as against the previous schedule of the insertion on Day 22. 

The Lunar Bound Phase will now be for 13 days, as against the previous schedule of 22 days. 

On Day 43, the lander and orbiter will separate from each other. The orbiter will continue to move in an orbit, 100 km from the moon's surface, while the lander will begin deboosting on Day 44, till it comes around 30 km away from the lunar surface. Then, on Day 48, it will start a powered descent, with its engines carefully controlling the speed of fall so that 15 “terrifying minutes'' later, the lander Vikram will reach the moon's surface, in a hopefully perfect touchdown. Under the previous schedule, the touchdown was to happen on Day 54. 

Thus, the lander is still expected to touchdown on September 6/7, which will give it an entire lunar day for its experiments.  Since both the lander, Vikram, and the six wheeled rover cart Pragyan, are powered by solar batteries, the mission aims to make full use of the sunshine for its research. Thus, the plan is to land at the beginning of the lunar day. A lunar day is equivalent to 14 earth days. That is the life of the lander and rover. The orbiter has a mission life of one year. 

The mission aims at exploring the mineralogy of the moon's surface, specially in the unexplored south pole. It hopes to detect more evidence of water, a find that Chandrayaan 1 had first confirmed. Other tests include understanding the moon's ionosphere as well as seismic activities below surface.