Image of Vikram, the lander on Chandrayaan-2.

BENGALURU: Vikram, the Lander on India’s ambitious mission that envisages to land a probe on Moon, has suffered minor injuries in two of its legs during a test late February, putting Chandrayaan-2 on the bench at least until May. But the need to find the most suitable launch window could see the mission take off only in the second half of the year.

A source in the know, said: “The rover and orbiter are in good health and tests met all the parameters. However, after the ‘Lander Drop Test’, we found that Vikram (the lander) needed to be strengthened in its legs. Prima facie, it appears that not all parameters were set correctly before the test, it could also be that the additional mass—a result of the new configuration—caused the problem.”

The TOI has learnt that Isro has formed a 12-member special task force headed by Srinivasan RK from UR Rao Satellite Centre (URSAC) to “address the anomaly during the Lander Drop test” on the qualification model of Vikram. They are tasked with submitting a report to Kunhikrishnan P, director, URSAC.

Indian Space Research Organisation (Isro) Chairman Sivan K confirmed to TOI: “Some structural damage was found during the test. And then it has been found that this was because the test configuration and orientation was wrong.”

“We will now do some modifications, but we cannot say that Chandrayaan-2 is delayed or postponed as we are looking for an optimal launch window,” he said.

This mission, unlike Chandrayaan-1 , involves a Lander (Vikram) soft-landing on Moon and unloading a rover to study and take measurements, while the orbiter will go around the Earth’s satellite.

Isro, which has for some time been aiming to launch Chandrayaan-2 for a while now, had thought it could achieve it in April, after several changes to Vikram’s configuration resulted in the agency missing two targets earlier—October 2018 and January 2019.

TOI had reported first about the new plan for Chandrayaan that now involves the Lander hovering the Moon before landing in August 2018. The original plan would have seen the lander deescalate soon after reaching the Lunar orbit.

“Now, the committee will propose modifications to the structure, which means that everything needs to be tested again and we will need more than two months to launch the mission,” the source said. The other option would be to qualify all other systems and simulate the weight to test the legs separately and later integrate them, which will save some time.

14 Days Of Clear Sun

“We cannot say that Chandrayaan-2 is delayed. It has not been postponed as the system will be ready for launch by May. However, despite it being ready, we will need a launch window that provides a clear 14 days (One Lunar Day) given that our systems will be powered completely by Solar energy,” Sivan said.

Another scientist explained that the site India landing on Moon is known to have evening sunlight for 14 days and complete darkness for another 14 days.

“We need the Earth, moon and the sun all positioned in the right place for us to launch. We want to get clean sunlight for 14 days… We are studying all of this before finalising the date,” Sivan said.

