CHANDRAYAAN-2, INDIA’S first lander mission to the moon, whose launch had to be aborted early Monday morning after a technical problem was detected with less than an hour to go, will now lift off on July 22, the Indian Space Research Organisation (ISRO) said Thursday. This time, the launch has been scheduled at 2.43 pm.
The week-long delay will not impact the date of landing of the spacecraft on the moon’s surface. The lander and rover modules will land on September 6, as scheduled, ISRO officials said.
“There is no change in the landing date as of now. But the intermediate journey would probably have to be altered. The changed path is being worked out right now,” Vivek Singh, who heads ISRO’s public relations office, said.
ISRO had earlier said, in a statement on May 1, that the launch window of Chandrayaan-2 was available between July 9 and 16.
According to the original schedule, Chandrayaan-2 was to take 54 days to reach the moon. It was to remain in the earth’s orbit for the first 17 days after launch, incrementally increasing its orbit several times before embarking on a five-day journey towards the lunar orbit. After spending 28 days orbiting the moon, the lander and rover would separate and prepare for landing on the surface on September 6 — both will remain operational for 14 days.
Why Sept 6 will be crucial
It is crucial for ISRO to land on September 6 to maximise data collection by instruments on the lander and rover. The date has been chosen to avoid any lunar eclipse, and ensure illumination from sunlight.
The moon, which is slightly less than 4,00,000 km away, can be reached within three to four days if the spacecraft travels directly, in a straight line. In fact, the Apollo missions that landed human beings on the moon’s surface in the 1960s and 1970s completed the journey in that time. But those missions used a rocket, Saturn V, that remains the most powerful ever built.
Other missions to the moon have taken substantially longer. Chandrayaan-1, for example, had taken 12 days to reach the lunar orbit. The path to the moon is dictated by a number of factors, like the strength of the rocket carrying the spacecraft, the nature of experiments to be carried out, and the position of the moon in its orbit.
Chandrayaan-2 is riding the GSLV Mk-III rocket, which is the most powerful built by ISRO but not enough to reach the lunar orbit in one shot. It will go around the earth’s orbit for a few days, fire thrusters to slowly increase its orbit and acquire energy to reach the moon’s orbit.
ISRO has so far refused to reveal the nature or extent of the technical problem that caused last Monday’s launch to be aborted. It has only said that the expert committee constituted to look into the problem had identified the reasons and taken remedial action.
“The expert committee identified the root cause of the technical snag and all corrective actions are implemented. Thereafter, the system performance is normal,” ISRO said in a statement. It did not give any details of the problem that had led to the launch getting aborted.