india

Updated: Sep 20, 2019 00:14 IST

New Delhi: For the Indian Space Research Organisation (Isro), it may be the last chance to establish some form of communication with Chandrayaan-2’s Vikram lander, with lunar night [equal to 14 Earth days] setting in at the landing site by Saturday, plunging the temperatures to -180 degrees Celsius.

A national committee is still examining the cause of communication loss with the Vikram lander, a key component of India’s second moon mission, during the powered descent phase in the early hours of September 7.

US space agency Nasa, which has sent a passive experiment on Chandrayaan-2 mission, is also attempting to gather as much information about the mission as possible. The scientists at Nasa are in the process of analysing data from the Lunar Reconnaissance Orbiter (LRO) that flew over the Vikram lander’s intended landing site on September 17.

During the 15 minutes of powered descent on September 7, Isro scientists lost contact with the lander just 2.1 km above the lunar surface, about two minutes before the landing manoeuvre was to be completed.

“The Lunar Reconnaissance Orbiter Camera (LROC) acquired images around the targeted landing site, but the exact location of the lander was not known so the lander may not be in the camera field of view,” said Nasa officials in a statement to HT on Wednesday.

The chances of spotting the lander were further reduced because of the lighting conditions. At the time when the Nasa orbiter passed over the landing site, it was lunar dusk. With the sun remaining low on the horizon, the images have long shadows that might be hiding the lander.

“At the end of the day, the cameras on-board our own and NASA’s orbiter are trying to find an object that is of just a couple of metres in dimension from a distance of nearly 100 kms. That means it would be captured in just about four pixels,” Jatan Mehta, former science officer of TeamIndus, a Bengaluru-based private company that aims to send a lander-rover to moon.

The third part of the mission — the orbiter — going around the moon at a nearly 100-km circular orbit is performing as per expectations and will keep collecting data for nearly 7 years.

“All the payloads of the orbiter are powered and the initial trials of the payloads have been completed successfully. Performance of all orbiter payloads is satisfactory and they continue to perform scheduled science experiments to complete satisfaction,” said a statement from Isro on Thursday.

This is the first official update from the Indian space agency after it announced that the orbiter had captured an image of the lander. A national level committee consisting of academicians and Isro experts are analysing the cause of the communication loss with the lander.

“Isro already has the telemetry data, which has information on velocity, altitude, thrust etc, till about 2.1 km from the surface of the moon. The images taken by the orbiters will give details of the orientation of the lander, whether it was slightly damaged or parts were broken, the location and its deviation from the planned path will tell the scientists whether the lander hit the lunar surface at a high velocity, whether it spun out or what happened in the last moments,” said Dr Nirupam Roy, assistant professor of physics at the Indian Institute of Science (IISc), Bengaluru.