Bengaluru: The Indian Space Research Organisation (ISRO) is racing against time to spring Vikram back to life and salvage the lander-rover part of the Chandrayaan-2 mission. The lander Vikram, with rover Pragyan tucked inside it, lost communication with the ground-stations during its final descent, just 2.1 km above the lunar surface, minutes before the planned soft-landing in the early hours of Saturday.
ISRO said on Sunday Vikram had had a “hard-landing”. The Bengaluru-headquartered space agency on Tuesday again confirmed that the lander had been located on the lunar surface by the on-board cameras of the Chandrayaan-2 orbiter which is circling the moon in its intended orbit.
“All possible efforts are being made to establish communication with (the) lander,” ISRO further said in a tweet.
— ISRO (@isro) September 10, 2019
A senior ISRO official associated with the mission said, “The images from the orbiter camera showed that Vikram is in single piece lying on the lunar surface; not broken into pieces. it is in a tilted position. It’s not in its four legs, as usual.” This official added on condition of anonymity, “It’s not upside down. It’s lying on its side.”
ISRO officially did not comment on the condition of the lander. Chandrayaan-2 comprises an orbiter, lander (Vikram) and rover (Pragyan). The mission life of the lander and rover is one Lunar day, which is equal to 14 earth days. ISRO Chairman K Sivan had said on Saturday evening that the space agency would try to restore a link with the lander for 14 days and it has been reiterating the resolve since then.
An ISRO official said Vikram hit the lunar surface at a place about 500 m away from where it was originally planned to touch-down. But there was no official word on this from ISRO. Sources said an ISRO team was trying to see if they can reorient the antennas of the lander in such a way that communication can be restored. “Efforts are going on,” they said.
According to a senior ISRO official, orientation may have been lost during the final descent when velocity was reduced, due “sensor or on-board software or computer anomaly.” “A committee is looking into what has gone wrong. They will come out with answers soon,” this official said.
Meanwhile, flawless and precise launch and efficient management of the Chandrayaan-2 mission — till the lander Vikram lost communication with ground-stations — has paid rich dividends to the ISRO on the orbiter front. The 2,379 kg orbiter, the mission life of which was designed to be of one year, would now be able to function for almost seven years.
“Enough fuel is available with the orbiter. Up to (lunar) orbit insertion, we did not have any flaw. Additional fuel which was anticipated was not used at all. Everything went as per the plan. Additional fuel is available with us (on-board the orbiter),” an ISRO official said.
Another ISRO official said, “One of the limiting factors is on-board fuel availability. Because the performance of GSLV-MK III (which launched the spacecraft) and efficient mission management, we have enough fuel for continuing it forward for seven years.”
The space agency said the precise launch and mission management has ensured a long life of almost seven years instead of the planned one year for the orbiter.
ISRO had said 90 to 95% of the Chandrayaan-2 mission objectives have been accomplished and it would continue to contribute to Lunar science, notwithstanding the loss of communication with the Lander which hit lunar surface after failing in its planned attempt to soft-land in the early hours of Saturday.
Noting that Chandrayaan-2 mission was a highly complex one, which represented a significant technological leap compared to the previous missions of ISRO, the space agency said it brought together an orbiter, lander and rover to explore the unexplored south pole of the Moon. This was a unique mission which aimed at studying not just one area of the Moon but all the areas combining the exosphere, the surface as well as the sub-surface of the moon in a single mission, it added.