‘95% of Chandrayaan-2 intact as orbiter flying around moon’     

Even though the fate and the status of Vikram India's moon lander is not known - whether it crash-landed or the communication link got cut - all is not lost as far as the Rs 978 crore Chandrayaan-2 mission is concerned, an ISRO official said on Saturday. Former ISRO Chairman G Madhavan Nair said on Saturday the Chandrayaan-2 has achieved 95 per cent of its mission objectives, the lander's unsuccessful bid to touch-down on the Lunar surface notwithstanding.

With a mission life of one year, the Orbiter can take several pictures of the moon and send it to the ISRO. The Orbiter can also take pictures of the lander to know its status, the space agency official said. The Chandrayaan-2 spacecraft comprised three segments - the Orbiter (weighing 2,379 kg, eight payloads), 'Vikram' (1,471 kg, four payloads) and 'Pragyan' (27 kg, two payloads).

On September 2, the Vikram separated from the Orbiter. On July 22, the ₹978 crore Chandrayaan-2 was launched into the space by India's heavy lift rocket Geosynchronous Satellite Launch Vehicle-Mark III (GSLV Mk III) in a textbook style. After five earth-bound orbit raising activities, Chandrayaan-2 was inserted into lunar orbit.

In a last stage snag, the communication link between the moon lander and the orbiter got snapped as the former was descending towards the moon's South Pole early on Saturday, throwing suspense over the mission's fate.

"I think we need not worry too much...I will rate more than 95 per cent of the mission objectives have been achieved," G Madhavan Nair said after lander 'Vikram' lost contact with ground-stations during final descent to the Lunar surface in the early hours of Saturday.

"Already, orbiter is in space and it should do an excellent job of mapping", he added.

Chandrayaan-2, a follow-on mission to theChandrayaan-1 mission undertaken more than a decade ago, comprises an orbiter, lander (Vikram) and rover (Pragyan).

The orbiter payloads will conduct remote-sensing observations from a 100 km orbit.

Nevertheless, Nair said the lander's contact-loss was highly disappointing, and he never expected such a scenario.

"It's disappointing for all of us. The entire country was looking forward to it."

He said the entire mission -- from the launch till the lander lost its communication with ground-stations at an altitude of to 2.1 km from the Moon's surface -- went like text-book precision.

"When you look at operation 2.1 km down below, it's really complex; half of us were keeping our fingers crossed because there are several instruments and thrusters will have to work very precisely; only then the final objective can be achieved," the former ISRO Chief said.

"If you start listing, there are at least ten points where it could have gone wrong. What has really gone wrong is difficult to predict now", he said.

"Only thing is in the last ten seconds (of the mission), there was a deviation in the trajectory and velocity path.

Looking at the data available till that point I am sure ISRO will be able to identify (where things went wrong)," he added.

There could be any number of reasons, including sensor failure, on-board software anomaly and thrust deviation, for the loss of communication.

Earlier in the day, contact from the lander to the ground stations was lost during its powered descent to the Lunar surface minutes before the planned touch-down.

"Vikram lander descent was as planned and normal performance was observed up to an altitude of 2.1 km.

Subsequently, the communication from the lander to ground-stations was lost," ISRO chief K Sivan said.

"The data is being analysed," he added.

with IANS and PTI inputs