Chandrayaan-2 lander spotted, but 14-day period crucial to connect with Vikram

The Indian Space Research Organisation (ISRO) are yet to establish any connection with Chandrayaan-2 mission's lander Vikram, which was located on the Moon's South Pole on September 8.

However, former ISRO scientists have stated that all is not lost and there is hope, though challenging.

Madhavan Nair, former ISRO chairman, told Moneycontrol, “There is hope because the images show that the lander is one piece, has hard landed instead of crashing.”

What has happened so far

On September 7, 47 days after the successful launch of Chandrayaan-2, the lander Vikram was expected to soft land on the Moon’s South Pole, where no one has ventured before. The landing was expected at 1.55 am.

However, ISRO ground station lost contact with Vikram at 1.53 am. K Sivan, Chairman, ISRO, said, “Normal performance was observed in lander Vikram till about 2.1 km. Subsequently, connection with the lander was lost. Data is being analysed.” A day later, reports of Vikram having hard-landed emerged.

What is hard landing?

A hard landing means that Vikram had landed with more speed than was intended but not hard enough to have crashed. Look at it like this -- it is the difference between crashing at 100 km per hour and 40 km per hour when driving a car.

KR Sridhar Murthy, former executive director, Antrix, ISRO's commercial arm, said, “Yes, velocity reduction that should have happened did not happen and it is likely to impact the lander.” To understand the extent of impact, details like the speed of landing would be needed and currently is not available in the public domain.

Possibilities of establishing connection with Vikram

Murthy said it is hard to say since there are different conditions to be fulfilled.

For one, for the connection to be revived, antenna of the lander and orbiter have to be in the same line of sight. The lander’s antenna is mounted in the solar panel, which needs to be powered. This can only be realised when the solar panel is facing towards the Sun. “For that, the solar panel should look towards the Sun at a certain angle,” Murthy added.

Most of all, the components should be working fine and not damaged by the impact of the fall. Only if all these criteria are in place, will the communication is established.

All this have to be done within 14 days.

Why 14 days?

Is it impossible? No. Challenging? Extremely.

The 14-day cycle started on September 7, which is when the South Pole part of the moon gets the sun. This is important as Vikram has solar panels that power it, and needs sun for the energy. Beyond the cycle, it will be too cold for the lander to survive.

What about the payloads? Will they be intact?

This is again hard to predict. Nair said, “Many of the payloads are tested for shock.” But the extent of shock they can absorb depends on the speed at which Vikram landed on the Moon.

Vikram carried three payloads such as RAMBHA to study the Moon’s ionosphere, ChaSTE to conduct thermos-physical experiment and ILSA for studying the Moon’s seismic activity.

Pragyan, the rover, had X-ray spectrometer to identify the elemental composition of the moon and laser induced breakdown spectroscope to identify and determine elements near the landing site.

Overall, the mission had 14 payloads, eight of which is in the orbiter and will continue to operate.